RPA2
RPA2 (replication protein A2) is the 32 kDa subunit of the heterotrimeric replication protein A (RPA) complex, which binds and stabilises single-stranded DNA during replication and DNA stress. It supports DNA replication, repair and the cellular response to DNA damage. Browse Assay Genie's current range of RPA2 research reagents below, or read on for the biology behind the target.
RPA2 is a subunit of the heterotrimeric replication protein A (RPA/RP-A) complex. The complex binds and stabilises single-stranded DNA (ssDNA) intermediates that form during DNA replication or upon DNA stress, preventing their reannealing and protecting them from nucleases. It also prevents formation of secondary structures that would interfere with repair, and recruits and activates proteins and complexes involved in DNA metabolism. In this way it has an essential role in both DNA replication and the cellular response to DNA damage.
In the damage response, the RPA complex controls DNA repair and DNA damage checkpoint activation. Through recruitment of ATRIP it activates ATR kinase, a master regulator of the DNA damage response. It is required for recruitment of the double-strand break repair factors RAD51 and RAD52 to chromatin, and it brings XPA and XPG, which act in nucleotide excision repair, to sites of damage. RPA also appears to contribute to base excision repair, probably through interaction with UNG, and recruits SMARCAL1/HARP, which is involved in replication fork restart. It stimulates the 5'-3' helicase activity of BRIP1/FANCJ and may play a role in telomere maintenance.
The complex has low-affinity and high-affinity modes of ssDNA binding, determined by which oligonucleotide/oligosaccharide-binding (OB) domains are used. The RPA2 protein contains a single OB domain that participates in high-affinity DNA binding, and a carboxy-terminal winged helix domain that interacts with many genome maintenance proteins. Post-translational modifications of the complex help co-ordinate different damage response pathways. The RPA2 gene belongs to the HGNC nucleotide excision repair group, and the protein is found in the nucleus, including PML bodies. It was formerly named replication protein A2 (32kD). RPA1 encodes another subunit of the complex.
RPA2 recruits ATRIP to activate ATR kinase, making it central to studies of checkpoint activation and DNA damage signalling.
RPA supports recruitment of RAD51, RAD52, XPA and XPG, linking RPA2 to double-strand break, nucleotide excision and base excision repair.
By stabilising single-stranded DNA and recruiting SMARCAL1/HARP, RPA2 is relevant to replication fork restart and responses to replication stress.
RPA is involved in recombination and may play a role in telomere maintenance, placing RPA2 within genome stability research.
RPA2 is a subunit of the RPA complex, which binds single-stranded DNA, prevents its reannealing and recruits repair and signalling factors. It is needed for DNA replication, DNA repair and activation of the ATR-driven DNA damage checkpoint through ATRIP recruitment.
RPA2 is also known as replication protein A 32 kDa subunit in UniProt. Earlier HGNC names were replication protein A2 (32kD) and replication protein A2, 32kDa. No alternative gene symbols are listed. It is one subunit of the heterotrimeric RPA complex.
The mouse ortholog is Rpa2, and the rat ortholog in the supplied data is listed as Polr1b. Researchers working outside human samples should check the datasheet of any product for its validated reactivity.
Other subunits of the RPA complex and related DNA repair targets with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P15927; product specifications from Assay Genie datasheets.