REGULATION OF SPERM FUNCTION BY PROTEIN PHOSPHORYLATION

描述：（改编自申请人摘要）这是第一次 旨在评估精子生化调节的修订申请 能动性长期的目标是确定潜在的生化机制 运动的发展和调节，重点考虑 与轴丝相关的蛋白质的磷酸化。水平 磷酸化是蛋白激酶和蛋白质磷酸化之间的平衡。 磷酸酶申请人已经鉴定了一种精子特异性蛋白 磷酸酶，PP 1g 2参与调节精子运动。高 这种酶的活性导致精子活力低，而积极 活动精子表现出低酶活性。PP 1g 2的特异性抑制导致 启动不动精子的运动和刺激速度， 鞭毛跳动幅度在运动精子。遗传和生化研究 支持申请人的假设，即PP 1g 2是关键组分 调节精子磷酸化从而调节精子活力 这项特别建议的重点是研究生物化学机制 调节PP 1g 2。研究人员假设，两个精子特异性 调节蛋白P33和P72控制活性和亚细胞 PP 1g 2的定位。此外，他认为PP 1g 2的相互作用 与P33的结合受糖原合成酶激酶-3磷酸化的调节。三 具体目标是测试这些想法制定如下：（1）净化和 对抑制剂P33进行测序，并确定它如何调节PP 1g 2。(2)到 确定PP 1g 2的亚细胞靶向的分子基础， 精子鞭毛和精子头前部。(3)以确定如何 PP 1g 2及其激活酶糖原合成酶激酶-3受 精子细胞内第二信使。 阐明这种新的精子生化机制应该会导致更好的 了解雄性配子的功能，导致新的方法， 调节精子活力，并可以更好地诊断和治疗 男性因素不孕症

DESCRIPTION: (Adapted from the applicant's abstract) This is a first time revised application intended to assess biochemical regulation of sperm motility. The long-term goal is to define the biochemical mechanisms underlying development and regulation of motility with emphasis on considerations of phosphorylation of proteins associated with the axoneme. Levels of phosphorylation are a balance between the action of protein kinases and protein phosphatases. The applicant has identified a sperm-specific protein phosphatase, PP1g2 that is involved in regulation of sperm motility. High activity of this enzyme results in low sperm motility, whereas vigorously motile sperm exhibit low enzyme activity. Specific inhibition of PP1g2 leads to initiation of motility in immotile sperm and to the stimulation of velocity and flagellar beat amplitude in motile sperm. Genetic and biochemical studies support the hypothesis of the applicant that PP1g2 is a key component regulating sperm phosphorylation and, hence, motility. The focus of this particular proposal is to study the biochemical mechanisms regulating PP1g2. The investigator hypothesizes that two sperm-specific regulatory proteins, P33 and P72, control the activity and the sub cellular localization of PP1g2. Furthermore, he believes that the interaction of PP1g2 with P33 is regulated by glycogen synthase kinase-3 phosphorylation. Three Specific Aims to test these ideas are formulated as follows: (1) To purify and sequence the inhibitor P33 and to determine how it regulates PP1g2. (2) To determine the molecular basis for the sub cellular targeting of PP1g2 to the sperm flagellum and the anterior region of the sperm head. (3) To determine how PP1g2 and its activating enzyme glycogen synthase kinase-3 are regulated by sperm intracellular second messengers. Elucidation of such novel sperm biochemical mechanisms should lead to a better understanding of male gamete function, result in novel approaches for the regulation of sperm motility, and could enable better diagnosis and treatment of male factor infertility.