Monitoring the dynamics of exosomes through the tracking of Rab7 partners

Abstract Extracellular vesicles (EVs) play a crucial role in cell-cell signaling, and their dysregulation is linked to various pathologies. EVs can originate from the plasma membrane as microvesicles, or form within endosomal compartments that fuse with the plasma membrane, releasing their intraluminal vesicles in the extracellular space as exosomes. However, distinguishing between these two types of EVs is challenging due to their common protein markers, necessitating cumbersome isolation methods. To overcome this limitation, we developed an innovative tool using Rab7-mediated proximity labelling and mass spectrometry. This technological advancement enables the covalent labeling of Rab7 partners allowing the tracking of intracellular and extracellular exosomal cargoes.