Membrane bending: the power of protein imbalance.
Many cellular processes require membrane deformation, which is driven by specialized protein machinery and can often be recapitulated using pure lipid bilayers. However, biological membranes contain a large amount of embedded proteins. Recent research suggests that membrane-bound proteins with asymmetric distribution of mass across the bilayer can influence membrane bending in a nonspecific manner due to molecular crowding. This mechanism is physical in nature and arises from collisions between such 'mushroom-shaped' proteins. It can either facilitate or impede the action of protein coats, for example COPII, during vesicle budding. We describe the physics of how molecular crowding can influence membrane bending and discuss the implications for other cellular processes, such as sorting of glycosylphosphatidylinositol-anchored proteins (GPI-APs) and production of intraluminal vesicles.
Institute of Biophysics, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia.
Jure
J
Derganc
Bruno
B
Antonny
Alenka
A
Copič
D002462:Cell Membrane / Q000502:physiology*; D008051:Lipid Bilayers; D008565:Membrane Proteins / Q000502:physiology*
D008051:Lipid Bilayers; D008565:Membrane Proteins
COPII vesicle budding membrane protein asymmetry; GPI-anchored proteins; membrane bending; protein coats; protein crowding