MOLECULAR ANALYSIS OF THE SEA URCHIN SPERM RECEPTOR

受精是一系列精心设计的过程的结果， 精子和卵子成功的配子相互作用导致 激活卵子并启动发育途径。不成功 由于精子或卵子功能障碍， 灾难性的尽管对绑定之前的步骤有很多了解， 精卵融合，结合事件的机制和由此产生的 在卵内发生的信号转导途径一直是难以捉摸的。 海胆卵浆的鉴定与克隆 精子的膜受体现在使研究这些成为可能 问题，并确定受体如何在卵子激活时发挥作用。 该提案描述了旨在解决这一问题的实验 海胆的结构/功能问题，一个特征良好的模型 受精和早期发育系统。的一般问题 集中在受体在传递信号中的作用， 对精子结合的反应，无论是直接的还是间接的。我们的初步数据 表明该受体与卵皮质蛋白酪氨酸相互作用 激酶，并可能有助于组织肌动蛋白细胞骨架重排 发生在受精时。具体目标是：（一）确定 膜中受体的拓扑结构，以确定 结构域可能与其他卵蛋白相互作用;（ii）为了识别卵蛋白， 与受体相互作用的蛋白质;（iii）测试功能 通过注射特异性抗体， 肽;和（iv）为了启动受体的突变分析， 使用异源表达系统。这些实验将提供 为了更好地了解精子结合如何引发变化， 发生在鸡蛋里，增加了我们对基本过程的一般知识 受精对我们理解生育力非常重要 不孕

Fertilization is the result of a set of well-choreographed events between the sperm and the egg. Successful gamete interactions result in the activation of the egg and initiate developmental pathways. Unsuccessful interactions, as a result of either sperm or egg dysfunction, are disastrous. Although much is known about the steps preceding binding and sperm-egg fusion, the mechanism of the binding event and the resulting signal transduction pathways that occur within the egg have been elusive. The recent identification and cloning of the sea urchin egg plasma membrane receptor for sperm now makes it possible to investigate these questions and to determine how the receptor functions at egg activation. This proposal describes experiments designed to address this structure/function question in the sea urchin, a well-characterized model system for fertilization and early development. The general question centers on the role that the receptor plays in transducing a signal in response to sperm binding, be it direct or indirect. Our preliminary data indicate that the receptor interacts with an egg cortical protein tyrosine kinase and may serve to organize the actin cytoskeletal rearrangements that occur at fertilization. The specific aims are: (i) To define the topology of the receptor in the membrane in order to establish which domains may interact with other egg proteins; (ii) To identify egg proteins that interact with the receptor; (iii) To test the functional role(s) of the cytoplasmic domain by injection of specific antibodies and peptides; and (iv) To initiate mutational analyses of the receptor, employing a heterologous expression system. These experiments will provide for a greater understanding of how sperm binding triggers the changes that occur in the egg, adding to our general knowledge of the basic processes of fertilization so important to our understanding of fertility and infertility.