STEROID-INITIATED EXOCYTOSIS IN SPERM

精子中类固醇引发的胞吐作用

基本信息

批准号：
2888944
负责人：
STANLEY MEIZEL
金额：
$ 24.16万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
1997
资助国家：
美国
起止时间：
1997-07-01 至 2002-06-30
项目状态：
已结题

项目摘要

DESCRIPTION (Adapted from the Investigator's Abstract): Research in this three-times revised proposal is aimed at understanding the molecular steps involved in the initiation of the human sperm acrosome reaction. Progesterone secreted by follicular cells of the cumulus oophorus, is regarded as an in vivo acrosome reaction initiator by interacting with sperm membrane receptors to trigger an influx of Ca2+ and an efflux of Cl-. In addition, progesterone or a 3a-OH progesterone metabolite may bind or activate a unique human sperm GABAA-like receptor Cl- channel as well as bind to a receptor for a Ca2+ channel. The possibility exists that progesterone binds to one receptor/channel site and then activate the other receptor/channel by cross-talk. The application includes a series of studies concerned with the receptors, channels and ionic interactions through which progesterone initiates the human sperm acrosome reaction. The proposed specific aims will determine first whether a sperm GABAA-like receptor/Cl- channel is involved in progesterone-mediated Cl- efflux by using pharmacological agents which will determine differences between sperm and neuronal GABAA-like receptor/Cl-channels. A second aim is to determine which region of the sperm head the progesterone-mediated cytosolic Cl- efflux through the steroid receptor/Cl-channel begins during acrosome reaction. A third aim is to use available monoclonal antibodies against domains of the intracellular progesterone receptor and neuronal GABAA-like receptor/Cl- channel subunits to identify and further characterize the human sperm progesterone receptor(s). A fourth aim is to compare the effect of progesterone stereo isomers on Cl- and Ca2- flux to determine whether two separate progesterone receptors operate to elicit ion fluxes. A fifth aim is to determine whether human sperm can convert progesterone into an 3a-hydroxy metabolite known to activate neuronal GABAA-like receptor/Cl- channels and able to initiate the human acrosome reaction. A sixth aim is to determine whether Cl- efflux mediated by the GABAA-like receptor/Cl- channel controls progesterone-mediated Ca2+ influx. Finally, a seventh aim will use immunoelectron microscopy to determine the distribution of the human progesterone receptor(s) and human sperm GABAA-like receptor/Cl- channel at a high resolution level.

描述（根据调查员的摘要改编）：研究经修订的三局提案旨在了解分子步骤参与了人类精子质体反应的启动。卵形卵形细胞分泌的孕酮是卵形的，通过与精子相互作用，被视为体内Adrosom反应引发剂膜受体触发Ca2+的流入和Cl-的外排。在另外，孕酮或3A-OH孕酮代谢产物可能结合或激活独特的人类精子GABAA样受体Cl-通道以及结合Ca2+通道的受体。存在的可能性孕酮与一个受体/通道位点结合，然后激活另一个受体/通道位点通过串扰的受体/通道。该应用程序包括一系列与受体，通道和离子相互作用有关的研究孕酮通过该人类的精子属性反应引发。这提出的特定目的将首先确定精子gabaa是否样受体/Cl-通道参与孕激素介导的Cl-流出。使用将确定精子之间差异的药理剂和神经元GABAA样受体/CL通道。第二个目的是确定孕酮介导的胞质Cl-的精子头的哪个区域通过类固醇受体/CL通道的外排开始在高级杂志期间反应。第三个目的是使用可用的单克隆抗体细胞内孕酮受体和神经元GABAA样的结构域受体/Cl-通道亚基，以识别和进一步表征人精子孕酮受体。第四个目标是比较 Cl-和Ca2-通量上的孕酮立体异构体，以确定是否两个单独的孕激素受体起作用以引起离子通量。第五目标是确定人类精子是否可以转化为孕酮 3A-羟基代谢物已知会激活神经元GABAA样受体/Cl- 通道并能够启动人类的青色反应。第六个目标是确定Cl-外排是否由GABAA样受体/Cl-介导通道控制孕酮介导的Ca2+涌入。最后，第七个目标将使用免疫电子显微镜确定人孕酮受体和人类精子样受体/Cl- 高分辨率水平的通道。