Anti-DNA Helicase B (HELB) from rabbit

DNA helicase B (UniProt: Q6NVF4; also known as EC: 3.6.4.12, HELB) is encoded by the Helb gene (Gene ID: 117599) in murine species. HELB helicase B is is a predominantly nuclear helicase that can undergo phosphorylation at Serine 942 by CDK2 during the G1/S transition that results in its export into the cytoplasm as cells approach and progress through S phase. Its nuclear export signal lies within amino acids 1022-1046. It serves as a 5 -3' DNA helicase involved in DNA damage response by acting as an inhibitor of DNA end resection. It is shown to bind to RPA1 and this interaction promotes HELB recruitment to chromatin following DNA damage. Following DNA damage it is recruited to sites of double-strand breaks by the Replication Protein A (RPA) complex. Recruitment to single-stranded DNA (ssDNA) following DNA damage leads to inhibit the nucleases catalyzing resection, such as EXO1, BLM and DNA2, possibly via the 5'-3' ssDNA translocase activity of HELB. HELB is reported to act independently of TP53BP1. Loss of DNA helicase B results in PARP inhibitor resistance in BRCA1-deficient tumor cells.