Transcriptional transformation of Walker tumor chromatin by nonhistone proteins.

It is concluded that the nonhistone proteins are tissue specific in the alteration of transcription of chromatin in Walker tumor and normal rat liver and Walker carcinosarcoma.

Abstract

Nonhistone proteins fractionated from normal rat liver and Walker carcinosarcoma can stimulate chromatin-templated RNA synthesis in vitro . This has been demonstrated by using RNA polymerase prepared from rat liver, Walker tumor, or Micrococcus luteus . The RNA isolated from these fractionated nonhistone proteins does not activate transcription from chromatin. As judged by DNA-RNA hybridization studies, the altered transcription of chromatin effected by the nonhistone proteins reflects the characteristic transcription from chromatin homologous to the nonhistone proteins. Thus, when rat liver nonhistone proteins were used to activate transcription from Walker tumor chromatin, the activated transcript was found to contain RNA species similar to that synthesized in vitro from rat liver chromatin. Conversely, Walker tumor nonhistone proteins can activate the synthesis of RNA from rat liver chromatin to that partly characteristic of Walker tumor chromatin transcript. It is concluded that the nonhistone proteins are tissue specific in the alteration of transcription of chromatin.