Action of Pasteurella multocida toxin on Galpha(q) is persistent and independent of interaction with G-protein-coupled receptors.
Cell Signal
; 19(10): 2174-82, 2007 Oct.
Article
em En
| MEDLINE
| ID: mdl-17669624
ABSTRACT
Pasteurella multocida toxin (PMT) activates Galpha(q) and facilitates stimulation of inositol phosphate accumulation induced by agonists via G(q)-coupled membrane receptors. Here, we studied the effects of PMT on agonist-induced GTPgammaS binding to G(q) in cell membranes and a role of G-protein-coupled receptors in the action of PMT. Pre-treatment of Swiss 3T3 cells with PMT increased bombesin or vasopressin-induced GTPgammaS-binding in cell membranes by about 50 to 150%. Increase in agonist-stimulated GTPgammaS-binding caused by PMT pretreatment was specific for Galpha(q) and not observed with Galpha(11). PMT-induced effects on GTPgammaS-binding were persistent after removing the toxin or in the presence of anti-PMT antibody. Stimulation of agonist-induced GTPgammaS-binding by PMT was independent of phosphorylation of the C-terminal tyrosine356 of Galpha(q). Activation of phospholipase C by PMT occurred via Galpha(q) which was fused to the alpha(1b)-adrenoceptor and also with a C-terminally deleted Galpha(q), which is not able to interact with G protein-coupled membrane receptors. The data indicate that activation of Galpha(q) by PMT is persistent and independent of a functional interaction of G(q) with G-protein-coupled receptors.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Toxinas Bacterianas
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Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP
/
Receptores Acoplados a Proteínas G
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article