2.1.1.13 | medicine |
fibroblasts of patients with cblG-variant megaloblastic anaemia, i.e. undetectable methionine synthase activity, show decreased conversion of cyanocobalamin to hydroxocobalamin, similar to that observed in cblC fibroblasts. Alternative splicing in cells from the cblG variant produces an MTR-201 transcript that encodes a truncated methionine synthase, and a MTR-001 transcript with two insertions containing stop codons. Interactions between methionine synthase and cytosolic cobalamin trafficking chaperone MMACHC suggest a regulatory role of methionine synthase in the intracellular metabolism of cobalamin, through splicing of two transcripts that encode the full-size enzyme and a non-functional truncated protein, respectively |
733952 |