MEMBRANE EVENTS--FOLLOW HORMONE BINDING TO L H RECEPTOR

在人类中，黄体生成素 (LH) 和人绒毛膜 促性腺激素 (hCG) 调节孕激素的分泌 月经周期和早期的黄体 怀孕。 该提案将加深对这些问题的理解 促性腺激素通过添加到我们的 有关激素的身体事件的知识 与细胞表面受体和其他膜的相互作用 组件。 人类和绵羊黄体细胞之间的相似之处 使母羊成为研究物理的优秀模型系统 伴随 hCG 或 LH 与 LH 受体结合的事件。 的 结合亲和力、内化率和细胞反应 短暂和长期激素暴露的特征 绵羊黄体细胞上的 hCG 和 LH。 该提案的目标是 检查 LH 受体聚集、分布和分子水平 发情黄体期绵羊黄体细胞的运动 循环并探索 LH 受体的物理行为如何 受其与 oLH 或 hCG 相互作用的影响。 一、程度 将在活细胞上测量 LH 受体聚集的情况 使用荧光能量结合激素之前和之后 LH 受体旋转运动的传输和测量。 将使用计算机增强技术检查受体分布 弱光显微镜和电子显微镜。 二、作用 hCG 和 oLH 的 α 和 β 亚基以及 与这些分子相关的碳水化合物在修饰中 激素占据的 LH 受体的横向和旋转运动 将被确定。 异源二聚体的作用 hCG 和 oLH 亚基以及去糖基化 hCG 的分布 并检查 LH 受体的运动。 三、我们的 初步研究表明 hCG-LH 受体外侧 运动受到细胞骨架成分的限制。 我们会 表征细胞骨架与 LH 受体的相互作用 激素结合之前和之后。 最后，我们将尝试 确定其他黄体细胞膜蛋白是否 与激素占据的 LH 受体相互作用。 这样的 相互作用可能会显着限制横向运动 LH 受体。 科罗拉多州立大学有一个不寻常的 生殖生理学和生殖生理学专业知识的融合 用于膜蛋白动力学研究的仪器设施。 这种情况为我们提供了一个独特的机会来获得新的和 有关发生的膜事件的详细信息 激素与 LH 受体结合后。

In humans, luteinizing hormone (LH) and human chorionic gonadotropin (hCG) regulate the secretion of progesterone from the corpus luteum during the menstrual cycle and early pregnancy. This proposal will enhance understanding of how these gonadotrophs regulate luteal cell function by adding to our knowledge of the physical events surrounding hormone interactions with cell surface receptors and other membrane components. Similarities between human and sheep luteal cells make the ewe an excellent model system for studying physical events accompanying hCG or LH binding to the LH receptor. The binding affinity, rate of internalization, and cellular response to brief and prolonged hormone exposure have been characterized for hCG and LH on ovine luteal cells. The goal of this proposal is to examine LH receptor aggregation, distribution, and molecular motions on ovine luteal cells during the luteal phase of the estrous cycle and to explore how the physical behavior of the LH receptor is affected by its interactions with oLH or hCG. First, the extent of LH receptor aggregation will be measured on viable cells before and after hormone binding using fluorescence energy transfer and measurements of LH receptor rotational motions. Receptor distribution will be examined using computer-enhanced low light microscopy and electron microscopy. Second, the role of the alpha and beta subunits of hCG and oLH and the carbohydrates associated with these molecules in modifying lateral and rotational motions of hormone-occupied LH receptors will be determined. The effects of heterodimers formed from hCG and oLH subunits and deglycosylated hCG on the distribution and motion of LH receptor will be examined. Third, our preliminary studies indicate that hCG-LH receptor lateral motions are constrained by cytoskeletal components. We will characterize cytoskeletal interactions with the LH receptor before and after hormone binding. Finally, we will attempt to determine whether other luteal cell membrane proteins are interacting with the hormone-occupied LH receptor. Such interactions may significantly restrict the lateral movement of the LH receptor. Colorado State University has an unusual confluence of expertise in reproductive physiology and of instrumental facilities for studies of membrane protein dynamics. This situation affords us a unique opportunity to obtain new and detailed information regarding membrane events which occur following hormone binding to the LH receptor.