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: 6641159
• 负责人: ALAN M. JONES
• 金额: $ 30.06万
• 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 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6641159
• 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， 异源三聚体G蛋白复合物偶联许多不同的上游信号， 不同的下游效应物，如腺苷酸环化酶、离子通道和 磷脂酶然而，在拟南芥中， 异源三聚体G蛋白复合物，尽管如此，它控制不同植物 应答我们不知道这是如何实现的，也不知道这是什么。 受体激活这种G蛋白复合物。我的最新技术进展 使用功能获得和功能丧失方法来理解 拟南芥G蛋白亚基的功能将使我们能够确定 这种G蛋白复合物在各种信号通路中的分子作用。那里 是这个项目的三个重点领域：生长素控制根的发育， 下胚轴发育和种子萌发的多信号控制。 具体来说，我们将：1。测定G蛋白突变体的生长素反应性 并检查信号串扰控制种子 萌发，2.确定和表征遗传和物理相互作用， 使用包括激活的基因外抑制筛选的G α和G β 诱变和使用胞质蛋白质-蛋白质相互作用测定，和3.测试 使用反向遗传学的一小组候选GPCR的推定功能 接近。总之，目标是检验生长素利用 异源三聚体G蛋白在信号转导中的作用。这项工作还解决了一个 信号串扰机理的长期问题。因为，单曲 拟南芥异源三聚体G蛋白似乎是多重信号的中心 利用拟南芥进行的遗传研究可能揭示了 信号集成，这可能是普遍共享的。