Studies on histones and non-histone proteins from rats treated with dimethylnitrosamine.
A study has been made of the histone and non-histone chromosomal proteins of rat liver after treatment in vivo with dimethylnitrosamine (DMN) (2 mg/kg). DMN was found not to affect histone turnover, as measured by 3H-labelled amino-acids incorporation. A decrease was observed in specific activity of the histones with time after injection of [14C]DMN or [14C]-formate and this was attributable to demethylation of both abnormal and normal methylation sites in these proteins. In the case of the non-histone proteins, DMN was found to increase greatly the turnover of those non-histone proteins loosely associated with chromatin DNA and RNA; turnover of those non-histone proteins tightly bound to chromatin DNA and RNA was unaffected. Demethylation of both normal and abnormal methylation sites was found to take place from both non-histone protein fractions. In the case of the loosely bound non-histone proteins a lower rate of demethylation was observed after DMN treatment.
D000818:Animals; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D004128:Dimethylnitrosamine / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D006657:Histones / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D012313:RNA / Q000378:metabolism; D051381:Rats
D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D012313:RNA; D004247:DNA; D004128:Dimethylnitrosamine