Molecular Mechanisms of Phytochrome Signaling

光敏色素信号传导的分子机制

• 批准号: 6787687
• 负责人: JOHN CLARK LAGARIAS
• 金额: $ 30.85万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-05 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6787687
• 关键词: adenosine triphosphate; bile pigments; biological signal transduction; enzyme activity; enzyme mechanism; enzyme substrate; eukaryote; fluorescence resonance energy transfer; gene mutation; molecular dynamics; nonvisual photoreceptor; phosphorylation; photobiology; prokaryote; protein kinase; protein protein interaction; protein structure function; serine threonine protein kinase; tetrapyrroles

DESCRIPTION (provided by applicant): Phytochromes are biliprotein light sensors that enable photosynthetic organisms to adapt to positive and negative light environments. The recent discovery of phytochromes in nonphotosynthetic bacteria and fungi document that phytochrome ancestors and their ancient signaling partners have evolved into components of signaling systems found in higher eukaryotes. These studies seek to define how tetrapyrrole and light signals are perceived by and propagated within the phytochrome molecule and transduced to downstream target molecules, specifically addressing the hypothesis that phytochromes function as sensors of linear tetrapyrrole (bilins) and light via regulation of their intrinsic protein kinase activities. Ubiquitous to aerobic organisms, bilins appear to play important signaling roles in metazoans, their levels being linked to anoxia, xenobiotic-induced oxidative stress and vascular damage. The mechanism of this ancient signaling pathway is therefore of fundamental importance for understanding and regulating analogous signaling systems in other eukaryotes, including humans. In addition to leading to new approaches to regulate light responsiveness and productivity of plants, our primary food source, another long term consequence of these studies is the development of phytochrome-based approaches for new light-based therapies. The long term goal is to define the structural basis for the regulatory functions of each member of the extended phytochrome family at the molecular level. This understanding will not only enable the design of new approaches for regulation of light-mediated growth and development of agronomically important crop species, but will facilitate development of phytochrome-based technologies for regulation of important biochemical processes (e.g., transcription, protein stability and/or protein localization) within living cells.

说明(申请人提供)：光敏色素是一种胆蛋白光感受器，能使光合作用的有机体适应正负光环境。最近在非光合作用细菌和真菌中发现的光敏色素证明，光敏色素的祖先和他们古老的信号伙伴已经进化成高等真核生物中发现的信号系统的组成部分。这些研究试图确定四吡咯和光信号是如何被光敏色素分子感知和在光敏色素分子内传播并被传递到下游靶分子的，特别是解决了光敏色素通过调节其固有的蛋白激酶活性作为线性四吡咯(Bilins)和光的传感器的假说。胆蛋白在有氧生物中普遍存在，在后生动物中似乎发挥着重要的信号作用，它们的水平与缺氧、外源生物诱导的氧化应激和血管损伤有关。因此，这个古老的信号通路的机制对于理解和调节包括人类在内的其他真核生物中的类似信号系统具有重要的意义。除了导致新的方法来调节植物的光响应性和生产力，我们的主要食物来源，这些研究的另一个长期结果是开发基于光敏色素的新的基于光的疗法。长期目标是在分子水平上确定扩展的光敏色素家族每个成员的调控功能的结构基础。这一认识不仅将有助于设计新的方法来调控具有重要农学意义的作物物种的光介导生长和发育，而且将促进基于光敏色素的技术的开发，以调控活细胞内的重要生化过程(例如，转录、蛋白质稳定性和/或蛋白质定位)。