Positive and negative regulatory elements control the steroid-responsive ovalbumin promoter.

摘要: Steroid hormones regulate the transcriptional activity of chicken ovalbumin gene both in vivo and cell culture. To identify regulatory elements involved, primary oviduct cultures were transfected with constructs containing promoter 5'-flanking region fused to bacterial chloramphenicol acetyltransferase (CAT) gene. Induction OvCAT genes by estrogen, progesterone, or corticosterone mimics that endogenous gene, indicating DNA is accurately regulated. Deletion analysis revealed a steroid response element (SRE) resides between nucleotide coordinates -880 -585 negative (NRE) -350 -248 Thus, an NRE represses expression unless relieve this control through interactions involving more distal SRE. Neither SRE nor alone regulates heterologous thymidine kinase promoter, suggesting either they function as single entity are conditional elements. The functional MCF-7 cells, but cannot be activated steroids estrogen-responsive line. These data indicate steroid-receptor complex induces direct indirect actions at represssion NRE.