scholarly journals Cyclic Adenosine 3′,5′-Monophosphate (cAMP) Enhances cAMP-Responsive Element Binding (CREB) Protein Phosphorylation and Phospho-CREB Interaction with the Mouse Steroidogenic Acute Regulatory Protein Gene Promoter

Endocrinology ◽  
2005 ◽  
Vol 146 (3) ◽  
pp. 1348-1356 ◽  
Author(s):  
Brian F. Clem ◽  
Elizabeth A. Hudson ◽  
Barbara J. Clark
Keyword(s):  
Binding Protein ◽  
Regulatory Protein ◽  
Proximal Promoter ◽  
Steroidogenic Acute Regulatory Protein ◽  
Gene Promoters ◽  
Cis Acting ◽  
Steroidogenic Acute Regulatory ◽  
Responsive Element ◽  
Phosphorylated Creb ◽  
Camp Responsive Element Binding

Steroidogenic acute regulatory protein (StAR) transcription is regulated through cAMP-protein kinase A-dependent mechanisms that involve multiple transcription factors including the cAMP-responsive element binding protein (CREB) family members. Classically, binding of phosphorylated CREB to cis-acting cAMP-responsive elements (5′-TGACGTCA-3′) within target gene promoters leads to recruitment of the coactivator CREB binding protein (CBP). Herein we examined the extent of CREB family member phosphorylation on protein-DNA interactions and CBP recruitment with the StAR promoter. Immunoblot analysis revealed that CREB, cAMP-responsive element modulator (CREM), and activating transcription factor (ATF)-1 are expressed in MA-10 mouse Leydig tumor cells, yet only CREB and ATF-1 are phosphorylated. (Bu)2cAMP treatment of MA-10 cells increased CREB phosphorylation approximately 2.3-fold within 30 min but did not change total nuclear CREB expression levels. Using DNA-affinity chromatography, we now show that CREB and ATF-1, but not CREM, interact with the StAR promoter, and this interaction is dependent on the activator protein-1 (AP-1) cis-acting element within the cAMP-responsive region. In addition, (Bu)2cAMP-treatment increased phosphorylated CREB (P-CREB) association with the StAR promoter but did not influence total CREB interaction. In vivo chromatin immunoprecipitation assays demonstrated CREB binding to the StAR proximal promoter is independent of (Bu)2cAMP-treatment, confirming our in vitro analysis. However, (Bu)2cAMP-treatment increased P-CREB and CBP interaction with the StAR promoter, demonstrating for the first time the physical role of P-CREB:DNA interactions in CBP recruitment to the StAR proximal promoter.

scholarly journals Steroidogenic Acute Regulatory Protein-binding Protein Cloned by a Yeast Two-hybrid System

2003 ◽  
Vol 278 (43) ◽  
pp. 42487-42494 ◽  
Author(s):  
Teruo Sugawara ◽  
Hiroshi Shimizu ◽  
Nobuhiko Hoshi ◽  
Ayako Nakajima ◽  
Seiichiro Fujimoto
Keyword(s):  
Protein Binding ◽  
Hybrid System ◽  
Binding Protein ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Yeast Two Hybrid ◽  
Yeast Two Hybrid System ◽  
Steroidogenic Acute Regulatory ◽  
Two Hybrid

scholarly journals Synergistic Activation of Steroidogenic Acute Regulatory Protein Expression and Steroid Biosynthesis by Retinoids: Involvement of cAMP/PKA Signaling

Endocrinology ◽  
2014 ◽  
Vol 155 (2) ◽  
pp. 576-591 ◽  
Author(s):  
Pulak R. Manna ◽  
Andrzej T. Slominski ◽  
Steven R. King ◽  
Cloyce L. Stetson ◽  
Douglas M. Stocco
Keyword(s):  
Retinoic Acid ◽  
Leydig Cells ◽  
Binding Protein ◽  
Regulatory Protein ◽  
Liver X Receptor ◽  
Steroidogenic Acute Regulatory Protein ◽  
Type I ◽  
Steroid Biosynthesis ◽  
Steroidogenic Acute Regulatory ◽  
Star Gene

Both retinoic acid receptors (RARs) and retinoid X receptors (RXRs) mediate the action of retinoids that play important roles in reproductive development and function, as well as steroidogenesis. Regulation of steroid biosynthesis is principally mediated by the steroidogenic acute regulatory protein (StAR); however, the modes of action of retinoids in the regulation of steroidogenesis remain obscure. In this study we demonstrate that all-trans retinoic acid (atRA) enhances StAR expression, but not its phosphorylation (P-StAR), and progesterone production in MA-10 mouse Leydig cells. Activation of the protein kinase A (PKA) cascade, by dibutyrl-cAMP or type I/II PKA analogs, markedly increased retinoid-responsive StAR, P-StAR, and steroid levels. Targeted silencing of endogenous RARα and RXRα, with small interfering RNAs, resulted in decreases in 9-cis RA-stimulated StAR and progesterone levels. Truncation of and mutational alterations in the 5′-flanking region of the StAR gene demonstrated the importance of the −254/−1-bp region in retinoid responsiveness. An oligonucleotide probe encompassing an RXR/liver X receptor recognition motif, located within the −254/−1-bp region, specifically bound MA-10 nuclear proteins and in vitro transcribed/translated RXRα and RARα in EMSAs. Transcription of the StAR gene in response to atRA and dibutyrl-cAMP was influenced by several factors, its up-regulation being dependent on phosphorylation of cAMP response-element binding protein (CREB). Chromatin immunoprecipitation studies revealed the association of phosphorylation of CREB, CREB binding protein, RXRα, and RARα to the StAR promoter. Further studies elucidated that hormone-sensitive lipase plays an important role in atRA-mediated regulation of the steroidogenic response that involves liver X receptor signaling. These findings delineate the molecular events by which retinoids influence cAMP/PKA signaling and provide additional and novel insight into the regulation of StAR expression and steroidogenesis in mouse Leydig cells.

scholarly journals Angiotensin II-Dependent Transcriptional Activation of Human Steroidogenic Acute Regulatory Protein Gene by a 25-kDa cAMP-Responsive Element Modulator Protein Isoform and Yin Yang 1

Endocrinology ◽  
2012 ◽  
Vol 153 (3) ◽  
pp. 1256-1268 ◽  
Author(s):  
Renate K. Meier ◽  
Barbara J. Clark
Keyword(s):  
Rna Polymerase Ii ◽  
Reporter Gene ◽  
Transcriptional Activation ◽  
Regulatory Protein ◽  
Gene Activity ◽  
Proximal Promoter ◽  
Ang Ii ◽  
Reporter Gene Activity ◽  
Steroidogenic Acute Regulatory ◽  
Responsive Element

Transcriptional activation of the steroidogenic acute regulatory protein (STAR) gene is a critical component in the angiotensin II (Ang II)-dependent increase in aldosterone biosynthesis in the adrenal gland. The purpose of this study was to define the molecular mechanisms that mediate the Ang II-dependent increase in STARD1 gene (STAR) expression in H295R human adrenocortical cells. Mutational analysis of the STAR proximal promoter revealed that a nonconsensus cAMP-responsive element located at −78 bp relative to the transcription start site (−78CRE) is required for the Ang II-stimulated STAR reporter gene activity. DNA immunoaffinity chromatography identified a 25-kDa cAMP-responsive element modulator isoform and Yin Yang 1 (YY1) as −78CRE DNA-binding proteins, and Ang II treatment of H295R cells increased expression of that 25-kDa CREM isoform. Small interfering RNA silencing of CREM and YY1 attenuated the Ang II-dependent increases in STAR reporter gene activity and STAR mRNA levels. Conversely, overexpression of CREM and YY1 in COS-1 cells resulted in transactivation of STAR reporter gene activity. Chromatin immunoprecipitation analysis demonstrated recruitment of CREM and YY1 to the STAR promoter along with increased association of the coactivator cAMP response element-binding protein-binding protein (CBP) and increased phosphorylated RNA polymerase II after Ang II treatment. Together our data reveal that the Ang II-stimulated increase in STAR expression in H295R cells requires 25 kDa CREM and YY1. The recruitment of these transcription factors to the STAR proximal promoter results in association of CBP and activation of RNA polymerase II leading to increased STAR transcription.

scholarly journals Transcription of Steroidogenic Acute Regulatory Protein in the Rodent Ovary and Placenta: Alternative Modes of Cyclic Adenosine 3′, 5′-Monophosphate Dependent and Independent Regulation

Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 977-989 ◽  
Author(s):  
Natalie Yivgi-Ohana ◽  
Noa Sher ◽  
Naomi Melamed-Book ◽  
Sarah Eimerl ◽  
Moriah Koler ◽  
...  
Keyword(s):  
Binding Protein ◽  
Regulatory Protein ◽  
Giant Cells ◽  
Steroidogenic Acute Regulatory Protein ◽  
Maximal Response ◽  
Cis Elements ◽  
Tissue Specific ◽  
Steroidogenic Acute Regulatory ◽  
Trophoblast Giant Cells ◽  
Star Gene

Steroid hormone synthesis is a vital function of the adrenal cortex, serves a critical role in gonadal function, and maintains pregnancy if normally executed in the placenta. The substrate for the synthesis of all steroid hormones is cholesterol, and its conversion to the first steroid, pregnenolone, by the cholesterol side-chain cleavage cytochrome P450 (CYP11A1) enzyme complex takes place in the inner mitochondrial membranes. Steroidogenic acute regulatory protein (STAR) facilitates the rate-limiting transfer of cholesterol from the outer mitochondrial membrane to CYP11A1 located in the inner organelle membranes. The current study explored the mechanisms controlling transcription of the Star gene in primary cell cultures of mouse placental trophoblast giant cells and rat ovarian granulosa cells examined throughout the course of their functional differentiation. Our findings show that the cis-elements required for Star transcription in the rodent placenta and the ovary are centered in a relatively small proximal region of the promoter. In placental trophoblast giant cells, cAMP is required for activation of the Star promoter, and the cis-elements mediating a maximal response were defined as cAMP response element 2 and GATA. EMSA studies show that placental cAMP-responsive element binding protein (CREB)-1 and activating transcription factor-2 (ATF2) bind to a −81/−78 sequence, whereas GATA-2 binds to a −66/−61 sequence. In comparison, patterns of Star regulation in the ovary suggested tissue-specific and developmental controlled modes of Star transcription. During the follicular phase, FSH/cAMP induced CREB-1 dependent activity, whereas upon luteinization STAR expression becomes cAMP and CREB independent, a functional shift conferred by FOS-related antigen-2 displacement of CREB-1 binding, and the appearance of a new requirement for CCAAT enhancer-binding protein β and steroidogenic factor 1 that bind to upstream elements (−117/−95). These findings suggest that during evolution, the promoters of the Star gene acquired nonconsensus sequence elements enabling expression of a single gene in different organs, or allowing dynamic temporal changes corresponding to progressing phases of differentiation in a given cell type. Proximal cis-elements in the steroidogenic acute regulatory protein (Star) promoter allow versatile transcriptional regulation in tissue-specific manners and differentiation-dependent patterns of STAR expression in rodent ovary and placenta.

scholarly journals The Steroidogenic Acute Regulatory Protein Homolog MLN64, a Late Endosomal Cholesterol-binding Protein

2000 ◽  
Vol 276 (6) ◽  
pp. 4261-4269 ◽  
Author(s):  
Fabien Alpy ◽  
Marie-Elisabeth Stoeckel ◽  
Andrée Dierich ◽  
Jean-Michel Escola ◽  
Corinne Wendling ◽  
...  
Keyword(s):  
Binding Protein ◽  
Regulatory Protein ◽  
Steroidogenic Acute Regulatory Protein ◽  
Steroidogenic Acute Regulatory ◽  
Cholesterol Binding
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