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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Received: 28 September 1999 / Accepted: 12 October 1999
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Roisin, MP., Robert-Gangneux, F., Creuzet, C. et al. Biochemical characterization of mitogen-activated protein (MAP) kinase activity in Toxoplasma gondii . Parasitol Res 86, 588–598 (2000). https://doi.org/10.1007/PL00008535
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DOI: https://doi.org/10.1007/PL00008535