title: Evidence for the excision repair of O6-n-butyldeoxyguanosine in human cells.
abstract: The persistence of O6-n-butyldeoxyguanosine (O6-nBudG) in DNA, the presence of O6-alkylguanine DNA alkyltransferase (AT) activity in cell extracts, and cell survival following exposure to N-n-butyl-N-nitrosourea (BNU), have been measured in normal and xeroderma pigmentosum cell strains, both transformed and untransformed. The rates of removal of O6-nBudG did not correlate with AT activity but did correlate with the ability of strains to excise bulky DNA lesions. BNU and N-methyl-N-nitrosourea dose-response curves for cell killing suggests that both AT and excision may be involved in the repair of cytotoxic lesions.
mesh_terms: D000478:Alkylation; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000378:metabolism; D004260:DNA Repair; D003849:Deoxyguanosine / Q000031:analogs & derivatives*; D006151:Guanosine / Q000031:analogs & derivatives* / Q000378:metabolism; D006801:Humans; D008770:Methylnitrosourea / Q000633:toxicity; D008780:Methyltransferases / Q000032:analysis; D009607:Nitrosourea Compounds / Q000633:toxicity; D019853:O(6)-Methylguanine-DNA Methyltransferase
chemical_list: D009607:Nitrosourea Compounds; D006151:Guanosine; C035022:O(6)-n-butyldeoxyguanosine; D008770:Methylnitrosourea; C002738:N-nitrosobutylurea; D004247:DNA; D008780:Methyltransferases; D019853:O(6)-Methylguanine-DNA Methyltransferase; D003849:Deoxyguanosine