The plasma-membrane polyamine transporter PUT3 is regulated by the Na+/H+ antiporter SOS1 and protein kinase SOS2
The plasma-membrane polyamine transporter PUT3 is regulated by the Na+/H+ antiporter SOS1 and protein kinase SOS2
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DOI：
10.1111/nph.16407
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发表时间：
2020-02-06
期刊：
影响因子：
9.4
通讯作者：
Shi, Huazhong
中科院分区：
文献类型：
--
作者：
Chai, Haoxi;Guo, Jianfei;Shi, Huazhong
在拟南芥中，质膜转运蛋白PUT 3对维持多胺的细胞内稳态非常重要，并在稳定一些热诱导基因的mRNA中起作用。质膜Na+/H+转运蛋白SOS 1和蛋白激酶SOS 2是维持细胞内Na+和K+稳态的两个重要的耐盐决定因子，本文报道了PUT 3与SOS 1和SOS 2的遗传和物理相互作用，这些相互作用调节PUT 3的转运活性，PUT 3（PUT 3 OE）的过表达导致转基因植物对多胺和百草枯的敏感性。PUT 3 OE的超敏反应受到sos 1和sos 2突变的抑制，这表明SOS 1和SOS 2是PUT 3转运活性所必需的。蛋白质相互作用测定显示，PUT 3与酵母和植物细胞中的SOS 1和SOS 2发生物理相互作用。SOS 2在体外和体内磷酸化PUT 3。SOS 1和SOS 2协同激活PUT 3的多胺转运活性，PUT 3也通过激活SOS 2调节SOS 1的活性，总之，我们的研究结果表明，质膜蛋白PUT 3和SOS 1都可以与蛋白激酶SOS 2在应激条件下形成复合物，并通过蛋白质相互作用和磷酸化调节彼此的转运活性。
In Arabidopsis, the plasma membrane transporter PUT3 is important to maintain the cellular homeostasis of polyamines and plays a role in stabilizing mRNAs of some heat-inducible genes. The plasma membrane Na+/H+ transporter SOS1 and the protein kinase SOS2 are two salt-tolerance determinants crucial for maintaining intracellular Na+ and K+ homeostasis.Here, we report that PUT3 genetically and physically interacts with SOS1 and SOS2, and these interactions modulate PUT3 transport activity.Overexpression of PUT3 (PUT3OE) results in hypersensitivity of the transgenic plants to polyamine and paraquat. The hypersensitivity of PUT3OE is inhibited by the sos1 and sos2 mutations, which indicates that SOS1 and SOS2 are required for PUT3 transport activity. A protein interaction assay revealed that PUT3 physically interacts with SOS1 and SOS2 in yeast and plant cells. SOS2 phosphorylates PUT3 both in vitro and in vivo. SOS1 and SOS2 synergistically activate the polyamine transport activity of PUT3, and PUT3 also modulates SOS1 activity by activating SOS2 in yeast cells.Overall, our findings suggest that both plasma-membrane proteins PUT3 and SOS1 could form a complex with the protein kinase SOS2 in response to stress conditions and modulate the transport activity of each other through protein interactions and phosphorylation.