INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The PI 3-kinase regulator TcVps15 participates in autophagy in Trypanosoma cruzi
Autor/es:
SCHOIJET AC; FLAWIÁ MM; ALONSO GD
Lugar:
Mendoza
Reunión:
Congreso; XLVIII Reunión anual, Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB).; 2012
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)
Resumen:
The phosphatidylinositol 3-phosphate has been shown to be important for several membrane trafficking pathways. Previously, we have characterized the first class III PI3K in Trypanosoma cruzi, named TcVps34, which has a role in vital processes such as osmoregulation, acidification and endocytosis. In other organisms, it has been shown that Vps34 forms a complex with the Ser?Thr protein kinase Vps15. In this work, we biochemically characterized the regulatory kinase TcVps15 in T. cruzi, and provide evidence that this protein participates in autophagy. Analysis of the recombinant protein indicated that it is a catalytically active kinase, with a Km value between 1,5 and 3 nM, showing a cation preference for Mn2+. Moreover, parasites overexpressing TcVps15 showed an increase in their kinase activity comparing to wild type cells. Regarding to the functional role of TcVps15, immunofluorescence studies demonstrated that under starvation conditions TcVps15 colocalize with Atg8, an autophagosome marker in T. cruzi. Furthermore, assays using acridine orange, which is indicative of the lysosomal activity that is associated with autophagy, showed a higher level of acidification in TcVps15 transgenic parasites under nutritional stress compared to wild type controls. Taken together, our results unveil a previously unknown function for TcVps15 as a positive regulator of autophagy in T. cruzi.