Identification of Snare invelved in the formation of de Trypanosoma cruzi parasito-phorousvacuole.?

CUETO JA; CASASSA AF; VANRELL MC; ROMANO PS

Congreso; SAIB; 2013

IDENTIFICATION OF SNARES INVOLVED IN THE FORMATION OF THE Trypanosoma cruzi PARASITOPHOROUS VACUOLE Cueto JA, Casassa AF, Vanrell MC, Romano PS. IHEM-CCT Mendoza. E-mail: cueto.juanagustin@gmail.com Trypanosoma cruzi is the protozoan parasite that causes human Chagas disease. As an obligate intracellular parasite, T. cruzi resides transiently in a parasitophorous vacuole (TcPV). It is well established that TcPV must fusion with lysosomes to establish a productive intracellular infection. SNARE proteins are key molecules of the vesicle fusion machinery. The aim of this study is to identify SNARE proteins involved in the parasite infection process. Our results indicated that Vamp7 (v-SNARE) overexpression increased two fold the infection rate and more than 60% of TcPVs recruited Vamp7 to their limiting vacuole membrane. Silencing this SNARE protein, but not the overexpression of the truncated mutant of Vamp7 (Vamp7 NT), caused a marked decrease in the parasite infection rate. Moreover, we have detected in the vacuole membrane the Vamp7 partners (Vti1b, Snap23 and Stx3). In addition, we determined the participation of the motor protein Kif5, a kinesin implicated in the transport of VAMP7-vesicles to the cell periphery, in the infection process. We observed that cells overexpressing a dominant negative mutant of Kif5 reduced two fold the infection rate. Taken together, these results indicate that Vamp7 plays a major role in TcPV biogenesis, likely by facilitating the interaction with the endolysosomal compartment.