Ouabain-regulated phosphoproteome reveals molecular mechanisms for Na+, K+-ATPase control of cell adhesion, proliferation, and survival.
FASEB J
; 33(9): 10193-10206, 2019 09.
Article
in En
| MEDLINE
| ID: mdl-31199885
ABSTRACT
The ion pump Na+, K+-ATPase (NKA) is a receptor for the cardiotonic steroid ouabain. Subsaturating concentration of ouabain triggers intracellular calcium oscillations, stimulates cell proliferation and adhesion, and protects from apoptosis. However, it is controversial whether ouabain-bound NKA is considered a signal transducer. To address this question, we performed a global analysis of protein phosphorylation in COS-7 cells, identifying 2580 regulated phosphorylation events on 1242 proteins upon 10- and 20-min treatment with ouabain. Regulated phosphorylated proteins include the inositol triphosphate receptor and stromal interaction molecule, which are essential for initiating calcium oscillations. Hierarchical clustering revealed that ouabain triggers a structured phosphorylation response that occurs in a well-defined, time-dependent manner and affects specific cellular processes, including cell proliferation and cell-cell junctions. We additionally identify regulation of the phosphorylation of several calcium and calmodulin-dependent protein kinases (CAMKs), including 2 sites of CAMK type II-γ (CAMK2G), a protein known to regulate apoptosis. To verify the significance of this result, CAMK2G was knocked down in primary kidney cells. CAMK2G knockdown impaired ouabain-dependent protection from apoptosis upon treatment with high glucose or serum deprivation. In conclusion, we establish NKA as the coordinator of a broad, tightly regulated phosphorylation response in cells and define CAMK2G as a downstream effector of NKA.-Panizza, E., Zhang, L., Fontana, J. M., Hamada, K., Svensson, D., Akkuratov, E. E., Scott, L., Mikoshiba, K., Brismar, H., Lehtiö, J., Aperia, A. Ouabain-regulated phosphoproteome reveals molecular mechanisms for Na+, K+-ATPase control of cell adhesion, proliferation, and survival.
Key words
Full text:
1
Database:
MEDLINE
Main subject:
Ouabain
/
Protein Kinases
/
Protein Processing, Post-Translational
/
Sodium-Potassium-Exchanging ATPase
/
Calcium-Calmodulin-Dependent Protein Kinase Type 2
Language:
En
Journal:
FASEB J
Journal subject:
BIOLOGIA
/
FISIOLOGIA
Year:
2019
Type:
Article
Affiliation country:
Sweden