Dynamin: molecular scissors for membrane fission

Dynamin is a mechanochemical GTPase that plays an essential role in membrane fission in both clathrin-dependent and clathrin-independent endocytosis. Dynamin forms helical complexes at the neck of clathrin-coated pits, and their structural changes coupled with GTP hydrolysis promote membrane fission. The past 30 years of studies using genetical, biochemical, cell biological, and structural analyses raised consensus views on how dynamin functions during membrane fission. These studies strongly supported three unique features of dynamin: (1) dynamin polymerizes into a helical polymer, (2) the dynamin polymer constricts in the presence of GTP, and (3) dynamin severs membrane upon GTP hydrolysis. In this chapter, we present the current status of the field, showing several mechanistic models for dynamin-mediated membrane fission. We further discuss remaining open questions that should be studied in future perspectives.