Characterization of a steroidogenic factor-1-binding site found in promoter of sterol carrier protein-2 gene.
Sterol carrier protein-2 (SCP2) is thought to mediate intracellular cholesterol transport in steroidogenic tissues. To elucidate the mechanism underlying the expression of this gene, a 300-bp fragment of the SCP2 promoter was cloned and analyzed for regulatory motifs. This promoter region contained a SF-1 binding motif, three activator protein-1 elements, an insulin response element, and a peroxisomal proliferator response element. The putative SF-1 binding region reacted with recombinant SF-1 DNA-binding domain in a mobility shift assay. The SCP2 promoter fragment was linked to a luciferase reporter gene and cotransfected in the presence or absence of SF-1 into HTB-9 cells. The results indicated that SF-1 was able to increase SCP2 promoter activity, an effect that was enhanced by cAMP. Similar results were obtained when the SCP2 promoter construct was cotransfected into Y1 cells. Cotransfection studies carried out in Kin 8 cells, a Y1 cell line with a mutation that prevents cAMP activation of PKA, revealed that a functional PKA is required for cAMP induction of SCP2 gene transcription. These results demonstrated that SF-1 confers cAMP responsiveness to the SCP2 promoter suggesting that SF-1 activation may be critical in regulation of this cholesterol transport protein.
Lopez
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Department of Obstetrics and Gynecology, University of South Florida, Tampa 33706, USA.
Shea-Eaton
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W
McLean
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MP
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003994:Bucladesine / Q000494:pharmacology; D002352:Carrier Proteins / Q000235:genetics*; D018929:Cell Culture Techniques; D000242:Cyclic AMP / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010940:Plant Proteins; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D018160:Receptors, Cytoplasmic and Nuclear; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000378:metabolism*
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; C515060:steroidogenic factor 1, rat; C072087:sterol carrier proteins; D003994:Bucladesine; D004247:DNA; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases