Identification of nuclear export signal in UL37 protein of herpes simplex virus type 2.
The UL37 gene of herpes simplex virus (HSV) encodes a 120-kDa phosphoprotein associated with the virion. In this study, we have generated a rabbit polyclonal antiserum against HSV-2 UL37 protein, and examined its intracellular localization by immunofluorescence study. In infected cells, specific fluorescence was detectable in the perinuclear region. In transfected cells, UL37 protein was observed mainly in the cytoplasm. Transfection assays of deletion mutants of UL37 protein suggested that the leucine rich region (LRR) containing amino acids 263-273 may be important for cytoplasmic localization. Deletion of the LRR or substitution of the leucine residues resulted in nuclear remaining of UL37 protein. Moreover, the LRR could export green fluorescent protein (GFP) to the cytoplasm as a fusion protein and this export was blocked by leptomycin B treatment, indicating that the LRR acted as a nuclear export signal. These results suggest that UL37 protein fulfills a role as a shuttle between the nucleus and the cytoplasm through the LRR.
Watanabe
D
D
Laboratory of Virology, Research Institute for Disease Mechanism and Control, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
Ushijima
Y
Y
Goshima
F
F
Takakuwa
H
H
Tomita
Y
Y
Nishiyama
Y
Y
D021581:Active Transport, Cell Nucleus; D020816:Amino Acid Motifs / Q000235:genetics / Q000502:physiology; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D000918:Antibody Specificity; D002467:Cell Nucleus / Q000378:metabolism*; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D018258:Herpesvirus 2, Human / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D007106:Immune Sera / Q000276:immunology; D007930:Leucine / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals / Q000235:genetics / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid / Q000235:genetics / Q000502:physiology; D016415:Sequence Alignment; D017384:Sequence Deletion / Q000235:genetics; D014162:Transfection; D014709:Vero Cells; D015678:Viral Structural Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
D005231:Fatty Acids, Unsaturated; D007106:Immune Sera; D019913:Nuclear Localization Signals; D011993:Recombinant Fusion Proteins; C415868:UL37 protein, Herpes simplex virus type 2; D015678:Viral Structural Proteins; D007930:Leucine; C038753:leptomycin B