21 Matching Annotations
  1. Apr 2025
    1. To measure the relative fitness of all mutants in thelibrary for a single environmental condition, we uti-lize previously established methods that leverage DNAbarcoding and high-resolution lineage tracking. Wecompete a pool of barcoded strains against a highly-abundant reference strain, the wild type (WT) ances-tor, which takes up 95% of the culture. We quantifythe frequencies of barcodes over time via amplicon se-quencing. Based on these frequency trajectories, wecan infer the relative fitness of thousands of strains(see Methods for more details) (5, 22, 56).

      I appreciate this well-structured and efficient experimental design! However, I wonder about the potential for metabolic interactions between strains potentially confounding the results of this pooled competition set-up. Cells harboring mutations (particularly those in metabolic regulation pathways like Ras and TOR) might show altered secretion of nutritious or toxic compounds that could affect neighboring cells. This seems particularly relevant for interpreting fitness effects in the context of your "limiting functions" model. Perhaps these effects are not as concerning as I am flagging here since the local environment of neighboring cells for each mutant will differ across batch replicates, which could help counter some of the confounding nature of the pooled design.

    1. irst, we applied514different thresholds to classify genotypes as functional or nonfunctional, included promiscuous515genotypes when characterizing global production distributions, and characterized these516distributions using only genotypes with experimentally measured phenotypes.

      So glad to see this! Nearly commented about some of these assumptions above. I particularly appreciate the comparison between "active" and "functional" variants in Extended Data Figure 6.

  2. Mar 2025
  3. Feb 2025
    1. 146151156PositionwildtypeO5O5O5O5O5U5U5U5U5U5O10O10O10O10O10U10U10U10U10U10VariantF F K S A M P E G Y V Q E R T I F F K D D G N Y K T R A E V K F E G D T L V N R I E L K G I D F K E D G N I L G H K L E Y N Y N S H N V Y I M A D K Q K N G I KVI WYIV VS S VG E VVE T VWY IM W RE M RW161166171176181186191196201206211216221226231236PositionwildtypeO5O5O5O5O5U5U5U5U5U5O10O10O10O10O10U10U10U10U10U10VariantV N F K I R H N I E D G S V Q L A D H Y Q Q N T P I G D G P V L L P D N H Y L S T Q S A L S K D P N E K R D H M V L L E F V T A A G I T H G M D E L Y KR L Y WR L YR L Y T RL W HR L Y R FI K RR W C FR V RV R KM W MR L Y N T GWR L Y R F HL Y T R HL N T GW FR L Y T W HM E Y R M C I L RR V F W W QR V M Q M WV F W S N QK M F R RFigure S20. The 20 engineered GFP variants.

      It's interesting to see how many mutant positions these variants share, even across observed versus unobserved, as well as the preference for later residues in the primary sequence. I'm curious if the model is learning something more significant about the features driving activity, particularly if this pattern holds true for the other ten datasets.

  4. Nov 2024
    1. (among which de novo designed pro-teins)

      I think this parenthetical phrase may be missing a word. I suggest "(including de novo designed proteins)" or "(some of which are de novo designed proteins)."

    1. Percentactive

      I would be interested to see how this factor affects the extent to which MLDE can improve over DE. It seems to me the closer to 100% active or to 0% active would limit the training data such that the model may not be able to differentiate as clearly as it would with awareness of both active and inactive variants.

    2. Landscape and functional attributes affect ZS predictability

      This section was really interesting. I wonder where other aspects of function (stability, regulability/tunability) might fall in terms of ZS predictability. I'd be curious to see which aspects are most (and least) predictable with and without focused training.

    3. Figure 5. Decision tree summarizing recommended ML strategies based on total number of variants screenedexperimentally, landscape navigability (e.g. active variant percentage, pairwise epistasis), the quality of ZSactive/inactive variant classification (i.e. ROC-AUC > 0.5), and the number of available screening rounds (N)

      Love the format of a decision tree as a final summary! Looking forward to seeing it expand as more nuances are explored in this space.

  5. Aug 2024
    1. For future work, we plan to integrate the ProstT5 proteinlanguage model (37) to directly predict 3Di from aminoacid sequences, eliminating the need for slow structurepredictions. This integration will accelerate input generationfor FoldMason by over 3000× compared to optimizedColabFold prediction. Instead of structure input, an AAFASTA file can be provided for sequence-based MSTA.This approach would be particularly beneficial for studiesinvolving long proteins, as is the case in Mifsud et al

      This is a really exciting prospect! I wasn't 100% convinced given the marginal improvements to LDDT-vs-time presented, but with this speed increase I would be all-in on FoldMason. Looking forward to reading this, and thanks for your work so far!

  6. Jul 2024
    1. Abstract

      I enjoyed this paper! I'm excited to try detecting tyrosine phosphorylation using Raman in my own work. I have a couple of general suggestions: one is to use color (or add clearer keys) in the figures to differentiate between HER2+ and HER2- cell types, so that it is easier to understand the results. I also think this paper could use another round of general copyediting - Grammarly offers a free version of their software that can make this step very fast.

    2. No ligands for HER2 have yet been identified yet. 21 22 and dimerization with any of the other three subdomains is considered to activate HER2. 23 The dimerization in the extracellular region of HER2 induces intracellular conformational changes that trigger tyrosine kinase activation.

      This sentence is included verbatim in the introduction.

    3. Fig. 9 shows average normalized Raman intensity at 1618 cm-1 at membranes (A,B) and mitochondria (B) in breast cancer cells: triple-positive MCF-7 (B), (HTB-30) and AU-565 (C) overexpressing HER2, the normal cells (MCF-10A) (HER2 at the normal level) and triple - negative aggressive breast cancer (MDA-MB-231)

      I'm not sure what the letters in parentheses refer to here.

    4. One can see that that the highest concentration of cytochrome c represented by the vibration at 1584 cm-1 is located in mitochondria and support the results reported recently1

      The link for this citation is missing, but I would like to read it!

    5. Raman spectra of a typical breast cancer cell (HTB-30) for the cell organelles (nucleus (red), endoplasmic reticulum (blue), lipid droplets (orange), cytoplasm (green), mitochondria (magenta), membrane (light grey).

      For Figs 5 and 6, it would be helpful to include descriptions of each panel in the description & reference them directly in the text.

    6. The presented in Fig. 7 cells have HER2 protein expression on the surface of the cell that belongs to a family of receptor tyrosine kinases (RTKs) and consists of an extracellular domain that includes four subdomains (I-IV) [16], a single helix transmembrane lipophilic segment and an intracellular region that contains a tyrosine kinase domain (TKD).

      I'm not sure why this is mentioned here, it is established in the introduction. Unless this is implying that you can acquire all of this info directly from the Raman spectra?

    7. As it is well known these processes regulate efficiency of the oxidative phosphorylation and is directly related to many human diseases, including cancer, through a lack of energy, ROS production, cytochrome c release, and activation of apoptosis.

      I think this sentence may also have a typo - there is no follow up phrase to "As it is well known that X..." What did this knowledge lead you to?

    8. It has been proposed that reversible phosphorylation of cytochrome c mediated by cell signaling pathways is primary regulatory mechanism in living species that determines mitochondrial respiration, electron transport chain (ETC) flux, proton gradient ΔΨm, ATP production, and ROS generation

      Proposed by who? I think this claim could use a citation so that readers can look further into the evidence supporting it.

    9. Our data demonstrate that Raman based methods for HER2 quantitation of HER2 may offer significant progress in patient selection for HER2 targeted therapy over conventional HER2 identification.

      I think this sentence may have a typo - it says "HER2 quantitation of HER2," rather than just "quantitation of HER2" or "HER2 quantitation."

  7. Nov 2023
    1. Although both carboxysome lineages contain scaffolding proteins, these proteins are related in function alone; they have no sequence or structural similarity

      I'd be interested to see this compared for the three structural components of the carboxysome. Do the hexameric/pentameric shell proteins show more evidence of shared origin? Is there significantly lower conservation of sequence/structure in the scaffolding proteins?