encodes an ortholog of human XRCC5 (Ku80; OMIM:194364
, antigen ofsystemic lupus erythematosus); CKU-80 is required for resistance toionizing radiation (IR) in somatic tissues (such as motor neurons,vulva, uterus, or somatic gonad) and in endoreduplicating intestinalcells, but not in the germline (e.g., in dog-1
-induced lesions); CKU-80is required for growth on high NaCl, probably because excess NaClinduces extensive chromosome breakage; CKU-80 is also required forsurvival of dauer larvae subjected to IR, and resistance of developingembryos to methyl methane sulfonate; CKU-80 binds CKU-70 in yeasttwo-hybrid assays, and requires HIM-10 for fully effective DNA repair insomatic cells; by orthology, CKU-80 is expected to function (as aheterodimer with CKU-70) in nonhomologous end-joining of double-strandedbreaks in DNA; although CKU-80 is not strongly required in the germline,its absence enhances the hypersensitivity of rad-51
(RNAi) germlines toionizing radiation; mutant cku-80
late-stage embryos or dauer larvae arehypersensitive to radiation-induced DNA damage in somatic cells; afterirradiation, cku-80
mutants tend to display various postembryonicphenotypes (such as slow growth, uncoordinated locomotion, impairedegg-laying, or vulval defects) that are enhanced by him-10
mutations,and that are thought to reflect missegregation of fragmentedchromosomes; in two-hybrid assays, CKU-80 binds (in addition to CKU-70)DAF-21, CAH-3, and F59A2.5.