Regulation of C. elegans Sperm Differentiation

描述（由申请人提供）：本研究的长期目标是了解细胞外信号如何触发细胞分化为极化的运动状态。尽管细胞运动性是正常生物过程如形态发生和伤口愈合所必需的，但运动性也有助于癌症转移。因此，重要的是要严格调节运动的获得。C.线虫精子为研究这种调节提供了模型系统。像其他迁移细胞一样，这些精子通过爬行运动，它们的成熟-称为精子激活-涉及从对称的，不动的精子细胞转化为能够定向运动的高度极化的运动精子。虽然遗传学研究表明，精子激活受到男性和两性人之间不同的控制，并且已经确定了各种化合物可以在体外激活精子，但尚未确定体内激活触发因素。该建议旨在测试这样一种触发因素可能涉及蛋白水解的假设。我们的初步研究已经确定了一种蛋白酶抑制剂，SWM-1，和丝氨酸蛋白酶，TRY-5，这似乎是拮抗作用，以调节男性精子激活。为了扩展这些观察，我们的具体目标是（1）确定在何种情况下try-5功能是精子激活所必需的，以及其活性在不同组织中是如何协调的;（2）确定SWM-1/TRY-5是否可以作为蛋白酶抑制剂系统在体外测定中调节精子激活，并测试try-5依赖性体内切割的候选靶点;和（3）鉴定促进SWM-1下游精子活化的其它因子。这些研究将提供深入了解两个广泛重要的生物学现象：细胞运动和蛋白酶介导的信号调节。此外，由于蛋白酶是癌症和其他疾病的重要治疗靶点，因此这项工作可能适用于开发新型抑制剂。公共卫生相关性：获得极化的、迁移的细胞形态对于发育和伤口愈合的正常过程是至关重要的，并且还有助于癌细胞向转移的异常转变。C.线虫精子分化提供了一个模型系统，用于研究触发细胞向迁移形态转变的信号。我们使用C。elegans研究一种由蛋白酶介导的信号，蛋白酶是一种重要的酶家族，存在于所有动物和人类中。

DESCRIPTION (provided by applicant): The long-term goal of this research is to understand how extracellular signals trigger cells to differentiate into a polarized, motile state. Whereas cellular motility is required for normal biological processes such as morphogenesis and wound healing, motility also contributes to cancer metastasis. Therefore it is important that the acquisition of motility be tightly regulated. The differentiation of C. elegans sperm provides a model system for studying this regulation. Like other migratory cells, these sperm move by crawling, and their maturation - termed sperm activation -- involves a transformation from a symmetrical, immotile spermatid to a highly polarized, motile spermatozoon capable of directional motility. While genetic studies have shown that sperm activation is subject to controls that differ between males and hermaphrodites, and a variety of compounds have been identified that can activate sperm in vitro, no in vivo activation trigger has been identified. This proposal is designed to test the hypothesis that one such trigger may involve proteolysis. Our preliminary studies have identified a protease inhibitor, SWM-1, and serine protease, TRY-5, that appear to function antagonistically to regulate sperm activation in males. To extend these observations, our specific aims are to (1) determine in which contexts try-5 function is required for sperm activation and how its activity is coordinated among different tissues; (2) determine whether SWM-1/TRY-5 can function as a protease-inhibitor system to regulate sperm activation in in vitro assays, and test candidate targets for try-5-dependent cleavage in vivo; and (3) identify additional factors that promote sperm activation downstream of swm-1. These studies will provide insight into two widely important biological phenomena: the regulation of cellular motility and protease-mediated signaling. Furthermore, since proteases are important therapeutic targets for cancer and other diseases, this work may be applicable to the development of novel inhibitors. PUBLIC HEALTH RELEVANCE: The acquisition of a polarized, migratory cellular morphology is crucial for the normal processes of development and wound healing, and also contributes to the abnormal transition to metastasis in cancer cells. C. elegans sperm differentiation provides a model system for studying the signals that trigger the transition of cells to a migratory morphology. We are using C. elegans to study one such signal that is mediated by proteases, an important family of enzymes that is present in all animals and in humans.