Adhesion of Trypanosoma cruzi Trypomastigotes to Fibronectin or Laminin Modifies Tubulin and Paraflagellar Rod Protein Phosphorylation

Abstract

BackgroundThe unicellular parasite Trypanosoma cruzi is the causative agent of Chagaś disease in humans. Adherence of the infective stage to elements of the extracellular matrix (ECM), as laminin and fibronectin, is an essential step in host cell invasion. Although members of the gp85/TS, as Tc85, were identified as laminin and fibronectin ligands, the signaling events triggered on the parasite upon binding to these molecules are largely unexplored.Methodology/Principal FindingsViable infective parasites were incubated with laminin, fibronectin or bovine serum albumin for different periods of time and the proteins were separated by bidimensional gels. The phosphoproteins were envisaged by specific staining and the spots showing phosphorylation levels significantly different from the control were excised and identified by MS/MS. The results of interest were confirmed by immunoblotting or immunoprecipitation and the localization of proteins in the parasite was determined by immunofluorescence. Using a host cell-free system, our data indicate that the phosphorylation contents of T. cruzi proteins encompassing different cellular functions are modified upon incubation of the parasite with fibronectin or laminin.Conclusions/SignificanceHerein it is shown, for the first time, that paraflagellar rod proteins and α-tubulin, major structural elements of the parasite cytoskeleton, are predominantly dephosphorylated during the process, probably involving the ERK1/2 pathway. It is well established that T. cruzi binds to ECM elements during the cell infection process. The fact that laminin and fibronectin induce predominantly dephosphorylation of the main cytoskeletal proteins of the parasite suggests a possible correlation between cytoskeletal modifications and the ability of the parasite to internalize into host cells.

Trypanosoma cruzihighjacks TrkC to enter cardiomyocytes and cardiac fibroblasts while exploiting TrkA for cardioprotection against oxidative stress

“…Earlier studies showed that activation of transforming growth factor‐β (TGF‐β) receptor enhances T. cruzi entry into cardiomyocyte and other cell types (Ming et al ., ; Waghabi et al ., 2005; 2007), as does binding to kinin receptors (Todorov et al ., ). Although our results suggest that PDNF family member gp85 does not initiate a cascade of events triggering TrkC‐dependent cardiomyocyte invasion, independent studies showed that gp85 is important in T. cruzi adhesion to laminin and other ECM components (Alves and Colli, ; Mattos et al ., ).…”

Structure and function of Per-ARNT-Sim domains and their possible role in the life-cycle biology of Trypanosoma cruzi

“…cruzi contain homologues of the MAP kinase ERK and the peptidyl-prolyl cis/trans isomerase (PPIase) PIN1 which in the human tumour cells are involved in the signalling resulting in translocation of PGK1 to mitochondria and exhibiting protein kinase activity [156][157][158][159]. The T. brucei and T. cruzi ERK homologues are called Erk-like (TbECK1) and Erk2 (TcMAPK2), respectively [156,157]. These proteins are associated with functions related to phenotype, karyotype, cell cycle and growth modulation.…”

Down Regulation of NO Signaling in Trypanosoma cruzi upon Parasite-Extracellular Matrix Interaction: Changes in Protein Modification by Nitrosylation and Nitration

“…Adhesion to laminin or fibronectin leads to changes in the phosphorylation level of T . cruzi proteins, including paraflagellar rod proteins and tubulins, probably involving the ERK1/2 pathway [ 50 ].…”