Rho GTPases dictate the mobility of the Na/H exchanger NHE3 in epithelia: role in apical retention and targeting.

ABSTRACT: Proximal tubular reabsorption of filtered sodium by the sodium/hydrogen exchanger isoform 3 (NHE3), located on the apical membrane, is fundamental to the maintenance of systemic volume and pH homeostasis. NHE3 is finely regulated by a variety of hormones and by changes in ionic composition and volume, likely requiring redistribution of the exchangers. We analyzed the subcellular distribution and dynamics of the exchangers by generating an epithelial line expressing NHE3 tagged with an exofacial epitope, which enabled us to monitor exchanger mobility and traffic in intact cells. Using determinations of fluorescence recovery after photobleaching in combination with dynamic measurements of subcellular distribution, we found that, in renal epithelial cells, NHE3 exists in four distinct subcomp

SUBMITTER: Alexander RT 

PROVIDER: S-EPMC1189301 | biostudies-literature | 2005 Aug

REPOSITORIES: biostudies-literature