Structural difference recognized by a monoclonal antibody #404-11 between the rabies virus nucleocapsid (NC) produced in virus infected cells and the NC-like structures produced in the nucleoprotein (N) cDNA-transfected cells.
We investigated structural changes in the rabies virus (HEP-Flury strain) nucleocapsid (NC) during the virus replication, for which we used two anti-nucleoprotein (N) monoclonal antibodies (mAbs), #404-11 (specific for a conformation-dependently exposed linear epitope) and #1-7-11 (specific for a conformational epitope which is exposed after the nucleocapsid formation). Both mAbs recognized the N protein of the viral NC, but not of the RNA-free N-P complex. The 1-7-11 and 404-11 epitopes could be mapped to the N-terminal and the C-terminal regions of N protein, respectively. Immunoprecipitation studies demonstrated that treatment of the NC either with the alkaline phosphatase or sodium deoxycholate (DOC) resulted in dissociation of most P proteins from the NC and in the reduced reactivity to mAb #404-11, but not to mAb #1-7-11. NC-like structures produced in the N cDNA-transfected cells displayed strong reactivity to mAb #1-7-11; however, reactivity to mAb #404-11 was very weak. And, coexpression with viral phosphoprotein (P) resulted in little increase in reactivity to mAb #404-11 of the NC-like structures, while the reactivity was significantly increased by cotransfection with P and the viral minigenome whose 3'- and 5'-end structures were derived from the viral genome. From these results, we assume that, although the 404-11 epitope is a linear one, the epitope-containing region is exposed only when N proteins encapsidate properly the viral RNA in collaboration with the P protein. Further, exposure of the 404-11 epitope region might be function-related, and be regulated by association and dissociation of the P protein.
Toriumi
Harufusa
H
Department of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.
Kawai
Akihiko
A
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology*; D000956:Antigens, Viral / Q000276:immunology; D002460:Cell Line; D006224:Cricetinae; D000939:Epitopes / Q000737:chemistry*; D019251:Nucleocapsid / Q000276:immunology / Q000302:isolation & purification*; D019590:Nucleocapsid Proteins; D011487:Protein Conformation
D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D000939:Epitopes; D019590:Nucleocapsid Proteins; C099601:nucleocapsid protein, Rabies virus