NameSIR3
OrganismSaccharomyces cerevisiae (replicative)
Aging PhenotypeNo effect on life-span
Allele TypeDominant
StrainW303
DescriptionThe 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.
Deletion of SIR3 shortens life-span by approximately 20% due to loss of HM silencing and co-expression of a and alpha mating type information (Kaeberlein et al., 1999)
Gene Functionsilencing factor
Other PhenotypesThe S275A allele of Sir3p results in increased rDNA silencing (Ray et al., 2003) and likely extends life-span by increasing SIR2 activity at the rDNA.
Sir3p appears to be phosphorylated in response to activation of the SLT2 pathway or the pheremone response pathway.
HomologsS.c. ORC1
S.p. orc1, cdc18
M.m. MM.42024
Primary ReferenceRay, 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.
Other ReferencesKaeberlein, 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]
Kaeberlein, 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]
Relevant LinksSGD: http://genome-www4.stanford.edu/cgi-bin/SGD/locus.pl?locus=sir3
KeywordsDNA damage, silencing, signaling, chromatin, telomeres, rDNA, sterility, recombination, yeast, replicative senescence, Saccharomyces, cerevisiae, DNA, non-homologous end-joining, transcription, phosphorylation, kinase