Mutation of the protein kinase C phosphorylation site on rat alpha1 Na+,K+-ATPase alters regulation of intracellular Na+ and pH and influences cell shape and adhesiveness.
J Biol Chem
; 272(32): 20179-84, 1997 Aug 08.
Article
en En
| MEDLINE
| ID: mdl-9242694
ABSTRACT
The enzyme Na+,K+-ATPase creates the transmembrane Na+ gradient that is of vital importance for functioning of all eukaryotic cells. Na+, K+-ATPase can be phosphorylated by protein kinase A (PKA) and protein kinase C (PKC), and these sites of phosphorylation have been identified. In the present study, we have examined the physiological significance of PKC phosphorylation of rat Na+,K+-ATPase. In COS cells transfected with wild type rat Na+,K+-ATPase alpha1, intracellular Na+ was higher and pH was lower than in cells transfected with rat Na+,K+-ATPase alpha1 in which the PKC phosphorylation site, Ser-23, had been mutated into alanine. Phorbol dibutyrate inhibited Na+,K+-ATPase-dependent ATP hydrolysis and Rb+ uptake in cells expressing wild type Na+,K+-ATPase but not in cells expressing S23A Na+,K+-ATPase. Cells expressing the S23A mutant had a more rounded appearance and attached less well to fibronectin than did untransfected cells or cells transfected with wild type rat Na+, K+-ATPase alpha1. These results indicate a functional role for PKC-mediated phosphorylation of rat Na+,K+-ATPase alpha1 and suggest a connection between this enzyme and cell adhesion.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Sodio
/
Proteína Quinasa C
/
ATPasa Intercambiadora de Sodio-Potasio
Límite:
Animals
Idioma:
En
Revista:
J Biol Chem
Año:
1997
Tipo del documento:
Article
País de afiliación:
Suecia