title: The USP1-UAF1 complex interacts with RAD51AP1 to promote homologous recombination repair.
abstract: USP1 deubiquitinating enzyme and its stoichiometric binding partner UAF1 play an essential role in promoting DNA homologous recombination (HR) repair in response to various types of DNA damaging agents. Deubiquitination of FANCD2 may be attributed to the key role of USP1-UAF1 complex in regulating HR repair, however whether USP1-UAF1 promotes HR repair independently of FANCD2 deubiquitination is not known. Here we show evidence that the USP1-UAF1 complex has a FANCD2-independent function in promoting HR repair. Proteomic search of UAF1-interacting proteins revealed that UAF1 associates with RAD51AP1, a RAD51-interacting protein implicated in HR repair. We show that UAF1 mediates the interaction between USP1 and RAD51AP1, and that depletion of USP1 or UAF1 led to a decreased stability of RAD51AP1. Protein interaction mapping analysis identified some key residues within RAD51AP1 required for interacting with the USP1-UAF1 complex. Cells expressing the UAF1 interaction-deficient mutant of RAD51AP1 show increased chromosomal aberrations in response to Mitomycin C treatment. Moreover, similar to the RAD51AP1 depleted cells, the cells expressing UAF1-interaction deficient RAD51AP1 display persistent RAD51 foci following DNA damage exposure, indicating that these factors regulate a later step during the HR repair. These data altogether suggest that the USP1-UAF1 complex promotes HR repair via multiple mechanisms: through FANCD2 deubiquitination, as well as by interacting with RAD51AP1.
authors.affiliation: a Department of Cell Biology , Microbiology, and Molecular Biology, College of Arts and Sciences, University of South Florida , Tampa , FL , USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Cukras
authors.affiliation: a Department of Cell Biology , Microbiology, and Molecular Biology, College of Arts and Sciences, University of South Florida , Tampa , FL , USA.
authors.forename: Euiho
authors.initials: E
authors.lastname: Lee
authors.affiliation: a Department of Cell Biology , Microbiology, and Molecular Biology, College of Arts and Sciences, University of South Florida , Tampa , FL , USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Palumbo
authors.affiliation: a Department of Cell Biology , Microbiology, and Molecular Biology, College of Arts and Sciences, University of South Florida , Tampa , FL , USA.
authors.forename: Pamela
authors.initials: P
authors.lastname: Benavidez
authors.affiliation: b Department of Biochemistry and Molecular Biology , Pennsylvania State University College of Medicine , Hershey , PA , USA.
authors.forename: George-Lucian
authors.initials: GL
authors.lastname: Moldovan
authors.affiliation: a Department of Cell Biology , Microbiology, and Molecular Biology, College of Arts and Sciences, University of South Florida , Tampa , FL , USA.
authors.forename: Younghoon
authors.initials: Y
authors.lastname: Kee
mesh_terms: D004268:DNA-Binding Proteins / Q000378:metabolism*; D017353:Gene Deletion; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006801:Humans; D050505:Mutant Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D010641:Phenotype; D011485:Protein Binding; D025941:Protein Interaction Mapping; D055550:Protein Stability; D016601:RNA-Binding Proteins; D059767:Recombinational DNA Repair; D064570:Ubiquitin-Specific Proteases / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D050505:Mutant Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D064570:Ubiquitin-Specific Proteases; C110410:RAD51AP1 protein, human; C526165:WDR48 protein, human; C579228:USP1 protein, human
keywords: RAD51AP1; UAF1; USP1; deubiquitinating enzyme; homologous recombination repair