Lipid kinases and Ca2+ signaling in Trypanosoma cruzi stimulated

VERONICA SANTANDER, MARIANA BOLLO, AND ESTELA MACHADO-DOMENECH

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS

Elseiver

Lugar: Amsterdam; Año: 2002 vol. 293 p. 314 - 320

0006-291X

The synthetic peptide carryingresidues 1–40 of chicken aD-globin, which promotes differentiation in Trypanosoma cruziaD-globin, which promotes differentiation in Trypanosoma cruzi epimastigote, stimulated PPtdIns-k, DAG-k, and PA-k activities in a dose-dependent manner. A biphasic behavior only for PPtdIns-k and DAG-k was demonstrated by changes in [32P]PPtdIns and PtdOH levels, the earlier phase peakingat 3 min with a return to basal levels by 6 min and then a second phase with a sustained increase in time. This behavior was not observed for PA-k; the DGPP levels peaked at 6 min and were sustained in time. PMA pretreatment only abolished the first peak of PPtdIns-k, DAG-k activities, and InsPs/InsP3 levels. There was also a transient elevation in intracellular calcium concentration, but this variation was modified only 50% by PMA. The results suggest that peptide 1–40 induces activation of the inositol cycle through lipid kinase activation in a biphasic manner. In this response, the early increase of enzymatic activities would be regulated by PKC and the InsP3 may only be responsible, in part, for the calcium signaling.
2002 Elsevier Science (USA). All rights reserved.32P]PPtdIns and PtdOH levels, the earlier phase peakingat 3 min with a return to basal levels by 6 min and then a second phase with a sustained increase in time. This behavior was not observed for PA-k; the DGPP levels peaked at 6 min and were sustained in time. PMA pretreatment only abolished the first peak of PPtdIns-k, DAG-k activities, and InsPs/InsP3 levels. There was also a transient elevation in intracellular calcium concentration, but this variation was modified only 50% by PMA. The results suggest that peptide 1–40 induces activation of the inositol cycle through lipid kinase activation in a biphasic manner. In this response, the early increase of enzymatic activities would be regulated by PKC and the InsP3 may only be responsible, in part, for the calcium signaling.
2002 Elsevier Science (USA). All rights reserved.3 levels. There was also a transient elevation in intracellular calcium concentration, but this variation was modified only 50% by PMA. The results suggest that peptide 1–40 induces activation of the inositol cycle through lipid kinase activation in a biphasic manner. In this response, the early increase of enzymatic activities would be regulated by PKC and the InsP3 may only be responsible, in part, for the calcium signaling.
2002 Elsevier Science (USA). All rights reserved.3 may only be responsible, in part, for the calcium signaling.
2002 Elsevier Science (USA). All rights reserved. Keywords: Trypanosoma cruzi; Lipid kinases; Phosphoinositide kinase; Calcium signaling; Protein kinase C; DifferentiationTrypanosoma cruzi; Lipid kinases; Phosphoinositide kinase; Calcium signaling; Protein kinase C; Differentiation