Alkylation of nuclear proteins in rat liver by diethylnitrosamine
Letnansky, K.
Cellular and Molecular Biology 28(3): 353-361
1982
ISSN/ISBN: 0145-5680 PMID: 7116373 Document Number: 193652
After the injection of the carcinogen N,N-di[1-14C]-ethylnitrosamine into hepatectomized rats incorporation of radioactive label into histone and non-histone proteins of liver nuclei is demonstrated. Differences are observed between the alkylation patterns of nuclear proteins from chromatin enriched in transcriptionally active sequences compared to inactive chromatin. Although many protein components are alkylated in both fractions, the increased incororation of ethyl residues into histone H2B and the diminished alkylation of histone H1' of the active sequences are particularly striking. H2B is ethylated only in the mononucleosomal fraction of nuclease digests which consists of particles released from actively transcribed sequences. While differences are less pronounced between H1' histones from monomeric and oligomeric particles, clear differences were demonstrated with respect to the incorporation of ethyl residues into certain non-histone proteins.