Role of Phospholipid Head Group Structure and Polarity in the Control of Membrane Fusion

Abstract

Mammalian cell membranes fulfill a multiplicity of functions, some of which appear quite contrasting. For example, plasma membranes need to constitute a stable and reliable permeability barrier but they also engage in membrane fusion events, known as endo- and exocytosis. Several intracellular membrane structures, such as parts of the endoplasmic reticulum, the Golgi apparatus, lysosomes, and small transport vesicles, take part in similar fusion processes. Membrane fusion can only be understood as a destabilization of the membrane structure at restricted sites of in-termembrane contact, followed by creation and stabilization of new membrane continuities. The molecular details of these events are not yet understood, nor the role of individual membrane components (lipids or proteins).