title: The BAH domain of BAF180 is required for PCNA ubiquitination.
abstract: Monoubiquitination of proliferating cell nuclear antigen (PCNA) is a critical regulator of post replication repair (PRR). The depletion of BAF180, a unique subunit of the PBAF chromatin remodeling complex in human cells results in reduced PCNA ubiquitination leading to less efficient fork progression following DNA damage, but little is known about the mechanism. Here, we report that the expression of exogenous BAF180 in cells promotes PCNA ubiquitination during S-phase after UV irradiation and it persists for many hours. No correlation was observed between the protein level of ubiquitin-specific protease 1 (USP1) and ubiquitinated PCNA in BAF180 expressing cells. Analysis of cells expressing BAF180 deletion mutants showed that the bromo-adjacent homology (BAH) domains are responsible for this effect. Surprisingly, a deletion construct encoding only the BAH domain region is able to increase the level of ubiquitinated PCNA, even though it is unable to be assembled into the PBAF complex. These results suggest that the ATPase-dependent chromatin remodeling activity of PBAF is not necessary, but instead the BAH domains are sufficient to promote PCNA ubiquitination.
authors.affiliation: Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Niimi
authors.affiliation: Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, UK.
authors.forename: Suzanna R
authors.initials: SR
authors.lastname: Hopkins
authors.affiliation: Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, UK.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Downs
authors.affiliation: Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan. Electronic address: masutani@riem.nagoya-u.ac.jp.
authors.forename: Chikahide
authors.initials: C
authors.lastname: Masutani
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000096:biosynthesis* / Q000235:genetics; D002460:Cell Line; D042002:Chromatin Assembly and Disassembly / Q000528:radiation effects; D004249:DNA Damage / Q000528:radiation effects; D004260:DNA Repair / Q000235:genetics / Q000528:radiation effects; D004261:DNA Replication / Q000528:radiation effects; D004268:DNA-Binding Proteins; D005786:Gene Expression Regulation / Q000528:radiation effects; D006801:Humans; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis* / Q000235:genetics; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000096:biosynthesis* / Q000378:metabolism; D064570:Ubiquitin-Specific Proteases / Q000096:biosynthesis* / Q000235:genetics; D054875:Ubiquitination / Q000235:genetics / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C102195:PBRM1 protein, human; D018809:Proliferating Cell Nuclear Antigen; D014157:Transcription Factors; C579228:USP1 protein, human; D064570:Ubiquitin-Specific Proteases; D000251:Adenosine Triphosphatases
keywords: BAF180; BAH domain; Chromatin remodeling; PCNA ubiquitination; Post replication repair