title: Torsin mediates primary envelopment of large ribonucleoprotein granules at the nuclear envelope.
abstract: A previously unrecognized mechanism through which large ribonucleoprotein (megaRNP) granules exit the nucleus is by budding through the nuclear envelope (NE). This mechanism is akin to the nuclear egress of herpes-type viruses and is essential for proper synapse development. However, the molecular machinery required to remodel the NE during this process is unknown. Here, we identify Torsin, an AAA-ATPase that in humans is linked to dystonia, as a major mediator of primary megaRNP envelopment during NE budding. In torsin mutants, megaRNPs accumulate within the perinuclear space, and the messenger RNAs contained within fail to reach synaptic sites, preventing normal synaptic protein synthesis and thus proper synaptic bouton development. These studies begin to establish the cellular machinery underlying the exit of megaRNPs via budding, offer an explanation for the "nuclear blebbing" phenotype found in dystonia models, and provide an important link between Torsin and the synaptic phenotypes observed in dystonia.
authors.affiliation: Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
authors.forename: Vahbiz
authors.initials: V
authors.lastname: Jokhi
authors.forename: James
authors.initials: J
authors.lastname: Ashley
authors.forename: John
authors.initials: J
authors.lastname: Nunnari
authors.forename: Akiko
authors.initials: A
authors.lastname: Noma
authors.forename: Naoto
authors.initials: N
authors.lastname: Ito
authors.forename: Noriko
authors.initials: N
authors.lastname: Wakabayashi-Ito
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Moore
authors.forename: Vivian
authors.initials: V
authors.lastname: Budnik
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004330:Drosophila; D004421:Dystonia / Q000378:metabolism; D006801:Humans; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009685:Nuclear Envelope / Q000378:metabolism* / Q000648:ultrastructure; D012261:Ribonucleoproteins / Q000378:metabolism*
chemical_list: D018832:Molecular Chaperones; D012261:Ribonucleoproteins; C108175:TOR1A protein, human