Polarization of IRON-REGULATED TRANSPORTER 1 (IRT1) to the plant-soil interface plays crucial role in metal homeostasis
Polarization of IRON-REGULATED TRANSPORTER 1 (IRT1) to the plant-soil interface plays crucial role in metal homeostasis
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DOI：
10.1073/pnas.1402262111
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发表时间：
2014-06-03
影响因子：
11.1
通讯作者：
Vert, Gregory
中科院分区：
文献类型：
--
作者：
Barberon, Marie;Dubeaux, Guillaume;Vert, Gregory
在植物中，根表皮细胞对土壤养分的控制吸收对于生长和发育至关重要。铁调节转运蛋白1（Iron-Regulated Transporter 1，IRT 1）是从土壤中吸收铁的主要根转运蛋白，也是潜在有毒金属如锰、锌、钴和镉进入植物的主要途径。以前的工作表明，IRT 1蛋白定位于早期内体/trans-Golgi网络（EE/TGN），并通过单泛素和网格蛋白依赖性机制组成性内吞。在这里，我们表明，第二非铁金属基板的IRT 1（锌，锰，钴）的可用性控制IRT 1的定位之间的外极域的质膜和EE/TGN在根表皮细胞。我们还确定FYVE 1，磷脂酰肌醇-3-磷酸结合蛋白招募到晚期内体，作为一个重要的调节IRT 1依赖的金属运输和金属稳态在植物中。FYVE 1控制IRT 1再循环到质膜，并影响该转运蛋白向外质膜结构域的极性递送。这项工作建立了动态和IRT 1的横向极性及其底物的运输之间的功能联系，并确定了驱动植物细胞表面蛋白极性定位的分子机制。
In plants, the controlled absorption of soil nutrients by root epidermal cells is critical for growth and development. IRON-REGULATED TRANSPORTER 1 (IRT1) is the main root transporter taking up iron from the soil and is also the main entry route in plants for potentially toxic metals such as manganese, zinc, cobalt, and cadmium. Previous work demonstrated that the IRT1 protein localizes to early endosomes/trans-Golgi network (EE/TGN) and is constitutively endocytosed through a monoubiquitin-and clathrin-dependent mechanism. Here, we show that the availability of secondary non-iron metal substrates of IRT1 (Zn, Mn, and Co) controls the localization of IRT1 between the outer polar domain of the plasma membrane and EE/TGN in root epidermal cells. We also identify FYVE1, a phosphatidylinositol-3-phosphate-binding protein recruited to late endosomes, as an important regulator of IRT1-dependent metal transport and metal homeostasis in plants. FYVE1 controls IRT1 recycling to the plasma membrane and impacts the polar delivery of this transporter to the outer plasma membrane domain. This work establishes a functional link between the dynamics and the lateral polarity of IRT1 and the transport of its substrates, and identifies a molecular mechanism driving polar localization of a cell surface protein in plants.