Dynamic Remodeling of Membranes Catalyzed by Dynamin

Abstract

This chapter discusses the dynamic remodeling of membranes catalyzed by dynamin. Members of the dynamin family of large GTPases are unique among proteins involved in remodeling cell membranes. They readily polymerize on favorable membrane templates and display reversible modes of membrane association that is coupled to their GTPase cycle. Recent studies with dynamin-1—a prototypical member of the dynamin superfamily—have highlighted their capacity to catalyze membrane fission under conditions of constant GTP turnover. Eukaryotic cells are characterized by an elaborate endomembrane system encapsulated by the plasma membrane. Comprised of the endoplasmic reticulum, Golgi apparatus, endosomes and lysosomes, the endomembrane system, and the plasma membrane constitute a dynamic membrane network. The striking observation that dynamin can spontaneously form highly ordered helical spirals to a large extent contributed to defining mechanochemical models for dynamin function. Preassembled helical spirals of dynamin are an obvious starting point as nucleotide-based conformational changes have traditionally compared the apo- and nucleotide-bound states.