title: The dynamin middle domain is critical for tetramerization and higher-order self-assembly.
abstract: The large multidomain GTPase dynamin self-assembles around the necks of deeply invaginated coated pits at the plasma membrane and catalyzes vesicle scission by mechanisms that are not yet completely understood. Although a structural role for the 'middle' domain in dynamin function has been suggested, it has not been experimentally established. Furthermore, it is not clear whether this putative function pertains to dynamin structure in the unassembled state or to its higher-order self-assembly or both. Here, we demonstrate that two mutations in this domain, R361S and R399A, disrupt the tetrameric structure of dynamin in the unassembled state and impair its ability to stably bind to and nucleate higher-order self-assembly on membranes. Consequently, these mutations also impair dynamin's assembly-dependent stimulated GTPase activity.
authors.affiliation: Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Ramachandran
authors.forename: Mark
authors.initials: M
authors.lastname: Surka
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Chappie
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Fowler
authors.forename: Ted R
authors.initials: TR
authors.lastname: Foss
authors.forename: Byeong Doo
authors.initials: BD
authors.lastname: Song
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Schmid
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D019281:Dimerization; D034284:Dynamin I / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006801:Humans; D017354:Point Mutation; D011108:Polymers / Q000737:chemistry*; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
chemical_list: D011108:Polymers; D034284:Dynamin I; D020558:GTP Phosphohydrolases