CHEMICAL & GENETIC APPROACHES TO DEFINE CELL ACTIVATION

描述：两条研究路线，一条涉及引发 高等植物细胞分裂和其他涉及发病机制， 这种植物的原核病原体，已经发现了一个单一的异种 生长因子参与了这两个事件的控制。 结构分析 的生长因子导致了一个机械模型的激活 活动 这种模式提供了宝贵的见解，并使发展 可逆和不可逆的农杆菌特异性抑制剂 根瘤菌毒力基因表达 通过利用抑制剂和 病原体分子遗传学，特异性受体蛋白，Xpb 蛋白质，已被鉴定。 这些实验将（i）分离出 并表征Xpa蛋白，（ii）表征其机制， 生长因子-Xpb复合物激活双组分磷酸化 级联控制毒力基因表达，（iii）选择和表征 改变对生长因子的敏感性的突变体，和（iv）分析 参与信号转导的自身激酶的特定突变体。 成功完成拟议的实验将大大扩大 我们对原核生物酚类感知的理解，至少提供了 如果不是真核生物感知的蛋白质， 第一次深入了解双组分调节系统如何识别和 信号输出。 相关的生长因子在以下方面发挥关键作用： 动物和植物系统以及研究这些机制的机会 在发病机制方面的因素是独特的。 获得的知识将 提供了对真核细胞分裂控制的深入了解， 定义发病机制中涉及的策略。 两个实验室联合 他们的专业知识，以利用化学，生物化学和分子 遗传学的方法，为有效执行这些 实验

DESCRIPTION: Two lines of study, one dealing with factors that initiate higher plant cell division and the other involving pathogenesis in a prokaryotic pathogen of this plant, have intersected at a single xenognostic growth factor involved in the control of both events. Structural analysis of the growth factor has led to a mechanistic model for the activation event. This model has provided valuable insight and enabled the development of both reversible and irreversible specific inhibitors of Agrobacterium tumefaciens virulence gene expression. By exploiting the inhibitors and the molecular genetics of the pathogen, specific receptor proteins, Xpb proteins, have been identified. The outlined experiments will (i) isolate and characterize the Xpa proteins, (ii) characterize the mechanism by which the growth factor-Xpb complex activates a two-component phosphorylation cascade controlling virulence gene expression, (iii) select and characterize mutants that alter sensitivity to the growth factor, and (iv) analyze specific mutants of the autokinase involved in the signal transduction. Successful completion of the proposed experiments will significantly expand our understanding of phenolic perception of prokaryotes, providing at least a model, if not the proteins for eukaryotic perception, as well as provide the first insight into how two-component regulatory systems recognize and transduce signal output. Related growth factors serve critical roles in animal and plant systems and the opportunity to study the mechanism of these factors in the context of pathogenesis is unique. The knowledge gained will provide insight into the control of eukaryotic cell division as well as define strategies involved in pathogenesis. Two laboratories have combined their expertise in order to exploit the chemical, biochemical and molecular genetic approaches necessary for the efficient execution of these experiments.