NameSIR3
OrganismSaccharomyces cerevisiae (replicative)
Aging PhenotypeShortened life-span
Allele TypeDeletion
StrainW303R
DescriptionDeletion of SIR3 shortens life-span by approximately 20% (Kaeberlein et al., 1999). This reduction in life span is suppressed by preventing mating type heterozygosity.
The S275A allele of Sir3p results in a 40% increase in mean and maximum life-span (Ray et al., 2003). This allele prevents phosphorylation of Sir3p.
Gene Functionsilencing factor
Other Phenotypessir3 mutants show loss of silencing at the silent mating type loci (Shore et al., 1984; Rine and Herskowitz, 1987) and telomeres (Aparicio et al., 1991) and have a slightly elevated level of rDNA marker loss (Kaeberlein et al., 1999).
HomologsS.c. ORC1
S.p. orc1, cdc18
M.m. MM.42024
Primary ReferenceKaeberlein, M., McVey, M., and Guarente, L. (1999). The SIR2/3/4 complex and SIR2 alone promote longevity in Saccharomyces cerevisiae by two different mechanisms. Genes Dev 13, 2570-80. [Abstract]
Other ReferencesRine, J., and Herskowitz, I. (1987). Four genes responsible for a position effect on expression from HML and HMR in Saccharomyces cerevisiae. Genetics 116, 9-22. [Abstract]
Shore, D., Squire, M., and Nasmyth, K. A. (1984). Characterization of two genes required for the position-effect control of yeast mating-type genes. Embo J 3, 2817-23. [Abstract]
Aparicio, O. M., Billington, B. L., and Gottschling, D. E. (1991). Modifiers of position effect are shared between telomeric and silent mating-type loci in S. cerevisiae. Cell 66, 1279-87. [Abstract]
Ray, A., Hector, R. E., Roy, N., Song, J., Berkner, K. L., and Runge, K. W. (2003). Sir3p phosphorylation by the Slt2p pathway effects redistribution of silencing function and shortened lifespan. Nat Genet Published online 17 March 2003.
Relevant LinksSGD: http://genome-www4.stanford.edu/cgi-bin/SGD/locus.pl?locus=sir3
YPD: http://www.proteome.com/databases/YPD/reports/SIR3.html
KeywordsDNA damage, silencing, signaling, chromatin, telomeres, rDNA, sterility, recombination, yeast, replicative senescence, Saccharomyces, cerevisiae, DNA, non-homologous end-joining, transcription