title: Nuclear envelope budding enables large ribonucleoprotein particle export during synaptic Wnt signaling.
abstract: Localized protein synthesis requires assembly and transport of translationally silenced ribonucleoprotein particles (RNPs), some of which are exceptionally large. Where in the cell such large RNP granules first assemble was heretofore unknown. We previously reported that during synapse development, a fragment of the Wnt-1 receptor, DFrizzled2, enters postsynaptic nuclei where it forms prominent foci. Here we show that these foci constitute large RNP granules harboring synaptic protein transcripts. These granules exit the nucleus by budding through the inner and the outer nuclear membranes in a nuclear egress mechanism akin to that of herpes viruses. This budding involves phosphorylation of A-type lamin, a protein linked to muscular dystrophies. Thus nuclear envelope budding is an endogenous nuclear export pathway for large RNP granules.
authors.affiliation: Department of Neurobiology, University of Massachusetts Medical School, Worcester, 01605, USA.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Speese
authors.forename: James
authors.initials: J
authors.lastname: Ashley
authors.forename: Vahbiz
authors.initials: V
authors.lastname: Jokhi
authors.forename: John
authors.initials: J
authors.lastname: Nunnari
authors.forename: Romina
authors.initials: R
authors.lastname: Barria
authors.forename: Yihang
authors.initials: Y
authors.lastname: Li
authors.forename: Bulent
authors.initials: B
authors.lastname: Ataman
authors.forename: Alex
authors.initials: A
authors.lastname: Koon
authors.forename: Young-Tae
authors.initials: YT
authors.lastname: Chang
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Moore
authors.forename: Vivian
authors.initials: V
authors.lastname: Budnik
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism* / Q000648:ultrastructure; D051157:Frizzled Receptors / Q000378:metabolism*; D006801:Humans; D034904:Lamin Type A / Q000378:metabolism*; D007814:Larva / Q000378:metabolism / Q000648:ultrastructure; D018485:Muscle Fibers, Skeletal / Q000648:ultrastructure; D009469:Neuromuscular Junction / Q000378:metabolism*; D009685:Nuclear Envelope / Q000378:metabolism* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D029721:Drosophila Proteins; D051157:Frizzled Receptors; D034904:Lamin Type A; D012333:RNA, Messenger; D012261:Ribonucleoproteins; C101703:fz2 protein, Drosophila; C440308:lamin C