A Cell Wall Associated, Receptor Like Kinase

细胞壁相关的受体，如激酶

• 批准号: 9603703
• 负责人: Bruce Kohorn
• 金额: $ 3.49万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 1998-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9603703&HistoricalAwards=false
• 关键词: Cell; Wall; Associated; Receptor; Like

Iohorn 9603703 Technical We have identified a family of Arabidopsis thaliana proteins, designated Waks for Wall Associated Kinase, that are tightly associated with the cell wall, and that have cytoplasmic kinase domains. The cell wall bound, extracytoplasmic domain of each family member contains several Epidermal Growth Factor (EGF) repeats. Waks differ, however, in the extracellular domain . In different 100 amino acid blocks one Wak has 54% identity (perfect spacings) to tenascin. In another there is identity with a neurexin and in another there identity with extensin. The Wak family is expressed in all vegetative tissues of Arabidopsis, and has relatives in other Angiosperms. Based on immunoelectron microscopy and biochemical analysis, Waks provides a physical continuum between the cell wall and the cytoplasm. Since the kinase is cytoplasmic it also has the potential to mediate signals to the cytoplasm from the cell wall. Indeed, we find that at least one Wak interacts with a cytoplasmic type 2C protein phosphatase that is likely the first step in the transduction pathway. Future experiments will focus on the genomic organization and specific expression of each family member, and their interaction with each other and cytoplasmic proteins. We have isolated a T-DNA disruption of the Wak locus that is tightly linked to an embryonic lethal phenotype, and we plan to use this mutant background to assay functional domains of the Waks. Moreover, expression of dominant negative Wak mutations also show that the family is essential for viability, and genetic screens will be used to identify interacting proteins. Non-Technical Extrinsic signals impinging upon plant cells first interact with the cell wall that surrounds the cell. Many of these extrinsic signals induce overt alterations in a plant's physiology and morphology. The site of detection of these most of these signals is unknown. Dr. Kohorn has discovered a class of signaling proteins (cell-wall associated kinase or Wak) that app ear to be associated with the inner surface of the cell wall directly adjacent to the cell surface. With this award Dr. Kohorn will characterize the genes encoding Wak and to examine how Wak interacts with other proteins to create a coupled cascade where signals perceived by Wak are transmitted into the cell to exert physiological effects. ***

我们已经鉴定了一个拟南芥蛋白质家族，命名为Waks for Wall Associated Kinase，它与细胞壁紧密结合，并具有胞质激酶结构域。每个家族成员的细胞壁结合的胞质外结构域含有几个表皮生长因子（EGF）重复序列。然而，在细胞外结构域中不同。在不同的100个氨基酸块中，一个Wak与腱生蛋白具有54%的同一性（完美间隔）。在另一种情况下，与neurexin相同，而在另一种情况下，与extensin相同。 Wak家族在拟南芥的所有营养组织中都有表达，并且在其他被子植物中有亲缘关系。 基于免疫电子显微镜和生化分析，Waks提供了细胞壁和细胞质之间的物理连续体。由于激酶是细胞质的，它也有可能介导信号从细胞壁到细胞质。事实上，我们发现至少有一个Wak与细胞质2C型蛋白磷酸酶相互作用，这可能是转导途径的第一步。未来的实验将集中在每个家族成员的基因组组织和特异性表达，以及它们彼此之间和细胞质蛋白之间的相互作用。我们已经分离出与胚胎致死表型紧密相关的Wak位点的T-DNA破坏，并且我们计划使用这种突变背景来测定Wak的功能域。此外，显性阴性Wak突变的表达也表明该家族对于生存力是必不可少的，并且遗传筛选将用于鉴定相互作用的蛋白质。 非技术外在信号冲击植物细胞首先与细胞周围的细胞壁相互作用。这些外在信号中的许多诱导植物的生理和形态的明显改变。这些信号中的大多数的检测位点是未知的。Kohorn博士发现了一类信号蛋白（细胞壁相关激酶或Wak），它们与细胞壁的内表面直接相邻。Kohorn博士将通过该奖项表征编码Wak的基因，并研究Wak如何与其他蛋白质相互作用，以创建一个耦合级联，其中Wak感知的信号被传递到细胞中以发挥生理作用。 ***