Periodic cdc25C transcription is mediated by a novel cell cycle-regulated repressor element (CDE).

摘要: We show that the cell cycle-regulated transcription of TATA-less cdc25C gene in late S/G2 is largely mediated by a novel promoter element (CDE) located directly 5' to one two major initiation sites. Genomic dimethylsulfate footprinting experiments, using either synchronized or sorted normally cycling cells, formation vivo CDE-protein complex both G0 and G1 cells its dissociation G2. Mutation CDE severely impairs cycle regulation results high expression G0/G1, indicating functions as cis-acting repressor element. Cell also lost upon removal enhancer region immediately upstream CDE, but restored when this enhancerless minimal fragment linked constitutive SV40 early enhancer. This indicates dependent on presence transcriptional effect regulation. Our observations suggest periodic activation brought about, at least part, unique regulatory mechanism involving from CDE.