title: Ovate family protein 1 as a plant Ku70 interacting protein involving in DNA double-strand break repair.
abstract: The Ku heterodimer, a DNA repair protein complex consisting of 70- and 80-kDa subunits, is involved in the non-homologous end-joining (NHEJ) pathway. Plants are thought to use the NHEJ pathway primarily for the repair of DNA double-strand breaks (DSBs). The Ku70/80 protein has been identified in many plants and been shown to possess several similar functions to its counter protein complex in mammals. In the present study, ovate family protein 1 (AtOFP1) was demonstrated to be a plant Ku-interacting protein by yeast two-hybrid screening and the GST pull-down assay. Truncation analysis revealed that the C-terminal domain of AtKu70 contains interacting sites for AtOFP1. The electrophoretic mobility shift assay (EMSA) indicated that AtOFP1 is also a DNA binding protein with its binding domain at the N-terminus. In 3-week-old seedlings, expression of the AtOFP1 gene increased after exposure to DNA-damaging agents (such as methyl methanesulfonate (MMS) and menadione) in a time dependent manner. Seedlings lacking the AtOFP1 protein were more sensitive to MMS and menadione as compared with wild-type. Furthermore, similar to AtKu70(-/-) and AtKu80(-/-), the AtOFP1(-/-) mutant showed relatively lower NHEJ activity in vivo. Taken together, these results suggest that AtOFP1 may play a role in DNA repair through the NHEJ pathway accompanying with the AtKu protein.
authors.affiliation: Institute of Bioinformatics and Structural Biology, College of Life Science, National Tsing Hua University, Hsin-Chu, 30013, Taiwan, ROC.
authors.forename: Yung-Kai
authors.initials: YK
authors.lastname: Wang
authors.forename: Wen-Chi
authors.initials: WC
authors.lastname: Chang
authors.forename: Pei-Feng
authors.initials: PF
authors.lastname: Liu
authors.forename: Mu-Kai
authors.initials: MK
authors.lastname: Hsiao
authors.forename: Chueh-Tsun
authors.initials: CT
authors.lastname: Lin
authors.forename: Shih-Ming
authors.initials: SM
authors.lastname: Lin
authors.forename: Rong-Long
authors.initials: RL
authors.lastname: Pan
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism*; D009153:Mutagens / Q000494:pharmacology; D025941:Protein Interaction Mapping; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C463462:KU70 protein, Arabidopsis; D009153:Mutagens; D012097:Repressor Proteins; C523451:ovate family protein 1, Arabidopsis