PLASMA MEMBRANE CHANGES IN FERTILIZATION

这些研究主要集中在先前的结构和功能上 鉴定出海胆卵表面的350 kDa糖蛋白 调节精子的结合。因为该绑定事件是一个先决条件 对于受精来说，从长远来看，这些信息可能对 促进或防止受精的新方法的发展 高等生物，包括人类。两个主要问题是关于 接收器将被寻址。第一个问题与它的模式有关 定位和生物合成。为了阐明分子基础 紫纹伊蚊卵细胞表面与受体的关系 将应用几种分析和生化技术。这些 生化研究将得到体内研究的补充 海星卵母细胞中受体的生物合成以确定是否 全长海胆受体可以合成，共和后 经过翻译修饰，并被路由到这些细胞表面 有功能的卵母细胞。第二个问题与 精子与受体结合的机制。它的结构和 已知受体的三个结构元件的功能 参与精子结合的研究将会展开。关于其中两个 元素、多肽结构域、缺失和突变分析 执行以定义以下各项所需的 精子结合。此外，hsp110同源性的意义 受体在结合精子方面的功能将被研究， 尤其是关于大鼠精子中的一种蛋白质，据信 与HSP70发生免疫交叉反应。将确定是否 受体的第三个结构元件，硫化O-连接 寡糖链，与两个多肽结构域竞争 与精子结合，或与精子上的不同结合部位相互作用 精子。对精子特异性调控的充分认识 结合需要与主要的和完整的结构进行比较 来自另一种海胆的受体。这将是 在皮卡特斯海胆中进行的，另一属的海胆不 与紫花链霉菌杂交受精。

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.