LH Receptor C-terminus in Receptor Desensitization

受体脱敏中的 LH 受体 C 末端

• 批准号: 6458827
• 负责人: Deborah A Roess
• 金额: $ 7.25万
• 依托单位: COLORADO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6458827
• 关键词: animal genetic material tag; cell membrane; chimeric proteins; fluorescence resonance energy transfer; gonadotropin releasing factor; growth hormone releasing hormone; hormone receptor; luteinizing hormone; protein structure function; receptor coupling; receptor sensitivity; tissue /cell culture

DESCRIPTION (provided by applicant): The desensitization of luteinizing hormone (LH) receptors, namely the appearance of a hormone-unresponsive state after hormone-induced signaling, is essential for completion of oocyte meiosis following the LH surge and for receptor internalization at other times in the ovarian cycle. Brief exposure to either LH or human chorionic gonadotropin (hCG) causes LH receptor desensitization and clustering of LH receptors in large, microscopically-visible structures. Receptors remain desensitized to hormone-triggered signaling until such time as these visible structures dissipate. The applicant hypothesizes that the C-terminus of the rat LH receptor contains information critical for desensitization of the receptor and for targeting of LH receptors to specific plasma membrane microdomains. To evaluate the role of the LH receptor C- terminus, the applicant will use chimeric receptors derived from "desensitization-resistant" gonadotropin releasing hormone (GnRH) receptors, which lack an intracellular C-terminus and which do not exhibit desensitization. The applicant will link these receptors to the LH receptor C-terminus (GnRH/cLH receptors) and determine whether the addition of this domain confers desensitization capacity on the GnRH receptor. In Specific Aim 1, the applicant will determine whether these chimeric receptors exhibit hormone-induced desensitization and, if so, how long this state, and related receptor self-association, persists. In Specific Aim 2, the applicant will assess whether hormone-treated GnRH/cLH receptors form large, visible clusters complexes like desensitized LH receptors or, if not, whether they form isolated dimers or small oligomers. In Specific Aim 3, the applicant will use single-particle tracking to determine whether desensitized GnRH/cLH and wild type LH receptors both occupy similar-sized membrane domains and whether these domain sizes change upon resensitization. These studies will draw on the experience of the Principal Investigator as well as the expertise of Dr. Colin Clay, a member of the Animal Reproduction and Biotechnology Laboratory, and of Dr. George Barisas, a biophysicist at Colorado State University. Although she will develop and utilize several state-of-the- art biophysical approaches to study G-protein receptor function, this project is, nonetheless, of somewhat limited scope and likely to be completed within two years.

描述（由申请人提供）：黄体化脱敏 激素 (LH) 受体，即出现激素无反应状态 在激素诱导的信号传导之后，对于卵母细胞减数分裂的完成至关重要 LH 激增后以及其他时间的受体内化 卵巢周期。 短暂接触 LH 或人绒毛膜促性腺激素 (hCG) 导致 LH 受体脱敏和 LH 受体聚集 大型的、显微镜下可见的结构。 受体仍然不敏感 激素触发的信号传导直到这些可见的结构出现 消散。 申请人假设大鼠 LH 的 C 末端 受体包含对受体脱敏至关重要的信息和 用于将 LH 受体靶向特定的质膜微区。 到 评估 LH 受体 C 末端的作用，申请人将使用 源自“脱敏抗性”促性腺激素的嵌合受体 释放激素 (GnRH) 受体，缺乏细胞内 C 末端， 不表现出脱敏作用。 申请人将连接这些受体 到 LH 受体 C 末端（GnRH/cLH 受体）并确定是否 添加该结构域赋予 GnRH 受体脱敏能力。 在具体目标 1 中，申请人将确定这些嵌合体是否 受体表现出激素诱导的脱敏作用，如果是这样，这种脱敏作用持续多久 状态和相关受体的自我关联持续存在。 在具体目标 2 中， 申请人将评估激素处理的 GnRH/cLH 受体是否形成 大的、可见的簇复合体，如脱敏的 LH 受体，或者，如果没有， 它们是否形成孤立的二聚体或小寡聚体。 在具体目标 3 中， 申请人将使用单粒子追踪来确定是否脱敏 GnRH/cLH 和野生型 LH 受体都占据相似大小的膜域 以及这些域的大小是否在重新敏化时发生变化。 这些研究 将借鉴首席研究员以及 科林·克莱博士 (Dr. Colin Clay) 的专业知识，他是动物生殖和 生物技术实验室和乔治巴里萨斯博士，生物物理学家 科罗拉多州立大学。 尽管她将开发和利用几种最先进的- 研究 G 蛋白受体功能的艺术生物物理方法，该项目 尽管如此，其范围有些有限，并且可能在年内完成 两年。