Characterization of the enhancer-like okadaic acid response element region of the cyclin-dependent kinase 1 (p34cdc2) promoter.
Expression of the cdk1 (p34cdc2) gene is enhanced 5-10 fold as cells re-enter the cell cycle from quiescence in response to serum-refeeding or following exposure to the protein phosphatase 1/2A inhibitor okadaic acid. Transient transfection analysis of nested deletions of the human cdk1 promoter identified regions that confer sensitivity to okadaic acid on a CAT-reporter gene. Putative okadaic acid response elements (OARE) were located between nt -942 to -763 (Site I) and nt -416 to -186 (Site II) before transcription start. The Site I element has enhancer-like characteristics as activity is independent of sequence orientation. Mobility shift analysis of Site I revealed the presence of 2 high molecular weight complexes, one of which was enhanced in the presence of okadaic acid-treated cell extracts. Site I contained several sequence motifs with conserved homology to heat shock response element core sequences and homeobox protein binding sites. Site II contained a myb-binding site, a G1/S phase enhancer, and 2 retinoblastoma response elements flanking an E2F binding site. Enhancement of cdk1 expression appears dependent on 2 nonhomologous okadaic acid-sensitive promoter regions.
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Department of Pathobiology, Auburn University, Alabama 36849-5519, USA.
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D001483:Base Sequence; D016203:CDC2 Protein Kinase / Q000096:biosynthesis / Q000235:genetics*; D017124:Conserved Sequence; D004252:DNA Mutational Analysis; D004742:Enhancer Elements, Genetic; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D017930:Genes, Reporter; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D019319:Okadaic Acid / Q000494:pharmacology*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D054645:Protein Phosphatase 1; D017384:Sequence Deletion
D004791:Enzyme Inhibitors; D019319:Okadaic Acid; D016203:CDC2 Protein Kinase; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1