Expression of steroidogenic factor 1 in the testis requires an interactive array of elements within its proximal promoter.
Steroidogenic factor 1 (SF-1) is an orphan nuclear receptor that is important for expression of genes involved in sexual differentiation, testicular and adrenal development, and hormone synthesis and regulation. To better understand the mechanisms required for SF-1 production, we employed transient transfection analysis and electrophoretic mobility shift assays to characterize the elements and proteins required for transcriptional activity of the SF-1 proximal promoter in testicular Sertoli and Leydig cells and adrenocortical cells. Direct comparison of SF-1-promoter activity in testis and adrenal cell types established that a similar set of regulatory elements (an E box, CCAAT box, and Sp1-binding sites) is required for proximal promoter activity in these cells. Further evaluation of the E box and CCAAT box revealed a novel synergism between the two elements and identified functionally important bases within the elements. Importantly, DNA/protein-binding studies uncovered new proteins interacting with the E box and CCAAT box. Thus, in addition to the previously identified USF and NF-Y proteins, newly described complexes, having migration properties that differed between Sertoli and Leydig cells, were observed bound to the E box and CCAAT box. Transient transfection analysis also identified several Sp1/Sp3-binding elements important for expression of SF-1 in the testis, one of which was previously described for expression in the adrenal gland whereas the other two were newly disclosed elements.
Scherrer
Serge P
SP
Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
Rice
Daren A
DA
Heckert
Leslie L
LL
D024506:5' Flanking Region; D000311:Adrenal Glands / Q000166:cytology / Q000502:physiology; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D024721:E-Box Elements; D051717:Fushi Tarazu Transcription Factors; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins; D007985:Leydig Cells / Q000378:metabolism; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear; D012708:Sertoli Cells / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000378:metabolism; D051704:Sp2 Transcription Factor; D051705:Sp3 Transcription Factor; D054339:Steroidogenic Factor 1; D013737:Testis / Q000166:cytology / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D024363:Transcription Initiation Site; D015533:Transcriptional Activation; D051720:Upstream Stimulatory Factors
D004268:DNA-Binding Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D016329:Sp1 Transcription Factor; C497122:Sp3 protein, mouse; C497123:Sp3 protein, rat; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; D051720:Upstream Stimulatory Factors; C497183:Usf1 protein, mouse; C497182:Usf1 protein, rat; C515058:steroidogenic factor 1, mouse; C515060:steroidogenic factor 1, rat; D051704:Sp2 Transcription Factor; D051705:Sp3 Transcription Factor