The Role of Janus Kinase 3 in the Regulation of Na+/K+ ATPase under Energy Depletion

• Published in: Cellular physiology and biochemistry Vol. 36; no. 2; pp. 727 - 740
• Main Authors: Hosseinzadeh, Zohreh, Honisch, Sabina, Schmid, Evi, Jilani, Kashif, Szteyn, Kalina, Bhavsar, Shefalee, Singh, Yogesh, Palmada, Monica, Umbach, Anja T., Shumilina, Ekaterina, Lang, Florian
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland Cell Physiol Biochem Press GmbH & Co KG 01.05.2015
• Subjects: 2,4-Dinitrophenol - pharmacology; Adenosine Triphosphate - metabolism; Animals; ATP; Cells, Cultured; Dendritic Cells - drug effects; Dendritic Cells - metabolism; DNP; Energy Metabolism - drug effects; Female; Gene Deletion; Janus Kinase 3 - antagonists & inhibitors; Janus Kinase 3 - genetics; Janus Kinase 3 - metabolism; K+-current; Male; Mice; Mutation; Oocytes - drug effects; Oocytes - metabolism; Original Paper; Ouabain; Quinazolines - pharmacology; Sodium-Potassium-Exchanging ATPase - metabolism; Xenopus; ATP; Ouabain; DNP; K+-current
• ISSN: 1015-8987; 1421-9778
• DOI: 10.1159/000430133

Background/Aims: Janus kinase-3 (JAK3) is activated during energy depletion. Energy-consuming pumps include the Na + /K + -ATPase. The present study explored whether JAK3 regulates Na + /K + -ATPase in dendritic cells (DCs). Methods: Ouabain (100 µM)-sensitive (I ouabain ) and K + -induced (I pump ) outward currents were determined by utilizing whole cell patch-clamp, Na + /K + -ATPase α1-subunit mRNA levels by RT-PCR, Na + /K + -ATPase protein abundance by flow cytometry or immunofluorescence, and cellular ATP by luciferase-assay in DCs from bone marrow of JAK3-knockout (jak3 -/- ) or wild-type mice (jak3 +/+ ). I pump was further determined by voltage clamp in Xenopus oocytes expressing JAK3, active A568V JAK3 or inactive K851A JAK3. Results: Na + /K + -ATPase α1-subunit mRNA and protein levels, as well as I pump and I ouabain were significantly higher in jak3 -/- DCs than in jak3 +/+ DCs. Energy depletion by 4h pre-treatment with 2,4-dinitro-phenol significantly decreased I pump in jak3 +/+ DCs but not in jak3 -/- DCs. Cellular ATP was significantly lower in jak3 -/- DCs than in jak3 +/+ DCs and decreased in both genotypes by 2,4-dinitro-phenol, an effect significantly more pronounced in jak3 -/- DCs than in jak3 +/+ DCs and strongly blunted by ouabain in both jak3 +/+ and jak3 -/- DCs. I pump and I ouabain in oocytes were decreased by expression of JAK3 and of A568V JAK3 but not of K851A JAK3. JAK3 inhibitor WHI-P154 (4-[(3'-bromo-4'-hydroxyphenyl)amino]-6,7-dimethoxyquinazoline, 22 μM) enhanced I pump and I ouabain in JAK3 expressing oocytes. The difference between A568V JAK3 and K851A JAK3 expressing oocytes was virtually abrogated by actinomycin D (50 nM). Conclusions: JAK3 down-regulates Na + /K + -ATPase activity, an effect involving gene expression and profoundly curtailing ATP consumption.