title: SRG3 interacts directly with the major components of the SWI/SNF chromatin remodeling complex and protects them from proteasomal degradation.
abstract: The mammalian SWI/SNF complex is an evolutionarily conserved ATP-dependent chromatin remodeling complex that consists of nine or more components. SRG3, a murine homologue of yeast SWI3, Drosophila MOIRA, and human BAF155, is a core component of the murine SWI/SNF complex required for the regulation of transcriptional processes associated with development, cellular differentiation, and proliferation. Here we report that SRG3 interacts directly with other components of the mammalian SWI/SNF complex such as SNF5, BRG1, and BAF60a. The SWIRM domain and the SANT domain were required for SRG3-SNF5 and SRG3-BRG1 interactions, respectively. In addition, SRG3 stabilized SNF5, BRG1, and BAF60a by attenuating their proteasomal degradation, suggesting its general role in the stabilization of the SWI/SNF complex. Such a stabilization effect of SRG3 was not only observed in the in vitro cell system, but also in cells isolated from SRG3 transgenic mice or knock-out mice haploinsufficient for the Srg3 gene. Taken together, these results suggest the critical role of SRG3 in the post-transcriptional stabilization of the major components of the SWI/SNF complex.
authors.affiliation: Department of Biological Sciences, Institute of Molecular Biology and Genetics, and Research Center for Functional Cellulomics, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Dong H
authors.initials: DH
authors.lastname: Sohn
authors.forename: Kyoo Y
authors.initials: KY
authors.lastname: Lee
authors.forename: Changjin
authors.initials: C
authors.lastname: Lee
authors.forename: Jaehak
authors.initials: J
authors.lastname: Oh
authors.forename: Heekyoung
authors.initials: H
authors.lastname: Chung
authors.forename: Sung H
authors.initials: SH
authors.lastname: Jeon
authors.forename: Rho H
authors.initials: RH
authors.lastname: Seong
mesh_terms: D000818:Animals; D019556:COS Cells; D018797:Cell Cycle Proteins / Q000235:genetics; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D042002:Chromatin Assembly and Disassembly / Q000502:physiology*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism*; D000071796:SMARCB1 Protein; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D000071796:SMARCB1 Protein; C445179:SWI-SNF-B chromatin-remodeling complex; C072981:SWI3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C513265:Smarcb1 protein, mouse; C491090:Smarcc1 protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors; C462943:mor protein, Drosophila; D046988:Proteasome Endopeptidase Complex; C513194:Smarca4 protein, mouse; D004265:DNA Helicases