Cell Wall Associated, Receptor Protein Kinases

MCB9728045 Lay摘要细胞胞外和胞内隔间的相互作用在控制生长发育中起着重要作用。这些相互作用对细胞的基本功能是必不可少的，如细胞极性的建立和细胞分裂、细胞分化、细胞迁移和细胞死亡的调节。胞外隔间包含以复杂结构排列的分子成分，称为细胞外基质(ECM)。众所周知，在动物细胞中，细胞外基质调节细胞过程的一个基本方式是通过它与细胞表面蛋白(受体)的相互作用，这些蛋白质(受体)结合到细胞外基质的特定黏附成分上。相比之下，在植物细胞中，尽管它们在地球上具有压倒性的重要性，但人们对ECM(植物细胞壁)和细胞内部之间的联系知之甚少。这项建议涉及在开花植物拟南芥的细胞中发现的四种细胞表面受体WAKS(壁相关蛋白的缩写)家族，它们似乎是在细胞外和细胞内之间传递信号的黏附蛋白。利用遗传学、分子生物学、生物化学和显微技术，我们将确定这些受体的组织位置以及它们在植物细胞内外之间传递信息的分子机制。我们认为，WAKs通过与特定的目标蛋白相互作用并修饰(磷酸化)特定的目标蛋白的能力在细胞内产生信号，然后在细胞质内启动一系列分子事件。这项提议描述了剖析这些相互作用和事件的实验。这项分析可能会阐明真核细胞如何与其直接环境相互作用并感知其细胞外基质结构变化的一般原理。

MCB9728045 Lay Abstract The interactions between the extracellular and intracellular compartments of cells play important roles in controlling growth and development. These interactions are essential for such basic cell functions as establishment of cell polarity and regulation of cell division, cell differentiation, cell migration and cell death. The extracellular compartment contains molecular components arranged in a complex architecture termed the extracellular matrix (ECM). It is well established that in animal cells a basic way in which the ECM can regulate cell processes is through its interaction with cell surface proteins (receptors) that bind to specific adhesive components of the ECM. By contrast, in plant cells, despite their overwhelming importance on earth, little is known about the communication between the ECM (the plant cell wall) and the cell interior. This proposal concerns a family of four cell surface receptors called Waks (short for wall-associated kinases), discovered in the cells of the flowering plant, Arabidopsis, which appear to be adhesion proteins that transmit signals between the extracellular and intracellular compartments. Using genetics, molecular biology, biochemistry, and microscopy, we will determine the tissue location of these receptors and the molecular mechanism by which they mediate communication between the inside and outside of the plant cell. We propose that the Waks generate a signal inside the cell by their ability to interact with and to modify (phosphorylate) specific target proteins which then initiate a cascade of molecular events within the cytoplasm. This proposal describes experiments to dissect these interactions and events. The analysis is likely to elucidate general principles of how eukaryotic cells interact with their immediate environment and perceive changes in the architecture of their ECM.