A Novel Membrane Fission Mechanism by Dynamin Complex: Clusterase Model

Abstract

Dynamin GTPase, an essential endocytotic protein, helically polymerizes at the neck of endocytic pits, and mechanically sever the membrane upon GTP hydrolysis. However, it is not known exactly how the dynamin disconnect the membrane. To clarify the mechanisms we analyzed structural changes of dynamin complexes during membrane fission using electron microscopy and high-speed atomic force microscopy (HS-AFM). Surprisingly, the dynamin ring complexes were clustered upon GTP hydrolysis and membrane constriction occurred at uncoated regions between the clusters, suggesting a novel mode of action of dynamin. In this commentary, we illustrate dynamin’s membrane fission models proposed thus far, and our novel “clusterase” model.