Department of Biological Sciences and Genomics and Breeding Institute, Seoul National University, Seoul 151-742, Korea.
Mol Cells. 2012 May;33(5):423-30. doi: 10.1007/s10059-012-0039-9. Epub 2012 Mar 26.
The asymmetry of environmental stimuli and the execution of developmental programs at the organism level require a corresponding polarity at the cellular level, in both unicellular and multicellular organisms. In plants, cell polarity is important in major developmental processes such as cell division, cell enlargement, cell morphogenesis, embryogenesis, axis formation, organ development, and defense. One of the most important factors controlling cell polarity is the asymmetric distribution of polarity determinants. In particular, phosphorylation is implicated in the polar distribution of the determinant protein factors, a mechanism conserved in both prokaryotes and eukaryotes. In plants, formation of local gradients of auxin, the morphogenic hormone, is critical for plant developmental processes exhibiting polarity. The auxin efflux carriers PIN-FORMEDs (PINs) localize asymmetrically in the plasma membrane and cause the formation of local auxin gradients throughout the plant. The asymmetry of PIN distribution in the plasma membrane is determined by phosphorylationmediated polar trafficking of PIN proteins. This review discusses recent studies on the role of phosphorylation in polar PIN trafficking.
环境刺激的不对称性和生物体水平上发育程序的执行需要在单细胞和多细胞生物的细胞水平上具有相应的极性。在植物中，细胞极性在细胞分裂、细胞增大、细胞形态发生、胚胎发生、轴形成、器官发育和防御等主要发育过程中很重要。控制细胞极性的最重要因素之一是极性决定因素的不对称分布。特别是，磷酸化参与了决定蛋白因子的极性分布，这一机制在原核生物和真核生物中都保守。在植物中，形态发生激素生长素的局部梯度的形成对于表现出极性的植物发育过程至关重要。生长素外排载体 PIN 形成蛋白（PINs）在质膜中不对称定位，并在整个植物中引起局部生长素梯度的形成。质膜中 PIN 分布的不对称性是由 PIN 蛋白的磷酸化介导的极性运输决定的。本文综述了磷酸化在极性 PIN 运输中的作用的最新研究进展。
