Function of a voltage-sensitive phosphatase in the regulation of sperm-egg fusion

电压敏感磷酸酶在精卵融合调节中的作用

• 批准号: 8009338
• 负责人: LAURINDA A. JAFFE
• 金额: $ 22.1万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-03 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8009338
• 关键词: Animals; Biology; Embryonic Development; Ensure; Experimental Models; Fertilization; Future; Head; Lipids; Membrane; Membrane Potentials; Methods; Molecular; Mutate; Phosphatidylinositols; Phosphoric Monoester Hydrolases; Physiological; Prevention; Process; Proteins; Rana; Regulation; Reproductive Medicine; Role; Sperm Head; Sperm Motility; Sperm Tail; Tail; Testing; Transgenic Organisms; Xenopus; base; biological systems; egg; insight; prevent; public health relevance; research study; response; sensor; sperm cell; voltage; voltage clamp

DESCRIPTION (provided by applicant): This project will investigate the molecular mechanisms that ensure that each egg is fertilized by only one sperm, thus allowing normal embryonic development to occur. In many animal species, one essential component of polyspermy prevention is an electrical depolarization of the egg membrane in response to fusion of the first sperm, which prevents the fusion of additional sperm. The sensor that detects the voltage change in the egg is known to be located in the sperm, but has not been identified on a molecular level. The proposed studies will investigate this question, focusing on a recently discovered voltage-activated phosphatidylinositol lipid phosphatase that is expressed in sperm. A close correlation between the voltage that activates the phosphatase and the voltage that inhibits sperm-egg fusion supports this hypothesis. Specific aim one will investigate the localization of the voltage-sensitive phosphatase (VSP) in the sperm membrane. Localization in the head region, where sperm-egg fusion occurs, would support a role for the VSP in the regulation of this process. Alternatively, localization in the tail region would support its role in the regulation of sperm motility. Specific aim two will investigate the function of the VSP, using a transgenic frog whose sperm express a point-mutated form of the protein in which the phosphatase activates at a more negative voltage. The direction of these functional experiments will be determined by the results of aim one. If the VSP is localized in the sperm head, transgenic sperm will be applied to voltage-clamped eggs to test whether the presence of the modified VSP shifts the voltage that inhibits sperm-egg fusion. Alternatively, if the VSP is localized in the sperm tail, the effect of the modified VSP on sperm motility will be investigated. By taking advantage of a unique biological system in which sperm-egg fusion is voltage dependent, these studies will provide insights into the possible function of phosphatidylinositol lipids in regulating the fusion process, and will test the role of a voltage-sensitive phosphatase in this and other physiological regulatory mechanisms in sperm. The findings will contribute to understanding of the biology of fertilization, and will provide a basis for future advances in reproductive medicine. PUBLIC HEALTH RELEVANCE: This project will investigate the molecular mechanisms that ensure that each egg is fertilized by only one sperm, thus allowing normal embryonic development to occur. The findings will contribute to understanding of the biology of fertilization, and will provide a basis for future advances in reproductive medicine.

描述（由申请人提供）：该项目将调查确保每个卵仅被一个精子施肥的分子机制，从而使正常的胚胎发育发生。在许多动物物种中，预防多植物的一个必不可少的组成部分是响应第一精子的融合而导致卵膜的电去极化，这阻止了其他精子的融合。已知检测到鸡蛋电压变化的传感器位于精子中，但尚未在分子水平上鉴定。拟议的研究将研究这个问题，重点是最近发现的电压激活的磷脂酰肌醇脂质脂质磷酸酶，该磷酸酶在精子中表达。激活磷酸酶的电压与抑制精子 - 蛋白融合的电压之间的密切相关性支持了这一假设。特定目标将研究精子膜中电压敏感磷酸酶（VSP）的定位。精子融合发生的头部区域中的定位将支持VSP在调节该过程中的作用。另外，尾部区域的定位将支持其在调节精子运动中的作用。具体目标两个将使用一种转基因青蛙来研究VSP的功能，其精子表达蛋白质的点突变形式，其中磷酸酶在更负电压下激活。这些功能实验的方向将取决于AIM ONE的结果。如果VSP位于精子头中，则将转基因精子应用于电压夹鸡蛋，以测试修饰VSP的存在是否会迁移抑制精子蛋白融合的电压。或者，如果VSP位于精子尾部，则将研究修饰的VSP对精子运动的影响。通过利用一种独特的生物学系统，精子融合取决于电压，这些研究将提供有关磷脂酰肌醇脂质在调节融合过程中的可能功能的见解，并将测试电压敏感的磷酸酶在该和其他物理学调节机制中在精子中的作用。这些发现将有助于理解受精的生物学，并为生殖医学的未来进步提供基础。 公共卫生相关性：该项目将调查确保每个卵仅被一个精子施肥的分子机制，从而使正常的胚胎发育发生。这些发现将有助于理解受精的生物学，并为生殖医学的未来进步提供基础。