Transcriptional Regulation of the Ovine Follicle-Stimulating Hormone-β Gene by Activin and Gonadotropin-Releasing Hormone (GnRH): Involvement of Two Proximal Activator Protein-1 Sites for GnRH Stimulation*

• DOI: 10.1210/endo.142.6.8203
• Publication Date: 2014-01-08T16:11:46Z
• Authors: Huey-Jing Huang; Joseph Sebastian; Brian D. Strahl; Joyce C. Wu; William L. Miller
• Keywords: Follistatin; Gonadotropin

Previous studies from our laboratory demonstrated that a transgene consisting of the promoter for ovine FSH β-subunit gene and luciferase reporter (wt-oFSHβLuc) was expressed regulated like FSHβ in vivo vitro. In present study pituitary cultures were prepared these transgenic mice as well carrying mutated oFSHβLuc lacking two functional activator protein-1 (AP-1) sites at −120 −83 bp (mut-oFSHβLuc). These AP-1 reported necessary induction by GnRH HeLa cell system. To examine importance mediating activin effects primary gonadotropes, derived pretreated with follistatin to remove or activin-like factors cultures. Follistatin lowered expression both wt-oFSHβLuc mut-oFSHβLuc transgenes 74–86%, subsequent addition induced wt- mut-transgenes 4- 14-fold within 4 h, suggesting are not involved stimulation transcription. When added along activin, 200% compared alone, but this effect observed transgene. data confirmed showing signals through increase oFSHβ transcription gonadotropes. However, mutation had no apparent on regulation (basal, castration, down-regulation, cycle stage, immunoneutralization), it appears have little influence over major vivo. also showed plays role transcriptional gene, contains response element(s) is yet undefined.