Multifarious roles of the smallest Arabidopsis thaliana MAPKKKs clade (MAPKKK19, 20 and 21) as an integrative hub for plant pathogen interactions, growth, development and reproduction.

最小的拟南芥 MAPKKK 进化枝（MAPKKK19、20 和 21）作为植物病原体相互作用、生长、发育和繁殖的综合中心，具有多种作用。

• 批准号: RGPIN-2019-05931
• 负责人: Matton, Daniel
• 金额: $ 2.03万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=765222
• 关键词: Multifarious; roles; smallest; Arabidopsis; thaliana

Communication and information transfer is everything, not only for our day-to-day lives but also for each and every cell of an organism. Information transfer in cells is better known as signal transduction. Numerous elements take part in cellular signaling and generally act through cascades that mediate sensing and processing of stimuli. These molecular circuits precisely detect, amplify, and integrate external signals to generate downstream responses. Thus, perception of a stimulus can lead to changes in gene expression, enzyme activity, localization of a protein or its half-life, leading to major changes in cell homeostasis. The protein kinase family exemplifies such a major group of signaling proteins. Kinases are enzyme that modifies other proteins by chemically adding a phosphate groups to specific amino acids, the most prevalent targets being serine, threonine and tyrosine. How can such a small modification exert profound effects on proteins? Because phosphorylated amino acids in proteins act as new entities, modifying the chemical nature of the protein's surface, thereby enabling the formation of new protein-protein interactions. Why is it so widely used? Because it is reversible: the kinase adds a phosphate group on a substrate - this modifies the substrate's properties, which in turn influence its interaction potential - then a phosphatase can remove the phosphate group. This leads to the writer-reader-eraser triad of phosphorylation based signaling. Phosphorylation as a means of communication seems to be even more important in sessile organisms like plants that cannot flea danger or adverse environmental conditions. This can be illustrated by the contribution of the protein kinase's family in plants, which represent a much larger fraction of the proteome (the protein ensemble of an organism) compared to other eukaryotes. For example, in the plant model species Arabidopsis thaliana, kinases represent 4% of the proteome compared to ~2% in humans, nematodes, fruit fly or brewer's yeast. Of these, two major families, the receptor kinase (RK) family (>600) and the MAPK (Mitogen-Activated Protein Kinases) superfamily (>100), account for 70% of all Arabidopsis protein kinases. Kinases are thus at the forefront of signaling. Our current research program focuses on multiple aspects of cell-cell communication, from plant reproduction to the role of signaling cascades involving protein kinases in gametophytes development, e.g., the embryo sac of the ovule and the pollen, and in plant innate immunity. In this research project, we focus on the role of a newly assembled MAPK cascade that affects numerous aspects of the life of a plant, e. g., growth, sexual reproduction, and diseases (plant innate immunity) as determined by the analysis of mutant plants lacking these kinases.

通信和信息传递是一切，不仅对我们的日常生活，而且对有机体的每个细胞都是如此。细胞内的信息传递更为人所知的是信号转导。许多元件参与细胞信号传递，通常通过级联作用，调节对刺激的感知和处理。这些分子电路精确地检测、放大和集成外部信号，以产生下游响应。因此，对刺激的感知可以导致基因表达、酶活性、蛋白质定位或半衰期的变化，从而导致细胞内环境平衡的重大变化。蛋白激酶家族就是这样一组重要的信号蛋白。激酶是一种通过在特定氨基酸上化学添加磷酸基团来修饰其他蛋白质的酶，最常见的靶标是丝氨酸、苏氨酸和酪氨酸。如此微小的修饰怎么会对蛋白质产生深远的影响呢？因为蛋白质中的磷酸化氨基酸作为新的实体，改变了蛋白质表面的化学性质，从而能够形成新的蛋白质-蛋白质相互作用。为什么它会被如此广泛地使用？因为它是可逆的：激酶在底物上添加一个磷酸基团-这会改变底物的性质，进而影响其相互作用潜力-然后磷酸酶可以去除磷酸基团。这导致了基于磷酸化的信号的写入器-读取器-擦除器三位一体。作为一种交流手段，磷酸化似乎在固着生物中更重要，比如无法逃脱危险或不利环境条件的植物。这可以通过植物中蛋白激酶家族的贡献来说明，与其他真核生物相比，蛋白激酶家族在蛋白质组(生物体的蛋白质集合)中所占的比例要大得多。例如，在植物模式物种拟南芥中，蛋白激酶占蛋白质组的4%，而在人类、线虫、果蝇或酿酒酵母中，这一比例为2%。其中，受体激酶(RK)家族和MAPK(丝裂原激活蛋白激酶)超家族(&gt；100)占拟南芥蛋白激酶总数的70%。因此，激酶处于信号传递的最前沿。我们目前的研究计划集中在细胞-细胞通讯的多个方面，从植物繁殖到涉及蛋白激酶的信号级联在配子体发育中的作用，例如，胚珠和花粉的胚囊，以及在植物先天免疫中的作用。在这个研究项目中，我们集中在一个新组装的MAPK级联蛋白的作用，它影响植物生命的许多方面，例如生长，有性繁殖和疾病(植物先天免疫)，通过对缺乏这些激酶的突变植物的分析确定的。