Conservation of histone H2A/H2B intergene regions: a role for the H2B specific element in divergent transcription.

ABSTRACT: The organization and function of potential regulatory elements associated with the promoters of chicken H2A and H2B genes pairs have been examined. The intergene regions of six dispersed and divergently-transcribed H2A/H2B gene pairs contain several extremely well conserved and spaced blocks of sequence homology. Adjacent coding regions are on average 342 base-pairs apart. Respective TATA boxes are separated by 180 base-pairs and within this confined region there are four CCAAT boxes and a previously identified 13 base-pair H2B-specific element (H2B-box) which has homology to the octamer motif present in a number of gene promoter/enhancer elements. Transcription of H2A and H2B genes from wild-type and mutant constructs was measured in transient assays by transfection into HeLa cells, and in permanently transformed clonal cell lines. In vitro separation of the two genes at a unique intergenic site significantly decreased transcription of each gene. This suggested that the H2A/H2B gene pairs contained overlapping promoters. Deletion or point mutagenesis of the H2B-specific element decreased the levels of H2B and the H2A transcripts indicating that this sequence is a common regulatory element of both genes in the divergent-pair configeration.

SUBMITTER: Sturm RA 

PROVIDER: S-EPMC338577 | biostudies-other | 1988 Sep

REPOSITORIES: biostudies-other