Kost Benedikt
Warwick HRI, University of Warwick, Wellesbourne, Warwickshire, CV35 9EF, UK.
Trends Cell Biol. 2008 Mar;18(3):119-27. doi: 10.1016/j.tcb.2008.01.003. Epub 2008 Feb 15.
Spatially restricted signaling by Rho GTPases is essential for the polarization of eukaryotic cells, which is required for the morphogenesis, mobility and division of single cells, and for the development of multicellular organisms. Rac-Rop GTPases, which constitute a plant-specific Rho GTPase subfamily, accumulate at the apical plasma membrane of pollen tubes and root hairs, where they control rapid polar cell expansion by a process known as tip growth. Here, recent insights into the spatial control of Rac-Rop-dependent signaling in tip-growing plant cells by regulatory proteins (i.e. Rho GTPase-activating proteins, Rho guanine nucleotide dissociation inhibitors, Rho guanine nucleotide-exchange factors and phosphoinositide-specific phospholipase C) and lipids [phosphatidylinositol (4,5)-bisphosphate and diacyl glycerol] are summarized. A model is presented, which integrates the current knowledge concerning the molecular mechanisms that maintain the polarization of Rho signaling in plant cells.
Rho GTP酶的空间限制信号传导对于真核细胞的极化至关重要，而真核细胞极化对于单细胞的形态发生、移动性和分裂以及多细胞生物的发育都是必需的。Rac-Rop GTP酶构成了植物特有的Rho GTP酶亚家族，它们聚集在花粉管和根毛的顶端质膜上，通过一种称为顶端生长的过程控制细胞的快速极性扩展。本文总结了近期关于调节蛋白（即Rho GTP酶激活蛋白、Rho鸟嘌呤核苷酸解离抑制剂、Rho鸟嘌呤核苷酸交换因子和磷脂酰肌醇特异性磷脂酶C）和脂质[磷脂酰肌醇（4,5）-二磷酸和二酰基甘油]对顶端生长的植物细胞中Rac-Rop依赖性信号传导进行空间控制的见解。本文还提出了一个模型，该模型整合了当前关于维持植物细胞中Rho信号极化的分子机制的知识。
