The CRES Gene in Reproduction

描述(申请人提供)：我们研究的长期目标是确定Cystatin相关的附睾生精蛋白(CRES)在附睾精子成熟和精子功能中的作用。我们已经确定，CRES定义了半胱氨酸蛋白酶抑制剂超家族的两个半胱氨酸半胱氨酸蛋白酶抑制剂家族中的一个新的亚群。尽管预测在结构上类似于原型家族两个半胱氨酸氨基转移酶，我们最近证明了CRES并不是一个典型的半胱氨酸氨基转移酶。我们确定CRES不抑制半胱氨酸蛋白酶，而是丝氨酸蛋白酶原激素转换酶2(PC2)的竞争性抑制物(Ki=25 nM)。由于PC2是蛋白水解酶家族中的一员，在前激素和前蛋白的蛋白分解成熟过程中起关键作用，我们认为CRES可能是一种新的转换酶抑制剂，介导对生殖功能重要的蛋白水解性加工事件。我的短期目标是确定CRES是否在体内与PC2或其他转换酶相互作用，以及更详细地研究CRES作为转换酶抑制剂，并特别研究其对细胞内原蛋白加工的影响。其他短期目标是研究CRES在体内的生物学作用，包括它在精子顶体和受精中的功能。我的长期目标是帮助我们理解原蛋白是如何被激活成其成熟和功能形式的，特别是在精子和附睾中，以及这些过程被调控的机制。最终，这可能会提供针对男性避孕开发的机制。如果获得RCDA，将帮助我实现我的目标。具体地说，它将使我从院系的义务中解脱出来，包括在医学院大体解剖学方面的大量教学，从而使我能够将全部精力投入到研究中。此外，有了这个奖项，我将不再需要在机构和部门层面的额外委员会任职。细胞生物学和生物化学系为我的研究事业的发展提供了一个有利的环境。在该部门内，有一大群由NIH资助的生殖生物学家，他们提供专业知识和一个合作的、互动的工作环境。此外，新购买的质谱仪将使上述研究的现场蛋白质分析成为可能。简而言之，TTUHSC的环境是特殊的，将完全支持我提议的学习。

DESCRIPTION (provided by applicant): The long-term objective of our research is to determine the role of the CRES (Cystatin-Related Epididymal Spermatogenic) protein in epididymal sperm maturation and sperm function. We have established that CRES defines a new subgroup in the family two cystatins of the cystatin superfamily of cysteine protease inhibitors. Although predicted to structurally resemble the archetype family two cystatins, we have recently demonstrated that CRES does not function as a typical cystatin. We determined that CRES does not inhibit cysteine proteases but rather is a competitive inhibitor (Ki = 25 nM) of the serine protease prohormone convertase 2 (PC2). Because PC2 is a member of a family of proteases with critical roles in the proteolytic maturation of prohormones and proproteins, we propose that CRES may be a new convertase inhibitor that mediates proteolytic processing events important for reproductive function. My short-term goals are to establish whether CRES interacts with PC2 or other convertases in vivo as well as to examine CRES as a convertase inhibitor in greater detail and specifically examine its effects on proprotein processing in cells. Other short-term goals are to examine the biological roles of CRES in vivo including its function in the sperm acrosome and fertilization. My long-term goals are to contribute to our understanding of how proproteins are activated to their mature and functional forms, specifically within spermatozoa and the epididymis, and the mechanisms by which these processes are regulated. Ultimately this may provide mechanisms to target for male contraceptive development. The RCDA, if awarded, will assist me in accomplishing my goals. Specifically, it will release me from Departmental obligations including substantial teaching in medical school gross anatomy, thereby allowing me to devote my full attention to research. In addition, with this award I will not be required to serve on additional committees both at the institutional and departmental levels. The Department of Cell Biology and Biochemistry provides a supportive environment for the development of my research career. Within the department is a large group of NIH-funded reproductive biologists who provide expertise and a collegial, interactive working environment. Also, the newly purchased mass spec will enable on site protein analysis for the studies described above. In short, the environment at TTUHSC is exceptional and will fully support my proposed studies.