OrganismSaccharomyces cerevisiae (replicative)
Aging PhenotypeLife-span extension
Allele TypeSemi-dominant
DescriptionThe C-terminal truncated Sir4-42 allele extends life-span in the short-lived BKx1-14c strain by approximately 50% (Kennedy et al., 1995). BKx1-14c was subsequently found to harbor a C-terminal truncation allele of UTH4/MPT5 (Kennedy et al., 1997). Sir4-42 has no effect on life-span in a UTH4 wild-type strain background.
Gene Functionsilencing factor
Other PhenotypesLike SIR4 deletion mutants, cells carrying the Sir4-42 allele are defective for telomere and mating type loci silencing (Kennedy et al., 1995).
Sir4-42 results in constitutive localization of SIR3 to the rDNA. Life-span extension by Sir4-42 is likely due to increased dosage of SIR2 at the rDNA (Kaeberlein et al., 1999)
HomologsS.c. YDR485, SPC105, CNM67
S.p. Spbc1639.02c, Spcc825.01
C.e. unc-89, Y55B1BR3
D.m. CG10562
M.m. Acz
H.s. P130
Primary ReferenceKennedy, B. K., Austriaco, N. R., Zhang, J., and Guarente, L. (1995). Mutation in the silencing gene SIR4 can delay aging in S. cerevisiae. Cell 80, 485-96. [Abstract]
Other ReferencesKennedy, B. K., Gotta, M., Sinclair, D. A., Mills, K., McNabb, D. S., Murthy, M., Pak, S. M., Laroche, T., Gasser, S. M., and Guarente, L. (1997). Redistribution of silencing proteins from telomeres to the nucleolus is associated with extension of life sp [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:
KeywordsDNA damage, silencing, chromatin, telomeres, rDNA, yeast, replicative senescence, Saccharomyces, cerevisiae, sterility, starvation resistance