Biochemical characterization of mitogen-activated protein (MAP) kinase activity in Toxoplasma gondii.
Parasitol Res
; 86(7): 588-98, 2000 Jul.
Article
en En
| MEDLINE
| ID: mdl-10935911
ABSTRACT
Mitogen-activated protein (MAP) kinase or extracellular signal-regulated kinase (ERK) are activated by many extracellular stimuli. In this study, we investigated whether MAP kinase and tyrosine kinases were involved in transducing signals in Toxoplasma gondii. Using anti-phosphotyrosine and anti-active ERK antibodies, we identified several phosphorylated proteins in Toxoplasma. In particular, phosphorylation of a 47 kDa and a 43 kDa protein increased strongly after calcium influx. MAP kinase activity, caused by calcium influx, was determined using either a specific synthetic peptide, or an in gel kinase assay. Conversely, calcium chelators (BAPTA and EGTA) and a calcium channel blocker (nifedipine) inhibited this activation. Also, a specific inhibitor of MAP kinase kinase (PD 098059) blocked MAP kinase activity. Three specific anti-MAP kinase antibodies recognized the 47 kDa and 43 kDa proteins, which were putatively identified as ERK1- and ERK2-homologs, respectively. These findings provide early evidence of signal transduction involving members of the MAP kinase family in T. gondii.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Toxoplasma
/
Proteínas Quinasas Activadas por Mitógenos
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Parasitol Res
Asunto de la revista:
PARASITOLOGIA
Año:
2000
Tipo del documento:
Article