Loss of calcineurin homologous protein-1 in chicken B lymphoma DT40 cells destabilizes Na+/H+ exchanger isoform-1 protein.

NHE1/SLC9A1 is a ubiquitous isoform of vertebrate Na(+)/H(+) exchangers (NHEs) functioning in maintaining intracellular concentrations of Na(+) and H(+) ions. Calcineurin homologous protein-1 (CHP1) binds to the hydrophilic region of NHE1 and regulates NHE1 activity but reportedly does not play a role in translocating NHE1 from the endoplasmic reticulum to the plasma membrane. However, an antiport function of NHE1 requiring CHP1 remains to be clarified.