Effect of histones and nonhistone chromosomal proteins on the transcription of histone genes from HeLa S3, cell DNA

Abstract

To elucidate the manner in which histones and nonhistone chromosomal proteins interact to render histone genes transcribable in human HeLa S3 cervical cancer cells, the transcription of histone mRNA sequences from DNA, as well as from several DNA-chromosomal protein complexes was examined. Histone mRNA sequences were assayed by hybridization to a 3H-labeled single-stranded DNA complementary to histone mRNAs. DNA was an effective template for transcription of histone mRNA sequences and histones by themselves inhibited, transcription from DNA, including transcription of histone genes, in a dose-dependent, nonspecific manner. When complexed with DNA alone, nonhistone chromosomal proteins did not affect the transcription of histone mRNA sequences. When associated with DNA in the presence of histones, nonhistone chromosomal proteins were capable of selectively rendering histone genes transcribable. Nonhistone chromosomal proteins played a possible role in mediating the interactions of histones with DNA to render histone genes transcribable.