Identification of the sequences responsible for nuclear targeting of the V protein of human parainfluenza virus type 2.
In human parainfluenza virus type 2 (hPIV-2)-infected cells, anti-phosphoprotein (P)-specific monoclonal antibody (MAb) densely stained the perinuclear regions of infected cells throughout infection, indicating that the P protein was localized exclusively in the cell cytoplasm. By contrast, antigens recognized by MAbs directed against the P-V-common domain of hPIV-2 were located predominantly in the cytoplasm, but in some hPIV-2-infected cells they were also found in the nuclei, suggesting that a fraction of hPIV-2 V protein is localized there. hPIV-2 V protein expressed from a cDNA clone was localized in the nuclei of transfected cells. By using indirect immunofluorescence analyses, we examined the intracellular localization of various sequentially deleted V proteins, to determine the nuclear localization signals (NLS) of the V protein. Two noncontiguous regions in the V protein were required for nuclear localization and retention, since deletion of these regions [region I (aa 1-46) and region II (aa 175-196)] resulted in cytoplasmic localization. Both regions resulted in nuclear localization independently. A nucleoplasmin-like NLS was identified in region II but no consensus targeting sequence could be found in region I. When NP protein was co-expressed with V protein or the N-terminal fragment (aa 1-46) of V protein, a fraction of the NP protein was translocated into cell nuclei.
Watanabe
N
N
Department of Microbiology, Mie University School of Medicine, Japan.
Kawano
M
M
Tsurudome
M
M
Kusagawa
S
S
Nishio
M
M
Komada
H
H
Shima
T
T
Ito
Y
Y
D000595:Amino Acid Sequence; D001483:Base Sequence; D002467:Cell Nucleus / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009698:Nucleoproteins / Q000032:analysis; D010223:Parainfluenza Virus 2, Human / Q000737:chemistry*; D010750:Phosphoproteins / Q000032:analysis; D015678:Viral Structural Proteins / Q000032:analysis* / Q000235:genetics
D009698:Nucleoproteins; D010750:Phosphoproteins; D015678:Viral Structural Proteins