MTHFD is a folate-dependent trifunctional protein comprised of three activities: N$ sp5$,N$ sp{10}$-methylenetetrahydrofolate dehydrogenase, N$ sp5$,N$ sp{10}$-methenyltetrahydrofolate cyclohydrolase and N$ sp{10}$-formyltetrahydrofolate synthetase. The enzymes catalyse the sequential interconversion of tetrahydrofolate derivatives required for purine, methionine and thymidylate synthesis. A Chinese hamster ovary cell line, reported to have reduced cyclohydrolase activity, was studied to characterize the nature of its mutation. / Enzymatic assays showed reduced activities of all three enzymes. Immunoblotting and immunoprecipitation of radiolabelled cell extracts indicated that the gene product was greatly reduced or absent in the mutant. Southern analysis showed no differences between normal and mutant cells, indicating that the defect was not due to a major gene rearrangement. RNA analysis, by Northern blotting and by RNA amplification using the polymerase chain reaction, showed that a mRNA for MTHFD of normal size was present in mutant cells. These results suggest that the mutation is post-transcriptional and that it disrupts the synthesis of MTHFD.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.60015 |
| Date | January 1990 |
| Creators | Mascisch, Allegra |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001239264, proquestno: AAIMM67711, Theses scanned by UMI/ProQuest. |
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