RAD9A
Function
Component of the 9-1-1 cell-cycle checkpoint response complex that plays a major role in DNA repair (PubMed:10713044, PubMed:17575048, PubMed:20545769, PubMed:21659603, PubMed:31135337). The 9-1-1 complex is recruited to DNA lesion upon damage by the RAD17-replication factor C (RFC) clamp loader complex (PubMed:21659603). Acts then as a sliding clamp platform on DNA for several proteins involved in long-patch base excision repair (LP-BER) (PubMed:21659603). The 9-1-1 complex stimulates DNA polymerase beta (POLB) activity by increasing its affinity for the 3'-OH end of the primer-template and stabilizes POLB to those sites where LP-BER proceeds; endonuclease FEN1 cleavage activity on substrates with double, nick, or gap flaps of distinct sequences and lengths; and DNA ligase I (LIG1) on long-patch base excision repair substrates (PubMed:21659603). The 9-1-1 complex is necessary for the recruitment of RHNO1 to sites of double-stranded breaks (DSB) occurring during the S phase (PubMed:21659603). RAD9A possesses 3'->5' double stranded DNA exonuclease activity (PubMed:10713044).
Post-translational modifications
Constitutively phosphorylated on serine and threonine amino acids in absence of DNA damage (PubMed:12628935). Hyperphosphorylated by PRKCD and ABL1 upon DNA damage (PubMed:11971963, PubMed:12709442). Its phosphorylation by PRKCD may be required for the formation of the 9-1-1 complex (PubMed:12628935). Phosphorylated at Ser-341 and Ser-387 by CK2, promoting interaction with TOPBP1 (PubMed:17575048, PubMed:20545769).
Sequence Similarities
Belongs to the rad9 family.
Cellular localization
- Nucleus
Alternative names
Cell cycle checkpoint control protein RAD9A, hRAD9, DNA repair exonuclease rad9 homolog A, RAD9A