Molecular Mechanisms of Hormone Regulated Gene Expression in the Pituitary

垂体激素调节基因表达的分子机制

基本信息

批准号：
8241142
负责人：
JOHN H. NILSON
金额：
$ 39.2万
依托单位：
WASHINGTON STATE UNIVERSITY
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：
2008-04-15 至 2013-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8241142
关键词：
3&apos Untranslated Regions Address Affect Alleles Binding Biological Cell Line Colon Carcinoma Complex Consensus Cues Cyclic AMP-Dependent Protein Kinases DNA-Binding Proteins Data Dependency Disease Docking Elements Endocrine System Diseases Ensure Exhibits Family Fertility Future G-Protein-Coupled Receptors Gametogenesis Gene Expression Gene Expression Profile Gene Family Gene Transfer Techniques Generic Drugs Genes Genetic Transcription Glycoproteins Gonadotrope Cell Hematologic Neoplasms Homeostasis Hormones Hypothalamic Hormones Hypothalamic structure Immediate-Early Genes In Vitro Infertility Malignant Neoplasms Mediating Messenger RNA Molecular N-terminal Orphan Pathway interactions Phosphorylation Phosphotransferases Pituitary Gland Pituitary Gonadotropins Play Post-Translational Protein Processing Promoter Regions Protein Kinase Proteins RNA-Binding Proteins Regulation Role Route SF1 Signal Pathway Signal Transduction Site Steroid biosynthesis System Technology Testing Therapeutic Agents Transgenic Mice Transgenic Organisms Translations WNT Signaling Pathway cancer cell extracellular gonad function hypothalamic pituitary gonadal axis in vivo jun Oncogene malignant endocrine gland neoplasm member new therapeutic target novel overexpression promoter receptor receptor binding recombinase reproductive reproductive function sensor

项目摘要

DESCRIPTION (provided by applicant): This application investigates three new and discrete aspects of the GnRH transcriptional network. Aim 1 should reveal to what extent post-transcriptional and post-translational mechanisms interface with GnRH regulated transcription of Egr1. While these mechanisms have been studied for IEGs in other systems, their role in gonadotropes remains unknown. We are convinced that the combination of post-transcriptional and post-translational contributions will provide a powerful one, two punch that ensures Egr1 mRNA and EGR1 protein reach maximally effective concentrations after transcriptional stimulation by GnRH. Aim 2 draws upon steadily emerging evidence, including our own, indicating that 2-catenin may be viewed as a new member of the GnRH signaling pathway that plays an instrumental role in regulating hormone stimulated expression of Jun mRNA and possibly Atf3 and Egr1 mRNA. Almost nothing is known about the signaling pathways GnRH uses to regulate transcription of Jun. Our approach addresses the role of 2-catenin as well as major pathway components such as PKC, PKA, and PI3K. Thus, Aim 2 is comprehensive and addresses a timely and important topic. The studies in Aim 3 address another novel feature of 2-catenin, namely its role as a required co-activator for SF1, certainly in acting permissively to allow Lhb to respond to transcriptional cues that flow from GnRH through Egr1. We suspect that the role of 2-catenin is broader and will extend to the other three signature genes that depend on SF1 for their expression. While Aims 1 and 2 are heavy on molecular detail and reliant on a gonadotrope cell line, Aim 3 uses transgenic technology to determine whether the requirement for 2-catenin and SF1 occurs in vivo and within the setting of a functional HPG axis. Most importantly, the transgenic approaches described in Aim 3 provide an exciting future direction that will be used to determine whether post-transcriptional and post-translational modifications uncovered for Egr1 have a significant impact when studied in vivo and in the context of a functional HPG axis. In short, we have charted an exciting new course that will deepen our mechanistic understanding of how GnRH controls gonadotrope homeostasis when signaling through a complex transcriptional network. Project Narrative: Normal reproductive function requires precise hypothalamic-gonadal control of the pituitary gonadotropins, LH and FSH. Too much or too little of either hormone disrupts gonadal function causing a spectrum of diseases ranging from infertility to endocrine cancer. This application focuses on GnRH, the hypothalamic hormone that signals through a cascade of protein kinases to regulate transcription, translation and ultimately secretion of LH and FSH from gonadotropes. Within this context, we consider how a tiered network of primary, secondary, and tertiary genes respond to the GnRH signal as well as contributions from components that act independently of GnRH. Completing these aims will deepen our understanding of the mechanistic coordination of gonadotrope gene expression required for maintaining reproductive homeostasis within the hypothalamic-pituitary-gonadal axis. Such an understanding is required for identifying new therapeutic targets and agents that can be used to either promote fertility or treat infertility and other endocrine disorders including hormone-dependent cancer.

描述（由申请人提供）：本申请研究了 GnRH 转录网络的三个新的和离散的方面。目标 1 应揭示转录后和翻译后机制与 GnRH 调节的 Egr1 转录相互作用的程度。虽然这些机制已在其他系统中针对 IEG 进行了研究，但它们在促性腺激素中的作用仍然未知。我们相信，转录后和翻译后贡献的结合将提供强大的一、二重打击，确保 Egr1 mRNA 和 EGR1 蛋白在 GnRH 转录刺激后达到最大有效浓度。目标 2 利用了不断出现的证据，包括我们自己的证据，表明 2-连环蛋白可能被视为 GnRH 信号通路的新成员，在调节激素刺激的 Jun mRNA 以及可能的 Atf3 和 Egr1 mRNA 的表达中发挥重要作用。关于 GnRH 用于调节 Jun 转录的信号通路几乎一无所知。我们的方法解决了 2-连环蛋白以及主要通路成分（如 PKC、PKA 和 PI3K）的作用。因此，目标 2 是全面的，并且解决了一个及时且重要的主题。 Aim 3 中的研究解决了 2-catenin 的另一个新特征，即它作为 SF1 所需的共激活剂的作用，当然可以允许 Lhb 对从 GnRH 流经 Egr1 的转录线索做出反应。我们怀疑 2-连环蛋白的作用更广泛，并将扩展到依赖 SF1 表达的其他三个特征基因。虽然目标 1 和 2 注重分子细节并依赖促性腺激素细胞系，但目标 3 使用转基因技术来确定体内和功能性 HPG 轴的设置内是否存在对 2-连环蛋白和 SF1 的需求。最重要的是，目标 3 中描述的转基因方法提供了一个令人兴奋的未来方向，该方向将用于确定 Egr1 发现的转录后和翻译后修饰在体内研究和功能性 HPG 轴背景下是否具有重大影响。简而言之，我们制定了一个令人兴奋的新课程，它将加深我们对 GnRH 在通过复杂转录网络发出信号时如何控制促性腺激素稳态的机制理解。项目叙述：正常的生殖功能需要下丘脑-性腺对垂体促性腺激素、LH 和 FSH 的精确控制。任何一种激素过多或过少都会破坏性腺功能，导致从不孕不育到内分泌癌症等一系列疾病。该应用重点关注 GnRH，这是一种下丘脑激素，通过一系列蛋白激酶发出信号来调节促性腺激素的转录、翻译和最终分泌 LH 和 FSH。在此背景下，我们考虑一级、二级和三级基因的分层网络如何响应 GnRH 信号，以及独立于 GnRH 发挥作用的成分的贡献。完成这些目标将加深我们对维持下丘脑-垂体-性腺轴内生殖稳态所需的促性腺激素基因表达的机制协调的理解。这种理解对于确定可用于促进生育或治疗不孕症和其他内分泌疾病（包括激素依赖性癌症）的新治疗靶点和药物是必需的。