Protein Kinase C Gamma in the Lens

晶状体中的蛋白激酶 C 伽玛

• 批准号: 7382335
• 负责人: DOLORES Jean TAKEMOTO
• 金额: $ 2.7万
• 依托单位: KANSAS STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7382335
• 关键词: 1,2-diacylglycerol; Address; Brain; Cataract; Caveolins; Cell membrane; Cells; Connexin 43; Connexins; Development; Diabetes Mellitus; Diglycerides; Docking; Dyes; Enzymes; Epithelial Cells; Gap Junctions; Growth; Growth Factor; Hydrogen Peroxide; Insulin-Like Growth Factor I; Ischemia; Knock-out; Lead; Membrane; Membrane Lipids; Membrane Microdomains; Modeling; Mus; Oxidative Stress; Peptides; Prevention; Process; Protein Isoforms; Proteins; Rattus; Research Personnel; Retinal; Role; Signal Transduction; Site; Streptozocin; Stress; Testing; biological adaptation to stress; caveolin 1; design; lens; lens gap junction; mouse model; prevent; programs; protein kinase C gamma; relating to nervous system; response; retinal damage; retinal ischemia; sensor

In the lens gap junction activity is decreased by activation of the lens/neural-specific PKC gamma isoform. This enzyme is activated by growth and stress factors such as IGF-1, LEDGF, and by hydrogen peroxide. Upon activation PKC gamma translocates to membranes and phosphorylates lens connexin proteins such as Cx43. This causes inhibiton of gap junctions through disassembly of gap junction plaques into caveolin-l-containing plasma membrane lipid rafts. This PKC gamma function could protect the lens from oxidative stress through disassembly of gap junctions and prevention of the passage of damaging signals to neighboring cells, a process which can occur during ischemia. Our hypothesis is that PKC gamma serves as a stress sensor in the lens. This isoform is more sensitive to oxidative and activation signals such as diacylglycerol, than other classical PKC isoforms. Thus, when present in cells it is the major PKC sensor of stress. The PKC gamma knock-out model is not able to decrease gap junctions in response to hydrogen peroxide and this model may be more sensitive to oxidative stress damage which causes cataracts. The specific aims, designed to test the role of PKC gamma as a lens stress sensor are: 1. Identify structural features of the lens PKC gamma which allow this to be a stress sensor. This will include identification of the docking protein and recognition sites which maintain this enzyme in an inactive state. 2. Determine how PKC gamma interacts with Cx43 and caveolin-1 in lipid rafts by identification of interaction sites on the proteins. 3. Determine the mechanism by which whole lens responds to hydrogen peroxide stress through activation of PKC gamma and decreased function of Cx46 and Cx50.4. Determine how the PKC gamma control of gap junctions is compromised during diabetes in the streptozotocin rat. 5. Assess the PKC gamma knock-out mouse model to determine the role of PKC gamma in the whole lens stress response. Peptides will be designed which can remove the PKC gamma from the 14-3-3 docking protein and activate PKC gamma in lens. This should cause disassembly of gap junctions and help to prevent damage from oxidative stress. These peptides could also be useful to prevent damage to retina from ischemia.

在透镜中，间隙连接活性通过透镜/神经特异性PKC γ亚型的激活而降低。 这种酶被生长和应激因子如IGF-1、LEDGF和过氧化氢激活。 激活后，PKC γ易位至膜并磷酸化透镜连接蛋白， Cx43这导致缝隙连接通过缝隙连接斑块的分解而形成， 含有小窝蛋白-L的质膜脂筏。这种PKC γ功能可以保护透镜免受 通过间隙连接的分解和防止破坏性信号的传递， 邻近的细胞，这是一个在局部缺血期间可能发生的过程。我们的假设是PKC γ作为 所述透镜中的应力传感器。这种亚型对氧化和活化信号更敏感， 二酰基甘油，而不是其他经典的PKC亚型。因此，当存在于细胞中时，它是PKC的主要传感器。 应力PKC γ基因敲除模型不能减少缝隙连接对氢的反应 过氧化物，并且该模型可能对引起白内障的氧化应激损伤更敏感。的 具体的目的，旨在测试PKC γ作为透镜应力传感器的作用是：1。识别结构 透镜PKC gamma的特征，其允许这是应力传感器。这将包括确定 对接蛋白和识别位点，其维持该酶处于失活状态。2.确定PKC如何 γ通过鉴定蛋白质上的相互作用位点与脂筏中的Cx43和小窝蛋白-1相互作用。3. 确定整个透镜通过激活 PKC γ和Cx46和Cx 50的功能降低。确定PKC γ如何控制间隙 在链脲佐菌素大鼠的糖尿病期间，连接受损。5.评估PKC γ敲除 小鼠模型，以确定PKC γ在整个透镜应激反应中的作用。肽将 设计了一种可以从14-3-3对接蛋白中去除PKC γ并激活PKC γ的方法， 透镜。这应该会导致间隙连接的分解，并有助于防止氧化应激造成的损害。 这些肽也可用于预防缺血对视网膜的损伤。