The ESCRT (Endosomal Sorting Complexes Required for Transport) machinery is a term used to describe protein complexes involved in intracellular membrane fission processes such as such as multivesicular body (MVB) formation, cytokinetic abscission and retroviral budding which involve membrane budding away from the cytosol. There are five complexes, ESCRT-0 to -III and the Vsp4 complex. These complexes are recruited sequentially to the cytosolic face of the membrane. They bring about membrane remodelling, resulting in the inward curvature of the membrane, budding and eventually membrane scission. Many of these proteins were identified via genetic analysis in yeast as VpsE (vacuolar protein sorting, class E) mutants important in endosomal maturation and the transport of proteins to the lysosome. (Adapted from PMID:22361144 and FBrf0209668).