Protein Carbonylation of an Amino Acid Residue of the Na/K-ATPase α1 Subunit Determines Na/K-ATPase Signaling and Sodium Transport in Renal Proximal Tubular Cells.
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 α1 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 α1 knockdown LLC-PK1-originated PY-17 cells were rescued by expressing wild-type rat α1 and rat α1 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 α1 subunit determines ouabain-mediated Na/K-ATPase signal transduction and subsequent regulation of renal proximal tubule sodium transport.
Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV.
Yanling
Y
Yan
Department of Medicine, University of Toledo College of Medicine, Toledo, OH.
Anna P
AP
Shapiro
Department of Medicine, University of Toledo College of Medicine, Toledo, OH.
Brahma R
BR
Mopidevi
Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV.
Muhammad A
MA
Chaudhry
Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV.
Kyle
K
Maxwell
Department of Medicine, University of Toledo College of Medicine, Toledo, OH.
Steven T
ST
Haller
Department of Medicine, University of Toledo College of Medicine, Toledo, OH.
Christopher A
CA
Drummond
Department of Medicine, University of Toledo College of Medicine, Toledo, OH.
David J
DJ
Kennedy
Department of Medicine, University of Toledo College of Medicine, Toledo, OH.
Jiang
J
Tian
Department of Medicine, University of Toledo College of Medicine, Toledo, OH.
Deepak
D
Malhotra
Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV.
Zi-Jian
ZJ
Xie
Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV Department of Medicine, University of Toledo College of Medicine, Toledo, OH.
Joseph I
JI
Shapiro
Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV liuj@marshall.edu.
Jiang
J
Liu
D000818:Animals; D030801:Animals, Genetically Modified; D000081247:CSK Tyrosine-Protein Kinase; D002478:Cells, Cultured; D055785:Gene Knockdown Techniques; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000378:metabolism*; D009154:Mutation; D010042:Ouabain / Q000494:pharmacology; D050050:Protein Carbonylation; D051381:Rats; D015398:Signal Transduction; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D013552:Swine; D019061:src-Family Kinases / Q000378:metabolism
D010042:Ouabain; D012964:Sodium; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C499075:Atp1a1 protein, rat; D000254:Sodium-Potassium-Exchanging ATPase
Na/K‐ATPase; protein carbonylation; protein trafficking; reactive oxygen species; signaling; sodium transport