Title: | Genetic analysis of Rap1p/Sir3p interactions in telomeric and HML silencing in Saccharomyces cerevisiae |
Address: | "Cornell University, Graduate School of Medical Sciences, New York, New York 10021, USA" |
DOI: | 10.1093/genetics/143.1.81 |
ISSN/ISBN: | 0016-6731 (Print) 0016-6731 (Linking) |
Abstract: | "We have identified three SIR3 suppressors of the telomeric silencing defects conferred by missense mutations within the Rap1p C-terminal tail domain (aa 800-827). Each SIR3 suppressor was also capable of suppressing a rap1 allele (rap1-21), which deletes the 28 aa C-terminal tail domain, but none of the suppressors restored telometric silencing to a 165 amino acid truncation allele. These data suggest a Rap1p site for Sir3p association between the two truncation points (aa 664-799). In SIR3 suppressor strains lacking the Rap1p C-terminal tail domain, the presence of a second intragenic mutation within the rap1s domain (aa 727-747), enhanced silencing 30-300-fold. These data suggest a competition between Sir3p and factors that interfere with silencing for association in the rap1s domain. Rap1-21 strains containing both wild-type Sir3p and either of the Sir3 suppressor proteins displayed a 400-4000-fold increase in telomeric silencing over rap1-21 strains carrying either Sir3p suppressor in the absence of wild-type Sir3p. We propose that this telomere-specific synergism is mediated in part through stabilization of Rap1p/Sir3p telometric complexes by Sir3p-Sir3p interactions" |
Keywords: | "Alleles Binding Sites Chromosomes, Fungal Fungal Proteins/*genetics/metabolism GTP-Binding Proteins/*genetics/metabolism *Genes, Fungal Genotype Mating Factor Peptide Biosynthesis Peptides/*genetics Restriction Mapping Saccharomyces cerevisiae/*genetics/m;" |
Notes: | "MedlineLiu, C Lustig, A J eng NCI-P30-CA08748/CA/NCI NIH HHS/ Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. 1996/05/01 Genetics. 1996 May; 143(1):81-93. doi: 10.1093/genetics/143.1.81" |