title: The chromatin-remodeling subunit Baf200 promotes homology-directed DNA repair and regulates distinct chromatin-remodeling complexes.
abstract: The efficiency and type of pathway chosen to repair DNA double-strand breaks (DSBs) are critically influenced by the nucleosome packaging and the chromatin architecture surrounding the DSBs. The Swi/Snf (PBAF and BAF) chromatin-remodeling complexes contribute to DNA damage-induced nucleosome remodeling, but the mechanism by which it contributes to this function is poorly understood. Herein, we report how the Baf200 (Arid2) PBAF-defining subunit regulates DSB repair. We used cytological and biochemical approaches to show that Baf200 plays an important function by facilitating homologous recombination-dependent processes, such as recruitment of Rad51 (a key component of homologous recombination) to DSBs, homology-directed repair, and cell survival after DNA damage. Furthermore, we observed that Baf200 and Rad51 are present in the same complex and that this interaction is mediated by C-terminal sequences in both proteins. It has been recognized previously that the interplay between distinct forms of Swi/Snf has profound functional consequences, but we understand little about the composition of complexes formed by PBAF protein subunits. Our biochemical analyses reveal that Baf200 forms at least two distinct complexes. One is a canonical form of PBAF including the Swi/Snf-associated Brg1 catalytic subunit, and the other contains Baf180 but not Brg1. This distinction of PBAF complexes based on their unique composition provides the foundation for future studies on the specific contributions of the PBAF forms to the regulation of DNA repair.
authors.affiliation: Cell Cycle and Cancer Biology Program, Oklahoma Medical Research Foundation.
authors.forename: Rodrigo O
authors.initials: RO
authors.lastname: de Castro
authors.affiliation: Cell Cycle and Cancer Biology Program, Oklahoma Medical Research Foundation.
authors.forename: Luciana
authors.initials: L
authors.lastname: Previato
authors.affiliation: Cell Cycle and Cancer Biology Program, Oklahoma Medical Research Foundation.
authors.forename: Victor
authors.initials: V
authors.lastname: Goitea
authors.affiliation: Cell Cycle and Cancer Biology Program, Oklahoma Medical Research Foundation.
authors.forename: Anna
authors.initials: A
authors.lastname: Felberg
authors.affiliation: Cell Cycle and Cancer Biology Program, Oklahoma Medical Research Foundation.
authors.forename: Michel F
authors.initials: MF
authors.lastname: Guiraldelli
authors.affiliation: Cell Cycle and Cancer Biology Program, Oklahoma Medical Research Foundation.
authors.forename: Adrian
authors.initials: A
authors.lastname: Filiberti
authors.affiliation: Cell Cycle and Cancer Biology Program, Oklahoma Medical Research Foundation; Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma 73104. Electronic address: Roberto-Pezza@omrf.org.
authors.forename: Roberto J
authors.initials: RJ
authors.lastname: Pezza
mesh_terms: D045744:Cell Line, Tumor; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism*; D059767:Recombinational DNA Repair / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D046912:Multiprotein Complexes; D009687:Nuclear Proteins; C445179:SWI-SNF-B chromatin-remodeling complex; D014157:Transcription Factors; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; C084108:SMARCA4 protein, human; D004265:DNA Helicases
keywords: Baf200; DNA damage; DNA recombination; DNA repair; PBAF; Rad51; chromatin remodeling; homologous recombination