Structural relationship between nucleocapsid-binding activity of the rabies virus phosphoprotein (P) and exposure of epitope 402-13 located at the C terminus.
The structural changes of the nominal phosphoprotein (P) of rabies virus using a monoclonal antibody, mAb #402-13, was investigated. This mAb recognized a linear epitope that was mapped roughly to a C-terminal region of the P protein, ranging from aa 256 to 297. The P gene products were detected by the mAb in immunoblot assays, the products of which were produced either in BHK-21 cells or in Escherichia coli cells. The mAb, however, detected very low levels of P gene products in immunoprecipitation assays. The mAb recognized the nucleocapsid (NC)-associated P proteins but recognized free P protein and free N-P complex produced in the infected cells much less efficiently. When the P proteins were released from the NC, however, they were no longer recognized by the mAb. Similar results were obtained from BHK-21 cells co-transfected with P and N cDNAs. Furthermore, studies with C-terminally truncated P protein mutants revealed that the NC-binding ability of the P protein was dependent on the presence of the C-terminal epitope region. From these results, it is thought that the 402-13 epitope region is concealed when the P protein is present in a free form or free N-P complex but is exposed when it is associated with the NC. The C-terminal epitope region seemed to be essential for the P protein to be associated with the NC but not for the formation of free N-P complexes with newly synthesized N protein.
Toriumi
Harufusa
H
Department of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan1.
Honda
Yoshikazu
Y
Department of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan1.
Morimoto
Kinjiro
K
Department of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan1.
Tochikura
Tadafumi S
TS
Department of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan1.
Kawai
Akihiko
A
Department of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan1.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology; D002460:Cell Line; D006224:Cricetinae; D018604:Epitope Mapping; D000939:Epitopes / Q000737:chemistry*; D018832:Molecular Chaperones; D019251:Nucleocapsid / Q000378:metabolism*; D019590:Nucleocapsid Proteins; D010750:Phosphoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D011820:Rabies virus / Q000276:immunology / Q000378:metabolism*; D013329:Structure-Activity Relationship; D015678:Viral Structural Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D000939:Epitopes; D018832:Molecular Chaperones; D019590:Nucleocapsid Proteins; C103961:P phosphoprotein, Rabies virus; D010750:Phosphoproteins; D015678:Viral Structural Proteins; C099601:nucleocapsid protein, Rabies virus