Characterization of the functional properties and nuclear binding proteins of the rat luteinizing hormone/chorionic gonadotropin receptor promoter in Leydig cells.
The experiments presented herein were designed to study the molecular basis of the restricted cellular localization and transcriptional regulation of the LH/CG receptor in Leydig cells. Using luciferase fusion constructs transfected into Leydig and Sertoli cell lines, we show that the proximal 186 basepairs (relative to the translation start site) of the 5'-flanking region of the rat LH/CG receptor represent a basal promoter that accounts for the Leydig cell-specific expression of this receptor. A region that confers negative transcriptional regulation by cAMP maps to nucleotides -40 to -70 of this basal promoter. Using mobility shift and deoxyribonuclease footprinting assays, we also report the detection of Leydig cell-specific protein(s) that bind to the basal LH/CG receptor promoter. The binding of this protein(s) to the promoter involves an AP-2 consensus sequence beginning at nucleotide -59 as well as additional sequences that remain to be identified. In spite of the fact that the AP-2 site is involved, the protein-DNA complexes detected in Leydig cells are not recognized by an antibody to AP-2.
Department of Pharmcology, University of Iowa College of Medicine, Iowa City 52242-1109.
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Nelson
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Liu
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Noblett
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Fabritz
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Ascoli
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D000242:Cyclic AMP / Q000494:pharmacology; D004247:DNA / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D007985:Leydig Cells / Q000737:chemistry* / Q000166:cytology / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000032:analysis / Q000378:metabolism / Q000502:physiology*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D051381:Rats; D011974:Receptors, LH / Q000032:analysis* / Q000235:genetics* / Q000378:metabolism; D012708:Sertoli Cells / Q000737:chemistry / Q000166:cytology / Q000502:physiology; D014158:Transcription, Genetic / Q000502:physiology
D009687:Nuclear Proteins; D011974:Receptors, LH; D004247:DNA; D000242:Cyclic AMP