Regulators of the sperm acrosome reaction

精子顶体反应的调节者

• 批准号: 6843114
• 负责人: Harvey M Florman
• 金额: $ 32.2万
• 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/6843114
• 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）：受精时的精子和鸡蛋结合是繁殖和发育的重要步骤。在包括人在内的哺乳动物中，精子必须首先与鸡蛋的Zona pellucida涂层结合，并在与鸡蛋融合之前完成ACROSOM反应。 Zona pellucida通过通过TRPC阳离子通道触发钙离子进入精子来启动Adrosom反应。然而，将钙信号融入高级反应的最终事件的下游机制知之甚少，这是我们对施肥的理解的主要差距。 我们在精子中发现了一种新型的TRPC结合蛋白Enkurin。该项目的目的是描绘恩库林在精子功能中的作用。该项目的这一阶段的工作假设是，enkurin是一种通过将调节分子绑定到TRPC通道而起作用的适配器，并且这些调节分子在开始质量体反应中起着至关重要的作用。这些假设将在实验中进行测试：（i）在enkurin上绘制TRPC通道上的相互作用位点，以及介导结合和功能活性的调节激酶； （ii）确定精子中活化调节激酶的产物； （iii）确定enkurin/激酶激活在控制邻化体反应时的下游后果； （iv）确定enkurin调节TRPC离子通道活性的机制； （v）确定转基因小鼠中恩库林作用的机理。 这些研究在两个方面都相关。首先，他们可能会提出我们对生殖过程中基本步骤的基本理解。其次，这些研究对人类不育症的治疗和新避孕药的设计可能会带来治疗后果。