Multiple distinct coiled-coils are involved in dynamin self-assembly
AuthorsOkamoto, Patricia M.
Tripet, Brian P.
Litowski, Jennifer R.
Hodges, Robert S.
Vallee, Richard B.
UMass Chan AffiliationsDepartment of Cell Biology
Document TypeJournal Article
Centrifugation, Density Gradient
Protein Structure, Secondary
Medicine and Health Sciences
MetadataShow full item record
AbstractDynamin, a 100-kDa GTPase, has been implicated to be involved in synaptic vesicle recycling, receptor-mediated endocytosis, and other membrane sorting processes. Dynamin self-assembles into helical collars around the necks of coated pits and other membrane invaginations and mediates membrane scission. In vitro, dynamin has been reported to exist as dimers, tetramers, ring-shaped oligomers, and helical polymers. In this study we sought to define self-assembly regions in dynamin. Deletion of two closely spaced sequences near the dynamin-1 C terminus abolished self-association as assayed by co-immunoprecipitation and the yeast interaction trap, and reduced the sedimentation coefficient from 7.5 to 4.5 S. Circular dichroism spectroscopy and equilibrium ultracentrifugation of synthetic peptides revealed coiled-coil formation within the C-terminal assembly domain and at a third, centrally located site. Two of the peptides formed tetramers, supporting a role for each in the monomer-tetramer transition and providing novel insight into the organization of the tetramer. Partial deletions of the C-terminal assembly domain reversed the dominant inhibition of endocytosis by dynamin-1 GTPase mutants. Self-association was also observed between different dynamin isoforms. Taken altogether, our results reveal two distinct coiled-coil-containing assembly domains that can recognize other dynamin isoforms and mediate endocytic inhibition. In addition, our data strongly suggests a parallel model for dynamin subunit self-association.
J Biol Chem. 1999 Apr 9;274(15):10277-86.
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/42416
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