CELL-TYPE-SPECIFIC REGULATION OF COUP-TF-II PROMOTER ACTIVITY

COUP-TF family orphan receptors regulate activity of ligand-activated nuclear hormone receptors or function independently in the regulation of gene expression, COUP-TF II has a complex expression pattern sugges ting that different mechanisms are involved in the regulation of its e xpression, We isolated the 5' regulatory region of the mouse COUP-TF I I gene and demonstrated that the basal promoter is localized in a -200 bp region 5' from the transcription start site, All-trans retinoic ac id and dibutyryl cyclic AMP have cell type specific effects on COUP-TF II promoter activity, The effect of cyclic AMP is mediated by the cyc lic AMP response element that is localized 74 nucleotides upstream fro m the major transcriptional start. In vitro promoter analyses also dem onstrated that the effect of all-trans RA is not directly mediated by the binding of RARs or RXRs to the promoter sequence.