A Novel Function of the DNA Repair Gene rhp6 in Mating-Type Silencing by Chromatin Remodeling in Fission Yeast

摘要: Recent studies have indicated that the DNA replication machinery is coupled to silencing of mating-type loci in budding yeast Saccharomyces cerevisiae, and a similar mechanism may operate distantly related Schizosaccharomyces pombe. Regarding gene regulation, an important function be coupling faithful chromatin assembly reestablishment parental states expression daughter cells. We been interested isolating mutants are defective this hypothesized coupling. An S. pombe mutant fortuitously isolated from screen for temperature-sensitive growth phenotype exhibited novel defect was dependent on switching competence loci, property differentiates other as well cerevisiae. This unique defined locus which we named sng1 (for not governed). Chromatin analysis revealed switching-dependent unfolding donor mat2P mat3M sng1(-) mutant, by increased accessibility vivo-expressed Escherichia coli dam methylase. Unexpectedly, cloning sequencing identified previously repair rhp6. RAD6, rhp6 homolog required postreplication ubiquitination histones H2A H2B. study implicates Rad6/rhp6 protein regulation and, more importantly, suggests transient window opportunity exists ensure remodeling structure during chromosome recombination. propose effects sng1(-)/rhp6(-) mutation indirect consequences changes structure.