Regulation of CLAVATA1 function in the Arabidopsis shoot apical meristem

拟南芥茎尖分生组织中 CLAVATA1 功能的调控

• 批准号: 7274945
• 负责人: ZACHARY L NIMCHUK
• 金额: $ 5.13万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7274945
• 关键词: Address; Adult; Affect; Alleles; Animals; Apical; Arabidopsis; Attenuated; Cell Proliferation; Cell membrane; Cells; Cellular biology; Chimeric Proteins; Control Animal; Development; Disease; Equilibrium; Family; Family member; Fertility; Genes; Genetic; Human; Image; Knowledge; Lateral; Lead; Leucine-Rich Repeat; Life; Ligands; Localized; Location; Mediating; Meristem; Modeling; Molecular; Mutation; Numbers; Organ; Pathway interactions; Peptides; Perception; Phenotype; Phosphotransferases; Plants; Population; Process; Production; Protein-Serine-Threonine Kinases; Rate; Regulation; Research; Role; Serine; Shapes; Signal Pathway; Signal Transduction; Stem cells; Study models; System; Testing; Threonine; Time; Tissues; Work; extracellular; genetic analysis; inhibitor/antagonist; mutant; novel strategies; plant growth/development; prevent; receptor; receptor internalization; stem; tool

DESCRIPTION (provided by applicant): Plant cell proliferation is restricted to specialized regions called meristems. Stem cell populations within meristems give rise to all tissues of the adult plant. Cells generated in the shoot meristems are eventually incorporated into above ground lateral organs. In order to prevent depletion of shoot meristems, the loss of cells to lateral organs is balanced with the rate of stem cell proliferation. Mutations in the CLAVATA loci disrupt this balance and lead to a hyper-accumulation of stem cells, extra organ production and a reduction in fertility and plant growth. CLAVATA1 (CLV1) is a conserved receptor-like kinase (RLK) defined first in Arabidopsis and proposed to act as a receptor for the secreted peptide CLV3. After 20 years of genetic analysis we still do not know how CLV1 functions at the cellular level. Genetic evidence suggests that CLV1 signaling is regulated by CLV3-mediated internalization (LME). LME is an important mechanism for attenuating RLK signaling in plants and animals. Understanding CLV1 LME at the molecular level would allow us to address where in the meristem CLV1 is active, how CLV1 activation is regulated by other potential signaling partners and how CLV1 might activate downstream pathways that regulate stem cell production. Recent advances in live imaging in the Meyerowitz lab now allow this to be dissected. This proposal aims to understand CLV1 LME at the cellular level in Arabidopsis. In specific, an active CLV1 YFP fusion protein will be used to address where CLV1 is localized in the cell and how localization is regulated to CLV3 perception. This will be examined by using clv3 mutants, exogenous CLV3 peptides and known inhibitors of LME. The requirement for different domains of CLV1 in LME will be addressed using mutant versions of CLV1 -YFP . In addition, a system for creating conditionally inhibitable kinase versions of CLV1 will be detailed which will allow us to test if CLV3 activates CLV1 directly and will provide a tool to explore the effects of CLV1 inhibition in real time in live tissue. Lastly, I will detail a genetic strategy to identify mutants in key regulators of CLV1 LME which have so far proved elusive. This research will greatly expand our knowledge of RLK activation in plants and will serve as a model for studying signaling by other CLV1 or CLV3 family members. The work will provide our first knowledge of how CLV1 functions at the cellular level, a key roadblock for understanding how stem cell pathways are regulated in plants. This work will enlighten our knowledge of how this kingdom differs in stem cell biology from humans and other animals. This knowledge may lead to novel approaches for studying stem cell biology in general and may lead to novel approaches to treating disease in humans.

描述（由申请人提供）：植物细胞增殖仅限于称为分生组织的专门区域。分生组织内的干细胞群产生成年植物的所有组织。在茎分生组织中产生的细胞最终并入地上侧生器官。为了防止茎分生组织的耗尽，细胞向侧部器官的损失与干细胞增殖的速率相平衡。CLAVATA基因座的突变破坏了这种平衡，导致干细胞的过度积累，额外的器官产生以及生育力和植物生长的减少。CLAVATA 1（CLV 1）是一种保守的受体样激酶（RLK），首先在拟南芥中定义，并被认为是分泌肽CLV 3的受体。经过20年的基因分析，我们仍然不知道CLV 1在细胞水平上的功能。遗传学证据表明，CLV 1信号转导受CLV 3介导的内化（LME）调节。LME是植物和动物中减弱RLK信号传导的重要机制。在分子水平上了解CLV 1 LME将使我们能够解决CLV 1在分生组织中的活性，CLV 1的激活如何受到其他潜在信号伴侣的调节，以及CLV 1如何激活调节干细胞生产的下游途径。Meyerowitz实验室在实时成像方面的最新进展现在允许对此进行解剖。本研究的目的是在拟南芥细胞水平上了解CLV 1 LME。具体地，活性CLV 1 YFP融合蛋白将用于解决CLV 1在细胞中定位的位置以及如何调节定位以感知CLV 3。这将通过使用clv 3突变体、外源性CLV 3肽和已知的LME抑制剂来检查。将使用CLV 1-YFP的突变形式来解决LME中对CLV 1的不同结构域的需求。此外，将详细介绍用于创建CLV 1的条件性可复制激酶版本的系统，这将使我们能够测试CLV 3是否直接激活CLV 1，并将提供一种工具来探索CLV 1抑制在活组织中的真实的时间的影响。最后，我将详细介绍一种遗传策略，以确定突变的关键监管机构CLV 1 LME迄今已被证明难以捉摸。这项研究将大大扩展我们对植物中RLK激活的了解，并将作为研究其他CLV 1或CLV 3家族成员信号传导的模型。这项工作将为我们提供CLV 1如何在细胞水平上发挥作用的第一个知识，这是理解植物干细胞通路如何调节的关键障碍。这项工作将启发我们对这个王国在干细胞生物学上与人类和其他动物有何不同的知识。这些知识可能会导致研究干细胞生物学的新方法，并可能导致治疗人类疾病的新方法。