Figures & data
Figure 1. A model highlighting the multiple functions of the ESCRT machinery during cargo sorting and vesicle biogenesis. Step 1: The membrane bound ESCRT-0 complex captures ubiquitin-modified transmembrane cargoes and subsequently recruits ESCRT-I onto the endosomal membrane. A combination of protein-lipid and protein-protein interactions leads to ESCRT-II accumulation on the membrane, establishing an ESCRT footprint that is ~80–130 nm in diameter. Step 2: The ESCRT-0 complex is released from the membrane, potentially due to conformational changes following ESCRT-I binding, and both ESCRT-I and ESCRT-II prevent the lateral diffusion of cargoes. Additionally, ESCRT-I and ESCRT-II may initiate membrane bending. Step 3: ESCRT-II nucleates filaments of ESCRT-III that associate tightly with membrane. In particular, the association of ESCRT-II with Vps20 generates a curvature-sensitive complex that may further bend the membrane to generate a highly curved vesicle bud neck. Polymerized ESCRT-III filaments ultimately drive the vesicle scission process through additional membrane remodeling events, which may include lipid demixing.
