title: K63-linked ubiquitination of FANCG is required for its association with the Rap80-BRCA1 complex to modulate homologous recombination repair of DNA interstand crosslinks.
abstract: DNA interstrand crosslinks (ICLs) are extremely deleterious lesions that are repaired by homologous recombination (HR) through coordination of Fanconi anemia (FA) proteins and breast cancer susceptibility gene 1 (BRCA1) product, but the exact role these proteins have remains unclear. Here we report that FANCG was modified by the addition of lysine63-linked polyubiquitin chains (K63Ub) in response to DNA damage. We show that FANCG K63Ub was dispensable for monoubiquitination of FANCD2, but was required for FANCG to interact with the Rap80-BRCA1 (receptor-associated protein 80-BRCA1) complex for subsequent modulation of HR repair of ICLs induced by mitomycin C. Mutation of three lysine residues within FANCG to arginine (K182, K258 and K347, 3KR) reduced FANCG K63Ub modification, as well as its interaction with the Rap80-BRCA1 complex, and therefore impeded HR repair. In addition, we demonstrated that K63Ub-modified FANCG was deubiquitinated by BRCC36 complex in vitro and in vivo. Inhibition of BRCC36 resulted in increased K63Ub modification of FANCG. Taken together, our results identify a new role of FANCG in HR repair of ICL through K63Ub-mediated interaction with the Rap80-BRCA1 complex.
authors.affiliation: 1] Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing, China [2] Institute of Systems Biology, Peking University, Beijing, China.
authors.forename: B
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing, China.
authors.forename: K
authors.initials: K
authors.lastname: Yan
authors.affiliation: Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing, China.
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing, China.
authors.forename: M
authors.initials: M
authors.lastname: Lin
authors.affiliation: Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing, China.
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Center of Medical and Health Analysis, Peking University, Beijing, China.
authors.forename: Q
authors.initials: Q
authors.lastname: He
authors.affiliation: School of Medicine, Shenzhen University, Shenzhen, Guangdong, China.
authors.forename: D
authors.initials: D
authors.lastname: Zheng
authors.affiliation: Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing, China.
authors.forename: H
authors.initials: H
authors.lastname: Yang
authors.affiliation: 1] Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing, China [2] Institute of Systems Biology, Peking University, Beijing, China.
authors.forename: G
authors.initials: G
authors.lastname: Shao
mesh_terms: D000595:Amino Acid Sequence; D019313:BRCA1 Protein / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D003434:Crossing Over, Genetic; D004268:DNA-Binding Proteins; D052241:Fanconi Anemia Complementation Group G Protein / Q000737:chemistry / Q000378:metabolism*; D057809:HEK293 Cells; D006367:HeLa Cells; D056488:Histone Chaperones; D006801:Humans; D008239:Lysine / Q000378:metabolism; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D011485:Protein Binding; D059767:Recombinational DNA Repair; D054875:Ubiquitination / Q000502:physiology*
chemical_list: D019313:BRCA1 Protein; C492913:BRCA1 protein, human; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C499909:FANCG protein, human; D052241:Fanconi Anemia Complementation Group G Protein; D056488:Histone Chaperones; D046912:Multiprotein Complexes; D009687:Nuclear Proteins; C466234:UIMC1 protein, human; D008239:Lysine