Adenine Nucleotide Metabolism and Signaling in Mammalian Sperm

描述(申请人提供)：人类生殖医学的进步需要对配子蛋白的结构和功能有深入的了解。在我们最近对小鼠精子尾巴附属结构的蛋白质组学分析中，我们证明了腺嘌呤核苷酸代谢的重要酶存在于鞭毛中。除了基本的精子运动能力外，精子的关键功能，如获能和高度激活的运动能力，都有赖于腺嘌呤核苷酸作为能量来源和信号分子的使用。然而，将腺核苷酸整合到精子合成、降解和信号传递的各种途径中的机制还知之甚少。因此，该项目的长期目标是确定ATP、ADP和AMP的相对作用如何影响精子的活力。我们认为，精子鞭毛特定区域的腺苷能荷通过ATP提供的能量影响每个微环境中的运动质量和活力，并受到由ATP、ADP和AMP介导的信号的调节。为了解决这些问题，我们提出了三个具体目标。目的1是确定腺苷酸激酶是如何通过ADP相互转化为ATP+AMP来调节精子活力的。要检验的假设是，给定精子细胞内的腺苷能荷影响精子的运动质量，并构成与过度激活相关的变化的基础。目的2鉴定精子的AK蛋白及其相互作用的鞭毛蛋白。要测试的假设是精子AKs与鞭毛的其他蛋白质形成调节复合体。目的3确定腺苷酶调节精子活力的调节途径(S)。需要检验的假设是，AMP敏感酶是精子生理的重要调节因素。我们认为，腺嘌呤核苷酸具有初级能量储存(ATP)、补充能量(ADP)和能量计(AMP)等多种功能，调节精子的代谢和运动。

DESCRIPTION (provided by applicant): Advances in human reproductive medicine require in-depth knowledge about the structure and function of gamete proteins. In our recent proteomic analysis of the accessory structures of mouse sperm tails, we demonstrated that important enzymes of adenine nucleotide metabolism are present in the flagellum. Besides basal sperm motility, key sperm functions such as capacitation and hyperactivated motility rely on the use of adenine nucleotides as energy sources and as signaling molecules. However, the mechanisms integrating adenine nucleotides into various pathways of synthesis, degradation, and signaling in sperm are poorly understood. Thus, the broad, long-term goal of this project is to determine how the relative roles of ATP, ADP, and AMP influence sperm motility. We propose that the adenylate energy charge in a given region of the sperm flagellum impacts the quality and vigor of movement in each microenvironment through the energy provided by ATP and modulated by signaling mediated via ATP, ADP, and AMP. To address these issues, we propose three specific aims. Aim 1 is to determine how sperm motility is regulated by adenylate kinase through the interconversion of ADP to ATP plus AMP. The hypothesis to be tested is that the adenylate energy charge within a given sperm cell affects the quality of motility and underlies the changes associated with hyperactivation. Aim 2 is to Identify AK proteins of sperm and the flagellar proteins that interact with them. The hypothesisto be tested is that sperm AKs form regulatory complexes with other proteins of the flagellum. Aim 3 is to determine the regulatory pathway(s) utilized by AMP to modify sperm motility. The hypothesis to be tested is that AMP-sensitive enzymes are important regulators of sperm physiology. We propose that adenine nucleotides serve multiple roles as primary energy stores (ATP), supplemental energy (ADP), and energy gauge (AMP) to regulate sperm metabolism and motility.