Scaffold protein involved in DNA single-strand break repair by mediating the assembly of DNA break repair protein complexes (, ). Negatively regulates ADP-ribosyltransferase activity of PARP1 during base-excision repair in order to prevent excessive PARP1 activity ( ). Recognizes and binds poly-ADP-ribose chains: specifically binds auto-poly-ADP-ribosylated PARP1, limiting its activity ( ).
Subcellular locations: Nucleus, Chromosome
Moves from the nucleoli to the global nuclear chromatin upon DNA damage . Recruited to DNA damage sites fowwing interaction with poly-ADP-ribose chains .
Expressed in fibroblasts, retinal pigmented epithelial cells and lymphoblastoid cells (at protein level).