N-methylpurine DNA glycosylase (MPG)

N-methylpurine DNA glycosylase (MPG) is a monofunctional DNA repair enzyme involved in the base excision repair (BER) pathway, responsible for recognizing and removing a variety of damaged purine bases, including alkylated (e.g., 3-methyladenine, 7-methylguanine), deaminated (hypoxanthine, xanthine), and exocyclic lesions from DNA[1][2][3][4][5]. MPG cleaves the N-glycosidic bond of target bases, leaving an abasic (apurinic/apyrimidinic, AP) site that is further processed by downstream repair enzymes[2][3][4]. This activity is critical for maintaining genomic stability and preventing mutations that can lead to cancer and other diseases[1][2][3]. MPG interacts with several proteins involved in genome maintenance, including p53, with which it can modulate cell cycle arrest and apoptosis responses to DNA damage[3]. Its expression is elevated in several tumors and inflammatory conditions, and it plays dual roles: facilitating repair to prevent carcinogenesis, but potentially increasing cell susceptibility to alkylating chemotherapy through AP site generation[3][4]. Overexpression, especially alongside wild-type p53, can alter tumor sensitivity to alkylating agents, making its regulation important for genomic integrity and as a potential therapeutic target in cancer[3][4].

Other names

DNA-3-methyladenine glycosylasealkyladenine DNA glycosylaseAAGANPGMID1MDG3-alkyladenine DNA glycosylase3-methyladenine DNA glycosidaseADPGN-methylpurine-DNA glycosylaseAPNGCRA36.1proliferation-inducing protein 11proliferation-inducing protein 16PIG11PIG16anpg

Hydrolysis (cleavage) of N-glycosidic bonds in damaged DNA bases (3-methyladenine, 7-methylguanine, others), Initiating base excision repair, Generation of abasic sites after lesion removal, Modulating cellular response to alkylating agents