Related Experiment Video
Updated: Feb 11, 2026

Determining Membrane Protein Topology Using Fluorescence Protease Protection FPP
Published on: April 20, 2015
Reverse-topology membrane scission by the ESCRT proteins
Johannes Schöneberg1, Il-Hyung Lee1, Janet H Iwasa2
1Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, USA.
Abstract:
The narrow membrane necks formed during viral, exosomal and intra-endosomal budding from membranes, as well as during cytokinesis and related processes, have interiors that are contiguous with the cytosol. Severing these necks involves action from the opposite face of the membrane as occurs during the well-characterized formation of coated vesicles. This 'reverse' (or 'inverse')-topology membrane scission is carried out by the endosomal sorting complex required for transport (ESCRT) proteins, which form filaments, flat spirals, tubes and conical funnels that are thought to direct membrane remodelling and scission. Their assembly, and their disassembly by the ATPase vacuolar protein sorting-associated 4 (VPS4) have been intensively studied, but the mechanism of scission has been elusive. New insights from cryo-electron microscopy and various types of spectroscopy may finally be close to rectifying this situation.
Related Concept Videos
Introduction to Membrane Proteins
Membrane Proteins
Protein Diffusion in the Membrane
Detergent Purification of Membrane Proteins
GPI Anchoring of Proteins in the ER Membrane
GPI-anchor structure
A sequence of 11 enzymatic reactions results in the synthesis of the complete GPI anchor consisting of a hydrophobic and a hydrophilic portion. The hydrophobic portion comprises phosphatidylinositol, while the hydrophilic part comprises polar groups like phosphoethanolamine,...
Tail-anchoring of Proteins in the ER Membrane

