Xu EY, et al. (1999) SAS4 and SAS5 are locus-specific regulators of silencing in Saccharomyces cerevisiae. Genetics 153(1):25-33
Abstract: Sir2p, Sir3p, Sir4p, and the core histones form a repressive chromatin structure that silences transcription in the regions near telomeres and at the HML and HMR cryptic mating-type loci in Saccharomyces cerevisiae. Null alleles of SAS4 and SAS5 suppress silencing defects at HMR; therefore, SAS4 and SAS5 are negative regulators of silencing at HMR. This study revealed that SAS4 and SAS5 contribute to silencing at HML and the telomeres, indicating that SAS4 and SAS5 are positive regulators of silencing at these loci. These paradoxical locus-specific phenotypes are shared with null alleles of SAS2 and are unique among phenotypes of mutations in other known regulators of silencing. This work also determined that these SAS genes play roles that are redundant with SIR1 at HML, yet distinct from SIR1 at HMR. Furthermore, these SAS genes are not redundant with each other in silencing HML. Collectively, these data suggest that SAS2, SAS4, and SAS5 constitute a novel class of regulators of silencing and reveal fundamental differences in the regulation of silencing at HML and HMR. We provide evidence for a model that accounts for the observation that these SAS genes are both positive and negative regulators of silencing.
|Status: Published||Type: Journal Article||PubMed ID: 10471697|
Topics addressed in this paper
Number of different genes curated to this paper: 9
- To find other papers on a gene and topic, click on the colored ball in the appropriate box.
- displays other papers with information about that topic for that gene.
- displays other papers in SGD that are associated with that topic.
The topic is addressed in these papers but does not describe a specific gene or chromosomal feature.
- To go to the Locus page for a gene, click on the gene name.