REGULATION OF GNRH RECEPTOR GENE EXPRESSION

GNRH受体基因表达的调控

基本信息

批准号：
2857453
负责人：
Colin M Clay
金额：
$ 10.93万
依托单位：
COLORADO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-01-01 至 1999-12-31
项目状态：
已结题

项目摘要

Gonadotropin-releasing hormone (GnRH) is synthesized and secreted from neuroendocrine cells of the hypothalamus. Upon binding to specific receptors located on gonadotropes of the anterior pituitary, GnRH not only stimulates but is obligatory for the s synthesis and secretion of LH and, to a lesser extent, FSH. In light of the pivotal role of GnRH in controlling reproductive function of mammals much effort has been devoted toward understanding the physiological consequences of regulation of this hormone and its's cognate receptor. For example, ovulation in mammals is dependent on a transitory increase in the secretory rate of LH that, in turn, results from both an increase in GnRH secretion and an increase in pituitary concentration of GnRH receptors. Recent availability of cDNA clones encoding the GnRH receptor has permitted direct measurement of mRNA for the GnRH receptor and researchers are beginning to establish the physiological importance of transcriptional mechanisms in mediating changes in the number of GnRH receptors. However, lack of genomic clones for the GnRH receptor has precluded any analysis of molecular mechanisms underlying transcriptional regulation of the GnRH receptor gene. Herein, we report the isolation of a partial genomic clone for the murine GnRH receptor and preliminary characterization of a cell-specific promoter located int he 5' flanking region. Thus, we are poised to begin a systematic analysis of the cis-acting DNA elements and trans-acting factors responsible for cell- specific and hormonally mediated expression of the GnRH receptor gene. Our long-term goals are to define the molecular mechanisms underlying both tissue-specific and hormonally-regulated expression of the GnRH receptor gene. Accordingly, in Specific Aim 1, we will use transient expression assays in alphaT3 cells, DNA-protein binding assays, and liposome-mediated gene transfer to study the requirements for cell-specific expression of the mouse GnRH receptor gene. In Specific Aim 2, we will use site-directed mutagenesis and transient expression assays to identify regions of the mouse GnRH receptor gene promoter that confer responsiveness to GnRH, PMA or cAMP. Also, we will determine if the mouse GnRH receptor gene contains high affinity binding site(s) for estrogen receptor. In Specific Aim 3, we propose to construct transgenic mice as an ultimate test for cell-specific expression of chimeric GnRH receptor genes and to serve as an in vivo model for studying hormonal regulation of GnRH receptor gene expression. Finally, limited progress has been made in identifying cis-acting elements or trans-acting factors required for GnRH activation of gonadotropin gene expression. Thus, we propose a fourth specific aim to address the molecular requirements for GnRH stimulation of expression of the glycoprotein hormone alpha subunit gene.

促性腺激素释放激素 (GnRH) 合成并分泌下丘脑的神经内分泌细胞。绑定到特定的位于垂体前叶促性腺激素上的受体不仅是GnRH 刺激但对于 LH 的合成和分泌是必需的，在较小程度上，FSH。鉴于 GnRH 在控制哺乳动物的生殖功能已投入大量精力以了解这种调节的生理后果激素及其同源受体。例如，哺乳动物的排卵是依赖于 LH 分泌率的短暂增加，反过来，GnRH 分泌增加和垂体 GnRH 受体浓度。 cDNA 的最新可用性编码 GnRH 受体的克隆允许直接测量 mRNA 对于 GnRH 受体，研究人员正在开始建立转录机制在介导变化中的生理重要性 GnRH 受体的数量。然而，缺乏基因组克隆 GnRH 受体排除了对其潜在分子机制的任何分析 GnRH 受体基因的转录调控。在此，我们报道鼠 GnRH 受体的部分基因组克隆的分离和位于 he 5' 的细胞特异性启动子的初步表征侧翼区域。因此，我们准备开始系统分析顺式作用DNA元件和反式作用因子负责细胞- GnRH 受体基因的特异性和激素介导的表达。我们的长期目标是确定两者背后的分子机制 GnRH 受体的组织特异性和激素调节表达基因。因此，在具体目标 1 中，我们将使用瞬态表达式 alphaT3 细胞测定、DNA-蛋白质结合测定和脂质体介导的测定基因转移以研究细胞特异性表达的要求小鼠 GnRH 受体基因。在具体目标 2 中，我们将使用站点定向诱变和瞬时表达测定来鉴定区域赋予对 GnRH、PMA 反应性的小鼠 GnRH 受体基因启动子或环磷酸腺苷。此外，我们还将确定小鼠 GnRH 受体基因是否含有雌激素受体的高亲和力结合位点。在具体目标 3 中，我们提议构建转基因小鼠作为细胞特异性的最终测试嵌合 GnRH 受体基因的表达并作为体内模型用于研究 GnRH 受体基因表达的激素调节。最后，在识别顺式作用元件方面取得的进展有限或促性腺激素基因 GnRH 激活所需的反式作用因子表达。因此，我们提出第四个具体目标来解决 GnRH 刺激表达的分子要求糖蛋白激素α亚基基因。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

The tripartite basal enhancer of the gonadotropin-releasing hormone (GnRH) receptor gene promoter regulates cell-specific expression through a novel GnRH receptor activating sequence.

促性腺激素释放激素 (GnRH) 受体基因启动子的三重基础增强子通过新型 GnRH 受体激活序列调节细胞特异性表达。

DOI：
10.1210/mend.11.12.0020
发表时间：
1997
期刊：
Molecular endocrinology (Baltimore, Md.)
影响因子：
0
作者：
Duval,DL;Nelson,SE;Clay,CM
通讯作者：
Clay,CM

Responsiveness of the ovine gonadotropin-releasing hormone receptor gene to estradiol and gonadotropin-releasing hormone is not detectable in vitro but is revealed in transgenic mice.

DOI：
10.1210/endo.141.3.7391
发表时间：
2000-03
期刊：
Endocrinology
影响因子：
4.8
作者：
Dawn L. Duval;Amy R. Farris;C. C. Quirk-C.;T. Nett;Debora L. Hamernik;C. Clay
通讯作者：
Dawn L. Duval;Amy R. Farris;C. C. Quirk-C.;T. Nett;Debora L. Hamernik;C. Clay

Is gonadotrope expression of the gonadotropin releasing hormone receptor gene mediated by autocrine/paracrine stimulation of an activin response element?

促性腺激素释放激素受体基因的促性腺激素表达是由激活素反应元件的自分泌/旁分泌刺激介导的吗？