STRUCTURAL STUDIES OF ARRESTINS

拟议研究的长期目标是了解 光传导的生化步骤，从视紫红质开始 激活，通过它的失活，和它的再生。 的 光解细菌灭活和再生重要性 视紫红质最近变得明显，因为这些 光转导过程中的生化事件导致退化 光感受器受损和视力受损。 逮捕是一个 光转导失活的重要组成部分， 有效的自身抗原 结构和功能的阐明 arrestin将大大提高我们对发病机制的理解， 与这种蛋白质功能障碍有关的疾病。 申请人建议检查 抑制蛋白和P44（抑制蛋白的剪接变体）以及它们如何 参与光传导的量子化， 周期 申请人试图理解：（1）功能和 结构域的抑制蛋白，继续他的晶体学 截断抑制蛋白的功能特性 和抑制蛋白的分子基础 （3）arrestin与 p44的电生理和生物化学方法;（4） 抑制蛋白和p44一级序列中的区域与 光解视紫红质，在生理相关的磷酸化 位点（Ser 338，Ser 343和Ser 334）;最后（5）失活 光解视紫红质和突变小鼠视觉周期的步骤 其中视紫红质激酶或抑制蛋白基因被破坏， 定向诱变

The long-term objective of the proposed studies is to understand the biochemical steps in phototransduction, leading from rhodopsin activation, through its inactivation, and to its regeneration. The importance of inactivation and regeneration of photolyzed rhodopsin has become apparent recently, as malfunctions of these biochemical events during phototransduction lead to degeneration of photoreceptors and impairment of vision. Arrestin is an important component of inactivation of phototransduction and a potent auto-antigen. Elucidation of the structure and function of arrestin will greatly enhance our understanding of the pathogenesis of disease involving dysfunction of this protein. The applicant proposes to examine the structural properties of arrestin and P44 (a splice variant of arrestin) and how they participate in the quanching of phototransduction and in the visual cycle. The applicant seeks to understand: (1) the functional and structural domains of arrestin, continuing his crystallographic approaches; (2) the functional properties of truncated arrestin found in Oguchi Disease, and the molecular basis of arrestin heterogeneity; (3) the functional differences between arrestin and p44 using electrophysiological and biochemical methods; (4) which regions in the primary sequence of arrestin and p44 interact with photolyzed rhodopsin, phosphorylated at physiologically relevant sites (Ser338, Ser343, and Ser334); and finally (5) inactivation of photolyzed rhodopsin and steps in the visual cycle of mutant mice in which the rhodopsin kinase or arrestin genes were disrupted by targeted mutagenesis.