Repression of the steroidogenic acute regulatory gene by the multifunctional transcription factor Yin Yang 1.
The transport of cholesterol to the inner mitochondrial membrane by the steroidogenic acute regulatory (StAR) protein is a critical step in steroidogenesis. The current study was designed to examine whether the multifunctional transcription factor Yin Yang 1 (YY1) was able to repress activation of the StAR gene. YY1 bound to three putative YY1-binding sites in the rat StAR promoter. Cotransfection of the StAR promoter linked to a luciferase reporter gene and YY1 in the presence or absence of sterol regulatory element binding protein-1a (SREBP-1a) resulted in transcriptional repression. YY1 was found to colocalize in the nucleus with SREPB-1a. YY1 inhibited SREBP-1a/nuclear factor Y (NF-Y) enhancement of StAR activation and YY1 decreased SREBP-1a binding to a sterol regulatory element in the presence or absence of NF-Y. YY1 also decreased NF-Y binding to a nonconsensus NF-Y-binding motif in the StAR promoter. These studies provide novel information on the mechanisms of YY1-mediated repression of the StAR gene.
Nackley
Anna C
AC
Department of Obstetrics and Gynecology, University of South Florida, Tampa, Florida 33606, USA.
Shea-Eaton
Wendy
W
Lopez
Dayami
D
McLean
Mark P
MP
D000818:Animals; D015153:Blotting, Western; D022762:CCAAT-Enhancer-Binding Proteins / Q000502:physiology; D019556:COS Cells; D004268:DNA-Binding Proteins / Q000502:physiology; D015536:Down-Regulation / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D050981:Erythroid-Specific DNA-Binding Factors; D016297:Mutagenesis, Site-Directed / Q000235:genetics; D010750:Phosphoproteins / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D051780:Sterol Regulatory Element Binding Protein 1; D014157:Transcription Factors / Q000235:genetics*; D014162:Transfection; D050986:YY1 Transcription Factor; D000098682:Steroidogenic Acute Regulatory Protein
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D010750:Phosphoproteins; C497389:Srebf1 protein, rat; D051780:Sterol Regulatory Element Binding Protein 1; D014157:Transcription Factors; D050986:YY1 Transcription Factor; C494700:Yy1 protein, rat; D000098682:Steroidogenic Acute Regulatory Protein