CA2+ - Mediated Signal Transduction in Plants

CA2 - 植物介导的信号转导

• 批准号: 9408101
• 负责人: Jeffrey Harper
• 金额: $ 27万
• 依托单位: The Scripps Research Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-01 至 1998-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9408101&HistoricalAwards=false
• 关键词: CA2+; Mediated; Signal; Transduction; Plants

Harper 9408108 The long range goal of this research is to understand the role of Ca2+ Dependent Protein Kinases(CDPKs)in plant growth and development. CDPKs are a novel family of protein kinases which are defined by a unique structural arrangement: Within a single polypeptide, a kinase domain is fused to a C-terminal calmodulin-like regulatory domain. The regulatory domain contains four Ca2+-binding EF-hands, which makes CDPKs a primary target (decoder) of Ca2+ signals. Understanding the process by which CDPKs decode and transduce a Ca2+ signal is the primary focus of the proposed research. The first specific aim addresses the question of how Ca2+ activates a CDPK? The second specific aim complements the first by investigating the mechanisms of autoinhibition and Ca2+ activation in the holo-enzyme. The third specific aim is to develop a tool which will permit the in vivo activity of CDPKs to be monitored using fluorescence ratio imaging on live cells. Finally, the fourth specific aim is to identify endogenous substrates for a specific CDPK isoform. Since there appear to be many CDPK isoforms, this research assumes that each may have a different substrate specificity, and that each may have evolved to decode a different Ca2+ signal. The short-term objective of this combined research is to propose a potential function for one specific CDPK, isoform AK1 from Arabidopsis. %%% In plants, calcium signals are involved in many aspects of growth and development, including regulation of water use, activation of plant pathogen defenses, and the ability to respond to gravity. The long range goal of the proposed research is to understand how calcium ions are used to communicate information within a cell. This research is being conducted with a model plant system, Arabidopsis, and will contribute to our basic knowledge of cellular function. It is anticipated that this research will be useful in exploring new approaches to improved agricultural crops and practices. The focus of the proposed research is on the structure and function of a family of novel protein kinases, called CDPKs. Protein kinases regulate many cellular functions by modifying key enzymes through phosphorylation. CDPKs, unlike any other protein kinase, are directly activated by calcium, making them primary targets of calcium signals. Nevertheless, it is not known what cellular functions are controlled by these kinases. ***

Harper 9408108这项研究的远距离目标是了解Ca2+依赖性蛋白激酶（CDPK）在植物生长和发育中的作用。 CDPK是一个新型的蛋白质激酶家族，由独特的结构排列定义：在单个多肽中，激酶结构域融合到C端钙调蛋白样调节域。调节域包含四个Ca2+结合的EF手，这使CDPK成为Ca2+信号的主要目标（解码器）。了解CDPK解码和转导Ca2+信号的过程是拟议研究的主要重点。第一个特定的目的解决了CA2+如何激活CDPK的问题？第二个特定目的通过研究全酶中自抑制和Ca2+激活的机制来补充第一个目标。第三个具体目的是开发一种工具，该工具将使用活细胞上的荧光比成像对CDPK的体内活性进行监测。最后，第四个特定目的是鉴定特定CDPK同工型的内源性底物。由于似乎有许多CDPK同工型，因此该研究假设每个CDPK同工型都可能具有不同的底物特异性，并且每个底物的特异性都可能发展为解码不同的Ca2+信号。这项合并研究的短期目标是提出一个特定CDPK的潜在功能，即来自拟南芥的同工型AK1。 在植物中，钙信号在生长和发育的许多方面都涉及钙信号，包括调节用水，植物病原体防御的激活以及对重力反应的能力。拟议研究的远距离目标是了解如何使用钙离子在细胞中传达信息。 这项研究是通过模型植物系统（拟南芥）进行的，将有助于我们对细胞功能的基本知识。可以预料，这项研究将有助于探索改善农作物和实践的新方法。拟议的研究的重点是一种称为CDPK的新型蛋白激酶家族的结构和功能。 蛋白激酶通过通过磷酸化修饰键酶来调节许多细胞功能。与任何其他蛋白激酶不同，CDPK被钙直接激活，使其成为钙信号的主要靶标。然而，尚不知道这些激酶控制了哪些细胞功能。 ***