title: Different intracellular distribution of avian reovirus core protein sigmaA in cells of avian and mammalian origin.
abstract: A comparative analysis of the intracellular distribution of avian reovirus (ARV) core protein sigmaA in cells of avian and mammalian origin revealed that, whereas the viral protein accumulates in the cytoplasm and nucleolus of avian cells, most sigmaA concentrates in the nucleoplasm of mammalian cells in tight association with the insoluble nuclear matrix fraction. Our results further showed that sigmaA becomes arrested in the nucleoplasm of mammalian cells via association with mammalian cell-specific factors and that this association prevents nucleolar targeting. Inhibition of RNA polymerase II activity, but not of RNA polymerase I activity, in infected mammalian cells induces nucleus-to-cytoplasm sigmaA translocation through a CRM1- and RanGTP-dependent mechanism, yet a heterokaryon assay suggests that sigmaA does not shuttle between the nucleus and cytoplasm. The scarcity of sigmaA in cytoplasmic viral factories of infected mammalian cells could be one of the factors contributing to limited ARV replication in mammalian cells.
authors: Departamento de Bioquímica y Biología Molecular, y Centro Singular de Investigación en Química Biológica y Materiales Moleculares, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain.
authors: Lorena
authors: L
authors: Vázquez-Iglesias
authors: Irene
authors: I
authors: Lostalé-Seijo
authors: José
authors: J
authors: Martínez-Costas
authors: Javier
authors: J
authors: Benavente
mesh_terms: D000818:Animals; D001717:Birds / Q000821:virology; D002460:Cell Line; D002466:Cell Nucleolus / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002642:Chick Embryo / Q000821:virology; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000378:metabolism; D005347:Fibroblasts / Q000821:virology; D006367:HeLa Cells / Q000821:virology; D006801:Humans; D008322:Mammals / Q000821:virology; D030101:Orthoreovirus, Avian / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D013045:Species Specificity; D013347:Subcellular Fractions / Q000378:metabolism* / Q000821:virology; D014709:Vero Cells / Q000821:virology; D014758:Viral Core Proteins / Q000378:metabolism*
chemical_list: D016601:RNA-Binding Proteins; D014758:Viral Core Proteins; C403292:sigmaA protein, avian reovirus