title: DNA binding properties of the actin-related protein Arp8 and its role in DNA repair.
abstract: Actin and actin-related proteins (Arps), which are members of the actin family, are essential components of many of these remodeling complexes. Actin, Arp4, Arp5, and Arp8 are found to be evolutionarily conserved components of the INO80 chromatin remodeling complex, which is involved in transcriptional regulation, DNA replication, and DNA repair. A recent report showed that Arp8 forms a module in the INO80 complex and this module can directly capture a nucleosome. In the present study, we showed that recombinant human Arp8 binds to DNAs, and preferentially binds to single-stranded DNA. Analysis of the binding of adenine nucleotides to Arp8 mutants suggested that the ATP-binding pocket, located in the evolutionarily conserved actin fold, plays a regulatory role in the binding of Arp8 to DNA. To determine the cellular function of Arp8, we derived tetracycline-inducible Arp8 knockout cells from a cultured human cell line. Analysis of results obtained after treating these cells with aphidicolin and camptothecin revealed that Arp8 is involved in DNA repair. Together with the previous observation that Arp8, but not γ-H2AX, is indispensable for recruiting INO80 complex to DSB in human, results of our study suggest an individual role for Arp8 in DNA repair.
authors.affiliation: Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Osakabe
authors.affiliation: Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Murakami
authors.affiliation: Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Otawa
authors.affiliation: Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tachiwana
authors.affiliation: Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.
authors.forename: Yukako
authors.initials: Y
authors.lastname: Oma
authors.affiliation: Department of Integrated Genetics, National Institute of Genetics, Mishima, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nishijima
authors.affiliation: Department of Integrated Genetics, National Institute of Genetics, Mishima, Japan.
authors.forename: Kei-ich
authors.initials: KI
authors.lastname: Shibahara
authors.affiliation: Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kurumizaka
authors.affiliation: Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Harata
mesh_terms: D000199:Actins / Q000378:metabolism; D045744:Cell Line, Tumor; D042002:Chromatin Assembly and Disassembly / Q000502:physiology; D004260:DNA Repair / Q000502:physiology*; D004261:DNA Replication / Q000502:physiology; D004277:DNA, Single-Stranded / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism*
chemical_list: C527779:ACTR8 protein, human; D000199:Actins; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D008840:Microfilament Proteins