PLANT PHOTOSENSORY RECEPTOR CRY2--SIGNALING MECHANISM

感知和应对不断变化的环境的能力 太阳辐射是大多数生物的基本特征。 黄素型蓝光受体被称为隐色素是一种主要的 一组光敏感受器，介导各种蓝光 高等植物的反应。尽管最近在以下方面取得了进展 对这类感光细胞的鉴定，我们对 关于隐花色素介导的分子机制 植物对蓝光的反应非常有限。拟议的研究 是基于我们最近对 拟南芥属第二成员CRY2基因 隐花色素基因家族。Cry2的独特之处不仅仅是因为它看起来 为了调节不同于CRY1调控的蓝光反应， 还因为它自身的表达受蓝光的调节。这个 我们研究的长期目标是了解植物对 蓝光，我们将采取生物化学的组合方法， 分子生物学和遗传学来实现这一特定目标 求婚。我们建议对其生物化学特性进行表征 从同源或异源中纯化的CRY2蛋白 表达系统。我们还将确定机制(S) 负责蓝光诱导的CRY2表达的调节。 CRY2的生物学功能将通过分离和鉴定进行研究。 CRY2损伤拟南芥Cry2突变体的鉴定 用不同的遗传方法构建基因。成就 这些特定的目标将允许对 CRY2介导蓝色的分子机制 光响应，这将使我们有可能获得更多 真核生物中一个重要的信号转导过程的理解 有机体。

The ability to perceive and respond to the changing environment of solar radiation is a fundamental feature of most living organisms. Flavin-type blue light receptors known as cryptochrome is a major group of photosensory receptors which mediate various blue light responses in higher plants. Despite the recent progress made in the identification of this type of photoreceptors, our understanding with respect to the molecular mechanisms by which a cryptochrome mediates plant response to blue light is very limited. The proposed research is based on our recent isolation and characterization of the Arabidopsis gene CRY2, the second member of the Arabidopsis cryptochrome gene family. CRY2 is unique not only because it appears to mediate different blue light responses from that regulated by CRY1, but also in that its own expression is regulated by blue light. The long term goal of our study is to understand how plants respond to blue light, and we will take the combined approaches of biochemistry, molecular biology, and genetics to achieve the specific aims of this proposal. We propose to characterize the biochemical properties of the CRY2 protein purified from either homologous- or heterologous- expression systems. We will also identify the mechanism(s) responsible for the blue light-induced regulation of CRY2 expression. The biological function of CRY2 will be investigated by isolation and characterization of Arabidopsis cry2 mutants impaired in the CRY2 structure gene using different genetic methods. Accomplishment of these specific aims will allow experimental dissection of the molecular mechanisms underlying the ability of CRY2 to mediate blue light responses, and it will make it possible to gain further understanding of a vital signal transduction process in eucaryotic organisms.