title: C-Terminal region of DNA ligase IV drives XRCC4/DNA ligase IV complex to chromatin.
abstract: DNA ligase IV (LIG4) and XRCC4 form a complex to ligate two DNA ends at the final step of DNA double-strand break (DSB) repair through non-homologous end-joining (NHEJ). It is not fully understood how these proteins are recruited to DSBs. We recently demonstrated radiation-induced chromatin binding of XRCC4 by biochemical fractionation using detergent Nonidet P-40. In the present study, we examined the role of LIG4 in the recruitment of XRCC4/LIG4 complex to chromatin. The chromatin binding of XRCC4 was dependent on the presence of LIG4. The mutations in two BRCT domains (W725R and W893R, respectively) of LIG4 reduced the chromatin binding of LIG4 and XRCC4. The C-terminal fragment of LIG4 (LIG4-CT) without N-terminal catalytic domains could bind to chromatin with XRCC4. LIG4-CT with W725R or W893R mutation could bind to chromatin but could not support the chromatin binding of XRCC4. The ability of C-terminal region of LIG4 to interact with chromatin might provide us with an insight into the mechanisms of DSB repair through NHEJ.
authors.affiliation: Research Laboratory for Nuclear Reactors and Department of Nuclear Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, Tokyo 152-8550, Japan.
authors.forename: Sicheng
authors.initials: S
authors.lastname: Liu
authors.forename: Xunyue
authors.initials: X
authors.lastname: Liu
authors.forename: Radhika Pankaj
authors.initials: RP
authors.lastname: Kamdar
authors.forename: Rujira
authors.initials: R
authors.lastname: Wanotayan
authors.forename: Mukesh Kumar
authors.initials: MK
authors.lastname: Sharma
authors.forename: Noritaka
authors.initials: N
authors.lastname: Adachi
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Matsumoto
mesh_terms: D000595:Amino Acid Sequence; D002460:Cell Line; D002843:Chromatin / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded; D059766:DNA End-Joining Repair; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D017434:Protein Structure, Tertiary
chemical_list: D002843:Chromatin; D004268:DNA-Binding Proteins; C000607893:LIG4 protein, human; C101467:XRCC4 protein, human; D011088:DNA Ligases; D000072481:DNA Ligase ATP
keywords: APLF; BRCT; BRCT domain; DNA double-strand break repair; DNA ligase IV; DNA ligase IV C-terminal; DNA ligase IV N-terminal; DSB; FBS; IR; LIG4; LIG4-CT; LIG4-NT; NHEJ; Non-homologous end-joining; PNKP; XIR; XRCC4; XRCC4-interacting region; aprataxin- and PNK-like factor; breast cancer associated 1 C-terminal; double-strand break; fetal bovine serum; ionizing radiation; non-homologous end-joining; polynucleotide kinase/phosphatase