PLASMA MEMBRANE CHANGES IN FERTILIZATION

这些研究集中在以前的结构和功能， 在海胆卵表面鉴定出350 kDa的糖蛋白， 介导精子的结合。 因为这个结合事件是一个先决条件 从长远来看，这一信息可能对施肥有价值， 开发新的方法来提高或防止受精， 高等生物包括人类两个主要问题 受体将被处理。 第一个问题涉及其模式， 定位和生物合成。 为了阐明 受体与S.紫孢菌卵， 将应用若干分析和生物化学技术。这些 生物化学研究将通过体内研究补充， 生物合成的受体在海星卵母细胞，以确定是否 全长海胆受体可以被合成，共合成和后合成。 修饰，并路由到这些细胞的细胞表面 功能性卵母细胞。 第二个问题涉及 精子与受体结合的机制。 结构和 已知受体的三个结构元件的功能 参与精子结合的研究。 关于其中两个 元件、多肽结构域、缺失和突变分析将被 执行，以定义所需的每个的最小大小和顺序， 精子结合 此外，HSP 110同源性的意义， 将研究受体在结合精子中的功能， 特别是关于大鼠精子中的一种蛋白质， 与HSP 70发生免疫交叉反应。 将确定是否 受体的第三个结构元件，硫酸化的O-连接的 寡糖链，与两个多肽结构域竞争 结合到精子上，或者与精子上的不同结合位点相互作用。 精子 对精子特异性控制的全面认识 绑定需要与原始和完整的结构进行比较 另一种海胆的受体。 这将是 在L. pictus是另一种海胆， 与S.紫色的

These studies focus on the structure and function of a previously identified 350kDa glycoprotein on the surface of the sea urchin egg that mediates binding of sperm. Since this binding event is a pre-requisite to fertilization, this information in the long term may be of value in the development of new methods to enhance or prevent fertilization in higher organisms, including humans. Two major questions about the receptor will be addressed. The first question pertains to its mode of localization and biosynthesis. To elucidate the molecular basis for association of the receptor with the cell surface of S. purpuratus eggs, several analytical and biochemical techniques will be applied. These biochemical studies will be complemented by in vivo studies on the biosynthesis of the receptor in starfish oocytes to determine if the full length sea urchin receptor can be synthesized, co- and post- translationally modified, and routed to the cell surface of these oocytes in a functional form. The second question pertains to the mechanism of sperm binding to the receptor. The structure and the function of three structural elements of the receptor known to be involved in sperm binding will be studied. With respect to two of the element, polypeptide domains, deletion and mutational analysis will be performed to define the minimum size and sequence of each required for sperm binding. Also, the significance of the hsp110 homology of the receptor with respect to its function in binding sperm will be studied, particularly with respect to a protein in rat sperm that is believed to be immunologically cross-reactive with hsp70. It will be determined if the third structural element of the receptor, the sulfated O-linked oligosaccharide chains, compete with the two polypeptide domains for binding to sperm, or interact with a different binding site on the sperm. A full understanding of the control of specificity of sperm binding requires a comparison with the primary and complete structure of the receptor from another species of sea urchin. This will be carried out in L. pictus, a sea urchin of another genus that does not cross fertilize with S. purpuratus.