Conformational maturation of measles virus nucleocapsid protein.
We have obtained a polyclonal antiserum, N-BE, against the denatured, amino-terminal half of the measles virus (MV) nucleocapsid (N) protein and a monoclonal antibody (MAb), N46, which recognizes a conformation-dependent epitope in the same region. Amino acid residues 23 to 239 were required and sufficient for the formation of the conformational epitope. Using these antibodies, we show that the N protein of MV is synthesized as a relatively unfolded protein which first appears in the free-protein pool. This nascent N protein undergoes a conformational change into a more folded mature form. This change does not require the participation of other viral proteins or genomic RNA. The mature N protein does not accumulate in the free-protein pool but is quickly and selectively incorporated into the viral nucleocapsids. The mature N protein is a target for interaction with the phosphoprotein (P protein) of MV. This interaction interferes with the recognition of the N protein by the N46 MAb. This suggests that the association with the P protein may mask the binding site for the N46 MAb or that it induces a conformational change in the N protein.
Gombart
A F
AF
Department of Microbiology, University of Washington School of Medicine, Seattle 98195.
Hirano
A
A
Wong
T C
TC
D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology; D000956:Antigens, Viral / Q000737:chemistry / Q000378:metabolism*; D002213:Capsid / Q000737:chemistry / Q000378:metabolism*; D002460:Cell Line; D000939:Epitopes; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008459:Measles virus / Q000378:metabolism / Q000648:ultrastructure*; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D012995:Solubility; D013329:Structure-Activity Relationship; D014758:Viral Core Proteins / Q000737:chemistry / Q000378:metabolism*; D014764:Viral Proteins / Q000276:immunology; D014779:Virus Replication
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D046911:Macromolecular Substances; D014758:Viral Core Proteins; D014764:Viral Proteins