LIGHT REGULATED RETINAL ENZYMES AND CYCLIC NUCLEOTIDES

光调节视网膜酶和环状核苷酸

• 批准号: 3263492
• 负责人: MARK W BITENSKY
• 金额: $ 22.93万
• 依托单位: UNIVERSITY OF CALIF-LOS ALAMOS NAT LAB
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-04-01 至 1991-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3263492
• 关键词: X ray crystallography; adenylate cyclase; cell membrane; conformation; cyclic GMP; cyclic nucleoside monophosphate; gangliosides; gene expression; genetic library; genetic manipulation; guanosine triphosphate; guanylate cyclase; neutron diffraction; nuclear magnetic resonance spectroscopy; oncogenes; phosphatidylinositols; phosphodiesterases; retina; rhodopsin; visual photoreceptor; visual stimulus

Long term objectives: 1) Identify and describe the complete set of gene products and cofactors which support and regulate the explosive light activation of photoreceptor phosphodiesterase. 2) Understand the significance of this pathway for the events of visual excitation and its relevance for more general mechanisms of transmembrane signal transduction. 3) Understand the protein conformational dynamics which provide the essential molecular infrastructure of transmembrane signaling. Study the genetic basis of the homology between light activated PDE and hormone responsive adenylate cyclase; thereby evaluate the postulated role of 'exon shuffling' in gene evolution and gene structure. Specific Aims: 1) Identify the biochemical species and processes which support the light activation of photoreceptor PDE. 2) Describe photoreceptor Ca2+ transport processes and define the roles of PDE-mediated cGMP hydrolysis, H+/Ca2+ exchange, and disk lipids such as GD3 and IP3 in the process of visual excitation. 3) Develop a comprehensive theoretical model which explains the rod electrical response in terms of the biochemical and ionic processes that produce it. 4) Study the sequence and nature of light induced macromolecular conformational changes, and subunit interactions using biochemical and biophysical techniques. 5) Screen human chromosome specific libraries for genes which share exons with rhodopsin; translate and characterize the putative receptor gene products. Health relevance: The proposed studies address basic questions of significance for endocrinology, metabolic regulation of cellular processes, sensory signal transduction, neurophysiology and the evolution and expression of genes. The studies have relevance for endocrinology, ophthamology, neurology, cardiology and oncology. Methodology: The proposed studies employ the methods of analytical biochemistry, enzymology, neutron scattering, x-ray crystallography, membrane biophysics, electrophysiology, nuclear magnetic resonance spectroscopy, theoretical modeling and molecular biology including recombinant DNA and cloning techniques.

长期目标：1）识别和描述完整的基因组 支持和调节爆炸光的产物和辅因子 光感受器磷酸二酯酶的活化。 2)了解 这条通路对视觉兴奋事件的意义及其 跨膜信号更一般机制的相关性 转导 3)了解蛋白质构象动力学， 提供跨膜信号传导的基本分子基础结构。 研究光激活PDE与 激素反应性腺苷酸环化酶;从而评估假定的作用 基因进化和基因结构中的“外显子改组”。 具体目标：1）确定生物化学物种和过程， 支持光感受器PDE的光激活。 2)描述 光感受器Ca 2+转运过程和定义PDE介导的作用 cGMP水解，H+/Ca 2+交换，和磁盘脂质，如GD 3和IP 3， 视觉刺激的过程。 3)建立一个全面的理论 该模型解释了杆电响应， 生物化学和离子过程产生它。4）研究序列， 光诱导大分子构象变化的性质，以及亚基 使用生物化学和生物物理技术的相互作用。 5)筛选人 与视紫红质共享外显子的基因的染色体特异性文库; 翻译并表征推定的受体基因产物。 健康相关性：拟议的研究涉及以下基本问题： 对内分泌学、细胞过程的代谢调节 感觉信号转导，神经生理学和进化， 基因的表达。 这些研究与内分泌学有关， 眼科、神经科、心脏科和肿瘤科。 方法：拟议的研究采用分析方法， 生物化学，酶学，中子散射，x射线晶体学， 膜生物物理，电生理，核磁共振 光谱学、理论建模和分子生物学，包括 重组DNA和克隆技术。