Stimulation of the murine type II transforming growth factor-beta receptor promoter by the transcription factor Egr-1.
Previous studies have demonstrated that differentiation of murine embryonal carcinoma (EC) cells leads to the appearance of high affinity receptors for transforming growth factor-beta (TGF-beta). Subsequently, it was demonstrated that differentiation of F9 EC cells leads to increases in the transcription of the type II TGF-beta-receptor gene (TbetaR-II) and leads to significant increases in the steady-state levels of TbetaR-II mRNA. Analysis of the human TbetaR-II promoter in F9-differentiated cells identified several cis-regulatory elements that influence the activity of the promoter, including a CRE/ATF site and a CCAAT box motif. In the work described in this report, we focused on the effect of the transcription factor Egr-1 on the murine TbetaR-II promoter. We have identified an Egr-1 response-element approximately 150 bp upstream of the major transcription start site of the murine TbetaR-II gene. We demonstrate by electrophoretic mobility shift analysis (EMSA) that this cis-regulatory element binds Egr-1, and we demonstrate that disruption of this site eliminates the response to Egr-1. As part of this analysis, we also examined the effect of Egr-1 on human TbetaR-II promoter. In contrast to a previous report, which reported that Egr-1 inhibits expression of human TbetaR-II promoter/reporter gene constructs, we did not observe an inhibitory effect of Egr-1 that was specific for the human TbetaR-II promoter. Taken together, the findings described in this report identify important differences between the human and the murine TbetaR-II promoter, and our findings identify an Egr-1 cis-regulatory element that is capable of stimulating the activity of the murine TbetaR-II promoter.
Wilder
Phillip J
PJ
Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA.
Bernadt
Cory T
CT
Kim
Jae-Hwan
JH
Rizzino
Angie
A
D024506:5' Flanking Region / Q000235:genetics; D000818:Animals; D004268:DNA-Binding Proteins / Q000378:metabolism*; D051766:Early Growth Response Protein 1; D004591:Electrophoresis, Polyacrylamide Gel; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation / Q000502:physiology; D005809:Genes, Regulator; D006801:Humans; D017874:Immediate-Early Proteins; D051379:Mice; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism*
D004268:DNA-Binding Proteins; C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D017874:Immediate-Early Proteins; D018125:Receptors, Transforming Growth Factor beta; D014157:Transcription Factors; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II