Molecular Genetic Analysis of det Loci of Arabidopsis thaliana

9631390了解控制拟南芥光调控发育的信号转导途径，特别是负调控基因det1所定义的途径是本研究的主要目的。DET1被克隆并被证明是一种新的核蛋白，似乎不直接与DNA结合。我们将研究DET1抑制光调控启动子表达的确切机制，并鉴定和克隆DET1的作用靶点。具体地说，将确定DET1的生化功能，鉴定与DET1功能相互作用的蛋白质，确定光或其他信号对DET1的翻译后修饰，分离并鉴定下游反应基因DET3，并对弱DET1等位基因的抑制子进行遗传分析。来自这些实验的数据将允许构建机制模型，通过光和其他信号来控制拟南芥的发育和基因表达。光信号是许多发育过程的诱导和调节所必需的。遗传分析表明，光响应不是简单的线性信号转导途径的终点，而是各种输入信号通过相互作用的信号成分组成的复杂网络整合的结果。所描述的实验将整合拟南芥的遗传、分子和生化方法，以努力了解植物对光的反应机制。在模式植物中的这种理解应该形成一个概念框架，说明所有陆地植物如何对环境变化做出反应。***

9631390 Chory An understanding of the signal transduction pathways controlling light-regulated development of Arabidopsis, with particular emphasis placed on the pathway defined by the negative regulatory gene, DET1, is the major goal of this research. DET1 was cloned and shown to be a novel nuclear protein that does not appear to bind DNA directly. The precise mechanism of action of DET1 in repressing expression of light-regulated promoters will be investigated and targets of DET1 action will be identified and cloned. Specifically, the biochemical function of DET1 will be determined, proteins that functionally interact with DET1 will be identified, any post-translationally modification of DET1 by light or other signals will be determined, DET3, a downstream response gene, will be isolated and characterized and the genetic analysis of suppressors of weak det1 alleles will be genetically analyzed. The data from these experiments will allow construction of mechanistic models for the control of development and gene expression by light and other signals in Arabidopsis thaliana. %%% Light signals are required for the induction and regulation of many developmental processes. Genetic analysis demonstrates that light responses are not simply endpoints of linear signal transduction pathways, but are the result of the integration of a variety of input signals through a complex network of interacting signaling components. The experiments described will integrate genetic, molecular and biochemical approaches in Arabidopsis in an effort to understand the mechanisms involved in plant response to light. Such an understanding in the model plant should form a conceptual framework for how all land plants respond to changes in their environment. ***