N-myristoylation and Ca2+ binding of calcineurin B homologous protein CHP3 are required to enhance Na+/H+ exchanger NHE1 half-life and activity at the plasma membrane

Abstract

Background: CHP3 is an N-myristoylated Ca2+-binding protein that up-regulates the cell surface expression and stability of the Na +/H+ exchanger NHE1 isoform. Results: N-Myristoylation or the Ca2+-binding site of CHP3 regulates the half-life and activity of NHE1 at the cell surface. Conclusion: CHP3 possesses a Ca2+- myristoyl switch mechanism to promote optimal NHE1 activity at the cell surface. Significance: These findings provide fundamental insight into the molecular mechanisms that regulate NHE1. © 2012 by The American Society for Biochemistry and Molecular Biology, Inc.