Figure 1.

Schema of the molecular mechanisms and interactions involved in exosome biogenesis. Exosomes can be formed as intraluminal vesicles (ILVs) in an endosomal sorting complex required for transport (ESCRT)-dependent manner, as well as via ESCRT-independent pathways involving molecules such as ceramide, tetraspanins, and proteoglycans prior to their secretion (a). Post-translational modifications of the vacuolar protein sorting-associated proteins (VPS) family proteins involved in the sorting of exosomal cargo and generation. Energy required for the scission of budding exsomes from membrane is dependent on the ATPase activity of the Vacuolar protein 4 (VPS4) complex (b).