Non-essential DNA repair protein involved in DNA non-homologous end joining (NHEJ); participates in double-strand break (DSB) repair and V(D)J recombination ( , ). May act as a scaffold required for accumulation of the Ku heterodimer, composed of XRCC5/Ku80 and XRCC6/Ku70, at double-strand break sites and promote the assembly and/or stability of the NHEJ machinery ( ). Involved in NHEJ by promoting the ligation of blunt-ended DNA ends . Together with NHEJ1/XLF, collaborates with DNA polymerase lambda (POLL) to promote joining of non-cohesive DNA ends (, ). Constitutes a non-essential component of classical NHEJ: has a complementary but distinct function with NHEJ1/XLF in DNA repair . Able to restrict infection by herpesvirus 1 (HSV-1) via an unknown mechanism .
Subcellular locations: Nucleus, Chromosome
Predominantly localizes to the nucleus. Accumulates at sites of DNA damage generated by laser microirradiation.
Subcellular locations: Cytoplasm
(Microbial infection) Upon infection by herpesvirus 1 (HSV-1), it is partially translocated into the cytoplasm in an HSV-1-dependent manner.