Autoinhibition and phospho-switch for the dynamic regulation of ion transport.

Membrane transporters, including ion channels and carriers, maintain ionic and nutrient homeostasis vital for growth and stress resilience in plants. Their activity is finely regulated, enabling dynamic responses to internal and external signals. Transporters often exist in an 'autoinhibited' resting state that can be switched on by post-translational modifications in response to environmental cues. Specifically, protein phosphorylation functions as a molecular switch that relieves autoinhibition of channels and carriers to modulate their activities. We examine the phospho-regulation of exemplary transporters involved in nutrient allocation, stress resistance, and signal transduction, providing a perspective on how plants orchestrate membrane transport processes to sustain ion and nutrient balance and adapt to environmental challenges.