BIOCHEMISTRY OF THE RETINA AND PIGMENT EPITHELIUM

视网膜和色素上皮的生物化学

• 批准号: 6518290
• 负责人: JOHN C SAARI
• 金额: $ 42.73万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-04-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6518290
• 关键词: NAD(H) phosphate; all trans retinol; amacrine cells; animal tissue; biochemistry; electrophysiology; enzyme complex; enzyme structure; enzyme substrate; high performance liquid chromatography; laboratory mouse; nucleic acid probes; nutrition related tag; protein structure function; retinal pigment epithelium; retinaldehyde; retinoate; retinoid binding proteins; tissue /cell culture; visual photoreceptor; visual phototransduction; vitamin metabolism

DESCRIPTION (Verbatim from applicant's abstract): Light activates the visual pigments in photoreceptor cells by converting the chromophore, 11-cis-retinal, to all-trans-retinal (bleaching). The visual pigment is regenerated in adjacent retinal pigment epithelial (RPE) cells where all-trans-retinal is converted to 11-cis-retinal in a series of chemical reactions. The reactions in the two cells are coupled into the visual cycle by intercellular diffusion of the retinoids. At any given physiologic level of illumination, a steady state is established in which the bleach rate is equal to the regeneration rate. The reactions, enzymes and processes of the visual cycle are as important to vision as those of phototransduction; however, they remain poorly characterized and present models of the cycle do not even include several important components. The long-range goal of this research is to use techniques of biochemistry, molecular biology and cell biology to provide new molecular information about the visual cycle. During the proposed project period, we shall: (1) Examine visual cycle function in mice with a targeted disruption of the CRALBP gene. Preliminary results suggest that these animals regenerate 11-cis-retinal very slowly, relative to a control. Thus, the phenotype of the CRALBP-/-mouse appears to resemble that of humans with a form of congenital stationary night blindness. (2) Explore mechanisms that could account for the apparent modulation of the rate of all-trans-retinal reduction, the rate-limiting step of the mouse visual cycle. One likely possibility, which will be tested, is that production of NADPH determined the rate of reduction of all-trans-retinal. (3) Employ HPLC retinoid analysis to determine whether the rate-determining step of the mouse visual cycle changes as the fractional bleach increases. In addition, the phenotype of mice bearing a targeted disruption of the gene encoding cellular retinal-binding protein (CRBP) will be examined. (4) Determine the subcellular localization in RPE of enzymes and proteins associated with visual cycle activity and examine the mechanism of retinoid secretion from cultured RPE cells. The proposed studies will provide information necessary for an understanding of visual cycle function and will provide a new animal model for human retinal disease (the CRALBLP-/- mouse).

描述（来自申请人摘要的逐字逐句）：光激活视觉 通过将发色团，11-顺式-视黄醛， 到全反式视网膜（漂白）。视色素在邻近的 视网膜色素上皮（RPE）细胞，其中全反式视网膜被转化为 11-顺式-视黄醛在一系列化学反应中。两人的反应 细胞通过细胞间的扩散被耦合到视觉周期中， 类维生素A。在任何给定的生理照明水平下， 建立其中漂白速率等于再生速率的系统。的 视觉循环的反应、酶和过程对视觉同样重要， 与光转导的那些一样;然而，它们仍然不太被表征， 目前的循环模型甚至不包括几个重要的组成部分。 这项研究的长期目标是利用生物化学技术， 分子生物学和细胞生物学提供新的分子信息， 视觉循环。 在建议的项目期间，我们将：（1）检查视觉循环功能 在CRALBP基因被定向破坏的小鼠中。初步结果 这表明，这些动物再生11-顺式-视网膜非常缓慢，相对于 控制因此，CRALBP-/-小鼠的表型似乎类似于CRALBP-/-小鼠的表型。 患有先天性静止性夜盲症的人类。(2)探索 机制，可以解释的速度明显调制 全反式视网膜减少，小鼠视觉周期的限速步骤。 一个可能的可能性，这将是测试，是生产的NADPH 测定全反式视黄醇的减少率。(3)采用HPLC类维生素A 分析以确定鼠标视觉的速率确定步骤是否 循环随着部分漂白的增加而改变。此外， 携带编码细胞的基因的靶向破坏的小鼠 将检查视黄醇结合蛋白（CRBP）。(4)确定亚细胞 与视觉周期相关的酶和蛋白质在RPE中的定位 活性，并检测培养的RPE分泌维甲酸的机制 细胞 拟议的研究将提供必要的信息，以了解 视觉周期功能，并将提供一个新的动物模型，人类视网膜 疾病（CRALBLP-/-小鼠）。