Activation of phospholipase D is not mediated by direct phosphorylation on tyrosine residues.
Biochim Biophys Acta
; 1631(3): 246-54, 2003 Apr 08.
Article
em En
| MEDLINE
| ID: mdl-12668176
ABSTRACT
The activation of phospholipase D (PLD) in PC12/PC2 pheochromocytoma cells involves a tyrosine kinase. However, it is not clear whether this is due to direct phosphorylation of the enzyme or some other intermediary protein. In this manuscript, we examined this issue by two methods:
(1) immunoprecipitation of phosphotyrosine containing proteins and assay of phospholipase D; (2) overexpression of HA-phospholipase D2 and susbsequent immunoprecipitation. The only agent that caused phosphorylation of phospholipase D on tyrosine residues was the phosphatase inhibitor, peroxyvanadate. Other agents that activate phospholipase D, including bradykinin, ionomycin, and phorbol dibutyrate did not cause phosphorylation of the enzyme. In addition, there was a lack of correlation between the peroxyvanadate-mediated phosphorylation and activation of phospholipase D, both in terms of time course and concentration dependence. These data demonstrate that phospholipase D is directly phosphorylated on tyrosine residues. However, phosphorylation of tyrosine residues does not correlate with activation of the enzyme.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfolipase D
/
Tirosina
Limite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
2003
Tipo de documento:
Article