title: Cell cycle regulation of H2b histone octamer DNA-binding activity in Chinese hamster lung fibroblasts.
abstract: The promoter regions of H2b histone genes contain a 14-base-pair element which includes the octamer ATTTGCAT. Mutational analysis has implicated the octamer element in the cell cycle-dependent expression of H2b histone genes. In this report, we address the question of whether the DNA-binding activity of the octamer transcription factor is itself cell cycle regulated. By using a gel mobility shift assay, we measured the relative amounts of octamer-binding activity during various phases of the cell cycle in serum-synchronized Chinese hamster fibroblasts. We found that the activity increased approximately fivefold between late G1 phase and early S phase and then decreased threefold between late S phase and G2 phase. These cell cycle-dependent changes in octamer DNA-binding activity may in part account for the selective transcription of H2b histone genes in late G1 and S phases.
authors.affiliation: Department of Biochemistry, University of Southern California School of Medicine, Los Angeles 90033.
authors.forename: M
authors.initials: M
authors.lastname: Ito
authors.forename: A
authors.initials: A
authors.lastname: Sharma
authors.forename: A S
authors.initials: AS
authors.lastname: Lee
authors.forename: R
authors.initials: R
authors.lastname: Maxson
mesh_terms: D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005786:Gene Expression Regulation; D006657:Histones / Q000235:genetics*; D008168:Lung / Q000166:cytology / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D006657:Histones; D004247:DNA