title: The pleckstrin-homology domain of dynamin is dispensable for membrane constriction and fission.
abstract: Classical dynamins bind the plasma membrane-localized phosphatidylinositol-4,5-bisphosphate using the pleckstrin-homology domain (PHD) and engage in rapid membrane fission during synaptic vesicle recycling. This domain is conspicuously absent among extant bacterial and mitochondrial dynamins, however, where loop regions manage membrane recruitment. Inspired by the core design of bacterial and mitochondrial dynamins, we reengineered the classical dynamin by replacing its PHD with a polyhistidine or polylysine linker. Remarkably, when recruited via chelator or anionic lipids, respectively, the reengineered dynamin displayed the capacity to constrict and sever membrane tubes. However, when analyzed at single-event resolution, the tube-severing process displayed long-lived, highly constricted prefission intermediates that contributed to 10-fold reduction in bulk rates of membrane fission. Our results indicate that the PHD acts as a catalyst in dynamin-induced membrane fission and rationalize its adoption to meet the physiologic requirement of a fast-acting membrane fission apparatus.
authors.affiliation: Indian Institute of Science Education and Research, Pashan, Pune Maharashtra 411008, India.
authors.forename: Srishti
authors.initials: S
authors.lastname: Dar
authors.affiliation: Indian Institute of Science Education and Research, Pashan, Pune Maharashtra 411008, India pucadyil@iiserpune.ac.in.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Pucadyil
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D003250:Constriction; D034281:Dynamins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure*; D004705:Endocytosis / Q000502:physiology; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D008566:Membranes / Q000378:metabolism / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism; D063154:Mitochondrial Dynamics / Q000235:genetics / Q000502:physiology*; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism; D000070539:Pleckstrin Homology Domains / Q000235:genetics / Q000502:physiology; D000072417:Protein Domains; D017434:Protein Structure, Tertiary
chemical_list: D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases; D034281:Dynamins