Institute of Plant and Microbial Biology, University Zurich, Zollikerstrasse 107, 8008 Zürich, Switzerland.
Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea.
Trends Plant Sci. 2017 Jun;22(6):455-461. doi: 10.1016/j.tplants.2017.03.003. Epub 2017 Mar 31.
Cytokinins are phytohormones essential for cytokinesis and many other physiological and developmental processes in planta. Long-distance transport and intercellular transport have been postulated. For these processes, the existence of cytokinin transporters has been suggested. Recently, a transporter loading the xylem (AtABCG14) and another for cellular import (AtPUP14) have been discovered. AtABCG14 participates in the xylem loading process of cytokinins and contributes to the positive regulation of shoot growth. The cellular importer AtPUP14 is required to suppress cytokinin signaling. A role of a transporter as stop signal is a new paradigm for a hormone transporter.
细胞分裂素是植物细胞分裂和许多其他生理和发育过程所必需的植物激素。已经推测存在长距离运输和细胞间运输。对于这些过程，已经提出了细胞分裂素转运蛋白的存在。最近，发现了一种木质部装载（AtABCG14）和另一种细胞内导入（AtPUP14）的转运蛋白。AtABCG14 参与细胞分裂素的木质部装载过程，并有助于促进芽生长的正向调控。细胞内导入器 AtPUP14 对于抑制细胞分裂素信号是必需的。作为停止信号的转运蛋白的作用是激素转运蛋白的一个新范例。
