Protein dynamics in sperm surface membrane domains

精子表面膜域的蛋白质动力学

• 批准号: 6756621
• 负责人: GARY R HUNNICUTT
• 金额: $ 26.57万
• 依托单位: POPULATION COUNCIL
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6756621
• 关键词: SDS polyacrylamide gel electrophoresis; Urodela; acrosome; biological signal transduction; biophysics; calcium; cellular polarity; cholesterol; crosslink; cyclic AMP; epididymis; high performance liquid chromatography; immunoprecipitation; lipid bilayer membrane; mass spectrometry; membrane permeability; membrane transport proteins; phosphomonoesterases; phosphorylation; protein binding; protein structure function; solubility; sperm; sperm capacitation; western blottings; yeast two hybrid system

DESCRIPTION: (provided by applicant) Sperm cells are exposed to many different environments in both male and female reproductive tracts. To function in disparate milieus, sperm have evolved into highly polarized, multifunctional cells whose surface is comprised of several large domains. Much of this membrane polarization occurs as sperm pass through the epididymis. For example, while in the epididymis, the plasma membrane surrounding the sperm head polarizes several proteins into either the posterior (PHD) or anterior (AHD) head domain. In many somatic cell systems, membrane polarization precedes a change in the cellular function. Thus redistribution of sperm proteins may be an important prerequisite for functional development of sperm seen in the epididymis. Likewise, maintaining a polarized membrane is critical if these functions are to continue. We are interested in understanding the molecular mechanisms that enable sperm to maintain a polarized membrane. To study this, we have focused on the transmembrane protein fertilin. Fertilin is found distributed over the whole head of testicular sperm. But on sperm that have moved through the epididymis (cauda sperm), it is only found in the PHD. We examined how fertilin is retained within the whole head domain of testicular sperm, and on just the PHD of cauda sperm. Using fluorescence redistribution after photobleaching (FRAP) analysis, we found fertilin is highly restricted from moving within the lipid bilayer of both testicular and cauda sperm, and thus does not diffuse out of these domains. However, when we examined capacitated cauda sperm or acrosome-reacted cauda sperm, fertilin was highly mobile, yet still retained within the PHD. In this proposal we have designed experiments to try answering the following: 1) What is the mechanism(s) responsible for restricting fertilin's diffusion in PHD of cauda sperm? 2) What is the signal during capacitation that causes fertilin to become mobile within the membrane? 3) Is fertilin physically modified during capacitation and/or the acrosome reaction, and if so how? We anticipate these studies will advance understanding of the sperm's cellular architecture and its relationship to cellular function. Information gained may also lead to development of novel male contraceptives and/or treatments for infertility.

描述：（由申请人提供）精子细胞暴露于许多不同的 男性和女性生殖道的环境。在功能中发挥作用 不同的环境，精子已经演变成高度极化的多功能 表面由几个大域组成的细胞。其中很多 膜极化是当精子穿过附睾时发生的。例如， 在附睾中，精子头周围的质膜 将几种蛋白质偏向后（PHD）或前（AHD） 头部域。在许多体细胞系统中，膜极化之前 细胞功能的变化。因此，精子蛋白的再分配可能是 精子的功能发展的重要先决条件 附睾。同样，如果这些膜保持两极分化至关重要 功能将继续。我们有兴趣了解分子 使精子能够维持偏振膜的机制。为了研究这一点， 我们专注于跨膜蛋白肥料。发现肥料 分布在睾丸精子的整个头上。但是关于精子的 通过附加膜（Cauda精子）移动，仅在博士学位中发现。我们 检查了如何保留在睾丸的整个头部结构域中 精子，仅在Cauda精子的博士学位上。使用荧光重新分布 光漂白（FRAP）分析后，我们发现肥料受到高度限制 从睾丸和卡达精子的脂质双层中移动，然后 因此，不会从这些域中扩散。但是，当我们检查 电容的Cauda精子或Acrosome反应的Cauda精子，肥料很高 移动设备，但仍保留在博士中。在这个建议中，我们设计了 尝试回答以下内容的实验：1）机制是什么 负责限制施肥素在Cauda精子博士学位中的扩散？ 2）什么 是导致导致肥料在内部移动的信号吗 膜？ 3）在电容和/或 ACROSOME反应，如果是的话？我们预计这些研究将进步 了解精子的细胞结构及其与 细胞功能。获得的信息也可能导致新颖的发展 男性避孕药和/或不孕治疗方法。