Entwicklungsbiologie der Pflanzen, Technische Universität München, Freising, Germany.
PLoS One. 2011;6(5):e19730. doi: 10.1371/journal.pone.0019730. Epub 2011 May 16.
Tissue morphogenesis in plants requires the coordination of cellular behavior across clonally distinct histogenic layers. The underlying signaling mechanisms are presently being unraveled and are known to include the cell surface leucine-rich repeat receptor-like kinase STRUBBELIG in Arabidopsis. To understand better its mode of action an extensive structure-function analysis of STRUBBELIG was performed. The phenotypes of 20 EMS and T-DNA-induced strubbelig alleles were assessed and homology modeling was applied to rationalize their possible effects on STRUBBELIG protein structure. The analysis was complemented by phenotypic, cell biological, and pharmacological investigations of a strubbelig null allele carrying genomic rescue constructs encoding fusions between various mutated STRUBBELIG proteins and GFP. The results indicate that STRUBBELIG accepts quite some sequence variation, reveal the biological importance for the STRUBBELIG N-capping domain, and reinforce the notion that kinase activity is not essential for its function in vivo. Furthermore, individual protein domains of STRUBBELIG cannot be related to specific STRUBBELIG-dependent biological processes suggesting that process specificity is mediated by factors acting together with or downstream of STRUBBELIG. In addition, the evidence indicates that biogenesis of a functional STRUBBELIG receptor is subject to endoplasmic reticulum-mediated quality control, and that an MG132-sensitive process regulates its stability. Finally, STRUBBELIG and the receptor-like kinase gene ERECTA interact synergistically in the control of internode length. The data provide genetic and molecular insight into how STRUBBELIG regulates intercellular communication in tissue morphogenesis.
植物组织形态发生需要在克隆不同的组织层中协调细胞行为。目前正在揭示潜在的信号机制，已知包括拟南芥中的细胞表面富含亮氨酸重复的受体样激酶 STRUBBELIG。为了更好地理解其作用模式，对 STRUBBELIG 进行了广泛的结构功能分析。评估了 20 个 EMS 和 T-DNA 诱导的 strubbelig 等位基因的表型，并应用同源建模来合理化它们对 STRUBBELIG 蛋白结构的可能影响。该分析通过携带编码各种突变 STRUBBELIG 蛋白与 GFP 融合的基因组挽救构建体的 strubbelig 缺失等位基因的表型、细胞生物学和药理学研究进行了补充。结果表明，STRUBBELIG 可以接受相当多的序列变异，揭示了 STRUBBELIG N-帽结构域的生物学重要性，并加强了激酶活性对于其体内功能不是必需的观点。此外，STRUBBELIG 的单个蛋白结构域不能与特定的 STRUBBELIG 依赖的生物学过程相关联，这表明过程特异性是由与 STRUBBELIG 一起作用或下游的因素介导的。此外，证据表明，功能性 STRUBBELIG 受体的生物发生受内质网介导的质量控制的影响，并且 MG132 敏感的过程调节其稳定性。最后，STRUBBELIG 和受体样激酶基因 ERECTA 在控制节间长度方面协同作用。这些数据提供了遗传和分子方面的深入了解，即 STRUBBELIG 如何调节组织形态发生中的细胞间通讯。
