Clustered basic amino acids of the small sendai virus C protein Y1 are critical to its RAN GTPase-mediated nuclear localization.
The Sendai virus (SeV) C proteins are shown to exert multiple functions during the course of infection. Perhaps reflecting their many functions, they occur at multiple sites of the cell. In this study, we focused on the nuclear-localizing ability of the smaller C protein, Y1, and found that this translocation is mediated by Ran GTPase but not by passive diffusion, and that basic residues within the 149-157 amino acid region are critical for that. The mechanism of inhibition of interferon (IFN)-signaling seemed to differ between the C and Y1 proteins, since deletion of 12 C-terminal amino acids resulted in a loss of the function for the C but not for the Y1 protein. The ability of Y1 mutants to inhibit IFN-α-induced, ISRE-driven expression of a reporter gene almost paralleled with that to localize in the nucleus. These results suggest that nuclear localization of the Y1 protein might be important for the inhibitory effect on type-I IFN-stimulated gene expression.
Department of Virology, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan. tirie@hiroshima-u.ac.jp
Takashi
T
Irie
Asuka
A
Yoshida
Takemasa
T
Sakaguchi
D021581:Active Transport, Cell Nucleus; D024361:Amino Acids, Basic / Q000737:chemistry / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure / Q000821:virology*; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D054884:Host-Pathogen Interactions; D006801:Humans; D050838:Interferon Regulatory Factor-3 / Q000235:genetics / Q000378:metabolism; D016898:Interferon-alpha / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D029082:Sendai virus / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D020931:ran GTP-Binding Protein / Q000235:genetics* / Q000378:metabolism
D024361:Amino Acids, Basic; D050838:Interferon Regulatory Factor-3; D016898:Interferon-alpha; C120587:RAN protein, human; D014764:Viral Proteins; C051221:nonstructural C protein, Sendai virus; D049452:Green Fluorescent Proteins; D020931:ran GTP-Binding Protein