RUI: Cell Wall Associated Kinases As Pectin Receptors

RUI：细胞壁相关激酶作为果胶受体

• 批准号: 1556057
• 负责人: Bruce Kohorn
• 金额: $ 59.78万
• 依托单位: Bowdoin College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1556057&HistoricalAwards=false
• 关键词: RUI; Cell; Wall; Associated; Kinases

All complex organisms are composed of cells that must bind to and communicate with each other, and all cells are surrounded by an extra-cellular matrix that provides some of these abilities. In plants, the extracellular matrix is termed the cell wall, and is partially composed of the carbohydrates cellulose and pectin. Several cell surface proteins act as sensors or receptors for the state of the cell wall, monitoring its integrity and composition. The Wall Associated Kinases (WAKs) are cell surface receptors that bind to the pectin in the cell wall, and regulate cell enlargement. WAKs are also activated by fragmented pectins generated by pathogens, mechanical stress and perhaps by normal developmental changes. The experiments that will be conducted during this project will begin to help in understanding the mechanism by which WAKs can distinguish and respond to different types of pectin in the cell wall, and thereby how plants sense the state of their cell wall, essential for their growth and development. This work will be carried out at a small liberal arts college where the focus is on undergraduate education and research. Students receive a thorough training in experimental science through work in this project, and a significant portion go on to graduate and professional school. The PI also incorporates many aspects of plant cell biology and genetics from his lab into the core cell biology and genetics lab course at the scientist's institution, and is involved in courses for underprepared students in the sciences.The cell walls of angiosperms are composed of a complex arrangement of cellulose, hemicellulose and pectin. The pectins can be selectively and locally modified to be cross-linked into a structural network that can have dramatic effects on cell enlargement. Localized digestion by plant secreted polygalacturonases can also modify the pectin network by loosening the cell wall to permit directional expansion of cells. Numerous pathogens and mechanical disruptions fragment pectin, often leading to a plant stress response. This project involves the Wall Associated Kinases (WAKs) that bind to both long polymers of cross-linked pectin and to pathogen and damage induced pectin fragments, or oligo-galacturonides (OGs). WAKs bound to native polymers are required for normal cell expansion, but bind newly generated OGs with higher affinity, and subsequently activate a distinct stress response pathway. This project will characterize receptor like kinases, cytoplasmic kinases, and potential scaffolding proteins that are phosphorylated upon OG treatment of Arabidopsis. The role of each of the 5 individual WAK isoforms, clustered in one 30 kb locus in Arabidopsis will be genetically dissected using a new CRISPR/Cas9 based WAK deletion mutant. The puzzle is how one receptor type can distinguish and respond in different ways to different types of pectin, during development and the response to environmental disturbance. The goal is to understand if this is achieved through different WAKs each binding different pectins, and in combination with different co-receptors and ligands to activate alternate pathways.

所有复杂的生物体都由必须相互结合和通信的细胞组成，并且所有细胞都被提供其中一些能力的细胞外基质包围。在植物中，细胞外基质称为细胞壁，部分由碳水化合物纤维素和果胶组成。 几种细胞表面蛋白充当细胞壁状态的传感器或受体，监测其完整性和组成。 壁相关激酶 (WAK) 是细胞表面受体，可与细胞壁中的果胶结合并调节细胞增大。 WAK 也会被病原体、机械应激以及正常发育变化产生的果胶碎片激活。该项目期间将进行的实验将开始帮助理解 WAK 区分和响应细胞壁中不同类型果胶的机制，从而了解植物如何感知细胞壁的状态，这对于植物的生长和发育至关重要。这项工作将在一所小型文理学院进行，重点是本科教育和研究。学生通过该项目的工作接受了实验科学方面的全面培训，其中很大一部分继续进入研究生和专业学校。 PI 还将他实验室的植物细胞生物学和遗传学的许多方面融入到科学家机构的核心细胞生物学和遗传学实验室课程中，并参与为科学准备不足的学生开设的课程。 被子植物的细胞壁由纤维素、半纤维素和果胶的复杂排列组成。果胶可以选择性地进行局部修饰，交联成结构网络，对细胞增大产生巨大影响。 植物分泌的多聚半乳糖醛酸酶的局部消化还可以通过松开细胞壁以允许细胞定向扩张来改变果胶网络。许多病原体和机械破坏会破坏果胶，通常会导致植物应激反应。该项目涉及与交联果胶长聚合物以及病原体和损伤诱导的果胶片段或寡聚半乳糖醛酸 (OG) 结合的壁相关激酶 (WAK)。正常细胞扩增需要与天然聚合物结合的 WAK，但以更高的亲和力与新生成的 OG 结合，随后激活独特的应激反应途径。该项目将表征受体，如激酶、细胞质激酶和潜在的支架蛋白，这些蛋白在 OG 处理拟南芥时被磷酸化。 将使用一种新的基于 CRISPR/Cas9 的 WAK 缺失突变体对聚集在拟南芥中一个 30 kb 基因座中的 5 种单独的 WAK 亚型中的每一种的作用进行基因剖析。令人困惑的是，在发育和对环境干扰的反应过程中，一种受体类型如何区分不同类型的果胶并以不同的方式做出反应。我们的目标是了解这是否是通过不同的 WAK 来实现的，每个 WAK 结合不同的果胶，并与不同的共受体和配体结合以激活替代途径。

项目成果

Mutation of an Arabidopsis Golgi membrane protein ELMO1 reduces cell adhesion

拟南芥高尔基体膜蛋白 ELMO1 的突变降低了细胞粘附

• DOI: 10.1242/dev.199420
• 发表时间: 2021
• 期刊: Development
• 影响因子: 4.6
• 作者: Kohorn, Bruce D.;Zorensky, Frances D.;Dexter-Meldrum, Jacob;Chabout, Salem;Mouille, Gregory;Kohorn, Susan
• 通讯作者: Kohorn, Susan