• 1 January 1981
    • journal article
    • research article
    • Vol. 41  (4) , 1253-1256
Abstract
The possible role of alterations of histone methylation by ethionine in the mechanism of ethionine carcinogenesis was studied. In regenerating rat liver, histone synthesis was inhibited by only 20-30% with large doses of ethionine (0.75- 1.0 mg/g body wt). The effect of ethionine on the in vivo methylation of histones was studied by giving 0.5 mg ethionine and [methyl-3H]methionine/g body wt. In vivo methylation of lysine was inhibited by 50%; the arginine methylation was inhibited by 89%. The cellular localization of the methyltransferases and S-adenosyl-L-ethionine may be related to this differential effect. Using an in vitro assay for protein-lysine and protein-arginine methyltransferases, it was demonstrated that the methyl-deficient histones are transported to the nucleus and with time lose their ability to accept methyl groups in vitro.