Adenine Nucleotide Metabolism and Signaling in Mammalian Sperm

描述（由申请人提供）：人类生殖医学的进展需要深入了解配子蛋白的结构和功能。在我们最近对小鼠精子尾部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，精子的关键功能，如获能和超活化运动依赖于使用腺嘌呤核苷酸作为能源和信号分子。然而，腺嘌呤核苷酸整合到精子合成、降解和信号传导的各种途径中的机制却知之甚少。因此，该项目的广泛，长期目标是确定ATP，ADP和AMP的相对作用如何影响精子活力。我们提出，在精子鞭毛的给定区域中的腺苷酸能荷通过由ATP提供的能量和由ATP、ADP和AMP介导的信号传导调制来影响每个微环境中运动的质量和活力。为了解决这些问题，我们提出了三个具体目标。目的1是确定腺苷酸激酶如何通过ADP相互转化为ATP加AMP来调节精子运动。待检验的假设是，给定精子细胞内的腺苷酸能荷影响运动性的质量，并成为与超活化相关的变化的基础。目的二是鉴定精子AK蛋白及与之相互作用的鞭毛蛋白。有待验证的假设是精子AK与鞭毛的其他蛋白质形成调节复合物。目的3是确定AMP调节精子活力的调节途径。待检验的假设是AMP敏感酶是精子生理学的重要调节剂。我们提出腺嘌呤核苷酸作为初级能量储存（ATP），补充能量（ADP）和能量计（AMP）的多重角色来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.