Multiple Distinct Coiled-coils Are Involved in Dynamin Self-assembly
| Autor: | Robert S. Hodges, Patricia M. Okamoto, Brian Tripet, Richard B. Vallee, Jennifer Litowski |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Dynamins
Protein Denaturation Protein Folding Circular dichroism Protein Conformation Protein subunit Endocytic cycle GTPase Biology Endocytosis Microtubules Biochemistry Protein Structure Secondary GTP Phosphohydrolases Structure-Activity Relationship Yeasts Centrifugation Density Gradient Animals Synaptic vesicle recycling Molecular Biology Dynamin I Dynamin Circular Dichroism C-terminus Cell Biology Cell biology Phenotype COS Cells Mutagenesis Site-Directed Ultracentrifugation Protein Binding |
| Zdroj: | Journal of Biological Chemistry. 274:10277-10286 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.274.15.10277 |
| Popis: | Dynamin, 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. |
| Databáze: | OpenAIRE |
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