MODIFICATION OF EGG PLASMA MEMBRANE

描述（改编自研究者摘要）：长期 该建议的目的是确定生物化学步骤， 将精卵融合的初始信号转化为各种反应 到受精。 现在已经确定卵的激活 涉及蛋白酪氨酸激酶（PTK）的作用， 调节原核迁移和融合，启动DNA合成， 分裂。 此外，最近的研究表明， 酪氨酸激酶活性在受精卵中起着独特和重要的作用。 卵在原肠胚阶段编程发育事件。 的目标 这个建议是为了确定鸡蛋中那些受调控的过程， 通过受精诱导的Fyn激酶活性的激活， 确定它们被控制的机制。 利用海胆 卵作为模型系统，PI提出Fyn激酶在下游发挥作用， 卵激活的初始信号，作用于调节一个或多个 特定的依赖于PTK的功能，可能包括原核迁移，DNA 合成和有丝分裂。 具体目标我将描述的鸡蛋亚型的 Fyn激酶，并研究其在卵子中的表达。 Fyn激酶在 卵的激活将通过显微注射实验来确定， 重组GST融合蛋白编码的独特的SH 2和SH 3结构域， Fyn N-末端作为Fyn功能的特异性抑制剂。 的假设 将测试Fyn通过RAS激活刺激DNA合成。 具体 目的二是鉴定卵子中Fyn激酶的蛋白底物。 这 将允许PI建立特定的生化途径， 对菲恩的活动做出反应 具体目标III将研究 受精时Fyn激酶活性被刺激的机制。 将特别强调其他蛋白激酶的作用 和磷酸酶调节Fyn催化活性。

DESCRIPTION (Adapted from the Investigator's Abstract): The long term objective of this proposal is to identify the biochemical steps which transduce the initial signal of sperm-egg fusion into the various responses of the egg to fertilization. It is now established that egg activation involves the action of protein tyrosine kineses (PTKs) which function to regulate pronuclear migration and fusion, initiation of DNA synthesis, and mitosis. In addition, recent studies have demonstrated that protein tyrosine kinase activity plays a unique and essential role in the fertilized egg to program developmental events at the gastrula stage. The objective of this proposal is to identify those processes in the egg that are regulated by the fertilization induced activation of Fyn kinase activity and to determine the mechanism by which they are controlled. Using the sea urchin egg as a model system, the PI proposes that Fyn kinase functions downstream of the initial signal for egg activation, acting to regulate one or more specific PTK-dependent functions which may include pronuclear migration, DNA synthesis, and mitosis. Specific aim I will characterize the egg isoform of Fyn kinase and study its expression in the egg. The role of Fyn kinase in egg activation will be determined through microinjection experiments using recombinant GST fusion proteins encoding the unique SH2 and SH3 domains of Fyn N-terminal as specific inhibitors of Fyn function. The hypothesis that Fyn stimulates DNA synthesis via RAS activation will be tested. Specific aim II will identify the protein substrates of Fyn kinase in the egg. This will allow the PI to establish the specific biochemical pathways that are activated in response to Fyn activity. Specific Aim III will study the mechanism by which Fyn kinase activity is stimulated at fertilization. Particular emphasis will be placed on the effect of other protein kinases and phosphatases in regulating Fyn catalytic activity.