A steroidogenic factor-1 binding site is required for activity of the luteinizing hormone beta subunit promoter in gonadotropes of transgenic mice.
Analysis of luteinizing hormone (LH) beta 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 LH beta promoter was confirmed by electrophoretic mobility shift assays. Furthermore, cotransfection of alpha T3-1 cells with an expression vector encoding SF-1 induced binding site-dependent transcription from the bovine LH beta promoter. Physiological significance of the LH beta 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 LH beta promoter activity in vivo and implicate SF-1 as at least one of the transcription factors that acts through this site.
Keri
R A
RA
Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Nilson
J H
JH
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002417:Cattle; D002460:Cell Line; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D051717:Fushi Tarazu Transcription Factors; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D018398:Homeodomain Proteins; D007986:Luteinizing Hormone / Q000235:genetics*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D018160:Receptors, Cytoplasmic and Nuclear; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D017931:DNA Primers; D004268:DNA-Binding Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; C515058:steroidogenic factor 1, mouse; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone