RRC ID 54570
著者 Okazaki K, Kato H, Iida T, Shinmyozu K, Nakayama JI, Murakami Y, Urano T.
タイトル RNAi-dependent heterochromatin assembly in fission yeast Schizosaccharomyces pombe requires heat-shock molecular chaperones Hsp90 and Mas5.
ジャーナル Epigenetics Chromatin
Abstract BACKGROUND:Heat-shock molecular chaperone proteins (Hsps) promote the loading of small interfering RNA (siRNA) onto RNA interference (RNAi) effector complexes. While the RNAi process is coupled with heterochromatin assembly in several model organisms, it remains unclear whether the Hsps contribute to epigenetic gene regulation. In this study, we used the fission yeast Schizosaccharomyces pombe as a model organism and investigated the roles of Hsp90 and Mas5 (a nucleocytoplasmic type-I Hsp40 protein) in RNAi-dependent heterochromatin assembly.
RESULTS:Using a genetic screen and biochemical analyses, we identified Hsp90 and Mas5 as novel silencing factors. Mutations in the genes encoding these factors caused derepression of silencing at the pericentromere, where heterochromatin is assembled in an RNAi-dependent manner, but not at the subtelomere, where RNAi is dispensable. The mutations also caused a substantial reduction in the level of dimethylation of histone H3 at Lys9 at the pericentromere, where association of the Argonaute protein Ago1 was also abrogated. Consistently, siRNA corresponding to the pericentromeric repeats was undetectable in these mutant cells. In addition, levels of Tas3, which is a protein in the RNA-induced transcriptional silencing complex along with Ago1, were reduced in the absence of Mas5.
CONCLUSIONS:Our results suggest that the Hsps Hsp90 and Mas5 contribute to RNAi-dependent heterochromatin assembly. In particular, Mas5 appears to be required to stabilize Tas3 in vivo. We infer that impairment of Hsp90 and Hsp40 also may affect the integrity of the epigenome in other organisms.
巻・号 11(1)
ページ 26
公開日 2018-6-4
DOI 10.1186/s13072-018-0199-8
PII 10.1186/s13072-018-0199-8
PMID 29866182
PMC PMC5985592
MeSH Argonaute Proteins / metabolism Carrier Proteins / metabolism Centromere / genetics Chromatin Assembly and Disassembly Epigenesis, Genetic Gene Expression Regulation, Fungal HSP40 Heat-Shock Proteins / genetics* HSP40 Heat-Shock Proteins / metabolism HSP90 Heat-Shock Proteins / genetics* HSP90 Heat-Shock Proteins / metabolism Heterochromatin / genetics* Methylation Mutation RNA, Small Interfering / genetics* Schizosaccharomyces / genetics* Schizosaccharomyces / metabolism Schizosaccharomyces pombe Proteins / genetics Schizosaccharomyces pombe Proteins / metabolism
IF 4.185
引用数 3
リソース情報
酵母