Molecular Genetic Analysis of det Loci of Arabidopsis thaliana

小行星9631390 本研究的主要目的是了解控制拟南芥光调控发育的信号转导途径，特别强调负调控基因DET1所定义的途径。DET1被克隆，并显示是一种新的核蛋白，似乎不直接结合DNA。将研究DET1在抑制光调节启动子表达中的确切作用机制，并鉴定和克隆DET1作用的靶点。具体而言，将确定DET1的生化功能，将鉴定与DET1功能性相互作用的蛋白质，将确定由光或其他信号引起的DET1的任何后修饰，将分离和表征下游反应基因DET3，并将对弱det1等位基因的抑制子进行遗传分析。从这些实验中获得的数据将允许在拟南芥中通过光和其他信号来控制发育和基因表达的机制模型的构建。 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，而是通过相互作用的信号组分的复杂网络整合各种输入信号的结果。所描述的实验将在拟南芥中整合遗传、分子和生物化学方法，以了解植物对光反应的机制。对模型植物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的变化作出反应。 ***

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. ***