THE TBVPS15 KINASE IS ESSENTIAL FOR TRYPANOSOMA BRUCEI SURVIVAL AND IS INVOLVED IN INTRACELLULAR TRAFFIC

SCHOIJET AC; MIRANDA K; DE SOUZA W; FLAWIÁ MM; ALONSO GD

CABA

Congreso; XXVII Reunión anual de la Sociedad Argentina de Protozoología; 2015

Sociedad Argentina de Protozoología

The phosphatidylinositol 3-kinase (PI3K) Vps34 is a protein that plays an important role in many processes such as vesicular trafficking, endocytosis and autophagy. This protein is found in yeast and mammalian forming a complex with the kinase Vps15. This kinase is postulated to be necessary for Vps34 activity, since its deletion leads to a loss of PI3P production and disruption of vesicular trafficking. Although Vps34 does not appear to be a substrate of Vps15, mutations in its catalytic domain prevent binding to Vps34. Overall; the role of this protein is not well elucidated. Previously, in our laboratory we have cloned and characterized the TcVps15 kinase in Trypanosoma cruzi, which showed to be involved in autophagy. In this work, we have identified the Vps15 orthologue in Trypanosoma brucei. Knockdown of TbVps15 expression in the procyclic form by RNA interference produces a severe growth defect, with a block of cytokinesis, accompanied by a variety of morphological abnormalities. Cells induced with tetracycline also showed a significant reduction of Concanavalin A transport to the lysosome, indicating that TbVps15 may be involved in intracellular transport. To further study the role of this protein we will perform experiments with dextran and transferrin to assess its role in endocytosis, as well as investigate its possible role in autophagy by starvation experiments. These experiments will complete those obtained in Trypanosoma cruzi, with the purpose of elucidate the role of this protein in both parasites and their participation in the signaling cascade involving Vps34.