Diet- and age-dependent modulation of O6-methylguanine-DNA methyltransferase levels in mouse tissues.
Methylation of guanine in the O6 position by N-nitrosodimethylamine is higher in liver DNA of mice fed a diet restricted in essential amino acids than in controls. A diminished content of the repair enzyme O6-methylguanine-DNA methyltransferase (AAT) may be responsible for the elevated level of O6-methylguanine observed after amino acid deficiency. A delayed repair of O6-methylguanine can be ascribed to diminished AAT activity in amino-acid-restricted mice. In adults, but not in subadults, the diminished AAT activity in liver correlated well with a 40% decrease in overall protein synthesis.
Klaude
M
M
Wenner-Gren Institute for Experimental Biology, University of Stockholm, Sweden.
von der Decken
A
A
D000375:Aging; D000601:Amino Acids, Essential / Q000008:administration & dosage; D000818:Animals; D004247:DNA / Q000187:drug effects; D004260:DNA Repair / Q000187:drug effects; D004044:Dietary Proteins / Q000008:administration & dosage*; D004128:Dimethylnitrosamine / Q000494:pharmacology; D008099:Liver / Q000187:drug effects; D008780:Methyltransferases / Q000378:metabolism*; D051379:Mice; D019853:O(6)-Methylguanine-DNA Methyltransferase; D014176:Protein Biosynthesis
D000601:Amino Acids, Essential; D004044:Dietary Proteins; D004247:DNA; D008780:Methyltransferases; D019853:O(6)-Methylguanine-DNA Methyltransferase; D004128:Dimethylnitrosamine