title: Sgf73, a subunit of SAGA complex, is required for the assembly of RITS complex in fission yeast.
abstract: RNA interference (RNAi) is a widespread gene-silencing mechanism and is required for heterochromatin assembly in a variety of organisms. The RNA-induced transcriptional silencing complex (RITS), composed of Ago1, Tas3 and Chp1, is a key component of RNAi machinery in fission yeast that connects short interference RNA (siRNA) and heterochromatin formation. However, the process by which RITS is assembled is not well understood. Here, we identified Sgf73, a subunit of the SAGA co-transcriptional complex, is required for pericentromeric heterochromatin silencing and the generation of siRNA. This novel role of Sgf73 is independent of enzymatic activities or structural integrity of SAGA. Instead, Sgf73 is physically associated with Ago1 and Chp1. The interactions among the subunits of the RITS, including those between Tas3 and Chp1, between Chp1 and Ago1, between Ago1 and Tas3, were all impaired by the deletion of sgf73(+). Consistently, the recruitment of Ago1 and Chp1 to the pericentromeric region was abolished in sgf73Δ cells. Our study unveils a moonlighting function of a SAGA subunit. It suggests Sgf73 is a novel factor that promotes assembly of RITS and RNAi-mediated heterochromatin formation.
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University.|Shanghai Engineering Research Center Of Industrial Microorganisms, Shanghai, China, 200438.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University.|Shanghai Engineering Research Center Of Industrial Microorganisms, Shanghai, China, 200438.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China, 201602.
authors.forename: Guiping
authors.initials: G
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University.|Shanghai Engineering Research Center Of Industrial Microorganisms, Shanghai, China, 200438.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University.|Shanghai Engineering Research Center Of Industrial Microorganisms, Shanghai, China, 200438.
authors.forename: Langyong
authors.initials: L
authors.lastname: Mao
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University.|Shanghai Engineering Research Center Of Industrial Microorganisms, Shanghai, China, 200438.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University.|Shanghai Engineering Research Center Of Industrial Microorganisms, Shanghai, China, 200438.
authors.forename: Yao
authors.initials: Y
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University.|Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China, 201602.|Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai, China, 200237.
authors.forename: Hong
authors.initials: H
authors.lastname: Lu
mesh_terms: D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000235:genetics; D002503:Centromere / Q000235:genetics; D042002:Chromatin Assembly and Disassembly / Q000235:genetics; D047369:Chromatin Immunoprecipitation; D006570:Heterochromatin / Q000235:genetics; D047468:Immunoprecipitation; D012331:RNA, Fungal / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D034743:RNA-Induced Silencing Complex / Q000737:chemistry*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012568:Schizosaccharomyces / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C481643:Ago1 protein, S pombe; D060565:Argonaute Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; C115018:Chp1 protein, S pombe; D006570:Heterochromatin; D012331:RNA, Fungal; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D034743:RNA-Induced Silencing Complex; D029702:Schizosaccharomyces pombe Proteins; C000591415:Sgf73 protein, S pombe; C499720:Tas3 protein, S pombe; D000123:Acetyltransferases