Receptor-mediated endocytosis and trafficking between endosomal–lysosomal vacuoles in Giardia lamblia

RIVERO MR., JAUSORO I., BISBAL M., FELIZIANI C., LANFREDI-RANGEL A., TOUZ MC.

PARASITOLOGY RESEARCH

SPRINGER

Lugar: Berlin; Año: 2013 vol. 112 p. 1813 - 1818

0932-0113

The early branching Giardia lambliahas highly polarized vacuoles, located underneath the plasma mem-brane, which have at least some of the characteristics ofendosomes and of lysosomes. These peripheral vacuoles (PVs) are necessary for nutrient uptake and the maintenance of plasma membrane composition, but whether they carry out sorting and segregation of receptors and ligands is a matter of debate. Here, we showed that the internalization of low-density lipoprotein (LDL) to the PVs is highly dynamic in trophozoites with a rate similar to the internalization ofthe low-density lipoprotein receptor-related protein 1. Moreover, by analyzing receptor-mediated and fluid-phase endocytosis in living cells, we showed that after endocytosis LDL but not dextran moved laterally between the PVs. We speculate on PV functional heterogeneity and maturation in this parasite.