title: Separation of a functional deubiquitylating module from the SAGA complex by the proteasome regulatory particle.
abstract: Gene expression is an intricate process tightly linked from gene activation to the nuclear export of mRNA. Recent studies have indicated that the proteasome is essential for gene expression regulation. The proteasome regulatory particle binds to the SAGA complex and affects transcription in an ATP-dependent manner. Here we report that a specific interaction between the proteasomal ATPase, Rpt2p and Sgf73p of the SAGA complex leads to the dissociation of the H2Bub1-deubiquitylating module (herein designated the Sgf73-DUBm) from SAGA both in vitro and in vivo. We show that the localization of the Sgf73-DUBm on chromatin is perturbed in rpt2-1, a strain of Saccharomyces cerevisiae that is specifically defective in the Rpt2p-Sgf73p interaction. The rpt2-1 mutant also exhibits impaired localization of the TREX-2 and MEX67-MTR2 complexes and is defective in mRNA export. Our findings collectively demonstrate that the proteasome-mediated remodelling of the SAGA complex is a prerequisite for proper mRNA export.
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Sungsu
authors.initials: S
authors.lastname: Lim
authors.forename: Jaechan
authors.initials: J
authors.lastname: Kwak
authors.forename: Minhoo
authors.initials: M
authors.lastname: Kim
authors.forename: Daeyoup
authors.initials: D
authors.lastname: Lee
mesh_terms: D021581:Active Transport, Cell Nucleus; D000251:Adenosine Triphosphatases / Q000172:deficiency / Q000235:genetics*; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D051548:Histone Acetyltransferases / Q000172:deficiency / Q000235:genetics*; D006657:Histones / Q000235:genetics / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D029543:Nucleocytoplasmic Transport Proteins / Q000235:genetics / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D034443:RNA Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D002843:Chromatin; D006657:Histones; C106898:MEX67 protein, S cerevisiae; D026901:Membrane Transport Proteins; C480169:Mtr2 protein, S cerevisiae; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C507785:SAGA complex, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D051548:Histone Acetyltransferases; C515833:Sgf73 protein, S cerevisiae; D046988:Proteasome Endopeptidase Complex; D000251:Adenosine Triphosphatases; C577243:Rpt2 protein, S cerevisiae