Serum- and glucocorticoid-induced kinase 3 in recycling endosomes mediates acute activation of Na+/H+ exchanger NHE3 by glucocorticoids.

ABSTRACT: Na(+)/H(+) exchanger 3 (NHE3) is the major Na(+) transporter in the intestine. Serum- and glucocorticoid-induced kinase (SGK) 1 interacts with NHE regulatory factor 2 (NHERF2) and mediates activation of NHE3 by dexamethasone (Dex) in cultured epithelial cells. In this study, we compared short-term regulation of NHE3 by Dex in SGK1-null and NHERF2-null mice. In comparison to wild-type mice, loss of SGK1 or NHERF2 significantly attenuated regulation of NHE3 by Dex but did not completely obliterate the effect. We show that transfection of SGK2 or SGK3 in PS120 cells resulted in robust activation of NHE3 by Dex. However, unlike SGK1 or SGK2, SGK3 rapidly activated NHE3 within 15 min of Dex treatment in both PS120 and Caco-2bbe cells. Immunofluorescence analysis showed that SGK3 colocalized wit

SUBMITTER: He P 

PROVIDER: S-EPMC3192861 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature