Isolation of congenital stationary night blindness genes

先天性静止性夜盲症基因的分离

• 批准号: 7082109
• 负责人: RONALD G GREGG
• 金额: $ 28.02万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-02-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7082109
• 关键词: antibody specificity; biophysics; cell type; chimeric proteins; congenital eye disorder; electrophysiology; expression cloning; genetically modified animals; glycosylation; immunocytochemistry; immunologic substance development /preparation; immunoprecipitation; laboratory mouse; membrane proteins; night blindness; protein localization; protein protein interaction; protein structure function; proteoglycan; proteomics; retina; retinal bipolar neuron; visual phototransduction; voltage /patch clamp; yeast two hybrid system

DESCRIPTION (provided by applicant): Under dark-adapted conditions, glutamate is released at a maximal rate at the terminals of rod and cone photoreceptors. The net result of light absorption by outer segment photopigments is to hyperpolarize the photoreceptor and to reduce the rate of glutamate release. This reduction, is detected by glutamate receptors on the second order neurons of the retina, the horizontal and bipolar cells. As ionotropic glutamate receptors are used by horizontal and hyperpolarizing bipolar cells, both of these cell types are maintained in a depolarized state in darkness and are hyperpolarized in response to light. In comparison, depolarizing bipolar cells (DBCs) incorporate a metabotropic glutamate receptor, mGluR6. As a result of an incompletely defined signal transduction cascade, DBCs are hyperpolarized in darkness and depolarize in response to light. To date, only two key proteins of this process have been identified, mGluR6 and Galpha/0, and much of the DBC signal transduction process remains to be elucidated. Nyctalopin is a newly identified protein that appears to play some key role in DBC signal transduction. Mutations in nyctalopin are known to underlie human CSNB 1 and the nob mutant mouse, and both disorders are characterized by a lack of DBC function. The overall goal of the present project is to define the functional role of nyctalopin in DBC activity. This question will be addressed in several complementary experiments. There are three specific aims; 1) Determine the cellular and subcellular location of the nyctalopin protein, 2) Determine the electrophysiological properties of DBCs from nob mice, and 3) Identify proteins that interact with nyctalopin. At the completion of this project, we expect to have a thorough understanding of the role that nyctalopin plays in DBC signal transduction, and to have identified additional proteins involved in this important process.

描述（由申请人提供）：在暗适应条件下，谷氨酸在视杆和视锥光感受器的末端以最大速率释放。外节色素吸收光的净结果是使感光细胞过度增殖并降低谷氨酸释放速率。这种减少通过视网膜的二级神经元（水平细胞和双极细胞）上的谷氨酸受体检测。由于离子型谷氨酸受体被水平和超极化双极细胞使用，这两种细胞类型在黑暗中保持去极化状态，并响应于光而超极化。相比之下，去极化双极细胞（DBCs）包含代谢型谷氨酸受体mGluR 6。作为一个不完全定义的信号转导级联反应的结果，DBCs在黑暗中是超极化的，而在对光的反应中是去极化的。到目前为止，只有两个关键蛋白的这一过程已被确定，mGluR 6和Galalpha/0，和许多的DBC信号转导过程仍有待阐明。夜来香肽是一种新发现的在DBC信号转导中起关键作用的蛋白质。已知夜盲素的突变是人类CSNB 1和nob突变小鼠的基础，并且这两种疾病的特征在于缺乏DBC功能。本项目的总体目标是确定夜盲素在DBC活动中的功能作用。这个问题将在几个补充实验中讨论。具体目标有三个：1）确定夜来香蛋白的细胞和亚细胞位置，2）确定来自nob小鼠的DBCs的电生理学特性，和3）鉴定与夜来香蛋白相互作用的蛋白质。在这个项目完成后，我们希望有一个透彻的了解，夜来香蛋白在DBC信号转导中发挥的作用，并确定了参与这一重要过程的其他蛋白质。