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StAR expression: Integration of Transcription with regulation via the mRNA 3'UTR

StAR 表达：通过 mRNA 3UTR 进行转录与调控的整合

基本信息

批准号：
8305619
负责人：
COLIN ROBERT JEFCOATE
金额：
$ 30.67万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-07-22 至 2013-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8305619
关键词：
3&apos Untranslated Regions Acetylation Acetylesterase Acute Address Adrenal Cortex Adrenal Glands Adrenal gland hypofunction Affect Attenuated Binding CREB1 gene Cardiovascular system Cattle Cell Line Cell Separation Cells Characteristics Cholesterol Cholesterol Monooxygenase (Side-Chain-Cleaving)Complex Corticotropin Cyclic AMP Cyclic AMP-Dependent Protein Kinases Dependence Excision Fingers Genes Genetic Transcription Genetic Translation Histone Acetylation Histones Human Hydrocortisone Laboratories Lead Ligands Lipids Mediating Mediation Mediator of activation protein Messenger RNA Metabolic syndrome Modification Mus Mutate Non-Insulin-Dependent Diabetes Mellitus Nuclear Nuclear Export Output Pathway interactions Phorbol Esters Phosphorylation Phosphotransferases Play Post-Transcriptional Regulation Post-Translational Protein Processing Pregnenolone Process Protein Kinase C Proteins RNA Polymerase II Reaction Time Regulation Research Role SF1 Site Specific qualifier value Staging Steroid biosynthesis Steroids Stimulus Stress Testing Time Tissues Transcript Transcriptional Activation Transgenes Translations Trichostatin A U-0126 Work base biological adaptation to stress butyrate response factor 1 chromatin immunoprecipitation dietary control genetic regulatory protein hypothalamic-pituitary-adrenal axis in vivo inhibitor/antagonist leptomycin B mRNA Transcript Degradation novel promoter response transcription factor

项目摘要

Cortisol synthesis in the adrenal cortex plays a central role in stress responses, in dietary control, and in cardiovascular regulation. Aberrations in this control of the hypothalamic pituitary adrenal axis play an important part in the Metabolic Syndrome that is often associated with Type 2 diabetes. ACTH stimulation of cortisol synthesis starts with the conversion of cholesterol to pregnenolone by mitochondrial cytochrome P450 11A1. Activation of this step depends on new synthesis of the steroidogenesis acute regulator (StAR) and its phosphorylation by protein kinase A (PKA). StAR deficiency causes hyperlipidemic adrenal insufficiency. This research focuses on the finding that StAR expression is stimulated in very different ways by PKA and by protein kinase C (PKC). We will show how these processes are clearly distinguished by essential contributions from, respectively, histone de-acetylatases and Erk kinase. We will characterize these processes for different contributions from nuclear factors, including the differentiation regulator, SF-1. This includes time-dependent modifications that cycle up and down during transcription (phosphorylation/de-phosphorylation and acetylation/de- acetylation). Evidence will be developed that PKA can also enhance a late stage in the PKC process, thus producing strong synergy in StAR transcription. Posttranscriptional regulation of StAR provides another point of distinction between PKA and PKC regulation. A novel regulator, the Zn finger protein, TIS11b, targets specific sequences in the extended 3'untranslated region of the 3.5 kb StAR mRNA. TIS11b is rapidly stimulated by PKA, but suppressed by PKC. We will identify specific TIS11b recognition sites at the end of the StAR 3.5 kb mRNA and show that this interaction can enhance StAR protein translation, while increasing mRNA degradation. We will test whether TIS11b is co-transcribed with StAR due to shared transcription factors, including SF-1. We will determine how these mechanisms interplay during ACTH stimulation, including in primary adrenal cell lines and in adrenals in vivo. The promoter and mRNA sequences that specify SF-1 and TIS11b interactions during StAR expression are substantially conserved from mouse to humans. We will test whether these mouse mechanisms are retained in human adrenal H295 cells. Our research shows that TIS11b interaction with StAR and predominance of an extended StAR mRNA are conserved in primary bovine adrenal cells and respond to ACTH. This work will bring together several laboratories to provide a first look at the interplay between PKA, SF-1, and TIS11b (or factors related to each), which is likely to occur in multiple steroidogenic tissues. Cortisol synthesis in the adrenal cortex plays a central role in stress responses, in dietary control, and in cardiovascular regulation. ACTH, which is elevated by stress, stimulates cortisol synthesis through enhanced conversion of cholesterol to pregnenolone. This step depends on new synthesis of the steroidogenesis acute regulator (StAR). The proposed research addresses a novel process, whereby ACTH stimulates not only transcription of StAR, but also a protein called TIS11b, which separately regulates StAR protein translation and mRNA degradation. We make a detailed analysis of regulatory processes that control StAR and TIS11b transcription in order to understand their potential coordination. TIS11b may accelerate the response time to stress, while also aiding in the removal of StAR when the ACTH stimulus is removed. TIS11b regulation is present in other tissues that make steroids (testis). Deficiency in this mRNA regulator may lead to more sluggish responses to ACTH and stress as well as abnormal cortisol output.

肾上腺皮质中皮质醇的合成在应激反应、饮食控制和心血管调节。在这种控制下丘脑-垂体-肾上腺轴的异常起着重要作用。代谢综合征的一部分，通常与2型糖尿病有关。促肾上腺皮质激素对皮质醇的刺激合成始于线粒体细胞色素P450 11A1将胆固醇转化为孕烯醇酮。这一步骤的激活依赖于类固醇合成急性调节因子(STAR)及其蛋白激酶A(PKA)的磷酸化。STAR缺乏症会导致高脂血症肾上腺功能不全。这项研究的重点是发现PKA和PKA以非常不同的方式刺激STAR表达蛋白激酶C(PKC)。我们将展示这些过程是如何通过基本贡献来明确区分的分别由组蛋白脱乙酰酶和ERK激酶组成。我们将针对不同的情况描述这些过程核因子的贡献，包括分化调节因子SF-1。这包括与时间相关的在转录过程中上下循环的修饰(磷酸化/去磷酸化和乙酰化/去磷酸化) 乙酰化)。将有证据表明，PKA还可以加强PKC进程的后期阶段，从而在STAR转录中产生很强的协同作用。 STAR的转录后调控提供了PKA和PKC调控的另一个区别。一个新的调控因子，锌指蛋白TIS11b，靶向延伸的3‘非翻译区的特定序列 3.5kb的STAR基因。TIS11b可被PKA迅速激活，但被PKC抑制。我们将确定具体的 TIS11b识别位点末端的STAR为3.5kb的mRNA，表明这种相互作用可以增强STAR 蛋白质翻译，同时增加了mRNA的降解。我们将测试TIS11b是否与STAR共转录由于共享的转录因子，包括SF-1。我们将确定这些机制如何在ACTH刺激过程中相互作用，包括在原代肾上腺细胞系中。在活体肾上腺中也是如此。调控SF-1和TIS11b相互作用的启动子和mRNA序列从老鼠到人类，STAR的表达基本上是保守的。我们将测试这些老鼠是否机制保留在人肾上腺H295细胞中。我们的研究表明，TIS11b与STAR和在原代培养的牛肾上腺细胞中，延伸的STAR基因的优势被保守，并对ACTH作出反应。这项工作将把几个实验室聚集在一起，以初步了解PKA、SF-1和 TIS11b(或与每一个相关的因子)，它可能出现在多个类固醇生成组织中。肾上腺皮质中皮质醇的合成在应激反应中起着核心作用饮食控制和心血管调节。促肾上腺皮质激素，因压力而升高，通过促进胆固醇转化为皮质醇来刺激皮质醇合成孕烯醇酮。这一步依赖于新合成的类固醇合成急性调节器(STAR)。这项拟议的研究涉及一种新的过程，即ACTH 不仅刺激STAR的转录，还刺激一种名为TIS11b的蛋白质，它分别调节STAR蛋白的翻译和mRNA的降解。我们做了一个控制STAR和TIS11b转录的调控过程的详细分析以了解它们之间的潜在协调。TIS11b可能会加速响应时间来强调，同时也有助于移除明星时，ACTH刺激是已删除。TIS11b调节在其他组织中也存在，这些组织产生类固醇(睾丸)。这种mRNA调节因子的缺失可能会导致对ACTH和压力以及皮质醇的异常输出。