Hereditary nonpolyposis colorectal carcinoma (HNPCC) is linked to inherited defects in human genes (hMLH1, hMSH2, hMSH6, hPMS1, and hPMS2) that are involved in the repair of mismatched bases that may occur during DNA replication. Germline missense mutations in human MLH1 (hMLH1) are frequently detected and their functional characterization is critical to the development of genetic testing for HNPCC. We used several functional assays to characterize two hMLH1 mutations: T117M and R182G. Saccharomyces cerevisiae were transformed with hMLH1 cDNA expression vectors containing either mutation. The presence of functional hMLH1 produces an accumulation of mutations in mismatch repair (MSM)-proficient yeast due to MLH1 protein homology and interference with normal MMR. The transformants were tested for increased mutation rates using three assays: mutation of the gene for canavanine resistance (CAN1 ), reversion of the hom 3--10 allele, and insertion-deletions at a dinucleotide repeat regulating expression of beta-galactosidase. Based on the results of these assays T117M is likely a functional mutation while R182G may be a polymorphism. We conclude that this assay may be applicable in genetic testing for HNPCC.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.79210 |
| Date | January 2002 |
| Creators | Zerey, Marc |
| Contributors | Trifiro, Mark (advisor), Gordon, Philip (advisor) |
| 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 (Division of Surgical Research.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001974947, proquestno: AAIMQ88335, Theses scanned by UMI/ProQuest. |
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