A Steroidogenic Factor-1 Binding Site Is Required for Activity of the Luteinizing Hormone Subunit Promoter in Gonadotropes of Transgenic Mice

Ruth A. Keri; John H. Nilson

doi:10.1074/jbc.271.18.10782

A Steroidogenic Factor-1 Binding Site Is Required for Activity of the Luteinizing Hormone Subunit Promoter in Gonadotropes of Transgenic Mice (*)

Ruth A. Keri and
John H. Nilson^(§),

From the Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106

↵^§ To whom correspondence should be addressed: Dept. of Pharmacology, School of Medicine, Case Western Reserve University, 2109 Adelbert Rd., Cleveland, OH 44106.

Abstract

Analysis of luteinizing hormone (LH) β subunit promoters from a broad range of species including teleosts and humans revealed strict conservation of a sequence homologous to the steroidogenic factor-1 (SF-1) regulatory element of cytochrome P-450 steroid hydroxylase genes. Interaction between SF-1 and this putative response element in the bovine LHβ promoter was confirmed by electrophoretic mobility shift assays. Furthermore, cotransfection of αT3-1 cells with an expression vector encoding SF-1 induced binding site-dependent transcription from the bovine LHβ promoter. Physiological significance of the LHβ SF-1 consensus sequence was established using transgenic mice containing either the wild type bovine promoter or a promoter with a site-specific mutation of this site. Mutation of the SF-1 binding site nearly eliminated promoter activity, and the mutant transgene remained inactive following induction of gonadotropin-releasing hormone accomplished by castrating male and female mice. Thus, increases of gonadotropin-releasing hormone within a physiological range did not compensate for the loss of the SF-1 binding site. Together, these findings indicate that the SF-1 binding site is a key regulator of LHβ promoter activity in vivo and implicate SF-1 as at least one of the transcription factors that acts through this site.

Footnotes

↵* This work was supported by United States Department of Agriculture Grant 94-37203-0718. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.