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运动状态。虽然细胞运动是正常生物过程如形态发生和伤口愈合所必需的，但运动也有助于癌症转移。因此，严格控制运动性的获得是很重要的。秀丽隐杆线虫精子的分化为研究这一调控提供了一个模式系统。像其他迁移细胞一样，这些精子通过爬行移动，它们的成熟——称为精子激活——包括从一个对称的、不动的精子细胞到一个高度极化的、能定向运动的精子细胞的转变。虽然遗传学研究表明，精子的激活受到男性和雌雄同体之间不同的控制，并且已经确定了多种可以在体外激活精子的化合物，但尚未确定体内激活触发器。这一提议旨在验证这样的一个触发因素可能涉及蛋白质水解的假设。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，它们似乎具有拮抗作用，可以调节男性精子的激活。为了扩展这些观察，我们的具体目标是：(1)确定在哪些情况下精子激活需要try-5功能，以及它的活动如何在不同组织之间协调；(2)通过体外实验确定SWM-1/TRY-5是否可以作为蛋白酶抑制剂系统调节精子激活，并在体内测试TRY-5依赖性切割的候选靶点；(3)确定在swm-1下游促进精子活化的其他因素。这些研究将为两个广泛重要的生物学现象提供见解：细胞运动的调节和蛋白酶介导的信号传导。此外，由于蛋白酶是癌症和其他疾病的重要治疗靶点，这项工作可能适用于开发新的抑制剂。公共卫生相关性：获得极化、迁移的细胞形态对正常的发育和伤口愈合过程至关重要，也有助于癌细胞的异常转移。秀丽隐杆线虫的精子分化为研究触发细胞向迁移形态转变的信号提供了一个模型系统。我们正在用秀丽隐杆线虫来研究一种由蛋白酶介导的信号，蛋白酶是一种存在于所有动物和人类体内的重要酶家族。

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.