ESCRTdependent

ESCRT-dependent refers to cellular processes that require the Endosomal Sorting Complexes Required for Transport (ESCRT) machinery to mediate membrane remodeling and scission. These processes typically involve membrane fission that occurs away from the cytosol, such as the formation of intraluminal vesicles within endosomes, the release of exosomes, and the final separation of two daughter cells during cytokinesis. The term is used to distinguish ESCRT-dependent pathways from those that rely on other mechanisms for membrane scission.

The ESCRT machinery comprises a sequence of protein complexes, commonly described as ESCRT-0, ESCRT-I, ESCRT-II, and ESCRT-III, along with the VPS4 ATPase and various accessory factors. Cargo recognition often involves ubiquitination and recruitment by ESCRT-0, followed by ESCRT-I and ESCRT-II–driven membrane deformation to form buds. ESCRT-III assembles into filaments that execute membrane scission, and VPS4 disassembles and recycles ESCRT components after the event.

Examples of ESCRT-dependent processes include multivesicular body formation and the sorting of ubiquitinated cargo into intraluminal vesicles, exosome biogenesis and release, and the abscission step of cytokinesis that finalizes cell division. Many enveloped viruses hijack ESCRT machinery to bud from the plasma membrane, illustrating the pathway’s broader role in membrane remodeling beyond normal endosomal trafficking.

Understanding ESCRT-dependent pathways informs cell biology and virology, and defects in ESCRT components have been linked to a range of diseases, highlighting their physiological importance.