Role of deamidation in human beta-crystallin structure

描述（由申请人提供）：我们研究的总体目标是确定脱酰胺在透镜中的作用。在上一个融资周期，我们令人信服地证明，脱酰胺导致可溶性聚集体，不稳定？晶体蛋白，改变了相互作用？- 亚单位，并增加了？-晶体蛋白需要陪伴吗？晶体蛋白。这些结果表明，脱酰胺诱导的晶体蛋白不溶的机制，并强烈支持脱酰胺直接有助于白内障的形成。基于我们的研究结果，我们假设脱酰胺降低晶状体蛋白的稳定性，导致聚集，最终触发白内障形成。目标1中的实验将识别透镜中潜在相关的脱酰胺。接下来，我们将通过使用体内模型来确定先前确定的引起聚集或降低稳定性的脱酰胺是否直接导致白内障形成。目标2中的实验将确定脱酰胺触发聚集的机制，通过确定改变内的相互作用？- 水晶蛋白和？-监护人许多脱酰胺位点存在于？- 水晶蛋白所提出的实验是创新的，因为它们将区分功能相关的位点和那些有害的位点，使用最先进的方法直接测试脱酰胺作用在体内的作用。未来的研究将筛选防止晶体蛋白聚集的药物。公共卫生相关性：白内障是全球失明的主要原因，也是美国政府医疗保健系统的最大支出之一。我们的研究表明，透镜中主要的年龄相关修饰，脱酰胺，改变了透镜晶体蛋白的结构和功能，并可能诱导体内与白内障相关的聚集。能够防止脱酰胺诱导的透镜晶体蛋白聚集可以预防白内障并有助于预防其他聚集性疾病。

DESCRIPTION (provided by applicant): The overall goal of our research is to determine the role of deamidation in the lens. During the last funding cycle, we convincingly demonstrated that deamidation led to soluble aggregates, destabilized ?-crystallins, altered interactions between ? -subunits, and increased the ?-crystallin needed to chaperone ?-crystallins. These results suggest a mechanism for deamidation-induced insolubilization of crystallins and strongly support that deamidation contributes directly to cataract formation. Based on our findings, we hypothesize that deamidation decreases crystallin stability leading to aggregation that eventually triggers cataract formation. Experiments in Aim 1 will identify potentially relevant deamidations in the lens. Next, we will determine if deamidations previously identified to cause aggregation or decrease stability directly lead to cataract formation by using an in vivo model. Experiments in Aim 2 will determine the mechanism by which deamidation triggers aggregation, by identifying altered interactions within ? -crystallins and with the ?-chaperone. Numerous deamidation sites exist in the ? -crystallins. The proposed experiments are innovative in that they will distinguish between functionally relevant sites and those that are detrimental, using state-of-the art approaches to directly test the role of deamidation in vivo. Future studies will screen for agents that prevent crystallin aggregation. PUBLIC HEALTH RELEVANCE: Cataracts are the leading cause of blindness worldwide and one of the largest expenses to the U.S. government's health care system. Our research suggests that the major age-related modification in the lens, deamidation, alters structure and function of the lens crystallins and may induce aggregation associated with cataracts in vivo. Being able to prevent deamidation-induced aggregation of lens crystallins may prevent cataracts and help to prevent other aggregation diseases.