The CRES Gene in Reproduction

描述（由申请人提供）：我们研究的长期目标是确定克雷斯（胱抑素相关附睾精子发生）蛋白在附睾精子成熟和精子功能中的作用。我们已经确定，克雷斯定义了一个新的亚组中的家庭两个半胱氨酸蛋白酶抑制剂的半胱氨酸蛋白酶抑制剂超家族。虽然预测结构类似于原型家族二半胱氨酸蛋白酶抑制剂，我们最近证明，克雷斯不作为一个典型的半胱氨酸蛋白酶抑制剂的功能。我们确定，克雷斯不抑制半胱氨酸蛋白酶，而是丝氨酸蛋白酶激素原转化酶2（PC 2）的竞争性抑制剂（Ki = 25 nM）。由于PC 2是蛋白酶家族的一员，在激素原和前蛋白的蛋白水解成熟中具有关键作用，我们建议克雷斯可能是一种新的转化酶抑制剂，介导蛋白水解加工事件对生殖功能很重要。我的短期目标是确定克雷斯是否在体内与PC 2或其他转化酶相互作用，以及更详细地检查克雷斯作为转化酶抑制剂，并特别检查其对细胞中前蛋白加工的影响。其他短期目标是研究克雷斯在体内的生物学作用，包括其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前蛋白是如何被激活到其成熟和功能形式的，特别是在精子和附睾中，以及这些过程的调节机制。最终，这可能为男性避孕药的开发提供机制。RCDA，如果获奖，将帮助我实现我的目标。具体来说，它将释放我从部门的义务，包括大量教学医学院大体解剖，从而使我能够把我的全部注意力放在研究。此外，有了这个奖项，我将不需要在机构和部门一级的其他委员会任职。细胞生物学和生物化学系为我的研究生涯的发展提供了一个支持性的环境。在该部门是一个由NIH资助的生殖生物学家谁提供专业知识和合议，互动的工作环境大集团。此外，新购买的质谱仪将能够进行上述研究的现场蛋白质分析。简而言之，TTUHSC的环境是特殊的，将完全支持我提出的研究。

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.