Initial Events in Photoreceptor Signaling

光感受器信号转导的初始事件

• 批准号: 6680210
• 负责人: JOANNE CHORY
• 金额: $ 37万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-05-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6680210
• 关键词: angiosperms; biological signal transduction; cytoplasm; enzyme activity; genetic screening; intermolecular interaction; laboratory rabbit; mass spectrometry; microscopy; molecular cloning; mutant; nonvisual photoreceptor; phosphoproteins; phosphorylation; phosphotransferases; pigments; plant genetics; plant proteins; protein localization; protein protein interaction; protein structure function; protein transport; proteomics; two dimensional gel electrophoresis; yeast two hybrid system

DESCRIPTION (provided by applicant): Light signals are required for the induction and regulation of many developmental processes in plants. Genetic analysis demonstrates that light responses are not simply endpoints of linear signal transduction pathways, but are the result of the integration of signals from a variety of photoreceptor systems. The phytochromes are red/far-red light absorbing receptors that have been shown to be light-regulated serine/threonine kinases. The subcellular location of phytochromes is regulated by light, being cytoplasmic in the dark, and imported to discrete nuclear sites in the light. Genetic and molecular analyses have identified a number of proteins that act downstream from phytochromes, in both the cytoplasmic and nuclear compartments, however traditional genetic screens have not identified all the components of the regulatory circuitry. Moreover, many mechanistic details are simply not known. It is proposed to use molecular, biochemical and genetic strategies to identify and characterize signal transduction components that act early in phytochrome signal transduction pathways. The primary aims of these studies are (1) to determine the mechanism of cytosolic retention of phytochrome B by PKS1, a cytoplasmic phosphoprotein; (2) to identify proteins involved in phytochrome B localization to subnuclear pool; (3) to characterize new components in the PHY signaling pathways identified in genetic screens; and (4) to assess the level of protein trafficking in response to light. In summary, the proposed experiments will further our knowledge of phytochrome-mediated signal transduction pathways, and will address the mechanism by which phytochromes transmit light signals to regulate such diverse responses as changes in gene expression, cell expansion and division, and chloroplast development. The long-term objective is to completely understand the signal transduction networks that allow plants to perceive and respond to their local light environment, and to relate this to general mechanisms of signal transduction in other organisms.

描述（由申请人提供）：光信号是对植物中许多发育过程的诱导和调节所必需的。遗传分析表明，光反应不仅仅是线性信号转导途径的终点，而是来自各种光感受器系统的信号整合的结果。植物色素是红色/远红色的光吸收受体，已被证明是光调节的丝氨酸/苏氨酸激酶。植物色素的亚细胞位置受光调节，在黑暗中是细胞质的，并在光线下进口以离散的核位点。遗传和分子分析已经鉴定出许多在植物色素下游的蛋白质，无论是在细胞质和核区室中，但传统的遗传筛选尚未鉴定出调节电路的所有组成部分。此外，许多机械细节是根本不知道的。建议使用分子，生化和遗传策略来识别和表征植物色素信号转导途径早期起作用的信号转导组件。这些研究的主要目的是（1）确定PKS1（一种细胞质磷酸蛋白）对植物色素B的胞质保留机制； （2）鉴定涉及植物色素B定位到亚核池的蛋白质； （3）在遗传筛选中鉴定出的PHY信号传导途径中表征新组件； （4）评估响应光的蛋白质运输水平。总而言之，提出的实验将进一步了解我们对植物色素介导的信号转导途径的了解，并将解决植物色素传递光信号以调节基因表达，细胞扩张和分裂和叶绿体发育等多样性反应的机制。长期目标是完全了解允许植物感知并响应其局部光环境的信号转导网络，并将其与其他生物体信号转导的一般机制联系起来。