SRG3/mBAF155 stabilizes the SWI/SNF-like BAF complex by blocking CHFR mediated ubiquitination and degradation of its major components

• Published in: Biochemical and biophysical research communications Vol. 418; no. 3; pp. 512 - 517
• Main Authors: Jung, Inkyung, Sohn, Dong H., Choi, Jinwook, Kim, Joo Mi, Jeon, Shin, Seol, Jae Hong, Seong, Rho Hyun
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 17.02.2012
• Subjects: 60 APPLIED LIFE SCIENCES; Animals; ATP; CELL PROLIFERATION; Cercopithecus aethiops; CHANNELING; CHROMATIN; Chromatin remodeling; Chromosomal Proteins, Non-Histone - metabolism; COS Cells; DNA Helicases - metabolism; E3 ubiquitin ligase; ELECTROPHORESIS; Enzyme Stability; GELS; GENES; Humans; LIGASES; Mice; NEOPLASMS; Nuclear Proteins - metabolism; Poly-ADP-Ribose Binding Proteins; Protein degradation; Proteolysis; SMARCB1 Protein; SODIUM; Transcription Factors - genetics; Transcription Factors - metabolism; Tumor Suppressor Proteins - metabolism; Ubiquitin-Protein Ligases - metabolism; Ubiquitination; Rb; Protein degradation; Ubiquitination; BRG1; DTT; BAF; HA; E3 ubiquitin ligase; BRM; SDS–PAGE; Chromatin remodeling
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2012.01.057

► CHFR mediates the ubiquitination of the major components of the SWI/SNF complex. ► CHFR mediated-ubiquitination induces the degradation of the major components. ► SRG3 stabilizes the SWI/SNF-like BAF complex by blocking the CHFR activity. The murine SWI/SNF-like BAF complex is an ATP-dependent chromatin remodeling complex that functions as a transcriptional regulator in cell proliferation, differentiation and development. The SWI/SNF-like BAF complex consists of several components including core subunits such as BRG1, BAF155/SRG3, BAF47/SNF5/INI1, and BAF170. We have previously shown that the interaction between SRG3/mBAF155 and other components of the complex stabilizes them by attenuating their proteasomal degradation. However, it has not been known how the major components of the SWI/SNF-like BAF complex such as BRG1, SNF5, and BAF60a are targeted for the ubiquitination and degradation, and how SRG3/mBAF155 protects them from the degradation process. Here we report that CHFR interacts with BRG1, SNF5, and BAF60a of the SWI/SNF-like BAF complex and ubiquitinates them to target for degradation through a proteasome-mediated pathway, and that SRG3/mBAF155 stabilizes these components by blocking their interaction with CHFR.