Is phosphorylation of the alpha1 subunit at Ser-16 involved in the control of Na,K-ATPase activity by phorbol ester-activated protein kinase C?

Details

Serval ID
serval:BIB_BA5C1ACD9A29
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Is phosphorylation of the alpha1 subunit at Ser-16 involved in the control of Na,K-ATPase activity by phorbol ester-activated protein kinase C?
Journal
Molecular Biology of the Cell
Author(s)
Feraille  E., Beguin  P., Carranza  M. L., Gonin  S., Rousselot  M., Martin  P. Y., Favre  H., Geering  K.
ISSN
1059-1524 (Print)
Publication state
Published
Issued date
01/2000
Volume
11
Number
1
Pages
39-50
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jan
Abstract
The alpha1 subunit of Na,K-ATPase is phosphorylated at Ser-16 by phorbol ester-sensitive protein kinase(s) C (PKC). The role of Ser-16 phosphorylation was analyzed in COS-7 cells stably expressing wild-type or mutant (T15A/S16A and S16D-E) ouabain-resistant Bufo alpha1 subunits. In cells incubated at 37 degrees C, phorbol 12, 13-dibutyrate (PDBu) inhibited the transport activity and decreased the cell surface expression of wild-type and mutant Na,K-pumps equally ( approximately 20-30%). This effect of PDBu was mimicked by arachidonic acid and was dependent on PKC, phospholipase A(2), and cytochrome P450-dependent monooxygenase. In contrast, incubation of cells at 18 degrees C suppressed the down-regulation of Na,K-pumps and revealed a phosphorylation-dependent stimulation of the transport activity of Na,K-ATPase. Na,K-ATPase from cells expressing alpha1-mutants mimicking Ser-16 phosphorylation (S16D or S16E) exhibited an increase in the apparent Na affinity. This finding was confirmed by the PDBu-induced increase in Na sensitivity of the activity of Na,K-ATPase measured in permeabilized nontransfected COS-7 cells. These results illustrate the complexity of the regulation of Na,K-ATPase alpha1 isozymes by phorbol ester-sensitive PKCs and reveal 1) a phosphorylation-independent decrease in cell surface expression and 2) a phosphorylation-dependent stimulation of the transport activity attributable to an increase in the apparent Na affinity.
Keywords
Animals Arachidonic Acid/metabolism Biological Transport COS Cells Cell Membrane/metabolism Cell Membrane Permeability Down-Regulation Enzyme Activation Enzyme Inhibitors/pharmacology Mutagenesis Na(+)-K(+)-Exchanging ATPase/genetics/*metabolism Ouabain/pharmacology Phorbol 12,13-Dibutyrate/*metabolism/pharmacology Phosphorylation Protein Kinase C/*metabolism Serine/*metabolism Temperature Transfection
Pubmed
Web of science
Create date
24/01/2008 12:28
Last modification date
20/08/2019 15:28
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