979 Matching Annotations
  1. May 2019
  2. sg.inflibnet.ac.in sg.inflibnet.ac.in
    1. To isolate primary peritoneal macrophages, 6-8 week old BALB/c mice were injected with 3% (w/v) thioglycollate broth (0.55% dextrose, 0.05% sodium thioglycollate, 0.5% sodium chloride, 0.05% agar)intraperitonealy (I.P. 50 μl/g body weight). After five days of injection, mice were euthanized by CO2inhalationand peritoneal macrophages were harvested byflushing the peritoneal cavity (lavage) with 10 mlDMEM medium(Zhang et al., 2008)
    2. THP-1 andLec-2 cell lines were obtained from ATCC (American Type Culture Collection). THP-1 and Lec-2 cells were cultured and maintained in RPMI-1640 and α-MEM media,respectively, supplemented with 10% heat inactivated fetal bovine serum, 2 mM glutamine and antibiotics (100units/ml of penicillin and 100μg/ml of streptomycin). Both cell lines were maintained at 37°C and 5% CO2in Thermo-Scientific cell culture incubator. After every 2-3 days, spent medium was replaced with fresh,pre-warmed medium. For splitting the culture, cells were harvested at 1,000 rpm for 3 min. Spent medium was discarded and cells were resuspended in 4-6 ml fresh prewarmed medium. Finally, 3-4 million cells were resuspended in 12mlmedium in 100 mm culture dishes.Cellswere cultured and maintained in tissue culture incubatorat37°C and 5% CO2
    3. Spheroplast resuspension buffer0.1M KCl15 mM HEPES (pH 7.5)3 mM Ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid(EGTA)10% GlycerolPhosphatidylinositol sonication buffer10 mM HEPES (pH 7.5)1 mM EGTA PI3-kinase reaction buffer40 mM HEPES (pH 7.5)20 mM MgCl280 μM ATP5 μCi γ-P32ATPDeveloping solution for thin layer chromatography(120.2 ml)Chloroform –60 mlMethanol –47 mlAmmonia –4.4 mlWater –8.8 ml
    4. SDS-loading buffer was prepared as a 4X stock solutionin H2Oand used at a 1X concentration.SDS-PAGE running buffer0.25 M Tris-HCl (pH 8.0)1.92 M Glycine1% SDSRunning buffer was preparedas a 10X stock solution and diluted to 1X concentration before use.Buffers for Western blotanalysisTransfer buffer (10X stock solution)0.25 M Tris-HCl (pH 8.0)1.92 M Glycine1% SDSTransfer buffer was prepared as a 10X stock solution and diluted to 1X concentration.1X Transfer buffer (1 litre)200 ml of methanol100 ml of 10X transfer buffer700 ml of waterTris-BufferSaline (TBS)25 mM Tris150 mM NaClpH was adjusted to 7.4 with HCl.TBS buffer was prepared asa10X stock solution and diluted to 1X concentration.Blocking and wash buffers (PBS-T and TBS-T)5% Fat-free milk0.1% Tween-20Volume was made to 100 ml with 1X TBS
    5. 1 mM sodium orthovanadate1 X protease inhibitor cocktail SDS-PAGE30% Acrylamide solution29 g Acrylamide1 gBis-acrylamideDissolved in 100 ml H2O.10% Sodium Dodecyl Sulfate (SDS)10 g SDS in 100 ml H2OResolving gel mix (12%) (20 ml)6.6 ml H2O8 ml 30% acrylamide:bisacrylamide (29:1) mix5 ml 1.5 M Tris-HCl (pH 8.8)200 μl 10% SDS200 μl 10% Ammonium persulfate(APS)8 μl N,N,N′,N′-Tetramethylethylenediamine(TEMED)Stacking gel mix (5%, 6 ml)4.1 ml H2O1 ml 30% acrylamide:bisacrylamide (29:1) mix750 μl 1 M Tris-HCl (pH 6.8)60 μl 10% SDS60 μl 10% APS6 μl TEMEDSDS loading buffer130 mM Tris-HCl (pH 8.0)20% (v/v) Glycerol4.6% (w/v) SDS0.02% Bromophenol Blue2% DTT
    6. Whole cell lysis buffer (Homogenizing buffer)50 mM Tris-HCl (pH 7.5)2 mM EDTA10 mM sodium fluoride
    7. 150 mM NaCl1% Triton-X1% SDSBuffer B50 mM Tris-HCl (pH 7.5)10 mM EDTA1.1 MSorbitol50 mM β-mercaptoethanol (To be added just before use)Buffer C100 mM Tris-HCl (pH 7.5)10 mM EDTA10% SDSAE buffer3 M Sodium acetate(pH 5.3)0.5 M EDTA (pH 8.0)Phenol:Chloroform:Isoamyl alcohol (25:24:1) solution25 ml Tris-equilibrated Phenol24 ml Chloroform1 ml Isoamyl alcholDNA sample loading buffer0.25% Bromophenol blue0.25% Xylene cyanol15% FicollDNA sample loading buffer was prepared in water
    8. Buffer A50 mM Tris-HCl(pH 8)10 mM EDTA
    9. Stripping solutionfor DNA1% SDS0.1% SSCDesired volume was adjusted with sterile water. Alternatively, 0.4 M NaOH was also used to stripthe bound probes fromnylon membranes.HEPES [4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid] buffer1 M HEPESpH was adjusted to 7.5 with NaOH.HEPES was used as a buffering agent for preparing plates of YNB medium of different pH. Buffer was filter-sterilized and stored in an amber-coloured bottle.INOUE transformation buffer10 mM PIPES15 mM CaCl2.2H2O250 mM KCl55 mM MnCl2.4H2OpH was adjusted to 6.7 with 1 N KOH.Yeast transformation reagents1 M Lithium acetate 50% Polyethylene glycol2 mg/ml carrier DNADimethyl sulfoxide (DMSO)Zymolyase cocktail buffer for yeast colony PCR2.5 mg/ml Zymolyase1.2 M SorbitolZymolyase buffer was prepared in 1X PBS
    10. pH was adjusted to 8.5 with glacial acetic acid.TAE buffer was prepared asa50Xstock solution and used at 0.5X concentration.Alkaline denaturing solution for DNAfor membrane preparation0.5 M NaCl0.25 M NaOHVolume was adjusted with sterile water.Denhardt’s solution (50X)1%Ficoll-4001% Polyvinyl pyrollidone1% Bovine serum albuminVolume was adjusted with water and solution was stored at -20°C.Saline Sodium Citrate (SSC) buffer(20X)3.0 M Sodium chloride0.3 M Sodium citrate Volume was adjusted with water and solution was sterilized by autoclaving.Prehybridization Buffer5X SSC5X Denhardt’s solution50% Filtered formamide1% SDSVolume was adjusted with sterile water.Post hybridization wash buffersWash buffer 12X SSC0.1% SDSWash buffer21X SSC0.1% SDS
    11. Phosphate-Buffered Saline (PBS)137 mM NaCl2.7 mM KCl10 mM Na2HPO42 mM KH2PO4pH was adjusted to 7.3 before autoclaving.PBS was prepared as a 10X stock solution and diluted to 1X concentration before autoclaving.Tris-HCl buffer0.5 M Trizma BasepH was adjusted to 7.6 using concentrated HCl.Tris-Cl buffer was prepared as a 10Xstock solution and used at a 1X concentration.Tris-EDTA (TE) buffer10 mM Tris-HCl (pH 8.0)1 mM EDTATris-Acetic acid EDTA (TAE) buffer40 mM Tris base0.5 M EDTA
    12. Luria Bertani (LB)0.5% Yeast Extract1% Tryptone1% NaClSuper Optimal Broth (SOB)0.5% Yeast Extract2% Peptone
    13. Yeast extract Peptone Dextrose (YPD)1% Yeast extract2% Peptone2% DextroseYeast Nitrogen Base (YNB)0.67% Yeast Nitrogen Base2% DextroseFor alternate carbon source utilization experiments, dextrose was replaced withother carbon sourcesviz.,sodium acetate, ethanol, oleic acid, glycerol and citric acid.Yeast Nitrogen Base (YNB) without ammonium sulphate and amino acids0.17% Yeast Nitrogen Base2% DextroseCasamino Acid (CAA)0.67% Yeast Nitrogen Base2% Dextrose0.6% Casamino acidsFor preparing plates, 2% agar was added tothe medium before autoclaving
    14. Table 2.4: List of the oligonucleotides used to confirm deletion of C. glabrataORFs
    15. Table 2.3: List of the oligonucleotides used in the study
    16. Table2.2: List of the antibodies used in the study
    17. Table 2.1: List of strains and plasmidsused in the study
    18. methanol, acetic acid, potassium dihydrogen orthrophosphate, dipotassium hydrogen phosphate, disodium hydrogen orthrophosphate, acetone and citric acid were purchased from Qualigen chemicals. Fluconazole was procured from Ranbaxy.Lysotracker-Red DND 99 and FM 4-64 were obtained from Molecular Probes. Hybond-N and Hybond-P membranes for nucleic acid and protein transfer, respectively, were purchased from Amersham Biosciences. SYBR-green kit for real-time PCR was procured from Eurogentech. Superscipt SS-III RT kit and Pfu polymerase were obtained from Invitrogen. Different restriction enzymes used for cloning and knock-out generation were purchased from New England Biolabs (NEB). High fidelity DNA Pfx polymerase waspurchased fromFinnzymes. Plasmid DNA purification, PCR purification, gel extraction and reaction clean up kits were procured from Qiagen.Medium components for C. glabrataand bacterial culture viz.,yeast extract, peptone, tryptone, cassamino acid hydrolysate, yeast nitrogen base, yeast nitrogen base without ammonium sulphate, yeast nitrogen base without ammonium sulphate and amino acids and yeast carbon basewere purchased from BD (Becton, Dickinson and Company, USA). Animal cell culture media RPMI-1640, DMEM and α-MEM were procured from Hyclone. Fetal bovine serum, glutamine and antibiotics for cell culture medium were obtained from Gibco-Invitrogen
    19. Agarose, phenol, dimethyl sulphoxide (DMSO), sodium acetate, sodium chloride, sodium hydroxide, sodium carbonate, sodium bicarbonate, trizma base, sodium dodecyl sulphate (SDS), formamide, calcium chloride, ethylenediaminetetraacetic acid(EDTA), glycerol, polyethylene glycol, ficoll, diphenyleneiodinium (DPI), methyl methanesulphonate (MMS), camptothecin, hydroxyurea, ammonium persulphate, TEMED, acrylamide, bis-acrylamide, coomassie brilliant blue (CBB), chloroform, formaldehyde, glycine, lithium chloride, lithium acetate, menadione, isopropanol, phorbol myrsityl acetate (PMA), nuclease free water, wortmannin, bafilomycin-A, diethylpyrocarbonate (DEPC), orthrophenylenediamine (OPD), tween-20, acid washed glass beads, trypan blue, Taq DNA Polymease, trisodium citrate dihydrate and uracil were purchased from Sigma Chemicals. β-mercaptoethanol was obtained from GE Biosciences.Protease inhibitor tablets were procured from Roche. Dextrose, sucrose, agar, ammonium sulphate, potassium chloride, caffeine, magnesium chloride and sorbitol were obtained from Himedia.Hydrogen peroxide, hydrochloric acid, sulphuric acid,
    20. Oligonucleotides used in this study were designed either by freely available online tool Primer 3 plus (http://www.bioinformatics.nl/cgi-bin/primer3plus/primer3plus.cgi/)or Generunner software. Oligonucleotides were commercially synthesised at MWG Biotech Pvt. Ltd., Bangalore, India. Oligonucleotides used in this study are listed in Table 2.3
    21. All antibodies, their sources, clonality and dilutions used are listed in Table 2.2
    22. All C. glabrataand bacterial strains and plasmids used in this study are listed in Table 2.1
    1. The immunoblots were quantified by densitometry software ImageJ 1.17 developed by Wayne Rasband, NIH Bethesda, MD (http://rsb.info.nih.gov/nih-image).All experiments were done at least in triplicates and results were expressed as mean ±s.e.m. A two tailedStudent’s t-test was done in Graph pad to arrive at p values and differences were considered statistically significant when p-value was less than 0.05 (*p≤ 0.05), highly significant(**p≤ 0.01)andextremely significant (***p≤ 0.001)
    2. competent cells pre-inoculum was prepared. A single bacterial colony was picked from LB agar plate that has been incubated for 16-20 hours at 37 °C and inoculated into 3 mlLB medium and incubated overnight at 37 °C temperature with 200 rpm shaking. 1% of this pre-inoculum was sub cultured in 100 ml LB-broth and incubated at 18 °C until OD 600 reached 0.5 -0.6 (approx.). Culture was kept on ice for 10 min. with constant shaking. Cells were pelleted by centrifugation at 2000xg/4°C/8 min. Pellet was resuspended in 40 ml of ice-cold Innoue buffer. Bacterial suspension was kept on ice for 30 min, re-spun at 2000 xg/4°C/8 min. Pellet was resuspended in 8 ml of TB buffer inwhich final concentration of DMSO was 7% and left on ice for 10 min. 100μl aliquots were made and snap frozenin liquid nitrogen and stored at -80 °C
    3. All the salts (10 mM PIPES, 15 mM CaCl2.2H2O, 250 mM KCl,55 mM MnCl2. 2H2O) except MnCl2were dissolved in water and pH was adjusted to 6.7 with 1N KOH. MnCl2was dissolved separately in water. MnCl2was added drop wise while stirring (MnCl2if added directly will give a brown colour to the solution and precipitates;hence it needs to be dissolved separately). Solution was then sterilized by filteringand stored. To prepare
    4. Of theligation mixture,2μl (of total volume of 10 μl reaction)was added to atube of 100μlultra competent DH5α bacterial cells and incubated in ice for 30 minutes. The tubewas quickly transferred to a water bath maintained at 42°C to give a heat shock for 90 seconds and again quickly transferred to ice. 1ml of LB broth was added to the tube and then incubated at 37°C for 1 hour. The bacterial cells were then pelletdownby centrifugation at 6000 rpm for 5 minutes and plated on LB agarcontaining appropriate antibiotic
    5. A total of 100-200ng of DNA was used in each ligation reaction. Vector to insert ratio of 1:3 to 1:5was maintained. The reaction volume was generally maintained at 10μl containing 1μl of 10X ligation buffer (provided by the manufacturer) and 0.05 Weissunit of T4-DNA ligase. The reaction was carried outat 16ºC for 14-to 16-hrs or at room temperature for 4hours
    6. Digested DNA fragments required for ligation were eluted from the agarose gel after electrophoresis. The gel was visualised over a UV illuminator and section of it containing the desired DNA fragment was carefully sliced out from the gel. The sliced agarose gel was then processed using commercially available gel elution kitsfor this purpose. The elution efficiency was checked by running a small aliquot of DNA sample on agarose gel
    7. For restriction digestion(either single or double), 0.5 to 1μg of DNA was used in a reaction containing2 to 5units of commercially available restriction enzyme(s)and 5μl of the recommended buffer (suppliedas 10X concentrationsby the vendor)in atotal reaction volume of 50μl. The reaction mixture was incubated for 2 h or overnight at 37°C. The digested DNA fragments were then visualised by ethidium bromide staining after electrophoresis on agarose gels. Commercially available DNA size markers were loaded along with the samples to ascertain or estimate the sizes of the digestedfragments
    8. Overnight grown bacterial culture (3ml)was pellet down by centrifugationat4ºC for10-min at 6000 rpm. The cells were re-suspended in 200μl of Resuspension solution(solutionI). 400μl of freshly prepared Lysissolution(solution II)was then added and mixed by gently inverting the tubesfor 4-6 times and allowed to lyse for 5 min at room temperature.The complete lysis was ascertained by uniformity and clarityof the contents. Subsequently, 400μl of Neutralization solution(solution III)was added and the tubes were inverted 4-6 timesand gently for homogeneous mixing followed byincubation for 5 min on ice. After centrifuging at 12,000 rpm for 15-min, supernatant was decanted into a fresh tube, and0.7 volume of iso-propanol was added.Theprecipitated nucleic acids were then recovered by centrifugation at 12,000 rpm for 30-min. The pellet was washed once with 70% ethanol, air-dried and re-suspended in 100μl of TE-buffer. It was treated with RNase at a concentration of 20μg/ml by incubating at 37ºC for 1hour. It was further extracted with an equal volume of phenol: chloroform: isoamyl alcohol (25:24:1) mixture. After centrifugation, the clear supernatant was used for recovering the nucleic acids. The nucleic acids were precipitated with 2.5 volumesof ethanolin presence of3 M sodium acetate. In case where high purity plasmid preparations are required (for transfection to cells) the plasmid isolation was carried out with the commercially available midiprep or miniprep kits following the manufacturer’s instruction. Plasmids were observed on 1% agarose gel
    9. Automated DNA sequencing on plasmid templates or on PCR products was carried out with dye terminator cycle sequencing kits from Perkin-Elmer on an automated sequencer (model 377, Applied Biosystems), following the manufacturer’s instructions
    10. Agarose gels were preparedby boiling appropriate amount of agarose in TAEbuffer. After dissolution, it was cooled and then poured in a casting tray containing a comb for desired number of wells. The gel was allowed to solidify and then shifted to horizontal electrophoresis tank containing TAE buffer. The DNA samples were mixed with appropriate volumes of 6X DNA loading dye, loaded on the gel andelectrophoresedat appropriate voltage and current conditions (generally 80 V,400 mA). The gel was stained in ethidium bromide solution(1 μg/ml)for 15-min at room temperature and visualisedby fluorescence under UV-light in a UV-transilluminator
    11. 2μg of total RNA was reverse-transcribed using SuperScript III Reverse Transcriptase which is a commercially available version of M-MLVRT with reduced RNase H activity and increased thermal stability.According to manufacturer’s protocol1μg of RNA,1μl oligo(dT)(500ng),1μl 10mM dNTPand nuclease freewater was added to afinal volume of 13μlin a PCR tube.Thismixture was then incubated at 65°C for 5 minutesin a thermo cyclerand then quicklytransferredtoicefor 1minute. To this 4μl of 5X first strand buffer 1μl of 0.1MDTTand1μl ofRNaseOUT (40U/μl) were added. Then contents were then mixed and 1μl (200 units/μl) of SuperScript III RT was added. Themixture was then incubated at 50°C for 60 minutesin a thermo cycler.Lastlythe reaction was stopped byincubating the mixture at 70°C for 15 minutes. The cDNA thus prepared was then usedas a template for PCR
    12. The quantity and purity of nucleic acids was determined by measuring the absorbance at 260 and 280 nm. The concentration of nucleic acids was calculated by considering the OD (λ260)= 1 corresponding to50μg/ml DNA and 40 μg/ml ofRNA. The purity of nucleic acids was checked by their A260/A280 ratioconsidering 1.8 for DNA and 2.0 for RNA. These measurements were done in NanoDrop 2000 UV-Vis Spectrophotometer
    13. Total RNA was isolated by TRIzol method using the manufacturer’s protocol. Briefly, medium was removed from culture dish and recommended amount of TRIzol wasadded directly on to the dish and kept at room temperature for 5 minutes for lysis of cells. The cellular homogenate was then transferred to a 1.5ml microcentrifuge tube. For each mlof TRIzol, 200μl of chloroform was added and tubes were shaken vigorously for 10 seconds to completely dissociate the nucleoprotein complexes, followed by vortexing for about 30 seconds. The mixture was kept for 3-5 minutes at room temperature and then centrifuged at maximum speed of 12,000 rpm for 10 minutes. The upper aqueous phase was transferred into a fresh micro centrifuge tube and RNA was precipitated by adding 500μl of iso-propanol. The RNA pellet was obtainedby centrifugation at 12,000 rpm for 30 minutes at 4°C. The pellet was washed with 1ml of chilled 70% ethanol followed by centrifugation at 12,000 rpmfor 5minutes. The supernatant was removed and the pellet air-dried for about 5 minutes. The pellet was resuspendedin 30-50μl RNase free deionisedwater and dissolved at 55ºC followed by quantificationusingnanodrop spectrophotometerfor further use.The RNA integrity was checked by evaluating the 18S and 28S rRNA signals by running 1μl of total RNA on denaturing agarose gel stained with ethidium bromide
    14. Total RNA isolation from cultured cells
    15. nvolved use of GFP based vector system, the expression of the transgene was visualized under fluorescent microscope with excitation filter of 485+20 nm
    16. Transient transfection of plasmid DNA in cellswas performed usingLipofectamine 2000transfection reagentaccording to manufacturer’s protocol. Briefly, 0.5 to 1million cellswere seeded in a 35mm tissue culture dish one day prior totransfection. For each 35mm dish, 4μg DNA was mixed in 250μl of Opti-MEMin one polypropylene tube. In another tube 10μl of Lipofectamine 2000 was diluted in250μl Opti-MEM and incubated at room temperature for 5 minutes. DNA and Lipofectamine 2000 were mixed together and allowed to form complexes for 30minutes at room temperature. Meanwhile, the adherent cells were washed twicewithPBS and 1ml of Opti-MEM was added. 500μl of complexes were then added to each dishcontaining cells and medium. After 6-8 hrs, the medium containing complexes wasremoved and complete medium was added and transgene expression was evaluated 24-48 hrs after transfection. Since most of the experiments
    17. Themixture is incubated in a water bath at 37⁰C for 15 min and afterwards transferred on ice and 4μl of DNA loading buffer is added. The samples were then run on a polyacrylamide gel electrophoresis which had been pre-run for 30 min. Electrophoresis was carried out at 4⁰C for 3h till the bromophenol blue migrated to 2cm above the bottom of gel. The gel was taken out and kept on Whatman filter paper sheet and covered by saran wrap followed by drying in a gel dryer at 80⁰C for 1h under suction. The dried gel was exposed to phosphoimager screen by keeping in phosphoimager cassette overnight
    18. A binding reaction mixture was prepared by adding the following components to a microcentrifuge tube on ic
    19. The reaction was carried out by incubating at 37⁰C for 30 min. The reaction was stopped by adding 2μl of 0.5M EDTA, pH 8.0 and keeping on ice. A spin column was prepared using 1ml syringe and packed with sterile Sephadex G50 slurry and reaction mixture is applied on the top. The eluate is collected in different microcentrifuge tubes and radioactivity was counted using Geiger counter. The tube showing 7 to 9X106was used for experiment. The column containing the unincorporated [γ-32P] ATP was discarded in radioactive waste bin. The radiolabelled oligonucleotides were annealed with their corresponding complementary unlabelled oligonucleotides. A 50 fold molar excess of the latter was used for annealing for conversion of labelled single strand to double strand. Thetubes were kept in boiling waterbath for 3 min followed by room temperature for 30 min. The tubes were transferred to ice and the oligonucleotides were diluted to 4fmoles/μl using sterile H2O
    20. The oligonucleotides were labelled at their 5'end with 32P using T4 polynucleotide kinase (T4 PNK) enzyme in a reaction given belo
    21. Adherent cells growing either on cover slips or chamber slides were fixed with 4% paraformaldehyde for 10 min at room temperature. The cells were washed with PBS thrice for 5 min each and blocking was done in 2% BSA(preparedin PBScontaining 0.3% Triton-X 100) for 1h.The cells were incubatedwith primary antibody(dilutedin PBScontaining 0.3% Triton-X 100)for 2h at room temperature or overnight at 4⁰C.The cells were washed with PBS thrice for 5 min each followed by incubation withAlexa Fluor 488-or 594-conjugatedsecondary (anti-mouse/rabbit) antibodiesfor 1h. Then the cells were mounted on microscopicslides using Vectashieldmountingmediumcontaining nuclear dye DAPI. Imaging was done byeither the laser scanning confocal LSM510 or LSM 750 (Carl Zeiss, Oberkochen, Germany) or fluorescence inverted (Olympus 1X51, Tokyo, Japan) microscope
    22. Equal amount of proteins were loadedon an appropriate percentageof denaturing SDS-PAGE gel. After completion ofthe run, the gel was over laid on a PVDF membranecut to the size of gel and sandwiched between filter paper sheets and kept inthe blotting cassette in the presence of transferbuffer. Finally the cassette was put in themini transblotapparatus and blotting was done for 2-3hours at a constantvoltage of 80Vat 4⁰C. For blocking the nonspecific sitesmembrane was incubated with blocking solution(5% non-fat milk solution in TBST)with gentle shaking for 1 hourat room temperature. Excess milk from the membrane was washedoff with TBST and themembrane was incubatedwith primary antibody diluted in 1XTBST for 3 hours atroom temperature or overnight at 4°C withshaking. After incubation the membrane was washedwith TBST and incubatedwithappropriate secondary antibody (conjugated with horse-radish peroxidase)diluted in5% fat free milk solution (in TBST) for 1hat room temperature.The blotwas later washed thricefor 10min eachwith TBST and processed for the detection of proteinsignal using ECL-prime chemiluminescencedetection reagent followed by detectionof signal either on X-ray filmor in a chemiluminescence detectionsystem(Proteinsimple, California, USA)
    23. BCA (Bicinchoninic acid) method was used to determine the proteinconcentrationin various samples. The Cu2+ions from cupric sulphate (present inBCA reagent B) reagent arereduced to Cu+by the protein in an alkaline medium. The cuprous ion (Cu+) then combines with BCA (present in BCA reagent A) to give a purple colour whose intensity is proportional to the amount of protein present in the samples. This intensity is measuredby colorimetry at 562 nm. BCA reagent was prepared by mixing reagent A with reagent B in avolumeratio of 50:1. A standard curve was generated using increasing concentrations of BSA (2-10μg) in a 25μl reaction, in a 96 well plate. Cell lysates were also dilutedto same volume in parallel wells. 200μl of BCA reagent was then added to each well and incubated at 370C for 30 minutes. The absorbance readings were then takenin a spectrophotometer at 562 nm. Total protein was quantified by calculation of the slopes of regression lines ofabsorbanceand BSA standards
    24. For preparation ofcellular homogenate from adherent cell culture, the medium was first removed and cells were washed with ice cold 1X PBS. The cells were then scraped in 1X PBS and pellet down by gentle centrifugation (4000 rpm for 2 minutes) at 40C. Cell lysis buffer was then added to the cell pellets and lysis was allowed for 30 minutes on a rotor at 4⁰C. Post lysis, cellswere centrifuged at 13000 rpm for 10min at 4°C. The pellet was discarded and supernatantwascollectedas cell homogenate
    25. drop wiseaddition and kept at 4⁰C for 24h. Cells were then washed with PBS and stained with DNA staining solutionat 370C in darkwith intermittent shaking. The DNA content of cells was measured by flow cytometryusing FACS-Aria (Beckton-Dickenson) at 695 ±20 nm using a 655 long pass filter.The DNA content was then analysed by FACSDivaor FlowJosoftwareto evaluate the various phases of cell cycle. The diploid 2N DNA content was referred as G1/G0 population and the 4N DNA content was referred as G2/M population. Cells with intermediary DNA content (between 2N -4N) content were considered as S phasecells and those below 2N DNA content as sub G0 cells
    26. Thecells were collected at various time points by trypsinization, washed in phosphate buffered saline (PBS, pH 7.2) and fixed in chilled 70% methanol: ethanol (1:1) solution by
    27. Cells were seeded in replicates of five @ 3X103cells per wellinfive different 96well cell culture platesand grown in complete media. The method described earlier was slightly modified and followed (Gillies et al., 1986). After every 24h of seeding, one plate was stained with 0.2% crystal violet in 2% ethanolfor 15 minutestill 4thday i.e. 96h.One plate was stained just after the cells get attached to use as 0h time point. Excess dye was removed from the plates by washing with ample amount of water. Crystal violet dye incorporated in the cells was extracted using 0.1% SDS solution by shaking for 10 minutes on a shaker. Absorbance of the extracted dye was then determined at 570 nm in a spectrophotometer. The experiment was repeated at least three times and the average absorbance was plotted for each time point to generate a growth curve
    28. Table2.2: Cell types used in the present study
    29. In the present thesis, various cell types were used for which the details are provided in the Table 2.2. SiHa, HeLa, HaCaT, U2OS, SaOs , A549,HPLD andHEK-293cells were grown in Dulbecco’s modified Eagle’s medium (HyClone, Thermo Scientific, Logan, Utah, USA) supplemented with 2 mM glutamine (Gibco BRL), 100 U/ml penicillin and streptomycin (Gibco BRL, Carlsbad, CA, USA), and 10% fetal bovineserum (Gibco BRL, Carlsbad, CA, USA) under humified conditions at 37°C and 5% CO2.Cells were grown in cell culture dishes till they attained 70% confluency. For sub culturing, these were then trypsinised using 0.05% Trypsin EDTA solution and incubated for 5 minutes at 370C for cells to be detached from surface. The detached cells were then collected by gentle tapping the dish and pipetting. Trypsin was then inactivated by addition of FBS containing culture medium, transferred to a 15 ml tube and centrifuged at 1500 rpm for 2 minutes in a hanging bucket centrifuge. The cell pellet was then resuspended in complete medium and counted in Neubauercell counting chamber. Viability of the cells was checked by trypan blue exclusion method.Appropriate number of cells wasthen sub cultured in fresh cell culture dishes with culture medium as per the experimental requirements
    30. Malachite green reagent
    31. Reaction Buffer
    32. Cell lysis Buffer
    33. DNA staining solution
    34. Fixative
    35. Inoue buffer
    36. DNA loading dye
    37. Agarose gel
    38. TAE
    39. Neutralization solution(Solution III)
    40. Lysissolution(Solution II)
    41. Resuspension solution(Solution I)
    42. Binding Buffer (10X)
    43. EMSA Buffer
    44. Nuclear lysis buffer
    45. Polydeoxy (Inosinate-cytidylate) (Poly dI-dC)
    46. Nuclear extractionbuffer (without protease inhibitors)
    47. Cytoplasmic extractionbuffer (without protease inhibitors)
    48. Blocking buffer: 2% BSA
    49. Permeabilization buffer: 0.2% Triton X100
    50. Fixative : 4% Formaldehyde
    51. Stripping Buffer
    52. Blocking Buffer
    53. TBST
    54. Transfer Buffer
    55. Running Buffer
    56. Stacking and resolving AcrylamidegelsResolving gel (10 ml)
    57. 6X protein loading buffer (Laemmlibuffer)
    58. Cell lysis buffer(RIPA Buffer)
    59. Tris Buffered Saline (TBS)
    60. Phosphate Buffered Saline (PBS)
    61. Ammonium persulfate(APS)
    62. Acrylamide (29:1)
    63. Phenylmethylsulfonyl fluoride (PMSF)
    64. Benzamidine
    65. Aprotinin
    66. Leupeptin
    67. NP-40ComponentsFinal concentrationFor 10 mlNP-4010%1mlH2O9ml
    68. Dithiothreitol (DTT)ComponentsFinal concentrationFor 5 mlDTT1.0M0.7725gH2Oq.s
    69. Ethylenediamine tetraacetic acid (EDTA), pH 8.0ComponentsFinal concentrationFor 500 mlEDTA0.5M93.05gH2Oq.sThe pH is adjusted to 8.0 using 10M NaOH
    70. Ethylene Glycol Tetraacetic acid (EGTA), pH 7.0ComponentsFinal concentrationFor 50 mlEGTA0.1M1.902gH2Oq.sThe pH is adjusted to 7.0 using 10M NaOH
    71. Potassium Chloride (KCl)ComponentsFinal concentrationFor 100 mlKCl2M14.91gH2Oq.s
    72. Sodium Chloride (NaCl)ComponentsFinal concentrationFor 100 mlNaCl5M29.22gH2Oq.s
    73. Potassium Chloride (KCl)
    74. HEPES pH 7.9ComponentsFinal concentrationFor 100 mlHEPES1M23.83gH2Oq.sThe pH wasadjusted to 7.9 using 10M NaOH
    75. forpreparation ofregular buffers and solutions viz. Tris, Glycine, SDS, Sodium Chloride, Potassium Chloride, Disodium Phosphate,NP-40, Tween 20, TritonX100, Formaldehyde, Glycerol, Agarose, Acrylamide,Bis-Acrylamide,Ammonium per sulphate (APS), TEMED,BSA, Propidium Iodide, RNase Aetc. were obtained from Sigma(St Louis, MO, USA). PVDF membrane, X –ray films and western blotting detection reagent (ECL prime) were obtained from GE Healthcare (Little Chalfont, UK). Proteaseinhibitor tablets were obtained from Roche (Penzberg,Germany). Anti mouse and anti-rabbit secondary antibodies tagged to HRP (Horse radish peroxidise) were obtained from Bangalore Genei(Peenya, India). Secondary antibodies for Immunofluorescence (anti mouseIgGand anti rabbitIgG) conjugated to Alexa Fluor (488 and 594) from Molecular Probes, Invitrogen and Vectashield mounting medium with DAPI wasobtained from vector laboratories(Burlingame, CA, U.S.A).Antibodies from different sources were used in the present study. The list of different antibodies used in the present thesis is provided in Table 2.1.Table 2.1: List of antibodies used
    76. Media for cell culture (DMEM and Ham’s F12) and foetal bovine serum (FBS) were obtained from Gibco, Invitrogen (Carlsbad, CA, USA). Cell culturereagents such asTrypsin, Phosphate Bufferedsaline (PBS), Antibiotics, Glutamine, etc. were also obtained from Gibco, Invitrogen (Carlsbad, CA, USA). Chemicals for cell culture experiments Aphidicholin, Nocadazole, Polybrene, and Puromycinwere obtained from Sigma (St Louis, MO, USA). Cyclosporine A, MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide), wortmannin, UO126, SP 600125, cycloheximide, camptothecin, Tacrolimus/FK506 , Tween 20 and Malachite green were obtained from Sigma-Aldrich (St. Louis, MO, USA). Specific calcineurin substrate RII peptide, calmodulin, eIF-2α inhibitor salubrinal, MG-132 and caspase inhibitor z-VAD FMK were obtained from Calbiochem (San Diego, CA, USA). Cytotoxicity detection kit (LDH) was obtained from Roche Diagnostics, (Mannheim, Germany).Live /Dead cytotoxicity assay kit was obtained from Molecular probes, Life technologies, USA.Lipofectamine-2000 and Opti-MEM for transient transfections were also obtained from Invitrogen(Carlsbad, CA, USA).Growth media for bacteria (LB) was obtained from HiMedia laboratories (Mumbai,India). Enzymes used for recombinant DNA experiments (Restriction endonucleases, DNA ligase) were obtained from New England Biolabs (Ipswich, MA, USA). Markers for DNA and protein gels were from Fermentas (Vilnius, Lithuania). Various kits used for macromolecular isolation (Plasmid isolation kit-Mini and midi, Gel extraction kit, PCR purification kit, RNA isolation kit) were procured from Qiagen(Hilden, Germany) or HiMedia (India).Trizol reagent for RNA isolation was obtained from Invitrogen (Carlsbad, CA, USA). BCA protein estimation kit was from Pierce (Rockford Illinois, USA). Cell fractionation kit was obtained from Fermentas (USA). Kitfor TUNEL assay kit wasobtained from Invitrogen(Carlsbad, CA, USA). PCR reagents (PCR buffer, dNTPs, MgCl2, Taq DNA polymerase) were obtained from Fermentas. Polymerasefor long PCRs (AccuTaq) was obtained from Sigma. Reverse transcriptase (SuperScript III) was obtained from Invitrogen. Various chemicals required
    1. All data were presented as mean ± standard deviation (SD)/standard error of mean (SEM) fromthree independent experiments. Statistical analysis was performed using Student's t-test and one-way ANOVA followed by a post hoc Tukey testwherever applicable. Results were analyzed and illustrated by SPSS statistical software package (SPSS for Windows,version 16). Comparisons are done within and between the test groups (i.e.,parentalcells and profilin-stable cells). Asterisk (*) symbol indicates statistical difference between parentaland profilin-stable cells, whereas Number (#) and Dollar ($) signsindicatestatistical difference within parentaland profilin-stable cells, respectively. Significance of results was determined as p ≤ 0.01 and p ≤ 0.05(*indicates p ≤0.05, **indicates p ≤0.01, *** indicates p ≤0.001 and **** indicates p ≤0.0001
    2. AutoDock tools 1.5.6 (Morris et al., 2009) and PyMOL (Sanner, 1999) was used to prepareand analyze the docking simulations.Preparation of protein structures for docking:The three dimensional structure of PTEN (PDB ID: 2PBD) (Lee et al., 1999)and profilin-1 (PDB ID: 1D5R) (Ferron et al., 2007)were obtained from protein data bank, PDB (www.rcsb.org).Prior to initiating the docking simulations, all non-protein molecules were removed from the intact PTEN and only the chain P was retained. In the same way, we retained (‘chain A’) for profilin-1. All the non-protein molecules were removed usingChimera(Pettersen et al., 2014).Protein PTEN was used as receptor and profilin-1was used as ligand. Kollman united atom charges and polar hydrogen were added to the receptor protein. Receptor protein was kept rigid in docking process, assuming there is no induced conformational change upon ligand binding. In contrast to the protein, torsional flexibility was permitted for the ligands via the side-groups and backbone of protein was kept rigid.Atomic affinity and electrostatic potentials were computed for a grid boxand positioned around the approximate centre of the binding site. The grid box size was set at 58.0 X 76.0 X 58.0 Å (x, y, and z) with the spacing between grid points at 1 Å and the center at 36.253 X 82.395 X 31.728 for x, y and z coordinates, respectively. All other docking parameters remained as the Autodock default settings.Analysis of docking data:AutoDockVina (Trott and Olson, 2010) software was used for docking simulations. The resulting docked conformations were clustered into families of similar conformations, with the root mean square deviation (r.m.s.d.) clustering tolerance of 2.0 A ̊. As a rule, the lowest docking-energy conformations were included in the largest cluster. The process was repeated for each remaining conformation, until all the conformations belonged to a single cluster. A new reference conformation was defined every time a new cluster was created. Following this, the best-docked conformation is selected as the lowest energy pose in the most populated cluster, i.e., the cluster with the highest convergence out of the 100 trials. This differs from the practice of simply choosing the overall lowest energy pose. Thus, we avoid picking lower energy ranked poses belonging to sparsely populated clusters, which can be considered as ‘chance-hits’ given that the docking algorithm was unable to converge to similar poses in other independent trials
    3. The highly efficient Ultra competent DH5α cells for transformation were prepared by Inoue method (Inoue et al., 1990). Briefly, a single bacterial colony was picked from LB agar plate, inoculated into 10 ml LB medium and incubated overnight at 37°C temperature with 200 rpm shaking. Following day, 1% of the pre-inoculum was sub-cultured in 100 ml LB-broth and incubated at 18°C until OD600 of 0.5-0.6 was reached. Culture was then kept on ice for 10 min with constant shaking. Cells were pelleted by centrifugation at 5000 rpm at 4°C for 10 min. Pellet was resuspended in 40 ml of ice-cold Inoue buffer. Bacterial suspension was kept on ice for 30 min, re-spun at 2000g at 4°C for 10 min. Pellet was resuspended in 8 ml of TB bufferin which 560 μl DMSO was added and left on ice for 10 min. Finally, 100 μl aliquots were made by snap freezing in liquid nitrogen and stored at -80°C
    4. In a typical ligation reaction, a total of 100 ng of vectorwas usedwhereas;theconcentration of insert varies from 300 to 500 ng. For10μlreaction volume, 1μlligation buffer (provided by the manufacturer) and 0.5μlof T4-DNA ligasewere added in vector-insertmixture. The reaction was maintainedat 16oC for 14-16h.After ligation, 2μl of the ligation mixture (of total volume of10 μl reaction) was added to a vial of ultra-competentDH5α bacterial cells and incubated in ice for 30 minutes. The ligation mixture was allowed toheat shock at 42oC for 90 seconds followed by quick transfer onice. About1ml of LB broth was added to the tube and incubated at 37oC for 1 hour. The bacterial cells were then pelleted by centrifugation at 6000rpm for 5 min and plated on LB plate containing appropriate antibiotic
    5. For construction of desired clones, 1-2 μg of DNA was used for restriction digestion. In a typical reaction, 2-5units of restrictionenzymeswereused in the total reaction volume of 50μl along with5μl ofrecommended buffer (supplied as 10X digestion buffer). The reaction mixture was incubated for 3-5 hat 37oC. The digested DNAwasthenloaded along with DNA size marker and separated on agarose gel electrophoresis. The gel was visualized over a UV illuminator and section containing the desired DNA fragment was carefully sliced out. The sliced agarose gel was then processed using commercially available Gel Extraction kit (Qiagens) for this purpose
    6. Plasmid DNA was isolated from10-100ml of bacterial culture grown overnight by using commercially available Miniprep or Midiprep kits (Invitrogen) as per manufacturers’protocol. Briefly, bacterial cells werepelleted by centrifugation at 6000 rpmfor10 min.The pelleted cells werere-suspended in 300μl-4ml of resuspensionsolution containing RNase H.About300μl-4ml of alkaline lysis solutionwas then added and mixed by gently inverting the tubesuntil clear and uniform lysatewas appeared. Subsequently, 350μl-5mlof neutralizing solutionwas added,the tubes were inverted repeatedly and gently to ensurehomogeneous mixing, followed by incubation for 5 min on ice. After centrifuging at 12,000 rpm for 15 min, supernatant was passed through commercially supplied filter columns by either gravity flow or high-speedcentrifugation. During this step, plasmid DNA binds to the column and was recovered by passing elution buffer through the column. The plasmid DNA present in the elution buffer was collected into a fresh tube and 70%(w/v)of iso-propanol was added.Theprecipitated nucleic acids were then recovered by centrifugation at 12,000 rpm for 30 min. The pellet was washed once with 70% ethanol, air-dried and re-suspended in desired amountof TE-buffer. Finally, the purity of plasmid wasobserved on 1% agarose gel
    7. Automated DNA sequencing on plasmid templates or on PCR products was carried out with dye terminator cycle sequencing kits from Perkin-Elmer on an automated sequencer (model 377, Applied Biosystems), following the manufacturer’s instructions
    8. For preparing agarose gels,appropriate amount of agarose(0.8-2%) was dissolved by boilingin TAEbuffer, until clear slurry was formed.It wasthen poured in a casting tray containing a comb for desired number of wells. The gel was allowedto solidify andshifted to horizontal electrophoresis tank containing TAE bufferwith 1 μg/ml ethidium bromide. Appropriate volumesof 6X DNA loading dye were added in the samples and subjected to electrophoresis atconstant voltage (generallyat80 V), along with appropriate DNA ladder,untilband were resolved. The gel was visualised underUV-light in a Gel-Doc or UV-transilluminator
    9. The quantityand purity of nucleic acids weredetermined by measuring the absorbance at 260 and 280 nmusing automated NanoDrop instrument. The concentration of nucleic acids was calculated by taking 1 OD at 260nm = 50μg/ml for DNA and 40 μg/ml for RNA. The purity of nucleic acids was checked by their A260/A280 ratio
    10. The reaction mixture was then placed on a thermo-cycler with the required cycling conditions for amplification of the desired gene, as described in Table 2.7. The amplified products were purified by PCR purification kit (Qiagen) and either quantified by spectrometry or separatedby agarose gel electrophoresis.Table2.7:Cycling conditions for PCR
    11. The PCR amplification of desired genes werecarried out using Taq polymerase reaction kit obtained from Fermentas.Typically, a reaction mixture containing primers with plasmid containing geneof interest or c-DNA was prepared as described in Table 2.6. Table2.6: Various components of PCR reaction mix
    12. Total RNA, isolated by TRIzol method was reverse transcribed into cDNA by One step Access RT-PCR kit (Promega, Madison, WI), as per manufacturer’sprotocol.Briefly, 1 μg of RNA, 1 μloligo-dT(500ng), 1 μl 10 mMdNTP and nuclease free water was added in a PCR tube. This reaction mixture was incubated at 65°C for 5 minutes in a thermo cyclerand then quickly transferred to ice. To the mixture, 4μl 5X firststrand buffer, 1μl 0.1M DTT,1μlRNase-OUT (40U/μl) and 1 μl (200 units/μl) of SuperScriptIII were added.The contents were mixed by gentle vortexing and incubated at 37°C for 60 minutes in a thermo cycler. Finally,the reaction was stopped by increasing the temperature to72°C for 10minuteson thermo cycler. The cDNA thus prepared, wasused as a template for PCR.PCR was then performed for either amplification of the gene of interest or relative expression of desired genes by the using gene specific primers(Table 2.5). Products were separated by agarose gel electrophoresis (2%) and visualized by ethidium bromide staining.Table2.5: List of RT-PCR primersused in the study
    13. Total RNA was isolated from the treated cells usingTRIzol method, essentially described by Donald and his co-worker (Donald et al., 2010).TRIzol is a single-phase solution of guanidinium isothiocyanate and phenolthat can concomitantly denature proteins and other biological material. Addition of chloroform to this leads to phase separation: proteins remains in organic phase whereas, DNA and RNA resolves to interphase and aqueous phase, respectively. Before starting the experiment, area was sanitized with RNAZap toremove any contamination of DNases. After treatment, culture media was gently removed from the dish without disturbing the cell monolayer. TRIzolreagentwas added directly on to the dish andcellswere allowed tosuspend in it by repeated pipetting. The cellular homogenate was then transferred into amicrofuge tubes. For each ml of TRIzolused, 200μl of chloroform was added andvortexedfor about 30 seconds, followed bycentrifugation at maximum speed of 13,000 rpm for 10 minutes. The upper aqueous phase wastransferred into a fresh micro-centrifuge tube and 500μl of ice-cold iso-propanol was addedto precipitate RNA.The RNA was pelleted by centrifugation at 13,000 rpm for 30 minutes at 4°C. The supernatant was decanted and the pelletwas allowed towash with 1ml of ice-cold 70% ethanol followed by centrifugation at maximum speed for 10 minutes. Finally, the supernatant was removed and the pellet was allowed toair-dryfor about 5-10 minutes and solubilized in 50μl RNase free deionized (DEPC-treated Milli-Q) water and quantified by spectrophotometry for further use
    14. Table 2.4: List of double-stranded oligonucleotides used in the present study
    15. The DNA-protein complexes were then separated from free oligonucleotides on 6.6% native PAGE gel. The samples were loaded into a native PAGE gel, which was pre-run at constant current (40-50 mA) for 15-30 minutes. Electrophoresis was performed at constant current (80-100 mA), till the bromophenol blue dye front reached 1-2 cm from bottom of the gel. The glass plate was carefully removed without disturbing the gel and the Whatmann filter paper no. 3, cut to the size of the gel, and wasplaced over it. The paper was pressed gently and the gel, which was now firmly stuck on the paper, was covered with saran wrap and kept for vacuum drying on the gel-dryer at 80oC for 1 h. After drying, gel was exposed on a Phospho-imager screen for 12-24 h and scanned on Phospho-imager to detect the band of interest.To determine the specificity of the transcription factor binding or sub-unit interacting to the desired oligonucleotide, super-shift assay was performed. For this, 8-10 μg of nuclear extracts were first incubated with desired antibodies (concentration varies for different) or their isotype control for 1h at 25°C, followed by incubation with binding reaction mixture. The various oligonucleotide sequences used in the present study are listed in Table2.4below
    16. For detection of protein-nucleic acid interaction, an electrophoretic mobility shift assay (EMSA) was conducted as described by Hellman and Fried (2007). Breifly, 8-10 μg of nuclear extract protein was incubated with binding reaction-mixture containing either 32P end-labeled double-stranded oligonucleotides (NF-κB, AP-1, p53 or SP-1) or unlabeled oligonucleotide as shown in table 2.3. The reaction mixture was incubated at 37°C for 45-60 min. After completion of reaction, 6μl of 6X DNA-loading dye was added and mixed well by gentle tapping.Table 2.3: Binding conditions for DNA-protein complexes in EMSA
    17. The mixture was then incubated at 37oC for 45 min to radiolabel the oligonucleotide. Simultaneously, the Sephadex G-50 column was prepared in 1 ml syringe. The reaction mixture was loaded on the column and the eluting fractions were collected in the microfuge tube by loading 200 μl milli-Q water on the top of the column. After collecting 5-6 fractions, the tubes were analysed using a GM counter for the amount of radioactivity. The fractions having specific activity between 3.5-4.5 X 106cpm/pmoles were pooled. To this, 100 pM of the complimentary strand of the oligonucleotide was added and heated at 95°C for 5 minutes. The mixture was allowed to annealat room temperature for 1 h and further used in Gel shiftassay
    18. The oligonucleotides of different transcription factors such as NF-B, AP-1, p53 and SP-1 were 5′-end labelled using radioactive γ32-ATP (obtained from BRIT, BARC, Mumbai, India) and Polynucleotide kinase, as per manufacturers’ protocol. The reaction mixture containing the different components, described in the table 2.2below was added in a microfuge tube.Table 2.2: Various components of oligonucleotide labeling reaction mixture
    19. and stained with ‘Live & Dead’ cell assay reagent (5 μM ethidium homodimer, 5 μM calcein-AM) for 30 min at room temperature. Red (as dead) and green (as live) cells were analyzed under a fluorescence microscope (Labophot-2, Nikon, Tokyo, Japan).For flow cytometry, cells were transiently transfected with either empty vector or various constructs. After 12 h, cells were treated with a combination of CHX (cycloheximide, 25 μg/ml) and TNF (5 nM) for 24 h. Cells were washed, trypsinised and then subjectedto flow cytometry (FACS Aria, BD Biosciences) using Live-Dead Cytotoxicity assay kit (Invitrogen). Live versus dead cells were analysed using FlowJo software
    20. Cytotoxicity assay: The drug-induced cytotoxicity was measured by the 3-(4,5-Dimethylthiazolyl-2)-2,3-diphenyltetrazoliumbromide (MTT) assay as essentially described by Mosmann et al., 1983. Briefly, 5x104cells/well were seeded in 96-well plate. After 12 h, cells were treated in triplicates with different agents for different concentrations and time (in a final volume of 100μl). After completion of treatment, 25 μl of MTT solution (5 mg/ml in PBS) was then added and incubated for 2 h. The cytotoxicity was evaluated by uptake and cleavage of yellow MTT dye to purple formazan crystals by dehydrogenase activity in mitochondria of the living cells. Thereafter, 100 μl of extraction buffer (20% SDS in 50% dimethlylformamide) was added. After an overnight incubation at 37ºC, the absorbance at 570 nm was measured using 96-well multiscanner autoreader(Bio-Rad) with the extraction buffer as blank. Absorbance values were normalized to untreated cells and represented in percent cell viability for different concentrations or treatments.Determination of nuclear fragmentation: The morphology of live and dead cells was observed by staining the nucleus with DNA intercalating dye, propidium iodide (PI).Briefly, cells were treated with several apoptotic inducers for different concentration or time. Thereafter, cells werewashed with PBSand fixed in ice-cold 80% methanol for overnight at 4°C. Following day,cells were washed and suspended in 100 μl of PI solution (0.1% Triton, 0.2 mg/ml RNase A and 50 μg/ml PI in PBS) for 30 min in dark. Cells were then mounted on slides and viewed under fluorescence microscope (in 560 nm filter) to determine morphology of intact or fragmentednucleus.Live &dead assay: The cytotoxicity of various drugs was determined using the commercially available Live/Dead assay kit (Molecular Probes, Eugene, OR). Live cells have intact membraneand active cellular metabolism,which allow Calcien-AM to permeate inside and get cleaved into green fluorescent compound, Calcein (ex/em ~495 nm/~515 nm) due to intrinsic cellular esterase activity. On the other hand, Ethidium homodimer-1 (EthD-1) enters cells with damaged membranes and undergoes a 40-fold enhancement of fluorescence upon binding to nucleic acids, thereby producing a bright red fluorescence in dead cells (ex/em ~495 nm/~635 nm). Hence, the cell viability can be assayed by either flow cytometry or fluorescence microscopy.For imaging, cells with different drugs treatments were washed with PBS
    21. Secretory alkaline phosphatase (SEAP) assay: For SEAP assay, the culture supernatant was analyzed for SEAP activity essentially as per the Clontech kit protocol (Palo Alto, CA). Briefly, cells were transiently co-transfected with Lipofectamine 2000 transfection reagent, 0.5 μg of required plasmid DNA(s) with the protein of interest or empty vector, 0.5 μg of reporter plasmid containing NF-κB binding site cloned upstream of heat-stable SEAP (designated asNF-κB-SEAP)and 0.5 μg of green fluorescence protein (GFP) expression plasmid (Clonetech) in Opti-MEM media.After 6 h of transfection, cells were washed and cultured for 12 h in complete media, followed by treatment with different inducers. GFP positive cells were then counted to ensure similar transfection efficiency. At the end of treatment, cell culture-conditioned medium was harvested and 25 μl of medium was mixed with 20 μl of 5X buffer (0.5 M Tris, pH 9 and 0.5% bovine serum albumin) in a total volume of 100 μl in a 96-well plate followed by incubation at 65°C for 30 min. The plate was chilled on ice for 2 min and 50 μl of 1 mM 4-methylumbelliferylphosphate (MUP, substrate) was added to each well and incubated at 37 °C for 2 h. The activity of SEAP was assayed on a 96-well fluorescent plate reader (Fluoroscan, Lab Systems, MA) with excitation set at 360 nm and emission at 460 nm. The average number (± SD) of relative fluorescent light units for each transfection was then determined and reported as fold activation with respect to empty SEAP-transfected cells.Luciferase (Luc) assay:The cell pellet was lysed and extract was analysed as per Promega kit protocol.Briefly, cells wereco-transfected with Lipofectamine with 0.5 μg of reporter plasmid containing p53 binding site cloned upstream of luciferase (designated as p53-luciferase) and 0.5 μg of GFP constructs. After 6 h of transfection, cells were washed and cultured for 12 h, followed by treatment with different inducers of apoptosis. GFP positive cells were then counted.Cellswere pelleted down and lysed using the lysis buffer. The samples were freeze-thawed twice by storing them at -70oC to ensure total lysis. The supernatant,obtained by centrifuging the same at 11,000 rpm for 2 min was transferred to a fresh tube. About 100 μl of the substrate (Firefly luciferin, Promega) was added to the supernatant and light emission wasmeasured in luminometer by using a delay time of 2 sec andread time of 10 sec.The values were calculated as fold of activation over vector-transfected value
    22. Uniquitination assay was performed as described by Choo and Zhang, 2009. Ubiquitination is an enzymatic process of the covalent attachment of polypeptide ubiquitin on specific lysine residuesof protein, which is thendegraded by proteasome complex. MG132 (carbobenzoxy-Leu-Leu-Leucinal), a proteolytic activity inhibitor of proteasome complex, is widely used to assess the stability of protein in vivo. Briefly, parental and profilin-stable cells were treated with 10 μM MG132 for 6 h. The whole cell extracts prepared in NTEN lysis buffer were then subjected to immunoprecipitation with anti-ubiquitin antibody. The analysis of ubiquitination was performed by immunoblotting with anti-PTEN antibody
    23. Retroviral based system was used for silencing of PTEN. BOSC23 packaging cells were grown in 100 mm culture dishes upto 80-85% confluency. Retroviral RNA vector containing either scrambled control shRNA or pool of PTEN shRNA along with a PCL-Ampho helper plasmid were co-transfected using Lipofectamine 2000 reagent to generate viral particles. After 48 h, supernatant containing viral particles were used to infect MDA-MB-231 cells in the presence of polybrene (8g/ml). For p53 gene knockdown, TP53 mission shRNAs obtained from Sigma Aldrich (St Louis, MO, USA) were transfected using Lipofectamine 2000 (Invitrogen, USA) and non-targeting shRNAs (Sigma) were used as controls. The cellular homogenates were prepared 36-48 h post transfection and were subjected to immunoblotting to check the levels of protein knockdown
    24. CHX pulse chase assay was performed as essentially described by Zhou (2004). Cycloheximide (CHX), a protein biosynthesis inhibitor was used to determine the half-life and stability of protein of interest. CHX blocks translation elongation step, thereby halting the synthesis of new proteins and therefore, time course degradation of protein can be studied. Briefly, parental and profilin-stable cells were seeded in 35 mm culture dishes and treated with CHX (50 μg/ml) the following day. Cells were harvested at different time points and level of protein was determined by immunoblotting
    25. Immunofluorescence assay was carried out as described by Bhattacharyyaet al., 2010.Adherent cells weregrown either on cover slips. After treatment, cells were fixed with 3.7% paraformaldehyde solution in PBS for 15 min and permeabilised with 0.5% Triton X-100 at room temperature for 10 min, followed by blockingin PBS containing 2% BSA for 1h. Post blocking, cells were incubated with a primary antibody in PBS (1:200 to 1:500) for 2 h. After washing, cells were incubated with fluorescent-conjugated secondary antibodyin PBS(Alexa Fluor 488 or 594 goat anti-rabbit or antii-mouse, 1:1000) for 30 min. After final wash with PBS, nuclei were counterstained with DAPI containing mounting medium (Vectashield, USA). All the steps were performed at room temperature, unless otherwise stated. Images were obtained using either the laser scanning confocal LSM510 (Carl Zeiss, Oberkochen, Germany) or fluorescence inverted (Olympus 1X51, Tokyo, Japan) microscopes
    26. Co-Immunoprecipitation assays were performed essentially as described by Lee (Lee, 2007). For a typical immunoprecipitation assay, cells were washed with ice-cold PBS and scapped in ice-cold microfuge tube. Then, cells were lysed with NETN buffer (containing 1 μg/ml each of leupeptin, aprotinin, 10mMeach ofNaF and phenylmethylsulfonyl fluoride (PMSF))on shaking rotator in cold room for 30 min. After centrifugation, the whole cell lysate (500 μg-1 mg) obtained was incubated with 1 μg of antibody of interest(orwithisotype control)on shaking rotator in cold room for 3 h, followed by addition of 10-20 μl of ProteinSepharose A/G beads (Santa Cruz) for 1 h. The immuno-complexes bound to beads were then pelleted atlow speed centrifugation (2500 rpm for 3 min) and washed three times with NETN buffer. The proteins bound to beadswere resolved by SDS-PAGE and immunoblotting was performed accordingto standard protocol described earlie

      r

    27. in 5% fat free milk solution in TBST (1:7000) for 45 min at room temperature and then washed thrice.The detection of signal was performed with ECL detection reagent (Amersham Biosciences) followed by detection of signal either on X-ray film (Hyperfilm-ECL, Amersham Biosciences)or in a chemidoc system (Proteinsimple, California, USA).The blot was reprobed with anti-tubulinor anti-GAPDHantibody to ensure equal loading of extracted protein
    28. Materials and Methods472.2.7 Estimationof protein concentration in cellular lysatesBradford method(Bradford, 1976)was used to determine the quantity of protein in various samplesin a 96-well plate. Bradford’s reagent was prepared by diluting Bradford dye with water in the ratio of 1:5.For estimating the concentration of protein in a particular sample, 50μl volume reactionwas set and200μl of freshly prepared Bradford’s reagent was added. The complex givesa purplish colorwhose intensity is proportional to the amount of protein present in the sample. A standard curve was also generated using increasing concentrations of BSA (50 μg/ml, 100 μg/mland 200μg/ml).Cell lysatesof test samples werediluted to1:50 in the same volume.Each sample (including blank and standards) was taken in duplicates.The concentration of protein was measuredusing the ELISA reader at 570 nm. The unknown protein concentration (X) was calculated as follows:where,OD1& OD2: Optical densities of Standard (Std) 1 & Standard (Std) 2, respectively.BSA: Bovine serum albuminX×50 (dilution factor)/1000 = YConcentration of unknown protein (μg/μl) = Y × OD2.2.8 Immunoblotting(Western Blotting)Immunoblotting was performed as essentailly described by Lee (Lee, 2007). Equal amounts of protein were resolved on a denaturating SDS-polyacrylamide gel (8-12%). After completion of the run, the gel was transferred onto PVDF membrane and placed in the blotting cassette. The cassette wasthenput intothe mini transblot apparatus and transfer was done for 2-3 hours at a constant voltage of 80 V, depending on the size of the protein. Post transfer, membrane was rinsed in TBS containing 0.1% Tween-20 (TBST) and blocked with 5% non-fat milk in TBST for 1 h at 37ºC,on a gentle shaking rotator. After blocking, membrane wasrinsed thrice in TBST and incubated with primary antibodydiluted in TBST (ranging from 1:1000 to 1:10000, depending upon antibody used) for either3h at room temperature or overnight in the cold room.The membrane was then washed thrice with TBST and incubated withhorseradish peroxidase(HRP)-conjugated secondary antibody diluted
    29. Bradford method(Bradford, 1976)was used to determine the quantity of protein in various samplesin a 96-well plate. Bradford’s reagent was prepared by diluting Bradford dye with water in the ratio of 1:5.For estimating the concentration of protein in a particular sample, 50μl volume reactionwas set and200μl of freshly prepared Bradford’s reagent was added. The complex givesa purplish colorwhose intensity is proportional to the amount of protein present in the sample. A standard curve was also generated using increasing concentrations of BSA (50 μg/ml, 100 μg/mland 200μg/ml).Cell lysatesof test samples werediluted to1:50 in the same volume.Each sample (including blank and standards) was taken in duplicates.The concentration of protein was measuredusing the ELISA reader at 570 nm. The unknown protein concentration (X) was calculated as follows:where,OD1& OD2: Optical densities of Standard (Std) 1 & Standard (Std) 2, respectively.BSA: Bovine serum albuminX×50 (dilution factor)/1000 = YConcentration of unknown protein (μg/μl) = Y × OD
    30. Materials and Methods462.2.5 Cell proliferation assayThe method described earlier by Gilliesand co-workerswas slightly modified and followed (Gillies et al.,1986). Briefly, parentaland profilin-stable cells were seeded in triplicates at a density of 20,000 cells per well of a 24-well culture plates. Each day after seeding, cells were washed with PBS and stained with 0.2% crystal violet in 2% ethanol for 15 minutes. Vigorous washing was done with PBS to remove excess dye. Crystal violet dye was then eluted using 1% SDS solution with extensive pipetting and diluted 10 fold. Absorbance of the extracted dye was then determined at 570 nm in a spectrophotometer. Absorbance data based on triplicate set of samples for each experimental condition were then averaged for each time point to generate a growth curve.2.2.6 Preparation of whole cell, cytoplasmic and nuclear lysatesIn order to extract the total cell homogenate, the culture media was removed and cells were washed with ice cold PBS. The cells were then gently scrapped and pelleted by centrifugation at 3000 rpm for 3 minutes at 4°C. The cell extraction buffer was added to the cell pellet and placed on rotor kept in cold room for 30 minutes for cell lysis. Lysed cellswere then centrifuged at 13000 rpm for 10min at 4°C. The supernatant was collected as cellular lysate. Protein concentration was estimated using Bradfordassay, described below.For a typical Western blot assay, 30-70μg of protein was loaded on theSDS-PAGE.For the preparation of cytoplasmic lysate,ice-cold hypotonic cytoplasmic extract buffer was added in the cell pellet andgently mixed with the pipette in a microfuge tube. The cell suspension was incubated on ice for 30 minto allow them to swell.After incubation, freshly prepared 10% NP-40was added andvortexed vigorously for 15 seconds torupture the plasma membrane. The contents were then centrifuged at 13000 rpmfor a minuteat 4°C and supernatant containing the cytoplasmic lysate was transferred to another pre-chilled microfuge tube and stored at –70°C.The pellet was then further processed for extraction of nuclear lysate.For this, ice-cold nuclear extractbuffer was added to the pellet and incubated on ice for 45 min with intermittent vortexingafter every 10 min of incubation. Finally, cell suspension wascentrifuged for 5 min at 14000rpm. The supernatant containing nuclear lysatewas stored at –70°C for further experiment
    31. The method described earlier by Gilliesand co-workerswas slightly modified and followed (Gillies et al.,1986). Briefly, parentaland profilin-stable cells were seeded in triplicates at a density of 20,000 cells per well of a 24-well culture plates. Each day after seeding, cells were washed with PBS and stained with 0.2% crystal violet in 2% ethanol for 15 minutes. Vigorous washing was done with PBS to remove excess dye. Crystal violet dye was then eluted using 1% SDS solution with extensive pipetting and diluted 10 fold. Absorbance of the extracted dye was then determined at 570 nm in a spectrophotometer. Absorbance data based on triplicate set of samples for each experimental condition were then averaged for each time point to generate a growth curve
    32. Cell proliferation assay
    33. Wound healing assay(Liang et al., 2007) was employed to study the difference in migration rates ofprofilin-stable compared to parentalcells. Briefly, cells were cultured upto 90-95% confluent monolayer and a scratch was created through the cell monolayer with sterile needle. Cell debris was then removed by washing with PBS before adding the media. Images of the open gap created by this “wound” were then captured at three random locations immediately (0 h) and then at the same locations after regular interval using phase contrast microscopy untilthey are closed by migrating cells. Captured images were then used to quantify wound closure by the percentage change in the wound area per unit time and averaged for three locations for each experimental condition. During the course of the experiment, cells were maintained in 0.1% FBS containing DMEM media to ensure that wound closurewas due to the migration of cells rather thandivisonof cells
    34. Briefly, cells were cultured on 35 mm culture dishes (Corning) and were transfected with pcDNA3.1 (+) empty vector or pcDNA3.1 (+) profilin-1 clone (encodes for neomycin resistance for selection in mammalian cells) using Lipofectamine 2000 reagent. The following day, cells were trypsinized and plated in four 10 cm culture dishes separately for each cell clones in selective media containing 800μg/ml of Geneticin, G418 (whose concentration was obtained from kill curve based on MTT assay). Over the time,it will select only those cells that have stably incorporated the plasmid into their genomic DNA. Cells were selected in G418 for about two weeks until colonies appeared. Meanwhile, cells were regularly washed with sterile PBSto remove dead cells from culture dishes. Colonies were picked using a pipettewith a sterile tip by loweringitto the surface of the colony of interest, followed by gentle scraping and rapid sucking.About 20 colonies were picked, followed by dilution plating in 96-well plates until single cell per well was obtained to establish a pure colony. Once colonies have reached to fair confluency, they were further expanded by dilution plating and screened for stable expression of profilinby immunoblotting and semi-quantitative RT-PCR. Once the clonal cell line is established, aliquots were freezed for future use and rest were maintained in lower concentration of G418 with proper track of passage number
    35. Transfection of plasmid DNAin cellswas performed using Lipofectamine 2000 reagent as per manufacturer’s protocolprovided with the reagent. Briefly, 0.5 to 1 million cells were seeded in a 60mm or 100mm tissue culture dish. After 12h of seeding,transfections were performed. 6-12 μg DNA was mixed in 500-1500 μl of Opti-MEM in one polypropylene tube and simultaneously, 15-30 μl of Lipofectamine 2000 was mixed in similar volumes of Opti-MEM in another tube and incubated at room temperature for 10minutes. Opti-MEM containingDNA and Lipofectamine 2000 were then mixed and incubated for 30 minutes at room temperature for the formation of DNA-lipid complex. Meanwhile, the cells were washed with sterile PBS and 4-10ml of Opti-MEM was addedin the plate. DNA-lipid complexes were then added to each dish for 6h. After that, the medium containing complexes was removed and complete medium (DMEM containing FBS) was added. Expression of transgene was evaluated 24-48hafter transfectioneitherby immunoblottingor immunofluorescence or by RT-PCR followed by PCR
    36. Inpresent thesis, various cell lines have been used as mentionedearlier. Cells were either cultured in DMEM or RPMI medium containing 10% fetal bovine serum (FBS)along with antibiotics such as penicillin (100 U/ml), and streptomycin (100 μg/ml).In general, cells were grownin tissue culture T-75 flaskupto 85-90% confluency. Cells are washedwith PBS, followed by trypsinization with 0.05% Trypsin EDTA solution. Cells were detachedfrom the surfaceeither by gentle tapping or gentlepipettingor incubated for 5 minutes at 37°C. Culture medium containing serum was then added to inactivate trypsin. After careful mixing, cells were transferred to a 15 ml tube and centrifuged at 800 rpm for 5minutes. The cell pellet wasre-suspended in a fresh culture media containing FBS. The cell viability was checked by trypan blue staining, followed bycounting in Neubauer cell-counting chamber. Appropriate number of cells wasthen either sub-culturedin the ratio of 1:4 to 1:6or seeded in culture dishes as per the experimental requirements.Cells were maintained in humidified incubator at 37ºC in 5% CO2-95% air, throughout the experiment
    37. Extraction buffer
    38. MTT reagent
    39. 6XEMSA sample loading dye
    40. 5X EMSA buffer
    41. Native EMSA PAGE
    42. 10XBinding buffer
    43. Inoue buffer
    44. 6X DNA loading dye
    45. Agarose gel
    46. TAE
    47. Nuclear lysis buffer (without protease inhibitors
    48. Cytoplasmic extraction buffer (without protease inhibitors)
    49. Blocking buffer: 2% BSA
    50. Permeabilisation buffer: 0.2% Triton X100
    51. 4% Formaldehyde fixative
    52. Stripping buffer
    53. Blocking buffer
    54. TBS-T
    55. Transfer buffer
    56. (f) Running buffer
    57. (e) Stacking polyacrylamide gel
    58. (d) Resolvingpolyacrylamide gel
    59. (c) 6X Protein loading buffer (Lammeli buffer)
    60. (b) Celllysis buffer B(For IB)
    61. Cell lysis bufferA(For IP)
    62. Table 2.1: Commonly used buffers and solutionsI. General buffers(a)Phosphate Buffered Saline (PBS)
    63. (b) Tris Buffered Saline (TBS)
    64. For DNA isolation and purification, various kitssuch as Miniand midi-prep plasmid isolation, Gel extraction, PCR purification,etc., wereprocured fromQiagen(Hilden, Germany) or HiMedia(India). For RNA extraction, TRIzol wasobtained from Gibco BRL(Grand Island, NY). cDNA was made from RNA byeither Reverse transcriptase (SuperScript III, Invitrogen) or One step Access RT-PCR kit (Promega, Madison, WI). Reagents for PCR such as PCR 10X buffer, dNTPs, MgCl2, Taqpolymerase or AccuTaq were obtained from Fermentas or Sigma Aldrich. Recombination enzymes such as Restriction Endonucleases and DNA ligaseused for recombinant DNA experiments (Bam-H1, Hind-III, Xho-I, Eco-RI, Not-I, and Sal-I) were obtained from New England Biolabs(Ipswich, MA, USA). Oligonucleotidesusedfor various Gel shift assays viz.AP-1, NF-κB, p53 and Sp-1 were commercially synthesizedfrom XCelris(Ahmedabad, India).For protein extraction, protease inhibitors such as aprotinin, leupeptin, PMSF, NaF, NaVO4,etc. were obtained from Sigma Aldrich.Bradford reagent for estimation of protein concentration wasobtained from Bio-Rad(Rockford Illinois, USA).ForImmunoblotting, PVDF membrane, X-ray films andchemi-luminiscentdetection reagent (ECL prime) were obtained from GE Healthcare(Little Chalfont, UK). For Immunofluorescence, vectashield-mountingmedium with DAPIand Propidium Iodide (PI)were obtained from Molecular Probes, Invitrogen.For detection of cytotoxicity, MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) dye, SDS and DMF (Dimethylformamide) wereobtained from SigmaAldrich. Live and dead cell assay kit was obtained from Molecular Probes.Various chemicals required for preparation of regular buffers and solutionsviz. Tris, Glycine, SDS, Sodium Chloride, Potassium Chloride, HEPES, Disodium Phosphate, Nonidet P-40, Tween 20, TritonX100, Formaldehyde, Glycerol, Agarose, Acrylamide,Bis-acrylamide,APS, TEMED, BSA,etc. were obtained from SigmaAldrich.The procedure of preparation of buffers and reagents usedin the present studied are described below:
    65. Wild type or H133S mutant of profilin-1 witheither FLAG or un-tagged werecloned in pcDNA3.1 (+).Mdm2 gene upstreampromoter region having p53 binding site was cloned in pLUC vector (designated as p53-Luc). The constructs of NF-κB-SEAP, p65 (RelA), wild type and dominant negativeIKKβ(IKKβ-WT and IKKβ-DN, respectively)were a kind gift fromProf.Bharat B. Aggarwal (M. D. Anderson Cancer Center,Houston, TX). The constitutive active mutant of IKKβ, in which two serine residues are mutated to glutamic acid, at position 177 and 181 (referred as IKKβ-EE or IKKβ-CA) was gifted byProf. GourisankarGhosh (University of California, San Diego, USA).FLAG or Myc tagged Full length andtruncationmutants of PTEN wereprovided by Dr.M.Subba Reddy (CDFD, Hyderabad).For p53 gene knockdownstudies, TP53 mission shRNA were obtained from Sigma Aldrich (St Louis, MO, USA). For PTEN silencing, retroviral vector based PTEN shRNA (shRNA#1-AGGCGCTATGTGTATTATTAT; shRNA#2-CCACAGCTAG-AACTTATCAAA; shRNA#3-CCACAAATGAAGGGATATAAA)wasgifted by Dr. M.Subba Reddy (CDFD, Hyderabad)
    66. obtained from Gibco, Invitrogen(Carlsbad, CA, USA). For cell culture transfections, Lipofectamine-2000 and Opti-MEM were alsoobtainedfrom Life Sciences, Invitrogen(Carlsbad, CA, USA).Commonly used chemicals in cell culture based experiments such asall-trans retinoic acid (ATRA), arabinoside cytosine (AraC),carbobenzoxy-Leu-Leu-Leucinal (MG-132), cycloheximide (CHX),DMSO, doxorubicin, hydrogen peroxide (H2O2),lipopolysaccharide (LPS, Escherichia coli055:B5), okadaicacid (OA), oleandrin,paclitaxel, phorbolmyristate acetate (PMA), vinblastine and vincristine wereobtained from SigmaAldrichChemicals.Benzofuran was synthesized as reported earlier (Manna et al., 2010).Recombinant human TNFα, IL-1and IL-8 were obtained from PeproTech Inc.(Rocky Hill, NJ, USA).Growth media for bacteria culture,Luria Broth (LB) and Agar were obtained from HiMedia laboratories (Mumbai, India). Bacterial strain DH5was used to make ultra-competent cells for transformation and plasmid isolation. Antibiotics, such as Ampicillin and Kanamycin used for selection of transformed colonies and culture were obtained from Sigma AldrichChemicals
    67. The cell lines used in the present study, HuT-78 (human T-cell lymphoma), MDA-MB-231 (human breast cancer) and MDA-MB-468 (human breast cancer) were obtained from American Type culture collection (Manassas, VA, USA). Human colon carcinoma cell lines HCT-116 (wild-type, p53+/+) and HCT-116 (null, p53-/-) were a kind gift fromProf. B. Vogelstein (Johns Hopkins Oncology Center, Baltimore, MD). Cells were cultured in DMEM or RPMI medium containing 10% FBS, penicillin (100 U/ml), and streptomycin (100 μg/ml). Cells were maintained in humidified incubator at 37ºC in 5% CO2-95% air. Media for mammalian cell culture (DMEM and RPMI),fetal bovine serum (FBS)and other reagentsused in cell culture such as, PBS, Trypsin-EDTA, Antibiotic-antimycotic, Freezing medium, Geniticin, L-Glutamine, HEPES, etc. were
    68. The following antibodies were used in the present study:Primary antibodies against GAPDH (anti-rabbit), FLAG (anti-mouse), Immunoglobulin (IgG, anti-rabbit or anti-mouse),profilin-1 (anti-rabbit), tubulin (anti-mouse) and ubiquitin (anti-rabbit) were obtained from Sigma Aldrich Chemicals(St Louis, MO, USA). Antibodies againstAKT (anti-rabbit), cleaved caspases-3, 8 and 9 (anti-rabbit),HA-tag(anti-rabbit), Myc-tag (anti-rabbit), p21 (anti-rabbit), phospho-p53 (anti-mouse), PTEN (anti-mouse), phospho-AKT (Ser473; anti-rabbit), phospho-GSK-3β (Ser9; anti-rabbit), phospho-IKKα/β (Ser177/181; anti-rabbit), phospho-IκBα (Ser32; anti-rabbit), and phospho-p65 (Ser276; anti-rabbit) were obtained from Cell Signaling Technologies(Danvers, MA, USA), whereas antibodies for cox-2 (anti rabbit), c-Rel (anti-rabbit), ICAM-1 (anti-rabbit), IKKα/β (anti rabbit), IκBα (anti-rabbit), Mdm2 (anti-rabbit), PARP-1/2 (anti-rabbit), Rel-B (anti-rabbit), p50 (anti-rabbit), p53 (anti-mouse), p65 (anti-rabbit) were obtained from Santa Cruz Biotechnology(Santa Cruz, CA, USA).HRP (Horse radish peroxidase)-conjugated secondary antibodies (anti mouse and anti-rabbit) were obtained from Bangalore Genie(Peenya, India). For immuno-fluorescencestudies, secondary antibodiesconjugated toAlexa Fluor (488 and 594, anti-mouse and anti-rabbit) were obtained from Molecular Probes, Invitrogen(Eugene, OR, USA)
    1. For each strain calls from a single colony, picked with a microtip from the appropriate medium were suspended in 10 μL zymolyase cocktail and incubated at 37ºC for 90 min. 2 μL of zymolyase-treated cell suspension was used as the template in a 25 μL PCR reaction
    2. was fused to the 5’ region of the nat1gene. The 3’ region of the nat1gene was in turn fused to the 5’ region of UBC11, the gene that is downstream of RPA43in the genome. These two fragments were transformed into the NOY222 rpa34strain using yeast transformation kit (Clontech) and selected on nourseothricin(NAT) 200 μg/mL to identify strains carrying mutant RPA43generated by homologous recombination (Fig. 2.4) containing YPD. Colony PCR was performed using primers that amplify the merged region of RPA43fragmentand natgene to verify the site of insertion
    3. To conduct yeast transformation competent cells were made from relevant haploid yeast strain using Frozen EZ Yeast Transformation II Kit from Zymo Research Corporation, according to the manufacturer’s instructions.To conduct plasmid shuffling in the NOY222, NOY222rpa34Δ and NOY222rpa34ΔRPA43S/322/323/325/A strainsto generate native and S/A mutant versions of the RPA190gene, the competent cells were transformed with either pRS314RPA190 or pRS314 RPA190S1413/1415/1417/A harbouring wild type a mutant versions of RPA190 generespectively,and transformants were selected by growing them on yeast nitrogen base containing leucine, G418 (200 g/mL) and canavanine (6 g/mL) but lacking uracil. The resulting strains have chromosomal deletions of RPA34 and RPA190 and harbour either wild type or mutant versions of RPA190on pRS314 plasmids
    4. genomic mutation on the A43 protein coding gene RPA43was inserted in the wild type BY4741 and NOY222 rpa34strains. Plasmid pGP5 RPA43, gifted by Dr.Herbert Tschochner, and a plasmid harbouring the nourseothricin N-acetyltransferase (nat1) gene(Goldstein and McCusker, 1999)were used for a PCR based site directedmutagenesis to create a DNA fragment to generate a genomic mutant of RPA43 (Fig

      A

    5. with 0.01% NP 40 in water, andwere diluted serially and plated on rich medium (YPD). RPA34in the genome was replaced with kanMx4that provides resistance toG418 and RPA190gene deletion was done by replacing it with URA3gene that supports growth of the strain in the absence of uracil in the medium. pNOY20, a shuffle plasmid harbours a LEU gene which supports yeast growth in the absence of uracil. Therefore germinated spores were streaked on a selection mediumlacking leucine and uracil and containing 200 g/mLG418to select the strain containing double mutation. The genotype of the strain was confirmed by growing the straindifferent combinations of media such as SC-Ura, SC-Leu, SC-Trp, SC-Met and SC-His. The procedure to generate RPA190 genome deletion in the background of rpa34Δ(NOY222 rpa34) was conducted by a colleague, Ms. Sitalakshmi Thampatty, in thelaboratory
    6. TheS. cerevisiaestrains used were BY4741 rpa34and NOY222 (Table 2.1) (Gerberet al., 2008).NOY222 harbours agenomic deletion of RPA190 with the RPA190encoded on pNOY20, a shuffle plasmid,as the genomic deletion is lethal. BY4741 rpa34(MATa), and NOY222(MATα)were mated by mixing these two strains and patched on the YPD agar. The resulting diploids were sporulated on yeast sporulating medium at 25°Cfor 2-3 weeks.Thespores were treated with 5U zymolyase and sonicated briefly in a bath sonicator to release the spores. The free spores were washed
    7. The pyrophosphorylation reaction was performed with proteins on beads in presence ofIP7 reaction buffer(Werneret al., 2010). 10X IP7 reaction buffer (Section2.1.6.7)was prepared, aliquoted andstored at 4°C. For the reaction, 30 μLof purified protein on GSH beads(1:1 beads in PBS suspension), 3.5μLof 10X buffer and 1 μCi of 5[β-32P]IP7were added, and made up to afinal volumeof 35 μL, and incubated at 37°C for 15 min. A 50 μLreaction was performed for proteins with low expression levels such as A190. To the reaction mix, 4X LDS sample buffer (Invitrogen) was added to a final concentration of 1X and incubated at 95°C for 5 min. The reaction mix was centrifuged at high speed and resolved on a 4%-12% gradient gel by Nu-PAGE(Invitrogen) using 1X MES buffer (Invitrogen). Proteins were transferred to a Hybond-P membrane (GE Lifescience) and the radiolabelled proteins were detected using a phosphorimager (Fuji Film FLA-9000). The membrane was blocked with 5% non-fat dry milk (Rockland)in 1X PBST(pH 7.4)for 2 h at room temperature followed by washes with 1X PBST at room temperature for 10 min three times.Proteins were detected by western blot using a rabbit anti-GST antibody. 1:5000 dilution of anti-GST antibody in 1X PBST containing 0.2% BSA, was added and incubated overnight at 4°C on a rotating platform. The membrane was washed in 1X PBST for 10 min three times, followed by incubation with HRP conjugated goat anti-rabbit IgG at 1:20,000 dilution in 5% non-fat dry milk (Rockland)in 1X PBST, for 1 h at room temperature. Membrane was washed with 1X PBST at room for 10 min three times.Protein bands were detected by using Super Signal West pico chemiluminiscence substrate (Perkin Elmer)
    8. of ice cold deionized water (water was kept in the cold room overnight) was added to a 250 mL volumetric flask which was placed on ice. To the water, 52.1 mL of triethylamine solution (~7.2 M, Cat. No-T088, Sigma-Aldrich) was added with the help of a glass measuring cylinder, and mixed well. The volume of the solution was made up with ice cold water till the mark on the volumetric flask, and the flask was mixed well. A pH meter (Eutech instruments 510) was calibrated using pH 7.0 and pH 10.0 solutions (Eutech instruments 510). Approximately 100 mL of 1.5 M triethylamine solution from the volumetric flask was added to a 250 mL conical flask that was placed on ice. A magenetic bead was placed in the flask and the ice bucket was placed on the magnetic stirrer. The pH measuring probe was immersed into the solution, and CO2was bubbled through the triethylamine solution and stirred until the pH reached 8.5. The conical flask was covered with paraffin film and kept on ice until the solution wasused (within 1-4 h)
    9. During the HPLC run,a triethylammonium bicarbonatesolution(1.5 M) was prepared. Triethylamine and water mixture generates heat, and therefore, approximately 100 mL
    10. On the HPLC system (Waters Empower Software), the instrument method was set to the programme ‘tritium small coloumn’ and the method set was set to ‘tritium small column’. The ‘set up’ icon was selected and once the flow rate was 1 mL/min, the ‘prepare’ icon was selected. A gradient was generated by mixing buffer A and bufferB as described below (Section 2.1.6.6). The injector was moved to the load position and sample was injected using a 1 mL syringe. The injector was moved to the inject position and the ‘inject’ icon was pressed immediately. On the fraction collector, the ‘run’ button was pressed immediately. The syringe was rinsed 5 times with buffer A
    11. HPLC set upA strong anion exchange partisphere SAX 4.6 mm diameter and 125 mm length column (Whatman) was fixed to the HPLC system (Waters 515 pumps). The column was equilibrated with buffer A (1 mM EDTA) (Section 2.1.6.6) overnight at 100 μL/min flow rate.Before starting the HPLC run, the fraction collector (BioRad 2110) was prepared by placing the outlet tube to vial 1 on the fraction collector. Fresh FACS tubes were placed at fraction numbers 40-65 on the fraction collector. The flow rate on the fractioncollector was set to 1 mL/min and it was kept ready.The SAX column was allowed to equilibrate (warmup programme) with Buffer A by slowly increasing theflow rate from 0.1 to 1 mL/min over a period of 70 min
    12. The reaction mix was mixed well using a 200 μLpipette and 20μLeach was dispensed into eight 1.5 mL microfuge tubes. To this reaction mix 5μLof purified hexa histidine tagged IP6K1 enzyme (2-3 μg) was added. Tubes were placed in an acrylic box and incubated at 37°C overnight in a hybridization oven. The next morning, reactions were pooled into two 1.5 mL microfuge tubes containing 100 μLeach.100μLof 0.6 M perchloric acid was added to neutralise the reaction, the tubes were kept on ice for 1 min, and 33.5 μL of 1 M potassium carbonate with 5 mM EDTA was added and mixed by gentle tapping. CO2was liberated leaving a white precipitate, while tubes were kept open on ice for 1 h with gentle tapping at 15 min intervals.Tubes were centrifuged at 12000 x gfor 2-5 min and the supernatant from each tube was pooled into a new 1.5 mL microfuge tube
    13. to hold 1.5 mL microfuge tubes.Acrylic shield was used through out to block the β radiation
    14. Synthesis of 5[β-32P]IP7was conducted as described earlier (Azevedoetal., 2010). An acrylic box was placed at a 37°C in a hybridization oven before settingup the reaction
    15. GST fusions of yeast RNA Pol I subunits were purified as described in (Werneret al., 2010). Yeaststrainsover expressing GST tagged RNA Pol I proteins were grown overnight at 30°C in 10 mL of SC-Ura medium with 2% glucose medium. Cells were pelleted, washed in SC-Ura with galactose. Protein expression was induced by transferring the entire pellet into200 mL of SC-Ura with 2% galatose to give a final OD600of 0.8-1.0. For proteins A190 and A43 that express at very low levels, the overnight culture volume and induction volume were doubled. Cells were cultured at 30°C harvested at 3.0-5.0 OD and washedwith ice cold water. The cell pellet was suspended in 5 mL of ice cold Buffer A (Section 2.1.6.7), 750 μL ofcell suspensions were aliquoted into 1.5 mL microfuge tubes and to this 500 μL glass beads were added. Cells were lysed by bead beating using a vortex mixer (VortexGenei -2 with mix-mate attachment), and the lysate was centrifuged at high speed for 15 min at 4°C. Supernatants were dispensed into a 15 mL conical tube and Triton X-100 was added to a final concentration of 1%. Pre-swollen glutathionebeads were washed in Buffer B(Section 2.1.6.7)from which 200 μL of 1:1 bead suspension was added to approximately 5 mL of A34 and A43 expressing cell lysate and 100 μL of 1:1 bead suspension was added to 5 mL of A190 cell lysate and incubated for 2 h at 4°C on a rotary mixer. Lysates were centrifuged at 5000 xgfor 2 min and the beads were washed with ice cold Buffer C (Section 2.2.6.6) twice. Beads were further washed with ice cold Buffer B followed by ice cold 1X phosphate buffered saline (PBS) twice. Beads were suspended in an equal volume of 1X PBS with protease inhibitor cocktail (Sigma)
    16. recovery, cells were centrifuged at 2,500x gfor 4 min. The medium supernatant was discarded and cells were resuspended in 200 μLfresh sterile LB medium. Cells were plated on LB agar medium containing appropriate antibiotics. Plates were incubated at 37°C for 12-16 hto allow growh of individual colonies
    17. E. coli DH5α strain was transformed with yeast plasmids carrying appropriate inserts that express S.cerevisiaeproteins (Sambrook and Russell, 2001). Ultracompetent cells stored at -80°C were thawed on ice for 5-10 min. 20μLligated plasmid was added to 100 μLultracompetent cells,and the cells were incubated on ice. After 30 min, competent cells were subjected to heat shock at 42°C for 90 seconds. Cells were immediately transferred to ice for 2-3 min. Next, 900 μLLB medium was added and cells were allowed to recover for 45 min on a shakerincubator set at 37°C. After the
    18. A single colony of E. coli DH5α strain was inoculated in 10 mL LB medium and incubated at 37°C overnight. Overnight culture was subculturedin 250 mL of LB medium of about 0.1 OD and incubated at 18°Cfor36 htillthe OD600reached approximately0.5. Cultures were centrifuged at 2,500 x gfor 10 min at 4 ̊C and harvested cells were washed gently with 80 ml ice-cold Inoue transformation buffer(Section 2.1.6.2). Cells were collected by centrifugation at 2,500x g for 10 min at 4 ̊C and gently resuspended in 20 mLice-cold Inoue transformation buffer. To this cell suspension, 1.5 ml sterile DMSO was added and swirled gently. The cell suspension waskept on ice for 30min,and 100 μLvolume was aliquoted into pre-chilled sterile microcentrifuge tubes. Cells were immediately snap-frozen in liquid nitrogen and stored at -80°C
    19. and A190middle (557-1100 a.a)fragments were amplified from the plasmid pRS314RPA190gifted byDr. Herbert Tschochner with primers containing BamHI and XhoI (Table 2.4).The mutant versions of A34 and A190 fragments were generated by overlap extension PCR based method. p416GPD GST-RPA43 used in ChIPwas generated by extracting the GST-RPA43fragmentsfrom pYesGex6p2 GST-RPA43by restriction digestion with HindIII and XhoIfollowed by ligation into p416GPD. Clones were verified by bacterial colony PCR, sequencing and western blot. For colony PCR a small amount of bacterial colony was taken with the help of tooth pick and touch the bottom of the 0.2 mL PCR tube to which PCR reaction mix was added and performed PCR
    20. The nomenclature system for RNA Pol I subunits, gene and protein name is given in Table 2.4 and The S.cerevisiaeRNA Pol I subunits Uaf30, A34.5, A43 full length and fragmentsof A135 (1-112 a.a) and A190 (1101-1664 a.a) were PCR amplified from genomic DNA of the wild-type strain using high fidelity DNA Taq polymerase, with primers carrying restriction sites for BamHI and NotI or BamHI and XhoI (Table 2.4). Amplified fragments were cloned downstream of the GAL4promoter in the pYesGex6p2 plasmid (Werneret al., 2010).These plasmids were generated by a colleague,Mr. Unnikannan CP,in the laboratory. Fragments and mutant versions of full length RNA Pol I subunits A34.5 and A43 weregenerated using above plasmids as templates (Table 2.3).A190 N-terminal (1-556 a.a)Calculation of adjusted input-Volume of cell lysate: 500 uL-Volume set aside as input: 10 uL, eluted into a final volume of 40 uL-Volume of lysate taken for IP: 490 uL; eluted into 100 uL after IP, of which 90 uL was eluted into a final volume of 40 uL. Therefore, volume of lysate for IP corresponds to (90/100)*490 = 440 uL (approx. 500 uL)1μLof input sample, and 3 μLof immunoprecipitated sample was taken from40μLof eluted volumes, for q-PCR reaction.The input sampletaken for q-PCR = 1/40x10 uL= 0.25 uLThe immunoprecipitated DNAtaken for q-PCR = 3/40x 500=37.5uLTherefore, the Ct values obtained for input samples (Ct input) were from 0.25 μL out of 37.5 uLoftotal lysateAdjusted Ct=[Ct(Input)-log2(input dilution factor)]The dilution factor forinput sample was 37.5/0.25 = 150Adjusted Ct = [Ct(Input)-log2(150)] = Ct(Input)-7.23Table. 2.6 The gene name and correspondingprotein name for RNA Pol Isubunits.RPA represents RNA polymerase I and protein name starts with A which represents that the subunit is present in RNA pol I
    21. Calculation of adjusted input-Volume of cell lysate: 500 uL-Volume set aside as input: 10 uL, eluted into a final volume of 40 uL-Volume of lysate taken for IP: 490 uL; eluted into 100 uL after IP, of which 90 uL was eluted into a final volume of 40 uL. Therefore, volume of lysate for IP corresponds to (90/100)*490 = 440 uL (approx. 500 uL)1μLof input sample, and 3 μLof immunoprecipitated sample was taken from40μLof eluted volumes, for q-PCR reaction.The input sampletaken for q-PCR = 1/40x10 uL= 0.25 uLThe immunoprecipitated DNAtaken for q-PCR = 3/40x 500=37.5uLTherefore, the Ct values obtained for input samples (Ct input) were from 0.25 μL out of 37.5 uLoftotal lysateAdjusted Ct=[Ct(Input)-log2(input dilution factor)]The dilution factor forinput sample was 37.5/0.25 = 150Adjusted Ct = [Ct(Input)-log2(150)] = Ct(Input)-7.23
    22. PCR reactions were set up with the immunoprecipitated DNA by using the primers thatamplify the 5’ETSand promoter regions. Real-time PCR was performed using Mesa Green 2X PCR MasterMix (Eurogentec)in a 20 μL reactionvolume using 1 μL from the input sample and 3 μL from the immunoprecipitated samplein an RT-PCR mechine (Applied Biosystems). Ct values of the immunoprecipitated samples were normalised to the adjusted Ct values of the inputsample, andthedata were plotted as ‘immunoprecipitated DNA as a percentage of input DNA (% Input)’, as described in (Haringet al., 2007; Livak and Schmittgen, 2001).Calculation of %InputThe amount of DNA taken for q-PCR analysis is inversely proportional to the Ct value% Input = 2-Ct(IP) / 2-Ct(Input)x 100, (% of gDNA immunoprecipitated from the total amount of gDNA taken)Ct(IP) = Ctvalue of immunoprecipitated DNACt(Input) = Ctvalue of Input DNAIn this experiment,10 μL of this lysate was taken as input and this has to be adjusted to the total volume of the lysate. Therefore, the formula would be,
    23. Immunoprecipitation of chromatin was performed by incubating the lysate with 3 μg of anti-GST antibody overnight at 4°C followed by50 μL of 1:1 suspension of Protein A beads for 4 h. Beads were washedtwice each in wash buffer I, wash buffer II, and TE buffer(Section 2.1.6.5). Each wash was performed for 15 min at 4oC by rotating on a Lab-net end over mixer. Chromatin was eluted in 100 μL of elution buffer(Section 2.1.6.5) by rigorous mixing on a Thermo mixer (Eppendorf) for 30 min at 65oC. 90 μLof this eluted sample was incubated overnight at 65oCto reverse the cross linking. 10 μLlysate taken as input was diluted to 90 μLwith elution buffer and incubated overnight at 65oC to reverse the crosslinking.DNA was extractedfrom the input and immunoprecipitated samplesintoafinal volumeof40μLusing aPCR purification kit (Qiagen)
    24. Yeast strains carrying p416GPD GST-RPA43were grown in SC-Ura medium overnight and sub cultured at 0.2 OD600.45 mL of mid-log phase yeast cultures were subjected to cross linking with 1% formaldehyde for 15 min at room temperature(Szijgyartoet al., 2011). Cross linking was quenched by adding glycine to a final concentration of 0.1 M. Cells were washed in ice cold Tris-buffered saline and were lysed in 500 μL of ice cold lysis buffer (Section 2.1.6.5) by bead beating. Chromatin was fragmented using a Diagenode bath sonicator, 15 sec on time and 30 sec off time, for 15 min. Cell lysates were centrifuged at high speed and the supernatant was pre-cleared with 3 μg of normal rabbit IgG followed by30 μL of 1:1 suspension ofProtein A beads. Supernatant was collected and 10 μL of this lysate was taken as input
    25. The desired S.cerevisiae strain was grown overnight in YPD liquid medium and yeast cells were harvested by centrifugation at 2,500x gin 15 mL polypropylene tubes. Yeast cells were washed with PBS, suspended in 500 μL lysis buffer (Section 2.1.6.2) and were transferred to a 1.5 mL microcentrifuge tube. Yeast cells were incubated for 15 min on a thermomixer set at 65 ̊C and 750 rpm.After incubation, a volume equivalent to 500 μLof glass beads (0.5 mm) were added and cells were lysedon a beating apparatus by mixing three times for 45 seconds each with intermittent cooling on ice to prevent overheating.Cell lysates were centrifuged at 12,000 x gfor 5 min and upper aqueous phase was transferred carefully to a new 1.5 mLmicrocentrifuge tube, to which 275 μL of 3M sodium acetate was added. To this solution, 500 μL of chloroform was added, mixed well, and centrifuged at 12,000 x gfor 5 min at 4°C (this step was repeated twice). Supernatant was transferred to a new 1.5 mLmicrocentrifuge tubeand500 μL of isopropanolwas added and mixed well by inverting the tube 3-4 times. To precipitate genomic DNA, the suspension was centrifuged at 12000 x gfor 15minat 4°C. Precipitated genomic DNA was washed with 70% ethanol and dried at room temperature. The genomic DNA pellet was dissolved either in 100μLof Sigma molecular biology grade water or TE buffer supplied with Qiagen plasmid mini prep kit, andadd 1 μL of RNase solution (30 mg/mL) was added to this and incubated at 37oC for 1 h. The extracted genomic DNA was checked for integrityon a 0.8%agarose gel by electrophoresis and stored at -20oC
    26. After 14-16 h incubation, hybridization buffer was decanted to a radioactive liquid waste container. Membranes were washed twice with 2X SSC (saline-sodium citrate) containing 0.1% SDS for 15 min at 55°C followed by two washes with 1X SSC containing 0.1% SDS for 15 min at room temperature. Post washes, membranes were rinsed with 1X SSC buffer at room temperature exposed to a phosphorimager screen for 1 h and scanned using a phosphorimager (Fuji Film FLA-9000). The data were analysed by densitometry using Fuji Film Multigauge software V3.11 and graphs were plotted using GraphPad Prism5 software.Note:Depending on signal saturation or non-specificity, high stringency washes were performed starting from 0.5X SSC followed by 0.2X SSC or 0.1X SSC wash buffers containing 0.1% SDSat room temperature
    27. Yeast were grown in appropriate medium while the logarithmicphase and 1 OD600cells wereharvested and chilled on an ice(Elion and Warner, 1986). Allsubsequent steps,unless specified, werecarried out at4°C or on ice. Cells were collected by centrifugation at 2500 gfor 6min and washed with2 mLof TMN (Section 2.1.6.4). Cells were suspended in 1 mL of ice cold permeabilization buffer (Section 2.1.6.4) and incubated for 15 min.Cells were pelleted and incubated with 100μLof transcription assay buffer (Section 2.1.6.4) containingradiolabelled [α-32P]UTP. After incubation for 10 min at30°C and 300 rpm in a shaking drybath (Eppendorf),1mLof cold TMN containing1 mM nonradioactive UTP was added, the cells were collected by centrifugation, and RNA was prepared by the hot phenol methodas described in Section 2.2.8. Equal counts of labelled RNA were used for hybridization. The membrane was pre incubated with 50 mL of hybridization buffer for 20-30 min, and hybridization was performed with labelled RNA at 65°C for 15 h in 20 mL of hybridization buffer
    28. apparatus.Membranes were neutralised in 2X SSC, and denatured plasmids were cross-linked to Hybond-N+membranes usingaUV cross linker at 2000 J/inch square energy for 2 min
    29. +610),end 5’ETS (+611 to +952),25S (+5270 to +5630) and NTS2(gifted byDr. Susan J Baserga) (Gallagheret al., 2004); ACT1 cDNA (+175 to +701) cloned into TOPO vector; pUC12 plasmid containing 5S rDNA construct (giftedby Dr. Purnima Bhargava). Empty TOPO plasmid and genomic DNA extracted from wild type yeast were used as controls. Plasmids and gDNA were extracted, quantitated and denatured in alkaline denaturing solution. 10 μg of each plasmid and gDNAin replicates weredenaturedin alkali, blotted on a Hybond N+membrane using a 96-well Dot Blot
    30. The following plasmids (Table 2.2)were used as probes to detect the transcribed RNA (Fig. 2.1). The TOPOplasmids containing rDNA start (+1 to +177), 5’ETS (+351 to
    31. Cellswere grown in YPD to an OD600of 0.5-0.7. Cells equivalent to 1OD600were washed with synthetic complete medium without uacil twice and suspended in SC-Ura containing 3 μCi/mLof [14C]uracil for 5 min. Cells were pelleted and washed with SC-Ura medium twice and suspended in 0.5 mLof AE solution(Section 2.1.6.2). 1OD600of this cell suspension was counted in a liquid scintillation counter (Perkin Elmer-Tricarb 2900). The cpm values obtained were and converted into moles based on thespecific activity of [14C] uracil and plotted using GraphPad Prism5
    32. labelled RNAs to N+Hybond membrane (GE Life Science), the radiolabelled rRNA was detected using a phosphorimager (Fuji Film FLA-9000)
    33. Overnight grown yeast were sub-cultured at 0.2 OD600and growntill 0.8 OD600.Cells equivalent to 1 OD600were harvested and were washed in SC-Ura medium, suspended in 1 mL of SC-Ura medium containing 3μCi/mL of [14C]uracil and pulselabelledfor 15 min at30°C.After incubation the cells were pelleted and a chase was performed by adding SC medium containing 240 mg/L unlabelled uracil. Samples were taken at 0, 1, 5, 10and 20min after the chase, centrifuged at 12000 x gfor 1 min at 4°C, and total RNA was isolated from cells by the hot-phenol techniquedescribed in Section 2.2.8.Equal total RNA was loaded on a 1.2% formaldehyde-agarose gel. After transfer of
    34. Overnight grown yeast were sub-cultured at 0.2 OD600and growntill 0.8 OD600. Cells equivalent to 1 OD600were harvested and washed twice with SC-Uramedium to remove any residual uracil from the cells. Cells were incubated in SC-Ura medium containing 3 μCi/mL [14C]uracil for 1, 5, 10 and 20 min, and RNA was extracted as described in Section 2.2.8. Equal total RNA was resolved on a formaldehyde agarosegel and transferred to an N+Hybond membrane (GE Life Sciences). Radiolabeled rRNA was detected using a phosphorimager scanner (Fujifilm FLA-9000)