Phosphatidylinositol kinase activities in Trypanosoma cruzi epimastigotes

Abstract

Phosphatidylinositol (PtdIns) metabolism through phosphatidylinositol kinase (PIKs) activities plays acentral role in different signaling pathways. In Trypanosoma cruzi, causative agent of Chagas disease, PIKshave been proposed as target for drug design in order to combat this pathogen. In this work, we studiedthe classes of PI4K, PIPK and PI3K that could participate in signaling pathways in T. cruzi epimastigoteforms. For this reason, we analyzed their enzymatic parameters and detailed responses to avowed kinaseinhibitors (adenosine, sodium deoxycholate, wortmannin and LY294002) and activators (Ca2+, phospha-tidic acid, spermine and heparin). Our results suggest the presence and activity of a class III PI4K, a classI PIPK, a class III PI3K previously described (TcVps34) and a class I PI3K. Class I PI3K enzyme, here namedTcPI3K, was cloned and expressed in a bacterial system, and their product was tested for kinase activity.The possible participation of TcPI3K in central cellular events of the parasite is also discussed.