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, simultaneouly, 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.
Highlights
Rotavirus, a member of the Sedovirinae subfamily within the reoviridae family, is an icosahedral, non-enveloped, triple-layered particle that encapsidates a genome consisting of eleven segments of double-stranded RNA
Staining of the plasma membrane and the nucleus of NSP5-EGFP/MA104 cells infected with simian rotavirus SA11 (Figure 1B) supported detection of a second event consisting of a gradual movement of viroplasms to the perinuclear region during the infection period
We performed time-lapse confocal microscopy of NSP5-EGFP/MA104 cells infected with simian rotavirus SA11 and followed the fate of individual viroplasms within the cell
Summary
A member of the Sedovirinae subfamily within the reoviridae family, is an icosahedral, non-enveloped, triple-layered particle that encapsidates a genome consisting of eleven segments of double-stranded RNA (dsRNA). The viral primary translation is required: i) for the subversion of the host translation machinery, mediated by NSP3 [10,11,12,13,14]; ii) to antagonize the host innate immune response, mediated by NSP1 [15] and iii) for the formation of viroplasms, the cytosolic machinery of replication [16,17,18,19,20,21] These structures correspond to electrondense inclusion bodies without lipidic membranes surrounded by polyribosomes [16]. The viroplasms are surrounded by a region rich in VP7, as detected by immunofluorescence, that corresponds to ER or assembled TLPs (triple layered particles) within ER [21,23]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
