The function of PARPBP (PARP1 binding protein, ENSG00000185480) is as follows. Required to suppress inappropriate homologous recombination, thereby playing a central role DNA repair and in the maintenance of genomic stability. Antagonizes homologous recombination by interfering with the formation of the RAD51-DNA homologous recombination structure. Binds single-strand DNA and poly(A) homopolymers. Positively regulate the poly(ADP-ribosyl)ation activity of PARP1; however such function may be indirect. {ECO:0000269|PubMed:20931645, ECO:0000269|PubMed:22153967}.