MEMBRANE EVENTS FOLLOWING HORMONE BINDING TO LH RECEPTOR

激素与 LH 受体结合后的膜事件

• 批准号: 2198794
• 负责人: Deborah A Roess
• 金额: $ 10.02万
• 依托单位: COLORADO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1996-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2198794
• 关键词: G protein; Leydig cells; MHC class I antigen; cell membrane; chorionic gonadotropin; cyclic AMP; cytoskeletal proteins; fertility; fluorescence polarization; glycosylation; hormone receptor; hormone regulation /control mechanism; laboratory rat; luteinizing hormone; membrane activity; membrane proteins; membrane structure; progesterone; protein structure function; radioimmunoassay; receptor binding; receptor expression; single cell analysis; testosterone; tissue /cell culture; western blottings

Luteinizing hormone/chorionic gonadotropic (LH/CG) receptors on the corpus luteum and on Leydig cells bind luteinizing hormone (LH) and human chorionic gonadotropin (hCG) to regulate steroid synthesis and secretion from these glands. The goal of this project is to better understand the role of LH/CG receptor structure in regulation of fertility and how gonadotropins may modulate events in LH/CG receptor function including G-protein interactions, receptor internalization and CAMP activation. First, we will examine whether gonadotropin binding causes size changes in functional LH receptor complexes using two laser optical methods for measuring protein molecular motions, polarized fluorescence depletion and fluorescence photobleaching recovery. Single-cell fluorescence energy transfer measurements will be used to assess receptor-receptor aggregation on the membrane. Second, the effect of LH/CG structure on receptor molecular motions will be assessed using tissue-cultured cells bearing LH/CG receptors with C-terminal truncations. Ligand binding to these truncated receptors results in increased CAMP activation and more rapid internalization, perhaps due to more rapid LH/CG receptor lateral diffusion in the plasma membrane. Third, the effects of deglycosylated hCG and native hCG on LH/CG receptor motions will be evaluated on rat Leydig cells and on MA-10 cells. Binding of deglycosylated hCG to the LH/CG receptor slows receptor down-regulation and internalization, effects that may result from slower receptor lateral diffusion and fewer receptor interactions with proteins needed for internalization. Finally, the association of non-receptor proteins including G-protein subunits and MHC class I antigen with LH/CG receptors will be explored by a photoproximity labeling technique that permits identification and isolation of proteins physically proximal to a known membrane site. Colorado State University has an unusual confluence of expertise is reproductive physiology and instrumental facilities for membrane structural studies. This situation provides us a unique opportunity to study both LH receptor organization and how this organization modulates receptor function.

黄体生成激素/绒毛膜促性腺激素（LH/CG）受体 黄体和Leydig细胞上结合黄体生成激素（LH）和人类 绒毛膜促性腺激素（HCG）调节类固醇的合成和分泌 从这些腺体。 该项目的目的是更好地了解 LH/CG受体结构在调节生育能力中的作用以及如何 促性腺激素可能调节LH/CG受体功能中的事件，包括 G蛋白相互作用，受体内在化和cAMP激活。 首先，我们将检查促性腺激素结合是否会导致大小变化 在功能性LH受体复合物中使用两种激光光学方法 测量蛋白质分子运动，极化荧光耗竭和 荧光光漂白恢复。 单细胞荧光能 转移测量将用于评估受体受体 膜上的聚集。 其次，LH/CG结构对 受体分子运动将使用组织培养细胞评估 带有C末端截断的LH/CG受体。 配体结合 这些截断的受体导致cAMP激活增加，更多 快速内在化，也许是由于LH/CG受体横向更快而引起的 质膜的扩散。 第三，脱糖基的影响 LH/CG受体运动的HCG和天然HCG将在大鼠上评估 Leydig细胞和MA-10细胞。 脱胶糖基化HCG的结合与 LH/CG受体减慢受体的下调和内在化， 受体横向扩散速度较慢而较少的影响 受体相互作用与内在化所需的蛋白质相互作用。 最后， 包括G蛋白亚基在内的非受体蛋白的关联和 MHC I类抗原与LH/CG受体将通过A探索 允许识别和 蛋白质在物理上分离到已知的膜位点。 科罗拉多州立大学的专业知识与 膜的生殖生理和仪器设施 结构研究。 这种情况为我们提供了一个独特的机会 研究LH受体组织以及该组织如何调节 受体功能。