title: Functional and anatomical identification of a vesicular transporter mediating neuronal ATP release.
abstract: ATP is known to be coreleased with glutamate at certain central synapses. However, the nature of its release is controversial. Here, we demonstrate that ATP release from cultured rat hippocampal neurons is sensitive to RNAi-mediated knockdown of the recently identified vesicular nucleotide transporter (VNUT or SLC17A9). In the intact brain, light microscopy showed particularly strong VNUT immunoreactivity in the cerebellar cortex, the olfactory bulb, and the hippocampus. Using immunoelectron microscopy, we found VNUT immunoreactivity colocalized with synaptic vesicles in excitatory and inhibitory terminals in the hippocampal formation. Moreover, VNUT immunolabeling, unlike that of the vesicular glutamate transporter VGLUT1, was enriched in preterminal axons and present in postsynaptic dendritic spines. Immunoisolation of synaptic vesicles indicated presence of VNUT in a subset of VGLUT1-containing vesicles. Thus, we conclude that VNUT mediates transport of ATP into synaptic vesicles of hippocampal neurons, thereby conferring a purinergic phenotype to these cells.
authors.affiliation: Department of Anatomy and Centre for Molecular Biology and Neuroscience, University of Oslo, N-0317 Oslo, Norway.
authors.forename: Max
authors.initials: M
authors.lastname: Larsson
authors.forename: Keisuke
authors.initials: K
authors.lastname: Sawada
authors.forename: Cecilie
authors.initials: C
authors.lastname: Morland
authors.forename: Miki
authors.initials: M
authors.lastname: Hiasa
authors.forename: Lasse
authors.initials: L
authors.lastname: Ormel
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Moriyama
authors.forename: Vidar
authors.initials: V
authors.lastname: Gundersen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D006624:Hippocampus / Q000378:metabolism; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D051379:Mice; D046529:Microscopy, Electron, Transmission; D016253:Microscopy, Immunoelectron; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D013572:Synaptic Vesicles / Q000378:metabolism / Q000648:ultrastructure; D033921:Vesicular Transport Proteins / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D033921:Vesicular Transport Proteins; D000255:Adenosine Triphosphate