RHODOPSIN IN STRUCTURE AND ENVIRONMENT IN VISION

视紫红质的结构和视觉环境

• 批准号: 3257661
• 负责人: ARLENE Diane ALBERT
• 金额: $ 13.35万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-05-01 至 1992-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3257661
• 关键词: G protein; adenosinetriphosphatase; binding proteins; biological signal transduction; calcium transporting ATPase; cholesterol; choline; chromatography; cow; eye regeneration; fluorescence; lipid structure; membrane lipids; membrane proteins; nuclear magnetic resonance spectroscopy; phosphodiesterases; phospholipids; phosphorylation; photolysis; protein structure; retina degeneration; retinitis pigmentosa; rhodopsin; rod cell; ultracentrifugation; vision

The rod cells of vertebrate retinas are responsible for vision at low levels of light. The visual pigment, rhodopsin, functions in the primary event in visual transduction. Absorption of light by rhodopsin leads to a hyperpolarization of the plasma membrane of the rod outer segment. Rhodopsin is found in the disk membranes of the rod outer segment. These disks are stacked and appear to differ in cholesterol content, depending upon their location in the stack. This may be related to aging of the disks. This proposal will separates disks based upon their cholesterol content and document the differences in protein and lipid composition of the separated fractions. The consequences of these compositional differences to disk membrane function will then be studied in disk membranes whose composition has been appropriately altered, mimic the above mentioned compositional differences, or in membranes in which rhodopsin has been reconstituted and whose composition has been determined by the reconstitution. The effects of cholesterol and phospholipid compositional differences on activation of PDEase, photolysis of rhodopsin and regenerability will be determined. Furthermore, since disks lipids participate in fusion events, preferentially at the end of the stack near the inner segment, the influence of the compositional differences on the ability to promote membrane fusion will be examined. And since the disk membrane lipids have been shown to be inherently unstable in the normal lamellar configuration required for disk membrane integrity (which may play a role in retinal degeneration), the effect of the compositional differences on the bilayer stability of the disk lipids will be determined. Finally, because cholesterol content is already known to be one of the compositional variables, the behavior of cholesterol in disk membranes under the influence of the defined compositional differences will be examined. This project will continue to examine an interesting co- reconstitution of a calcium pump protein with rhodopsin to delineate rhodopsin function under the influence of a naturally produced calcium gradient such as is expected in the disk membrane.

脊椎动物视网膜的杆细胞负责视力 低水平的光。 视觉色素，视紫红质，在 视觉转导的主要事件。 光吸收 视紫红质导致质膜的超极化 杆外段。 在磁盘膜中发现了视紫红质 杆外段。 这些磁盘已堆叠，似乎 胆固醇含量不同，具体取决于它们在 堆。 这可能与磁盘的衰老有关。 该提议将根据胆固醇将圆盘分开 内容并记录蛋白质和脂质的差异 分离分数的组成。 这些后果 然后，磁盘膜功能的组成差异将为 在磁盘膜上进行了研究，其成分已适当 改变，模仿上述组成差异，或 在膜的膜中，将视紫红质被重构，谁 组成是由重组决定的。 胆固醇和磷脂成分的作用 pdea​​se激活，视紫红质的光解和光解的差异 将确定可再生性。 此外，由于磁盘脂质 在结束时优先参加融合活动 堆叠在内部段附近，成分的影响 促进膜融合能力的差异将是 检查。 而且由于磁盘膜脂质已显示为 在普通层状配置中本质上不稳定 磁盘膜完整性所需（可能在 视网膜变性），组成差异的影响 将确定磁盘脂质的双层稳定性。 最后，因为胆固醇含量已经被称为 组成变量，胆固醇在磁盘中的行为 膜在定义成分的影响下 将检查差异。 该项目将继续研究一个有趣的共同 重建钙泵蛋白用Rhodopsin重构 在自然的影响下，描绘了视紫红质的功能 在磁盘膜中预期产生的钙梯度。