Genome replication of reovirus occurs in cytoplasmic inclusion bodies called viral factories or viroplasms. The viral nonstructural protein μNS, encoded by genome segment M3, is not a component of mature virions, but is expressed to high levels in infected cells and is concentrated in the infected cell factory matrix. Recent studies have demonstrated that μNS plays a central role in forming the matrix of these structures, as well as in recruiting other components to them for putative roles in genome replication and particle assembly.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Price excludes VAT (USA)
Tax calculation will be finalised during checkout.
Antczak J B, Joklik W K. 1992. Reovirus genome segment assortmen into progeny genomes studied by the use of monoclonal antibodies directed against reovirus proteins. Virology, 187: 760–776.
Attoui H, Fang Q, Mohd Jaafar F, et al. 2002. Common evolutionary origin of aquareoviruses and orthoreoviruses revealed by genome characterization of Golden shiner reovirus, Grass carp reovirus, Striped bass reovirus and golden ide reovirus (genus Aquareovirus, family Reoviridae). J Gen Virol, 83:1941–1951.
Becker M M, Goral M I, Hazelton P R, et al. 2001. Reovirus μNS protein is required for nucleation of viral assembly complexes and formation of viral inclusions. J Virol, 75: 1459–1475.
Becker M M, Peters T R, Dermody T S. 2003. Reovirus μNS and μNS proteins form cytoplasmic inclusion structures in the absence of viral infection. J Virol, 77: 5948–5963.
Broering T J, McCutcheon A M, Centonze V E, et al. 2000. Reovirus Nonstructural Protein μNS Binds to Core Particles but Does Not Inhibit Their Transcription and Capping Activities. J Virol, 74: 5516–5524.
Broering T J, Parker J S L, Joyce P L, et al. 2002. Mammalian Reovirus Nonstructural Protein μNS Forms Large Inclusions and Colocalizes with Reovirus Microtubule-Associated Protein μ2 in Transfected Cells. J Virol, 76: 8285–8297.
Broering T J, Kim J, Miller C L, et al. 2004. Reovirus nonstructural protein μNS recruits viral core surface proteins and entering core particles to factory-like inclusions. J. Virol. 78: 1882–1892.
Broering T J, Kim J, Miller CL, et al. 2005. Carboxyl-Proximal Regions of Reovirus Nonstructural Protein μNS Necessary and Sufficient for Forming Factory-Like Inclusions. J Virol, 79: 6194–6206.
Cheng L, Fang Q, Shah S, et al. 2008. Subnanometerresolution Structures of the Grass Carp Reovirus Core and Virion, J Mol Biol, DOI: 10.1016/j.jmb.2008.06.075.
Dryden K A, Wang G, Yeager M, et al. 1993. Early steps in reovirus infection are associated with dramatic changes in supramo-lecular structure and protein conformation: analysis of virions and subviral particles by cryoelectron microscopy and image recon-struction. J Cell Biol, 122: 1023–1041.
Gillian A L, Nibert M L. 1998. Amino terminus of reovirus nonstructural protein μNS is important for ssRNA binding and nucleoprotein complex formation. Virology, 240: 1–11.
Gillian A L, Schmechel S C, Livny J, et al. 2000. Reovirus nonstructural protein μNS binds in multiple copies to singlestranded RNA and shares properties with single-stranded DNA binding proteins. J Virol, 74: 5939–5948.
Karin M R, Nibert M L, Harrison S C. 2000. Structure of the reovirus core at 3.6Å resolution. Nature, 404: 960–967.
Kim J, Zhang X, Centonze V E, et al. 2002. The hydrophilic amino-terminal arm of reovirus core shell protein λ1 is dispensable for particle assembly. J Virol, 76: 12211–12222.
Kobayashi T, Chappell J D, Danthi P, et al. 2006. Gene-specific inhibition of reovirus replication by RNA interference. J Virol, 80: 9053–9063.
Mbisa J L, Becker M M, Zou S, et al. 2000. Reovirus μ2 protein determines strain-specific differences in the rate of viral inclusion formation in L929 cells. Virology, 272: 16–26.
McCutcheon A M, Broering T J, Nibert M L. 1999. Mammalian reovirus M3 gene sequences and conservation of coiled-coil motifs near the carboxyl terminus of the μNS protein. Virology, 264: 16–24.
Michelle M A, Murray K E, Nibert M L. 2008. Formation of the factory matrix is an important, though not a sufficient function of nonstructural protein μNS during reovirus infection. Virology, 375 (2008): 412–423.
Miller C L, Broering T J, Parker J S L, et al. 2003. Reovirus σNS protein localizes to inclusions through an association requiring the μNS amino-terminus. J Virol, 77: 4566–4576.
Miller C L, Arnold M M, Broering T J, et al. 2007. A cytoplasmic platform for easily visualizing protein — protein associations inside cells. Mol Cell Proteomics, 6: 1027–1038.
Parker J S L, Broering T J, Kim J, et al. 2002. Reovirus core protein μ2 determines the filamentousmorphology of viral inclusion bodies by interacting with and stabilizing microtubules. J Virol, 76: 4483–4496.
Sharpe A H, Chen L B, Fields B N. 1982. The interaction of mammalianreoviruses with the cytoskeleton of monkey kidney CV-1 cells. Virology, 120: 399–411.
Susanne L, Chandran K, Baker T S, et al. 2002. Structure of the Reovirus Membrane-Penetration Protein μ1, in a Complex with Its Protector Protein σ3. Cell, 108: 283–295.
Theron J, Huismans H, Nel L H. 1996. Site-specific mutations in the NS2 protein of epizootic haemorrhagic disease virus markedly affect the formation of cytoplasmic inclusion bodies. Arch Virol, 141: 1143–1151.
Touris O, Martinez C F J, Vakharia V N, et al. 2004. Avian reovirus nonstructural protein μNS forms viroplasmlike inclusions and recruits protein μNS to these structures. Virology, 319: 94–106.
Walker S B, Zhang X, Tang J H, et al. 2005. Structure of avian orthoreovirus virion by electron cryomicroscopy and image reconstruction. Virology, 343: 25–35.
Wiener J R, Bartlett J A, Joklik W K. 1989. The sequences of reovirus serotype 3 genome segments M1 and M3 encoding the minor protein μ2 and the major nonstructural protein μNS, respectively. Virology, 169: 293–304.
Xu P, Miller S E, Joklik W K. 1993. Generation of reovirus core-like particles in cells infected with hybrid vaccinia viruses that express genome segments L1, L2, L3, and S2. Virology, 197: 726–731.
Yeager M, Weiner S, Cooms K M. 1996. Transcriptional active reovirus core particles visualized by electron cryo-microscopy and image reconstruction. Biophys J, 1996(70): A116.
Zou G P, Fang Q. 2000. Study On Replication and Morphogenesis of the Grass Carp Reovirus (GCRV) in CIK Cells. Virol Sin, 15: 188–192.
Zweerink H J, Morgan E M, Skyler J S. 1976. Reovirus morphogenesis: characterization of subviral particles in infected cells. Virology, 73: 442–453.
Foundation items: National Basic Research Program of China (973 Program) (2009CB118701); National Natural Scientific Foundation of China (30671615, 30871940); Innovation project of the Chinese Academy of Sciences (KSCX2-YW-N-021 to QF).
Rights and permissions
About this article
Cite this article
Fan, C., Fang, Q. Functional analyses of mammalian reovirus nonstructural protein μNS. Virol. Sin. 24, 1–8 (2009). https://doi.org/10.1007/s12250-009-3016-5
- dsRNA virus
- Mammalian orthoreoviruses
- Nonstructural protein μNS