title: Dynamin 3 is a component of the postsynapse, where it interacts with mGluR5 and Homer.
abstract: The dynamins comprise a large family of mechanoenzymes known to participate in membrane modeling events. All three conventional dynamin genes (Dyn1, Dyn2, Dyn3) are expressed in mammalian brain and produce more than 27 different dynamin proteins as a result of alternative splicing. Past studies have suggested that Dyn1 participates in specialized neuronal functions such as rapid synaptic vesicle recycling, while Dyn2 may mediate the conventional clathrin-mediated uptake of surface receptors. Currently, the distribution, expression, and function of Dyn3 in neurons, or in any other cell type, are completely undefined. Here, we demonstrate that Dyn1 and Dyn3 localize differentially in the synapse. Dyn1 concentrates within the presynaptic compartment, while Dyn3 localizes to dendritic spine tips. Within the postsynaptic density (PSD), we found Dyn3, but not Dyn1, to be part of a biochemically isolated complex comprised of Homer and metabotropic glutamate receptors. Finally, although dominant-negative Dyn3 did not seem to inhibit receptor endocytosis, overexpression of a specific Dyn3 spliced variant in mature neurons caused a marked remodeling of dendritic spines. These data suggest that Dyn3 is a postsynaptic dynamin and, like its binding partner Homer, plays a significant role in dendritic spine morphogenesis and remodeling.
authors.affiliation: Molecular Neuroscience Program and Graduate School, Mayo Clinic, 200 First Street, S.W., Rochester, MN 55905, USA.
authors.forename: Noah W
authors.initials: NW
authors.lastname: Gray
authors.forename: Lawrence
authors.initials: L
authors.lastname: Fourgeaud
authors.forename: Bing
authors.initials: B
authors.lastname: Huang
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Hong
authors.initials: H
authors.lastname: Cao
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Oswald
authors.forename: Agnès
authors.initials: A
authors.lastname: Hémar
authors.forename: Mark A
authors.initials: MA
authors.lastname: McNiven
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D003712:Dendrites / Q000737:chemistry / Q000378:metabolism; D034284:Dynamin I / Q000378:metabolism; D034286:Dynamin III / Q000032:analysis / Q000378:metabolism*; D000072233:Homer Scaffolding Proteins; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D051381:Rats; D018092:Kainic Acid Receptors / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013569:Synapses / Q000737:chemistry / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D034284:Dynamin I; D034286:Dynamin III; D000072233:Homer Scaffolding Proteins; D009479:Neuropeptides; D018092:Kainic Acid Receptors