Regulators of the sperm acrosome reaction

精子顶体反应的调节者

• 批准号: 7018434
• 负责人: Harvey M Florman
• 金额: $ 31.44万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7018434
• 关键词: acrosome; binding proteins; bioassay; biological models; calcium flux; egg /ovum; exocytosis; fertilization; genetic mapping; genetically modified animals; immunologic assay /test; ion channel blocker; laboratory mouse; membrane channels; molecular assembly /self assembly; phosphatidylinositol 3 kinase; protein protein interaction; protein structure function; site directed mutagenesis; sperm; western blottings

DESCRIPTION (provided by applicant): The union of sperm and egg at fertilization is an essential step in reproduction and development. In mammals, including human, sperm must first bind to the egg's zona pellucida coat and complete the acrosome reaction before fusing with the egg. The zona pellucida initiates acrosome reactions by triggering the entry of calcium ions into sperm through TRPC cation channels. However, the downstream mechanisms that couple calcium signals into the final events of the acrosome reaction are poorly understood and represent a major gap in our understanding of fertilization. We discovered a novel TRPC binding protein, enkurin, in sperm. The objective of this project is to delineate the roles of enkurin in sperm function. The working hypotheses for this stage of the project is that enkurin is an adaptor that acts by tethering regulatory molecules to the TRPC channel, and that these regulatory molecules play essential roles in the initiation of the acrosome reaction. These hypotheses will be tested in experiments that: (i) map interaction sites on enkurin for TRPC channels and a regulatory kinase that mediate binding and functional activity; (ii) identify products of the activated regulatory kinase in sperm; (iii) determine the downstream consequences of enkurin/kinase activation in control of acrosome reactions; (iv) determine, the mechanism by which enkurin regulates TRPC ion channel activity; and (v) determine the mechanism of enkurin action in transgenic mice. These studies are relevant in two regards. First, they may advance our basic understanding of an essential step in the reproductive process. Second, there may be therapeutic consequences to these studies both with regard to the treatment of human infertility and for the design of new contraceptives.

描述（由申请人提供）：受精时精子和卵子的结合是生殖和发育的重要步骤。在包括人类在内的哺乳动物中，精子必须首先与卵子的透明带外壳结合，并在与卵子融合之前完成顶体反应。透明带通过触发钙离子通过 TRPC 阳离子通道进入精子来启动顶体反应。然而，人们对将钙信号耦合到顶体反应最终事件的下游机制知之甚少，这代表了我们对受精理解的一个主要差距。 我们在精子中发现了一种新型 TRPC 结合蛋白 enkurin。该项目的目标是描述 enkurin 在精子功能中的作用。该项目此阶段的工作假设是，enkurin 是一种接头，通过将调节分子束缚到 TRPC 通道来发挥作用，并且这些调节分子在顶体反应的启动中发挥重要作用。这些假设将在以下实验中得到检验：(i) 绘制 enkurin 上 TRPC 通道和介导结合和功能活性的调节激酶的相互作用位点； (ii) 鉴定精子中激活的调节激酶的产物； (iii) 确定 enkurin/激酶激活控制顶体反应的下游后果； (iv)确定enkurin调节TRPC离子通道活性的机制； (v) 确定 enkurin 在转基因小鼠中的作用机制。 这些研究在两个方面具有相关性。首先，它们可能会增进我们对生殖过程中一个重要步骤的基本理解。其次，这些研究可能对人类不孕症的治疗和新避孕药的设计产生治疗效果。