Role of PID Kinase in Auxin Regulation

PID 激酶在生长素调节中的作用

• 批准号: 6868218
• 负责人: SIOUX Kay CHRISTENSEN
• 金额: $ 30.12万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6868218
• 关键词: Arabidopsis; biological signal transduction; gas chromatography mass spectrometry; gene environment interaction; genetic screening; hormone regulation /control mechanism; in situ hybridization; indoleacetate; microarray technology; molecular cloning; northern blottings; phenotype; phosphorylation; phytohormones; plant growth /development; plant proteins; polymerase chain reaction; protein degradation; protein kinase; yeast two hybrid system

The plant hormone auxin controls diverse mitogenic and morphogenic events during plant development. Auxin signal- transduction regulates endogenous patterning processes, including early steps in meristem partitioning and formation of the plant vascular system. Auxin also regulates tropic responses to external stimuli such as light and gravity. Genetic screens have identified genes involved in auxin transport, auxin regulated gene transcription, and targeted protein degradation as critical elements in auxin signaling. However, the mechanisms by which these various components interact and are coordinately regulated is not yet known. The research proposed here is based on our recent isolation and characterization of the PINOID (PID) gene of Arabidopsis, that encodes a serine-threonine protein kinase. The pleiotropic PID loss-of-function and over-expression phenotypes resemble those of known auxin signaling and transport mutants, consistent with a specific role for this protein in auxin regulation. PID is the first kinase associated with auxin specific phenotypes. Therefore, PID offers a unique and powerful tool to explore the effects of protein phosphorylation on auxin- mediated processes. Analysis of the PID sequence indicates that PID is a member of a novel class of plant serine-threonine kinases. We will utilized genetic, molecular and biochemical strategies to initiate a detailed dissection of the role of PID and its homologues in the regulation of auxin activity in Arabidopsis. The primary aims of this study are (1) to use a genetic approach to identify pathway components that function upstream or downstream of PID in auxin signaling; (2) to use two- hybrid analysis to identify proteins that interact directly with PID; (3) to determine whether other PID-like genes in Arabidopsis also regulate auxin activity; and (4) to quantitatively measure the effects of PID mis-expression on global gene expression and auxin distribution. We will use in vitro and in vivo approaches to characterize candidate interacting genes and proteins and determine the specificity of the interactions. The proposed experiments will contribute to a fundamental understanding of the mechanisms behind auxin-mediated signal-transduction. This represents the first step toward the long-term objective of elucidating how endogenous and environmental signals interact with plant hormones to elicit specific developmental responses and to relate these mechanisms to signaling processes in other eukaryotic organisms.

植物激素生长素在植物发育过程中控制着各种有丝分裂和形态发生事件。生长素信号转导调节内源模式形成过程，包括分生组织分裂和植物维管系统形成的早期步骤。生长素还调节对外界刺激的趋向性反应，如光和重力。基因筛查发现，与生长素运输、生长素调控基因转录和靶向蛋白降解有关的基因是生长素信号的关键元件。然而，这些不同成分相互作用和协调调节的机制尚不清楚。这项研究是基于我们最近分离和鉴定的拟南芥PINOID(Pid)基因，该基因编码一种丝氨酸-苏氨酸蛋白激酶。多效性的Pid功能丧失和过度表达的表型类似于已知的生长素信号和运输突变体，与该蛋白在生长素调节中的特定作用一致。Pid是第一个与生长素特定表型相关的激酶。因此，PID为研究蛋白质磷酸化对生长素介导的过程的影响提供了一个独特而有力的工具。对该序列的分析表明，该蛋白是一类新的植物丝氨酸-苏氨酸激酶。我们将利用遗传学、分子和生物化学的方法，开始详细剖析Pid及其同系物在拟南芥生长素活性调节中的作用。本研究的主要目的是：(1)利用遗传学方法确定在生长素信号转导中起作用的Pid上游或下游的途径组件；(2)使用双杂交分析来确定与Pid直接相互作用的蛋白质；(3)确定拟南芥中其他类似Pid的基因是否也调节生长素的活性；以及(4)定量测量Pid错误表达对全球基因表达和生长素分布的影响。我们将使用体外和体内方法来表征候选的相互作用的基因和蛋白质，并确定相互作用的特异性。拟议的实验将有助于从根本上理解生长素介导的信号转导背后的机制。这代表着朝着阐明内源和环境信号如何与植物激素相互作用以引起特定的发育反应并将这些机制与其他真核生物的信号过程联系起来的长期目标迈出的第一步。