Anti-lipoate antibody detected strongly decreased levels of the expected lipoylated E2 subunits of α-oxoacid dehydrogenases in fibroblasts of individuals P1 and P2, whereas normal bands were seen in the control (Figure 3A). In fibroblasts of an individual with LIPT1 deficiency,7 these bands were undetectable (Figure 3A). Moreover, immunofluorescence staining examined by a confocal microscopy showed absence of protein lipoylation in P1 and P2 fibroblasts (Figure 3B).
ExperimentName: Reduced E2-lipoylation in LIPT2 patient cells
PatientCell: Fibroblast (not specified where it was derived)
GeneFunction: GO:0009249
GeneAlteration: Patient fibroblasts from P1 harboring the LIPT2 c.89T>C(p.Leu30Pro) and c.377T>G(Leu126Arg) and fibrobalsts from P2 harboring the c.377T>G(Leu126Arg) and c.314T>G(p.Leu105Pro) were used in this assay.
FunctionalEvidence: Patient fibroblasts both from P1 and P2, both with compound heterozygous mutation in LIPT2 that represent 3 different variants (one overlaps), were assayed for E2 lipoylation in PDHc and alpha-KGDHc (Figure 3), compared to control cells. The assay indicates reduced lipoylation of both PDHc and alpha KGSHc compared to controls both by western blot (Figure 3A) and immunocytochemistry (figure 3B). the reduction in lipoylation was consistent with that observed in patients with LIPT1 mutations, indicating a role for LIPT2 in lipoylation.
FAVariants:<br /> 1) CA224979286 (NM_001144869.1:c.377T>G(p. Leu126Arg))
2) CA224979330 (NM_001144869.1:c.89T>C(p.Leu30Pro))
3) CA381976642 (NM_001144869.1:c.314T>C(p.Leu105Pro)