FUNCTIONAL ANALYSIS OF A FAMILY OF CELL WALL ASSOCIATED RECEPTOR KINASES

在多细胞生物体中，细胞外和 细胞内区室在控制许多 发展决策。在动物细胞中有确凿的证据表明 细胞外基质（ECM）分子是选择性的 细胞-细胞识别和细胞-ECM粘附过程， 调节发育过程如细胞极性， 分化、细胞分裂、细胞死亡和细胞迁移。这 一项提案涉及一个五种ECM相关受体样蛋白家族 激酶，Waks（壁相关激酶），似乎是粘附 受体之间交换信号的细胞外和 拟南芥的细胞内区室。唤醒有一个跨膜 结构域，该结构域分隔氨基末端的胞质外结构域， EGF（表皮生长因子）重复序列和有限的序列同一性， 或者是腱生蛋白超家族，或者是神经毒素。的羧基区域 所有的Waks编码细胞质丝氨酸/苏氨酸蛋白激酶。韦克斯 位于质膜上。此外，Wak 1激酶结构域 与细胞质2C型蛋白磷酸酶相互作用。两者 Wak 1的插入突变和显性失活突变已经被 分离并发现是致命的，表明蛋白质是必需的。 该提案描述了解剖信号通路的实验 并确定Waks在信号中的作用 在植物ECM和细胞质之间的转导。的分析 Wak蛋白家族可能导致描述一种新的信号 植物细胞中的转导机制，也许对一般 真核细胞如何感知它们的结构变化的原理 细胞外基质和环境。

In multi-cellular organisms the interactions between extracellular and intracellular compartments play an important role in controlling many developmental decisions. In animal cells there has been solid evidence that extracellular matrix (ECM) molecules are constituents of selective cell-cell recognition and cell-ECM adhesion processes and are important in regulation of developmental processes such as cellular polarity, differentiation, cell division, cell death and cell migration. This proposal concerns a family of five ECM-associated receptor-like protein kinases, Waks (Wall Associated Kinase), which appear to be adhesion receptors that exchange signals between the extracellular and intracellular compartments of Arabidopsis. Waks have a transmembrane domain that separates an amino-terminal, extracytoplasmic domain that have EGF (Epidermal Growth Factor) repeats and limited sequence identities to either the tenascin superfamily, or the neurexins. The carboxyl region of all the Waks encode a cytoplasmic serine/threonine protein kinase. Waks are localized in the plasma membrane. Moreover, the Wak1 kinase domain interacts with a cytoplasmic type 2C protein phosphatase. Both an insertional mutation and a dominant negative mutation of Wak1 have been isolated and found to be lethal, indicating that the protein is essential. This proposal describes experiments to dissect the signaling pathways associated with Waks and to determine the role Waks have in signal transduction between the plant ECM and the cytoplasm. The analysis of the Wak family of proteins may lead to a description of a new signal transduction mechanism in plant cells, and perhaps toward general principals of how eukaryotic cells perceive architectural changes in their extracellular matrix and environment.