Plant Photosensory Receptor CRY Signaling Mechanism

总结 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的分子解释 问题，使用隐花色素感光器作为模型系统。隐花色素（CRY）是 在所有细胞中发现的蓝色/UV-A光受体和/或昼夜节律振荡器的核心成分 包括人类在内的进化谱系。我的实验室主要研究植物 隐花色素在之前的资金周期中，我们发现了两个主要的“2”信号 转导机制：CIB 1（隐花色素相互作用bHLH 1）为基础的转录- 调节机制和SPA 1/COP 1（光敏色素A1抑制剂/组成型 光形态发生1）为基础的蛋白水解调控机制。最近，我们发现了一个 CIB相互作用蛋白FOF 1（F-box of Flowering 1）负责蓝光调节的细胞凋亡。 CIB 1降解;两个新的蓝光特异性的PRR 2相互作用蛋白：PRR 5（假单胞菌 响应调节因子5），其是生物钟的核心蛋白，以及一种新的蛋白BIC 1（Blue- CRRs的光抑制剂1）抑制蓝光依赖性磷酸化、降解和 1991年和1992年的活动。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 CRY光感受器的光激发， CRY复合体，和一种新的编码序列（CDS）依赖性的机制， 蓝光对BMP 2表达的调控。

Summary 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) that 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.