Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA.
Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, 2-1-1, Katahira, Aobaku, Japan.
J Cell Sci. 2018 Jan 29;131(2):jcs203828. doi: 10.1242/jcs.203828.
AGD1, a plant ACAP-type ADP-ribosylation factor-GTPase activating protein (ARF-GAP), functions in specifying root hair polarity in To better understand how AGD1 modulates root hair growth, we generated full-length and domain-deleted AGD1-green fluorescent protein (GFP) constructs, and followed their localization during root hair development. AGD1-GFP localized to the cytoplasm and was recruited to specific regions of the root hair plasma membrane (PM). Distinct PM AGD1-GFP signal was first detected along the site of root hair bulge formation. The construct continued to mark the PM at the root hair apical dome, but only during periods of reduced growth. During rapid tip growth, AGD1-GFP labeled the PM of the lateral flanks and dissipated from the apical-most PM. Deletion analysis and a single domain GFP fusion revealed that the pleckstrin homology (PH) domain is the minimal unit required for recruitment of AGD1 to the PM. Our results indicate that differential recruitment of AGD1 to specific PM domains is an essential component of the membrane trafficking machinery that facilitates root hair developmental phase transitions and responses to changes in the root microenvironment.
AGD1 是一种植物 ACAP 型 ADP-ribosylation factor-GTPase 激活蛋白 (ARF-GAP)，在根毛极性的特化中发挥作用。为了更好地理解 AGD1 如何调节根毛生长，我们生成了全长和结构域缺失的 AGD1-绿色荧光蛋白 (GFP) 构建体，并跟踪它们在根毛发育过程中的定位。AGD1-GFP 定位于细胞质，并被募集到根毛质膜 (PM) 的特定区域。首先在根毛膨大部分形成的位置检测到独特的 PM AGD1-GFP 信号。该构建体继续标记根毛顶端穹顶的 PM，但仅在生长减缓期间如此。在快速顶端生长期间，AGD1-GFP 标记侧缘的 PM，并从最顶端的 PM 中消失。缺失分析和单个结构域 GFP 融合表明，pleckstrin homology (PH) 结构域是将 AGD1 募集到 PM 所必需的最小单位。我们的结果表明，AGD1 向特定 PM 结构域的差异募集是膜运输机制的一个重要组成部分，该机制促进根毛发育阶段转变和对根微环境变化的响应。
