SUMMARY PARAGRAPH for RAD2
In S. cerevisiae, nucleotide excision repair (NER) is mediated by Rad1p, Rad2p, Rad4p, Rad7p, Rad10p, Rad14p, Rad16p, Met18p, the transcription factor TFIIH, and the heterotrimeric complex RPA (Rfa1p, Rfa2p, Rfa3p). Together these proteins bind DNA lesions, including UV-induced photoproducts and chemical crosslinks, unwind the surrounding duplex, and make incisions on both sides of the damaged DNA, which releases a fragment of 25-30bp (reviewed in 1, 3).
Rad2p is an endonuclease that makes the incision 3' of the site of damage during nucleotide excision repair (NER) (4, 5, 6). Rad2p forms the nucleotide excision factor 3 (NEF3) with a subset of subunits of the transcription factor TFIIH (7). Although not a subunit of TFIIH, RAD2 is required for efficient transcription (8). Rad2p also interacts with genes involved in other DNA repair pathways, including mismatch repair and base excision repair (9, 10). As a member of extended family of nucleases that include Rad27p and Exo1p, Rad2p exhibits a 5' to 3' exonuclease activity in vitro and is proposed to be involved in base excision repair in the absence of Rad27p (11, 10).
Expression of RAD2 is induced in response to UV in alpha-factor arrested or stationary phase cells (12, 13). In addition, RAD2 is induced during meiosis although its meiotic role is unclear (14, 15, 12)
Rad2p is related to H. sapiens XPG, also known as ERCC5, which is mutated in patients with xeroderma pigmentosum (XP) and Cockayne's syndrome (16, 17). These diseases are collectively known as xeroderma pigmentosum complementation group G. Deletion of the carboxy terminus of S. cerevisiae Rad2p that mimics the mutation found in a patient witih XP results in a defect in transcription (8).
Last updated: 2007-11-07