Chemistry

Membrane transport

Enzyme

Spermine

Polyamine

Gene

Transporter

Membrane

Biochemistry

Antiporter

New Phytologist

Summary 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, an...

The plasma‐membrane polyamine transporter PUT3 is regulated by the Na <sup>+</sup> /H <sup>+</sup> antiporter SOS1 and protein kinase SOS2

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