RRC ID 36761
著者 Wanotayan R, Fukuchi M, Imamichi S, Sharma MK, Matsumoto Y.
タイトル Asparagine 326 in the extremely C-terminal region of XRCC4 is essential for the cell survival after irradiation.
ジャーナル Biochem Biophys Res Commun
Abstract XRCC4 is one of the crucial proteins in the repair of DNA double-strand break (DSB) through non-homologous end-joining (NHEJ). As XRCC4 consists of 336 amino acids, N-terminal 200 amino acids include domains for dimerization and for association with DNA ligase IV and XLF and shown to be essential for XRCC4 function in DSB repair and V(D)J recombination. On the other hand, the role of the remaining C-terminal region of XRCC4 is not well understood. In the present study, we noticed that a stretch of ∼20 amino acids located at the extreme C-terminus of XRCC4 is highly conserved among vertebrate species. To explore its possible importance, series of mutants in this region were constructed and assessed for the functionality in terms of ability to rescue radiosensitivity of M10 cells lacking XRCC4. Among 13 mutants, M10 transfectant with N326L mutant (M10-XRCC4(N326L)) showed elevated radiosensitivity. N326L protein showed defective nuclear localization. N326L sequence matched the consensus sequence of nuclear export signal. Leptomycin B treatment accumulated XRCC4(N326L) in the nucleus but only partially rescued radiosensitivity of M10-XRCC4(N326L). These results collectively indicated that the functional defects of XRCC4(N326L) might be partially, but not solely, due to its exclusion from nucleus by synthetic nuclear export signal. Further mutation of XRCC4 Asn326 to other amino acids, i.e., alanine, aspartic acid or glutamine did not affect the nuclear localization but still exhibited radiosensitivity. The present results indicated the importance of the extremely C-terminal region of XRCC4 and, especially, Asn326 therein.
巻・号 457(4)
ページ 526-31
公開日 2015-2-20
DOI 10.1016/j.bbrc.2015.01.015
PII S0006-291X(15)00037-6
PMID 25597996
MeSH Amino Acid Sequence Animals Antibiotics, Antineoplastic / pharmacology Asparagine / analysis Asparagine / genetics* Asparagine / metabolism Cell Line, Tumor Cell Survival / drug effects Cell Survival / radiation effects* DNA Breaks, Double-Stranded / drug effects DNA Breaks, Double-Stranded / radiation effects DNA End-Joining Repair / drug effects DNA End-Joining Repair / radiation effects DNA-Binding Proteins / analysis DNA-Binding Proteins / genetics* DNA-Binding Proteins / metabolism Fatty Acids, Unsaturated / pharmacology HeLa Cells Humans Mice Molecular Sequence Data Point Mutation* Sequence Alignment
IF 2.985
引用数 3
WOS 分野 BIOPHYSICS BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
ヒト・動物細胞 M10(RCB0136)