Rotavirus viroplasm fusion and perinuclear localization are dynamic processes requiring stabilized microtubules

• Published in: PloS one 2012-10, Vol.7 (10), p.e47947-e47947
• Main Authors: Eichwald, Catherine, Arnoldi, Francesca, Laimbacher, Andrea S, Schraner, Elisabeth M, Fraefel, Cornel, Wild, Peter, Burrone, Oscar R, Ackermann, Mathias
• Format: Article
• Language: English
• Subjects: Acetylation; Animals; Apoptosis; Biological Transport - physiology; Biology; Capsid Proteins - metabolism; Cell division; Cell Line; Cellular communication; Cercopithecus aethiops; Cores; Double-stranded RNA; Fluorescent Antibody Technique; Genetic aspects; Genetic engineering; Genomes; Genomics; Health aspects; Herpes viruses; Immunoblotting; Inclusion bodies; Inclusion Bodies - metabolism; Infection; Infections; Kinesin; Kinesin - metabolism; Localization; Macaca mulatta; Machinery and equipment; Medicine; Microscopy, Electron, Transmission; Microtubules; Microtubules - metabolism; Plasmids - genetics; Prevention; Proteins; Replication; RNA-Binding Proteins - metabolism; Rotavirus; Rotavirus - genetics; Rotavirus - physiology; Rotavirus infections; Transcription; Transcription (Genetics); Veterinary Science; Viral Nonstructural Proteins - metabolism; Virology; Viroplasm; Virus Replication - genetics; Virus Replication - physiology
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0047947

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.