PYK2 function during fertilization

描述(申请人提供)：受精涉及一系列信号转导事件，这些事件有助于激活阻止多精受精，诱导细胞周期恢复，整合父本基因组，并激活卵子新陈代谢。这一过程中的关键步骤包括肌动蛋白细胞骨架的修饰，它将精子核物理地结合到卵子中，随后重组卵子皮质。该实验室的最新发现表明，细胞骨架相关的PYK2激酶在受精过程中迅速激活，功能研究表明PYK2在精子掺入和卵子激活中发挥作用。这项研究的目的是验证PYK2激酶参与精子-卵子黏附或融合触发的信号事件的假设，这些信号事件对于精子的结合和卵子细胞骨架的修饰是至关重要的。该项目将利用经济的斑马鱼受精系统，该系统为识别精子-卵子接触点的信号事件以及对PYK2激酶底物的蛋白质组学分析提供了独特的优势。第一个特异性目标是确定PYK2激酶在卵子激活中的特定功能(S)。第二个目标是识别在受精时激活PYK2的信号。第三个目标将确定PYK2磷酸化的蛋白质靶标，以便找出它控制的下游途径。这项研究的结果将提供受精时卵子细胞骨架控制的重要细节，并可能有助于解决精子-卵子识别和融合激活的信号通路问题。这些发现将对开发辅助生殖技术以提高人类生育力具有重要的应用价值。总结：这项研究将找出精子在受精过程中激活卵子的机制。将分析PYK2激酶在将精子核带入卵子中的具体作用，最终目的是提高人类体外受精的成功率。

DESCRIPTION (provided by applicant): Fertilization involves a series of signal transduction events that serve to activate the block to polyspermy, induce resumption of the cell cycle, incorporate the paternal genome, and activate egg metabolism. Key steps in this process include the actin cytoskeleton modifications that physically incorporate the sperm nucleus into the egg and subsequently reorganize the egg cortex. Recent findings by this laboratory revealed that the cytoskeleton-associated PYK2 kinase is rapidly activated during fertilization and functional studies indicate a role for PYK2 in sperm incorporation and egg activation. The objective of the proposed study is to test the hypothesis that PYK2 kinase participates in the signaling events triggered by sperm-egg adhesion or fusion that are critical for sperm incorporation and modification of the egg cytoskeleton. The project will make use of the economical zebrafish fertilization system which provides unique advantages for identification of signaling events at the point of sperm-egg contact as well as for proteomic analysis of substrates of the PYK2 kinase. The first specific aim will identify the specific function(s) of PYK2 kinase in egg activation. The second aim will identify the signals which activate PYK2 at fertilization. The third aim will identify the protein targets phosphorylated by PYK2 in order to work out the downstream pathways that it controls. The results of this study will provide important details regarding control of the egg cytoskeleton at fertilization and possibly help resolve the question of signaling pathways activated by sperm-egg recognition and fusion. These findings will have significant application to the development of techniques for assisted reproductive technologies to enhance human fertility. Lay Summary: This study will work out the mechanism by which the sperm activates the egg during fertilization. The specific role of PYK2 kinase in bringing the sperm nucleus into the egg will be analyzed with the ultimate aim of enhancing the success of human in vitro fertilization.