Receptor kinase-mediated control of primary active proton pumping at the plasma membrane
Receptor kinase-mediated control of primary active proton pumping at the plasma membrane
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DOI：
10.1111/tpj.12680
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发表时间：
2014-12-01
期刊：
影响因子：
7.2
通讯作者：
Palmgren, Michael G.
中科院分区：
文献类型：
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作者：
Fuglsang, Anja T.;Kristensen, Astrid;Palmgren, Michael G.
植物生长需要质膜外细胞壁空间的酸化，这是质膜定位的 H+-ATP 酶挤出质子的结果。在这里，我们展示了拟南芥中主要的质膜质子泵 AHA1 和 AHA2 在体外和植物中与 PSY1R 直接相互作用，PSY1R 是质膜的受体激酶，充当肽生长激素 PSY1 的受体。 PSY1R 的胞内蛋白激酶结构域在 Thr-881 处磷酸化 AHA2/AHA1，该位点位于 C 端结构域的自身抑制区 I。当在酵母异源表达系统中表达时，在该位置引入负电荷引起泵激活。将 PSY1 应用于植物幼苗可诱导植物 Thr-881 快速磷酸化，同时根部质子流出量瞬时增加。观察到的 AHA2 和 PSY1R 之间的直接相互作用可能为受体激酶调节质膜质子转运提供一般范例。
Acidification of the cell wall space outside the plasma membrane is required for plant growth and is the result of proton extrusion by the plasma membrane-localized H+-ATPases. Here we show that the major plasma membrane proton pumps in Arabidopsis, AHA1 and AHA2, interact directly in vitro and in planta with PSY1R, a receptor kinase of the plasma membrane that serves as a receptor for the peptide growth hormone PSY1. The intracellular protein kinase domain of PSY1R phosphorylates AHA2/AHA1 at Thr-881, situated in the autoinhibitory region I of the C-terminal domain. When expressed in a yeast heterologous expression system, the introduction of a negative charge at this position caused pump activation. Application of PSY1 to plant seedlings induced rapid in planta phosphorylation at Thr-881, concomitant with an instantaneous increase in proton efflux from roots. The direct interaction between AHA2 and PSY1R observed might provide a general paradigm for regulation of plasma membrane proton transport by receptor kinases.