Protein Carbonylation of an Amino Acid Residue of the Na/K-ATPase ?1 Subunit Determines Na/K-ATPase Signaling and Sodium Transport in Renal Proximal Tubular Cells.

ABSTRACT: We have demonstrated that cardiotonic steroids, such as ouabain, signaling through the Na/K-ATPase, regulate sodium reabsorption in the renal proximal tubule. By direct carbonylation modification of the Pro222 residue in the actuator (A) domain of pig Na/K-ATPase ?1 subunit, reactive oxygen species are required for ouabain-stimulated Na/K-ATPase/c-Src signaling and subsequent regulation of active transepithelial (22)Na(+) transport. In the present study we sought to determine the functional role of Pro222 carbonylation in Na/K-ATPase signaling and sodium handling.Stable pig ?1 knockdown LLC-PK1-originated PY-17 cells were rescued by expressing wild-type rat ?1 and rat ?1 with a single mutation of Pro224 (corresponding to pig Pro222) to Ala. This mutation does not affect ouabain-induced inhibition of Na/K-ATPase activity, but abolishes the effects of ouabain on Na/K-ATPase/c-Src signaling, protein carbonylation, Na/K-ATPase endocytosis, and active transepithelial (22)Na(+) transport.Direct carbonylation modification of Pro224 in the rat ?1 subunit determines ouabain-mediated Na/K-ATPase signal transduction and subsequent regulation of renal proximal tubule sodium transport.

SUBMITTER: Yan Y 

PROVIDER: S-EPMC5079028 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature