Cell biology of the ESCRT machinery

The ESCRT (endosomal sorting complex required for transport) machinery comprises a set of protein complexes that regulate sorting and trafficking into multivesicular bodies en route to the lysosome. The physical mechanism responsible for generating lumenal vesicles in this pathway is unknown. Here we review recent studies suggesting that components of the ESCRT-III complex drive lumenal vesicle formation and consider possible mechanisms for this reaction.