title: Rotavirus viroplasm fusion and perinuclear localization are dynamic processes requiring stabilized microtubules.
abstract: Rotavirus viroplasms are cytosolic, electron-dense inclusions corresponding to the viral machinery of replication responsible for viral template transcription, dsRNA genome segments replication and assembly of new viral cores. We have previously observed that, over time, those viroplasms increase in size and decrease in number. Therefore, we hypothesized that this process was dependent on the cellular microtubular network and its associated dynamic components. Here, we present evidence demonstrating that viroplasms are dynamic structures, which, in the course of an ongoing infection, move towards the perinuclear region of the cell, where they fuse among each other, thereby gaining considerably in size and, simultaneously, explaining the decrease in numbers. On the viral side, this process seems to depend on VP2 for movement and on NSP2 for fusion. On the cellular side, both the temporal transition and the maintenance of the viroplasms are dependent on the microtubular network, its stabilization by acetylation, and, surprisingly, on a kinesin motor of the kinesin-5 family, Eg5. Thus, we provide for the first time deeper insights into the dynamics of rotavirus replication, which can explain the behavior of viroplasms in the infected cell.
authors.affiliation: Institute of Virology, University of Zurich, Switzerland. ceichwald@vetvir.uzh.ch
authors.forename: Catherine
authors.initials: C
authors.lastname: Eichwald
authors.forename: Francesca
authors.initials: F
authors.lastname: Arnoldi
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Laimbacher
authors.forename: Elisabeth M
authors.initials: EM
authors.lastname: Schraner
authors.forename: Cornel
authors.initials: C
authors.lastname: Fraefel
authors.forename: Peter
authors.initials: P
authors.lastname: Wild
authors.forename: Oscar R
authors.initials: OR
authors.lastname: Burrone
authors.forename: Mathias
authors.initials: M
authors.lastname: Ackermann
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000502:physiology; D036022:Capsid Proteins / Q000378:metabolism; D002460:Cell Line; D002522:Chlorocebus aethiops; D005455:Fluorescent Antibody Technique; D015151:Immunoblotting; D002479:Inclusion Bodies / Q000378:metabolism*; D016547:Kinesins / Q000378:metabolism; D008253:Macaca mulatta; D046529:Microscopy, Electron, Transmission; D008870:Microtubules / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D016601:RNA-Binding Proteins / Q000378:metabolism; D012401:Rotavirus / Q000235:genetics / Q000502:physiology*; D017361:Viral Nonstructural Proteins / Q000378:metabolism; D014779:Virus Replication / Q000235:genetics / Q000502:physiology*
chemical_list: D036022:Capsid Proteins; D016601:RNA-Binding Proteins; C442545:VP2 protein, Rotavirus; D017361:Viral Nonstructural Proteins; C079234:NS35 protein, rotavirus; D016547:Kinesins