Mechanism of evenness interrupted (Evi)-exosome release at synaptic boutons
Authors
Koles, KateNunnari, John J.
Korkut, Ceren
Barria, Romina
Brewer, Cassandra
Li, Yihang
Leszyk, John D.
Zhang, Bing
Budnik, Vivian
Student Authors
Ceren KorkutYihang Li
Academic Program
NeuroscienceUMass Chan Affiliations
Graduate School of Biomedical Sciences, Neuroscience ProgramBudnik Lab
Proteomics Core
Neurobiology
Document Type
Journal ArticlePublication Date
2012-05-11Keywords
Animals; Biological Transport; Drosophila Proteins; Drosophila melanogaster; Exosomes; Intracellular Signaling Peptides and Proteins; Membrane Proteins; Myosin Type V; Neuromuscular Junction; Synaptic Transmission; Synaptic Vesicles; rab GTP-Binding ProteinsBiochemistry
Cell Biology
Developmental Biology
Developmental Neuroscience
Metadata
Show full item recordAbstract
Wnt signaling plays critical roles during synaptic development and plasticity. However, the mechanisms by which Wnts are released and travel to target cells are unresolved. During synaptic development, the secretion of Drosophila Wnt1, Wingless, requires the function of Evenness Interrupted (Evi)/Wls, a Wingless-binding protein that is secreted along with Wingless at the neuromuscular junction. Given that Evi is a transmembrane protein, these studies suggested the presence of a novel vesicular mechanism of trans-synaptic communication, potentially in the form of exosomes. To establish the mechanisms for the release of Evi vesicles, we used a dsRNA assay in cultured cells to screen for genes that when down-regulated prevent the release of Evi vesicles. We identified two proteins, Rab11 and Syntaxin 1A (Syx1A), that were required for Evi vesicle release. To determine whether the same mechanisms were used in vivo at the neuromuscular junction, we altered the activity of Rab11 and Syx1A in motoneurons and determined the impact on Evi release. We found that Syx1A, Rab11, and its effector Myosin5 were required for proper Evi vesicle release. Furthermore, ultrastructural analysis of synaptic boutons demonstrated the presence of multivesicular bodies, organelles involved in the production and release of exosomes, and these multivesicular bodies contained Evi. We also used mass spectrometry, electron microscopy, and biochemical techniques to characterize the exosome fraction from cultured cells. Our studies revealed that secreted Evi vesicles show remarkable conservation with exosomes in other systems. In summary, our observations unravel some of the in vivo mechanisms required for Evi vesicle release.Source
J Biol Chem. 2012 May 11;287(20):16820-34. doi: 10.1074/jbc.M112.342667. Epub 2012 Mar 21. Link to article on publisher's siteDOI
10.1074/jbc.M112.342667Permanent Link to this Item
http://hdl.handle.net/20.500.14038/33425PubMed ID
22437826Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1074/jbc.M112.342667