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.

描述（由申请人提供）：光敏色素是胆蛋白光传感器，使光合生物能够适应正光和负光环境。最近在非光合细菌和真菌中发现的光敏色素证明了光敏色素的祖先及其古老的信号伙伴已经进化成为高等真核生物中发现的信号系统的组成部分。这些研究试图确定光敏色素分子如何感知四吡咯和光信号并在其内传播并转导至下游目标分子，特别解决光敏色素通过调节其内在蛋白激酶活性作为线性四吡咯（bilins）和光传感器的假设。胆素在需氧生物中普遍存在，似乎在后生动物中发挥着重要的信号作用，其水平与缺氧、异生素诱导的氧化应激和血管损伤有关。因此，这种古老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至关重要。除了开发出调节植物（我们的主要食物来源）的光反应性和生产力的新方法之外，这些研究的另一个长期成果是开发基于光敏色素的新光疗法方法。长期目标是在分子水平上定义扩展光敏色素家族每个成员的调节功能的结构基础。这种理解不仅能够设计出调节光介导的生长和农艺上重要作物品种发育的新方法，而且将促进基于光敏色素的技术的开发，以调节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）。