A VAPB mutant linked to amyotrophic lateral sclerosis generates a novel form of organized smooth endoplasmic reticulum

The FASEB JournalVolume 24, Issue 5 p. 1419-1430 Research CommunicationFree to Read A VAPB mutant linked to amyotrophic lateral sclerosis generates a novel form of organized smooth endoplasmic reticulum Elisa Fasana, Elisa Fasana Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, ItalySearch for more papers by this authorMatteo Fossati, Matteo Fossati Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, ItalySearch for more papers by this authorAnnamaria Ruggiano, Annamaria Ruggiano Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, ItalySearch for more papers by this authorSilvia Brambillasca, Silvia Brambillasca Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, Italy Department of Pharmacology, Universita degli Studi di Milano, Milan, ItalySearch for more papers by this authorCasper C. Hoogenraad, Casper C. Hoogenraad Department of Neuroscience, Erasmus Medical Center, Rotterdam, The NetherlandsSearch for more papers by this authorFrancesca Navone, Francesca Navone Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, ItalySearch for more papers by this authorMaura Francolini, Maura Francolini Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, ItalySearch for more papers by this authorNica Borgese, Corresponding Author Nica Borgese n.borgese@in.cnr.it Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, Italy Department of Pharmacology, Universita degli Studi di Milano, Milan, ItalyCorrespondence: Consiglio Nazionale delle Ricerche Institute of Neuroscience, via Vanvitelli 32, 20129 Milano, Italy. E-mail: n.borgese@in.cnr.itSearch for more papers by this author Elisa Fasana, Elisa Fasana Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, ItalySearch for more papers by this authorMatteo Fossati, Matteo Fossati Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, ItalySearch for more papers by this authorAnnamaria Ruggiano, Annamaria Ruggiano Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, ItalySearch for more papers by this authorSilvia Brambillasca, Silvia Brambillasca Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, Italy Department of Pharmacology, Universita degli Studi di Milano, Milan, ItalySearch for more papers by this authorCasper C. Hoogenraad, Casper C. Hoogenraad Department of Neuroscience, Erasmus Medical Center, Rotterdam, The NetherlandsSearch for more papers by this authorFrancesca Navone, Francesca Navone Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, ItalySearch for more papers by this authorMaura Francolini, Maura Francolini Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, ItalySearch for more papers by this authorNica Borgese, Corresponding Author Nica Borgese n.borgese@in.cnr.it Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, Italy Department of Pharmacology, Universita degli Studi di Milano, Milan, ItalyCorrespondence: Consiglio Nazionale delle Ricerche Institute of Neuroscience, via Vanvitelli 32, 20129 Milano, Italy. E-mail: n.borgese@in.cnr.itSearch for more papers by this author First published: 14 December 2009 https://doi.org/10.1096/fj.09-147850Citations: 7Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract VAPB (vesicle-associated membrane protein-associated protein B) is an endoplasmic reticulum (ER)-resident tail-anchored adaptor protein involved in lipid transport. A dominantly inherited mutant, P56S-VAPB, causes a familial form of amyotrophic lateral sclerosis (ALS) and forms poorly characterized inclusion bodies in cultured cells. To provide a cell biological basis for the understanding of mutant VAPB pathogenicity, we investigated its biogenesis and the inclusions that it generates. Translocation assays in cell-free systems and in cultured mammalian cells were used to investigate P56S-VAPB membrane insertion, and the inclusions were characterized by confocal imaging and electron microscopy. We found that mutant VAPB inserts post-translationally into ER membranes in a manner indistinguishable from the wild-type protein but that it rapidly clusters to form inclusions that remain continuous with the rest of the ER. Inclusions were induced by the mutant also when it was expressed at levels comparable to the endogenous wild-type protein. Ultrastructural analysis revealed that the inclusions represent a novel form of organized smooth ER (OSER) consisting in a limited number of parallel cisternae (usually 2 or 3) interleaved by a ~30 nm-thick electron-dense cytosolic layer. Our results demonstrate that the ALS-linked VAPB mutant causes dramatic ER restructuring that may underlie its pathogenicity in motoneurons.—Fasana, E., Fossati, M., Ruggiano, A., Brambillasca, S., Hoogenraad, C. C., Navone, F., Francolini, M., Borgese, N. A VAPB mutant linked to amyotrophic lateral sclerosis generates a novel form of organized smooth endoplasmic reticulum. FASEB J. 24, 1419–1430 (2010). www.fasebj.org Citing Literature Supporting Information Filename Description fsb2fj09147850-sup-0001.zipZip archive, 7.2 MB supplementary material Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. Volume24, Issue5May 2010Pages 1419-1430 RelatedInformation