Microsatellite instability in yeast: dependence on repeat unit size and DNA mismatch repair genes.

Journal Article (Journal Article)

We examined the stability of microsatellites of different repeat unit lengths in Saccharomyces cerevisiae strains deficient in DNA mismatch repair. The msh2 and msh3 mutations destabilized microsatellites with repeat units of 1, 2, 4, 5, and 8 bp; a poly(G) tract of 18 bp was destabilized several thousand-fold by the msh2 mutation and about 100-fold by msh3. The msh6 mutations destabilized microsatellites with repeat units of 1 and 2 bp but had no effect on microsatellites with larger repeats. These results argue that coding sequences containing repetitive DNA tracts will be preferred target sites for mutations in human tumors with mismatch repair defects. We find that the DNA mismatch repair genes destabilize microsatellites with repeat units from 1 to 13 bp but have no effect on the stability of minisatellites with repeat units of 16 or 20 bp. Our data also suggest that displaced loops on the nascent strand, resulting from DNA polymerase slippage, are repaired differently than loops on the template strand.

Full Text

Duke Authors

Cited Authors

  • Sia, EA; Kokoska, RJ; Dominska, M; Greenwell, P; Petes, TD

Published Date

  • May 1997

Published In

Volume / Issue

  • 17 / 5

Start / End Page

  • 2851 - 2858

PubMed ID

  • 9111357

Pubmed Central ID

  • PMC232137

International Standard Serial Number (ISSN)

  • 0270-7306

Digital Object Identifier (DOI)

  • 10.1128/MCB.17.5.2851


  • eng

Conference Location

  • United States