Characterization of the CDP-like/CTAS-1 binding site in the okadaic acid response element (OARE) of the human CDK1(p34cdc2) promoter.

Background: Transcription of CDK1 is induced at the G0/G1-phase of the cell cycle and after okadaic acid treatment and we identified the Site I okadaic acid response element (OARE -944 to -763nt) enhancer in the human CDK1 promoter.

Materials And Methods: The OARE region of the CDK1 promoter was characterized for enhancer/repressor activities.

Results: Transient transfection of upper and lower Site I subregions suggested enhanced transcription activity was divided between both while mobility shift assays demonstrated sequence-specific protein binding to Site IA. Site IA also formed shift complexes following serum starvation/refeeding and putative transcription factor binding sites clustered in Site IA. Oligonucleotides encoding a consensus CDP transcription factor binding site effectively competed against authentic Site IA in mobility shift assays. Mutation of the CDP-like binding sequence substantially reduced competition. DNaseI footprinting revealed binding at this site.

Conclusion: The CDP-like recognition sequence appears to comprise the OARE binding authentic CDP and/or related factors. We termed this site the CDK1 transcription activation sequence-1 (CTAS-1) enhancer of the human CDK1 promoter.