Plant photoreceptor CRY2 and Signaling Mechanism

描述（由申请人提供）：生物体如何对光做出反应以及感光受体如何介导光反应是生物学中的基本问题。我们的长期目标是找到这些问题的分子解释，使用隐花色素感光器作为模型系统。隐花色素（CRY）是在包括人类在内的所有进化谱系中发现的蓝色/UV-A光受体和/或昼夜节律振荡器的核心组分。我的实验室主要研究植物隐花色素。在之前的资助期间，我们发现了两种主要的BMP 2信号转导机制：基于CIB 1（隐花色素相互作用bHLH 1）的转录调节机制和基于SPA 1/COP 1（光敏色素A 1/组成型光形态发生抑制因子1）的蛋白水解调节机制。最近，我们发现了一个CIB相互作用蛋白FOF 1（开花1的F盒）负责蓝光调节的CIB 1降解;两种新的蓝光特异性CIB 2相互作用蛋白：PRR 5（伪反应调节因子5），其是生物钟的核心蛋白，以及新蛋白BIC 1（蓝光抑制剂1），其抑制蓝光依赖性的磷酸化、降解和蓝光抑制剂1和蓝光抑制剂2活性。基于这些发现和新开发的工具，我们建议研究光信号转导的三个关键问题：光化学机制的光激发的CRY光感受器，机制管理的功能和调控的CRY复合体，和一种新的编码序列（CDS）依赖的蓝光调控的CRYP 2表达的机制。

DESCRIPTION (provided by applicant): How organisms respond to light and how photosensory receptors mediate light responses are basic questions in biology. Our long-term goal is to find the molecular explanation of these questions, using the cryptochrome photoreceptor as a model system. Cryptochromes (CRY) are the blue/UV-A light receptors and/or core components of the circadian oscillator found in all evolutionary lineages including human. My laboratory focuses on the study of plant cryptochromes. In the previous funding periods, we discovered two major CRY2 signal transduction mechanisms: the CIB1 (Cryptochrome-Interacting bHLH 1)-based transcription- regulatory mechanism and SPA1/COP1 (Suppressor of Phytochrome A 1/Constitutive Photomorphogenesis 1)-based proteolysis-regulatory mechanism. More recently, we identified a CIB-interacting protein FOF1 (F-box of Flowering 1) responsible for the blue light-regulated degradation of CIB1; two new blue light-specific CRY2-interacting proteins: PRR5 (Pseudo Response Regulator 5) that is a core protein of the circadian clock, and a novel protein BIC1 (Blue- light Inhibitor of CRYs 1) tha suppresses blue light-dependent phosphorylation, degradation, and activities of CRY1 and CRY2. Based on these discoveries and newly developed tools, we propose to study three key issues of light signal transduction: the photochemical mechanism underlying photoexcitation of the CRY photoreceptor, mechanisms governing the function and regulation of the CRY complexome, and the mechanism underlying a novel coding sequence (CDS)-dependent blue light regulation of CRY2 expression.