A type 2C protein phosphatase activates high-affinity nitrate uptake by dephosphorylating NRT2.1
A type 2C protein phosphatase activates high-affinity nitrate uptake by dephosphorylating NRT2.1
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DOI：
10.1038/s41477-021-00870-9
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发表时间：
2021-03-08
期刊：
影响因子：
18
通讯作者：
Matsubayashi, Yoshikatsu
中科院分区：
文献类型：
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作者：
Ohkubo, Yuri;Kuwata, Keiko;Matsubayashi, Yoshikatsu
在根的高亲和力硝酸盐吸收中起核心作用的硝酸盐转运体NRT2.1在翻译后水平上被激活，以响应氮(N)饥饿(1，2)。然而，NRT2.1翻译后激活所需的关键酶仍有待确定。在这里，我们证明了一种2C型蛋白磷酸酶，被称为CEPD诱导磷酸酶(CEPH)，通过直接去磷酸化NRT2.1的Ser501激活高亲和力的硝酸盐摄取，NRT2.1是一种在拟南芥中起负磷酸开关作用的残基(2)。CEPHE主要在根的表皮和皮层细胞中表达，N饥饿通过CEPDL2/CEPD1/2介导的地上部长距离信号上调(3，4)。CEPH的丧失导致高亲和力硝酸盐吸收、组织硝酸盐含量和植物生物量显著下降。总之，我们的结果确认CEPH是NRT2.1依赖N饥饿激活的关键酶，并为植物如何在翻译后水平上调节高亲和力硝酸盐吸收以响应N环境提供了分子和机制方面的见解。系统氮信号控制根氮的获得。调控通路涉及CEP-CEPD网络和高亲和力硝酸盐转运蛋白NRT2.1。在这项研究中，作者发现CEPH是一种2C型蛋白磷酸酶，作用于CEPD/CEPDL下游，调节NRT2.1的活性和拟南芥对硝酸盐的吸收。
The nitrate transporter NRT2.1, which plays a central role in high-affinity nitrate uptake in roots, is activated at the post-translational level in response to nitrogen (N) starvation(1,2). However, the critical enzymes required for the post-translational activation of NRT2.1 remain to be identified. Here, we show that a type 2C protein phosphatase, designated CEPD-induced phosphatase (CEPH), activates high-affinity nitrate uptake by directly dephosphorylating Ser501 of NRT2.1, a residue that functions as a negative phospho-switch in Arabidopsis(2). CEPH is predominantly expressed in epidermal and cortex cells in roots and is upregulated by N starvation via a CEPDL2/CEPD1/2-mediated long-distance signalling from shoots(3,4). The loss of CEPH leads to marked decreases in high-affinity nitrate uptake, tissue nitrate content and plant biomass. Collectively, our results identify CEPH as a crucial enzyme in the N-starvation-dependent activation of NRT2.1 and provide molecular and mechanistic insights into how plants regulate high-affinity nitrate uptake at the post-translational level in response to the N environment.Systemic nitrogen signalling controls root nitrogen acquisition. The regulatory pathways involve the CEP-CEPD network and the high-affinity nitrate transporter NRT2.1. In this study, the authors identified CEPH, a type 2C protein phosphatase, acting downstream of the CEPD/CEPDLs to regulate the activity of NRT2.1 and nitrate uptake in Arabidopsis.