New insights into the function of Rab GTPases in the context of exosomal secretion.

In the last two decades, extracellular vesicle-mediated communication between cells has become a major field in cell biology. However, the function of extracellular vesicles is far from clear, especially due to the disparity of released vesicles by cells. Basically, one must consider vesicles budding from the cell plasma membrane (ectosomes) and vesicles released upon fusion of an endosomal multivesicular compartment (exosomes). Moreover, even for exosomes, we report and discuss here the possibility that different routes regulated by specific Rab GTPases might produce exosomes having various biologic functions.