OrganismSaccharomyces cerevisiae (replicative)
Aging PhenotypeShortened life-span
Allele TypeDeletion
StrainW3031-A, W303R, PSY316
DescriptionDeletion of SGS1 shortens life-span approximately 60% (Sinclair et al., 1997). Most cell death in sgs1 mutant cells is caused by a stochastic cell cycle arrest that is associated with a large-budded terminal morphology ( McVey et al., 2001).
Overexpression of SIR2 or deletion of FOB1 extend life-span of only those sgs1 mother cells that escape this arrest (McVey et al., 2001; Defossez et al., 1999).
Overexpression of SGS1 extends the maximum life-span of cells lacking SRS2 but not the mean life-span (Mankouri et al., 2002).
Gene FunctionDNA helicase with 3'-5' polarity (Bennett et al., 1998)
Other Phenotypessgs1 mutants display other biomarkers of aging, including progressive sterility, fragmentation of the nucleolus, and movement of the Sir complex to the nucleolus (Sinclair et al., 1997). sgs1 mutants have greater rate of telomere loss than wild-type cells in the absence of telomerase (Johnson et al., 2001).
HomologsS.c. DHH1, PRP5, DBP3
S.p. hus2, Spac212.11
D.m. BLM, RECQ5, CG7487
M.m. MM27407, BLM, WRN
Primary ReferenceSinclair, D. A., Mills, K., and Guarente, L. (1997). Accelerated aging and nucleolar fragmentation in yeast sgs1 mutants. Science 277, 1313-6. [Abstract]
Other ReferencesDefossez, P. A., Prusty, R., Kaeberlein, M., Lin, S. J., Ferrigno, P., Silver, P. A., Keil, R. L., and Guarente, L. (1999). Elimination of replication block protein Fob1 extends the life span of yeast mother cells. Mol Cell 3, 447-55. [Abstract]
Johnson, F. B., Marciniak, R. A., McVey, M., Stewart, S. A., Hahn, W. C., and Guarente, L. (2001). The Saccharomyces cerevisiae WRN homolog Sgs1p participates in telomere maintenance in cells lacking telomerase. Embo J 20, 905-13. [Abstract]
McVey, M., Kaeberlein, M., Tissenbaum, H. A., and Guarente, L. (2001). The Short Life Span of Saccharomyces cerevisiae sgs1 and srs2 Mutants Is a Composite of Normal Aging Processes and Mitotic Arrest Due to Defective Recombination. Genetics 157, 1531-42. [Abstract]
Mankouri, H. W., Craig, T. J., and Morgan, A. (2002). SGS1 is a multicopy suppressor of srs2: functional overlap between DNA helicases. Nucleic Acids Res 30, 1103-13. [Abstract]
Relevant LinksSGD:
KeywordsDNA damage, rDNA, recombination, telomeres, nucleolus cell cycle, DNA, yeast, replicative senescence, Saccharomyces, cerevisiae