LIGHT-REGULATED RETINAL ENZYMES

光调节视网膜酶

• 批准号: 3263497
• 负责人: MARK W BITENSKY
• 金额: $ 25.39万
• 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 1994-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3263497
• 关键词: G protein; active sites; biological information processing; calcium; calcium binding protein; chemical binding; cyclic GMP; enzyme complex; enzyme mechanism; guanosine diphosphate; guanosine triphosphate; light adaptations; molecular site; phosphodiesterases; photolysis; receptor sensitivity; retina; rhodopsin; rod cell; transducin; visual phototransduction

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)识别和描述全套基因 支持和调节爆炸性灯光的产品和辅因子 光感受器磷酸二酯酶的激活。2)了解 这一通路在视觉兴奋事件中的意义及其意义 更一般的跨膜信号机制的相关性 转导。3)了解蛋白质构象动力学 为跨膜信号转导提供必要的分子基础。 光激活PDE基因同源性的遗传基础研究 激素反应性腺苷环化酶；从而评估假设的作用 外显子洗牌在基因进化和基因结构中的作用。 具体目标：1)确定符合以下条件的生化种类和过程 支持光感受器PDE的光激活。2)描述 光感受器Ca~(2+)转运过程及PDE介导的作用 CGMP水解，H+/Ca~(2+)交换，以及GD3和IP3等盘脂 视觉刺激的过程。3)发展全面的理论 用来解释杆电响应的模型 产生它的生化和离子过程。4)研究序列和 光诱导的大分子构象变化和亚基的性质 使用生化和生物物理技术的相互作用。5)屏蔽人 与视紫红质有共同外显子的基因的染色体特异库； 翻译并鉴定可能的受体基因产物。 与健康相关：拟议的研究涉及以下基本问题 对内分泌学的意义，对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。 研究方法：建议的研究采用分析的方法。 生物化学，酶学，中子散射，X射线结晶学， 膜生物物理学、电生理学、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。