Heterotrimeric G Protein Signaling in Arabidopsis

拟南芥中的异三聚体 G 蛋白信号转导

• 批准号: 6942956
• 负责人: ALAN M. JONES
• 金额: $ 28.56万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6942956
• 关键词: Arabidopsis; G protein; biological signal transduction; cell proliferation; confocal scanning microscopy; gene expression; guanine nucleotide binding protein; hormone receptor; indoleacetate; phytohormones; plant growth /development; plant growth regulators; polymerase chain reaction; protein protein interaction; protein structure function; receptor coupling; root; seeds

DESCRIPTION (provided by applicant): In most metazoans, different heterotrimeric G protein complexes couple many different upstream signals to different downstream effectors such as adenyl cyclase, ion channels, and phospholipases. However, in Arabidopsis, there is only a single canonical heterotrimeric G protein complex that nonetheless controls different plant responses. We do not know how this is accomplished nor do we know what receptors activate this G protein complex. Recent technical advances from my group using both gain- and loss-of-function approaches to understand the function of Arabidopsis G protein subunits will enable us to determine the molecular role of this G protein complex in various signaling pathways. There are three focus areas for this project: auxin control of root development, hypocotyl development; and multi-signal control of seed germination. Specifically, we will: 1. determine auxin responsiveness of G protein mutants and overexpressors and examine the signal cross-talk controlling seed germination, 2. identify and characterize genetic and physical interactors of Galpha and Gbeta using extragenic suppressor screens including activation mutagenesis and using cytosolic protein-protein interaction assays, and 3. test putative functions of a small set of candidate GPCRs using reverse genetic approaches. In summary, the goal is to test the hypothesis that auxin utilizes heterotrimeric G proteins in signal transduction. This work also addresses a longstanding problem on the mechanism of signal cross-talk. Because, the single Arabidopsis heterotrimeric G protein appears to be central to multiple signal pathways, genetic studies using Arabidopsis may reveal the core mechanism of signal integration, which is likely to be shared universally.

描述(由申请人提供)：在大多数后生动物中，不同 异三聚体G蛋白复合体将许多不同的上游信号偶联到 不同的下游效应因子，如腺苷环化酶、离子通道和 磷脂酶。然而，在拟南芥中，只有一个典型的 控制不同植物的异三聚体G蛋白复合体 回应。我们不知道这是如何实现的，也不知道是什么 受体激活这种G蛋白复合体。我的最新技术进步 小组使用增益和损失函数的方法来理解 拟南芥G蛋白亚基的功能将使我们能够确定 这种G蛋白复合体在各种信号通路中的分子作用。那里 是该项目的三个重点领域：根发育的生长素控制， 下胚轴发育；种子萌发的多信号调控。 具体地说，我们将：1.确定G蛋白突变体的生长素反应性 和过表达因子，并检测信号串扰控制种子 萌发，2.确定和表征遗传和物理交互作用 Galpha和Gbeta使用包括激活在内的基因外抑制物筛选 诱变和利用胞浆蛋白-蛋白相互作用分析，以及3.测试 基于反向遗传的一小部分候选GPCR的推测功能 接近了。总而言之，我们的目标是检验生长素利用 异三聚体G蛋白在信号转导中的作用这项工作还解决了一个 关于信号串扰机制的长期问题。因为，单曲 拟南芥异源三聚体G蛋白似乎是多种信号的中心 利用拟南芥的途径、遗传学研究可能揭示 信号集成，这很可能是普遍共享的。