The calcineurin homologous protein-1 increases Na(+)/H(+) -exchanger 3 trafficking via ezrin phosphorylation.

ABSTRACT: The Na(+)/H(+)-exchanger 3 (NHE3) is essential for regulation of Na(+) transport in the renal and intestinal epithelium. Although changes in cell surface abundance control NHE3 function, the molecular signals that regulate NHE3 surface expression are not well defined. We found that overexpression of the calcineurin homologous protein-1 (CHP1) in opossum kidney cells increased NHE3 transport activity, surface protein abundance, and ezrin phosphorylation. CHP1 knockdown by small interfering RNA had the opposite effects. Overexpression of wild-type ezrin increased both NHE3 transport activity and surface protein abundance, confirming that NHE3 is downstream of ezrin. Expression of a pseudophosphorylated ezrin enhanced these effects, whereas expression of an ezrin variant that could not be pho

SUBMITTER: Di Sole F 

PROVIDER: S-EPMC2723990 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature