DNA-binding protein involved in single-strand DNA break repair, double-strand DNA break repair and base excision repair (  ). Resolves abortive DNA ligation intermediates formed either at base excision sites, or when DNA ligases attempt to repair non-ligatable breaks induced by reactive oxygen species (, ). Catalyzes the release of adenylate groups covalently linked to 5'-phosphate termini, resulting in the production of 5'-phosphate termini that can be efficiently rejoined ( ). Also able to hydrolyze adenosine 5'-monophosphoramidate (AMP-NH(2)) and diadenosine tetraphosphate (AppppA), but with lower catalytic activity . Likewise, catalyzes the release of 3'-linked guanosine (DNAppG) and inosine (DNAppI) from DNA, but has higher specific activity with 5'-linked adenosine (AppDNA) (By similarity).
Subcellular locations: Nucleus, Nucleoplasm, Nucleus, Nucleolus
Upon genotoxic stress, colocalizes with XRCC1 at sites of DNA damage . Colocalizes with MDC1 at sites of DNA double-strand breaks . Interaction with NCL is required for nucleolar localization .
Subcellular locations: Cytoplasm
Widely expressed; detected in liver, kidney and lymph node (at protein level) . Isoform 1 is highly expressed in the cerebral cortex and cerebellum, compared to isoform 2 (at protein level) . Widely expressed; detected throughout the brain, in liver, kidney, skeletal muscle, fibroblasts, lymphocytes and pancreas ( ).