Protein Kinase A Anchoring in Spermatozoan Function

蛋白激酶 A 锚定精子功能

• 批准号: 6740191
• 负责人: DANIEL W CARR
• 金额: $ 27.18万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6740191
• 关键词: A kinase anchoring protein; Chlamydomonas; binding proteins; biological signal transduction; calcium ion; cyclic AMP; enzyme structure; gene targeting; genetically modified animals; laboratory mouse; muscle contraction; phosphorylation; plant proteins; protein kinase A; protein localization; protein protein interaction; protein structure function; smooth muscle; sperm; sperm motility; spermatogenesis; yeast two hybrid system

DESCRIPTION: (provided by applicant) The cAMP-dependent protein kinase (PKA) is targeted to specific subcellular compartments through its interaction with A kinase anchoring proteins (AKAPs). Membrane permeable peptides, designed to disrupt PKA/AKAP interaction, inhibit sperm motility, suggesting PKA anchoring is required for the maintenance of motility. The overall goal of this proposal is to characterize the interaction of sperm AKAPs with the type two regulatory subunit of PKA (RII) and RII-homologues, and determine how these interactions regulate spermatozoan function(s). We will focus on two sperm AKAPs. AKAP110 is a predominant sperm AKAP and the focus of our previous proposal. Radial Spoke Protein 3 (RSP3) is a newly discovered AKAP in Chlamydomonas. It is the first flagellar AKAP to be found in the axoneme. Mutation of this protein disrupts flagellar beating. We have recently identified, cloned and expressed the human homolog of this protein. Based on the location of this AKAP, we hypothesize that RSP3 regulates motility by coordinating the action of kinases and/or phosphatases in the axoneme. We have recently identified four sperm-specific human proteins, in addition to PKA, which interact with sperm AKAP110. All of these proteins have a strong sequence similarity to the AKAP docking and dimerization domains of RII. Although these sperm proteins appear to be functional homologues of RII in their ability to bind AKAPs, they do not share other functions of RII such as the ability to bind cAMP or the catalytic subunit of PKA. Two of these RII homologues appear to be part of the Rho signaling pathway. One is homologous to murine ropporin. Ropporin is found along the principal piece of the flagellum and binds to rhophilin, a target protein for Rho. A second protein, named AKAP-associated sperm protein (ASP), is 39 percent identical with ropporin. Agents that inhibit Rho signaling inhibit sperm motility. One goal of this proposal is to test the hypothesis that Rho signaling regulates sperm motility via a mechanism similar to that observed in smooth muscle and that sperm AKAPs coordinate this mechanism by acting as scaffolding molecules. Studies outlined in this proposal should facilitate the design of new and highly specific pharmacological reagents for inhibiting sperm function in vivo. Knowledge gained from these studies may also be useful for the diagnosis and treatment of patients with defects in sperm movement and fertility.

描述：（由申请人提供）cAMP依赖性蛋白激酶（PKA）是 通过与A的相互作用靶向特定的亚细胞区室 激酶锚定蛋白（AKAP）。膜渗透性肽，设计用于 破坏PKA/AKAP相互作用，抑制精子活力，提示PKA锚定 是维持运动所必需的本提案的总体目标是 是表征精子AKAP与第二类调节因子的相互作用 PKA亚基（RII）和RII同源物，并确定这些相互作用 调节精子功能。我们将重点介绍两种精子AKAP。AKAP 110是 一个主要的精子AKAP和我们以前的建议的重点。径向辐条 蛋白3（Protein 3，RSP 3）是在衣原体中新发现的一种AKAP。是第一 鞭毛AKAP被发现在轴丝。该蛋白质的突变会破坏 鞭毛跳动我们最近鉴定、克隆并表达了人类 这种蛋白质的同源物。根据AKAP的位置我们推测 RSP 3通过协调激酶的作用调节运动性和/或 轴丝中的磷酸酶。我们最近发现了四种精子特异性 人类蛋白质，除了PKA，与精子AKAP 110相互作用。所有 这些蛋白质与AKAP对接具有很强的序列相似性， RII的二聚化结构域。尽管这些精子蛋白似乎 RII的功能同源物结合AKAP的能力，它们不共享 RII的其他功能，如结合cAMP或催化cAMP的能力， PKA亚基。其中两个RII同系物似乎是Rho的一部分， 信号通路一个与鼠的ropporin同源。发现Ropporin 沿着鞭毛的主要部分，并结合到rhophilin，一个目标 蛋白质Rho第二种蛋白质，称为AKAP相关精子蛋白（ASP）， 与Ropporin有39%的相同性。抑制Rho信号传导的药剂 抑制精子活力。这个提议的一个目的是检验这个假设 Rho信号通过一种类似于 在平滑肌中观察到，精子AKAP通过以下方式协调这种机制： 作为支架分子。本建议中概述的研究应 促进新的和高度特异性的药理学试剂的设计， 在体内抑制精子功能。从这些研究中获得的知识也可能 有助于诊断和治疗精子缺陷患者 运动和生育。