The intracellular lipid-binding domain of human Na/H exchanger 1 forms a lipid-protein co-structure essential for activity.

Dynamic interactions of proteins with lipid membranes are essential regulatory events in biology, but remain rudimentarily understood and particularly overlooked in membrane proteins. The ubiquitously expressed membrane protein Na/H-exchanger 1 (NHE1) regulates intracellular pH (pH) with dysregulation linked to e.g.

Molecular basis for the binding and selective dephosphorylation of Na/H exchanger 1 by calcineurin.

Very little is known about how Ser/Thr protein phosphatases specifically recruit and dephosphorylate substrates. Here, we identify how the Na/H-exchanger 1 (NHE1), a key regulator of cellular pH homeostasis, is regulated by the Ser/Thr phosphatase calcineurin (CN). NHE1 activity is increased by phosphorylation of NHE1 residue T779, which is specifically dephosphorylated by CN.