Replication protein A (RPA) is a heterotrimeric single-stranded DNA-binding protein that plays essential roles in nucleic acid metabolism including DNA replication, nucleotide excision repair and homologous recombination. It is a complex of three polypeptides of molecular mass 70, 32, and 14 kDa (RPA70, RPA32 and RPA14). The middle subunit, RPA32, is phosphorylated in a cell cycle-dependent manner which begins in parallel to the degradation of DNA to high molecular weight fragments and slowly continues until late apoptosis. RPA32 has been reported to be a useful prognostic indicator in colon cancer patients and an attractive therapeutic target for regulation by tumor suppressors or other proteins involved in the control of cell proliferation.
