| First Author | Susa T | Year | 2007 |
| Journal | Biochem Biophys Res Commun | Volume | 357 |
| Issue | 3 | Pages | 712-7 |
| PubMed ID | 17445765 | Mgi Jnum | J:239206 |
| Mgi Id | MGI:5825430 | Doi | 10.1016/j.bbrc.2007.03.197 |
| Citation | Susa T, et al. (2007) Homeodomain transcription factor Hesx1/Rpx occupies Prop-1 activation sites in porcine follicle stimulating hormone (FSH) beta subunit promoter. Biochem Biophys Res Commun 357(3):712-7 |
| abstractText | Homeodomain repressor factor Hesx1/Rpx plays a crucial role in the formation of Rathke's pouch at the start of pituitary organogenesis and represses the Prop-1-dependent expression of Pit-1 gene, which promotes the differentiation of Pit-1-dependent hormone producing cells. Recently, we discovered a novel function of Prop-1 by which it activates the porcine follicle stimulating hormone beta subunit (FSHbeta) gene through Fd2 region (-852/-746). The present study aimed to determine whether Hesx1 exerts its role in the Prop-1-dependent activation of FSHbeta gene. Transient transfection assay for the porcine FSHbeta promoter -985/+10, electrophoretic mobility shift assay (EMSA) and DNase I footprinting analysis for Fd2 region were carried out. Transfection assay in GH3 cells demonstrated that expression of Hesx1 alone does not change the promoter activity but the coexpression with Prop-1 represses the Prop-1-dependent activation of FSHbeta promoter. Similar results were obtained for the mutant reporter vector deleting the region -745/-104 indicating that Fd2 region is a target site of Hesx1 as well as Prop-1. EMSA and DNase I footprinting analysis using recombinant Hesx1 and Prop-1 protein demonstrated that Hesx1 and Prop-1 certainly bind to the AT-rich regions in a different manner. These results suggest that Hesx1 blocks the advanced expression of FSHbeta gene in the early stage of pituitary development, and Prop-1 thereafter appears and activates this gene. |
