PSF Regulates the Porcine P450scc IFGRE

PSF 监管猪 P450scc IFGRE

• 批准号: 6875318
• 负责人: Randall J Urban
• 金额: $ 27.18万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-12-01 至 2009-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6875318
• 关键词: DNA binding protein; RNA binding protein; antisense nucleic acid; cell line; cholesterol; chromatin immunoprecipitation; cytochrome P450; enzyme activity; enzyme mechanism; enzyme structure; gene expression; genetic regulatory element; granulosa cell; insulinlike growth factor; mitogen activated protein kinase; molecular site; oligonucleotides; phosphorylation; protein kinase C; protein protein interaction; recombinant proteins; steroid biosynthesis; threonine; transcription factor

DESCRIPTION (provided by applicant): Our work focuses on IGF-I regulation of gene expression for P-450 cholesterol side-chain cleavage (P450scc), the rate-limiting enzyme in the steroidogenic pathway. We identified an IGF-I response element (IGFRE) of the porcine P450scc gene that binds Sp1(stimulator) and polypyrimidine tract-binding protein (PTB)-associated splicing factor (PSF, repressor). In this proposal we will investigate mechanisms of PSF regulation of IGFRE activity. Studies will be conducted in a stable porcine granulosa cell line, the JC-410 cells. We hypothesize that PSF repression of the IGFRE involves a mechanism that prevents IGF-I-stimulated phosphorylation of Sp1. In specific aim 1 we will determine IGF-I-mediated Sp1 phosphorylation sites having already demonstrated that IGF-I stimulates phosphorylation of threonine 739 on Sp1, a known erk 1/2 phosphorylation site. In specific aim 2 we will investigate the erk 1/2 signaling pathway as at least a partial mechanism for regulating IGF-I stimulation of the IGFRE through Sp1 phosphorylation. Finally, we will investigate protein kinase C (PKC) iota as a modulator of PSF-Sp1 interactions regulating the IGFRE (specific aim 3). We will determine the fundamental mechanisms whereby IGF-I controls P450scc gene expression through interactions of Sp1, PSF, and PKC iota. This knowledge will increase our understanding and provide the basic background for novel concepts on hormonal control of ovarian steroidogenesis.

描述（由申请人提供）：我们的工作着重于P-450胆固醇侧链裂解（P450SCC）的IGF-I基因表达调节，这是类固醇生成途径中的限速酶。我们鉴定了结合SP1（刺激剂）和多吡啶胺裂纹结合蛋白（PTB）相关的剪接因子（PSF，抑制剂）的猪P450SCC基因的IGF-I反应元件（IGFRE）。 在此提案中，我们将研究iGfre活性调节PSF调节的机制。研究将在稳定的猪颗粒细胞系（JC-410细胞）中进行。我们假设PSF抑制Igfre涉及一种防止IGF-I刺激SP1的磷酸化的机制。在特定目标1中，我们将确定IGF-1介导的SP1磷酸化位点已经证明IGF-I刺激SP1上苏氨酸739的磷酸化，SP1是已知的ERK 1/2磷酸化位点。在特定的目标2中，我们将研究ERK 1/2信号通路，至少是通过SP1磷酸化来调节IGFRE的部分机制。最后，我们将研究蛋白激酶C（PKC）IOTA作为调节IGFRE的PSF-SP1相互作用的调节剂（特定目标3）。 我们将通过SP1，PSF和PKC IOTA的相互作用来确定IGF-I通过SP1，PSF和PKC IOTA的相互作用来控制P450SCC基因表达的基本机制。这些知识将提高我们的理解，并为卵巢类固醇生成的激素控制新颖概念提供基本背景。