Structural Protein Requirements in Equine Arteritis Virus Assembly
| Autor: | Antoine A.F. de Vries, Eric J. Snijder, Hans van Tol, Gert-Jan Godeke, Peter J. M. Rottier, Jannes van der Meulen, Henk K. Koerten, Jos J. M. Onderwater, Roeland Wieringa, A. Mieke Mommaas |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
viruses
Immunology Context (language use) Microbiology Virus Arterivirus Viral Matrix Proteins Equartevirus Viral Envelope Proteins Virology Heterotrimeric G protein Cricetinae Animals Cells Cultured chemistry.chemical_classification Viral Structural Proteins Viral matrix protein biology Structure and Assembly Virus Assembly Virion RNA virus biology.organism_classification Molecular biology Microscopy Electron Membrane protein chemistry Insect Science Glycoprotein Dimerization |
| Popis: | Equine arteritis virus (EAV) is an enveloped, positive-stranded RNA virus belonging to the family Arteriviridae of the order Nidovirales . EAV particles contain seven structural proteins: the nucleocapsid protein N, the unglycosylated envelope proteins M and E, and the N-glycosylated membrane proteins GP 2b (previously named G S ), GP 3 , GP 4 , and GP 5 (previously named G L ). Proteins N, M, and GP 5 are major virion components, E occurs in virus particles in intermediate amounts, and GP 4 , GP 3 , and GP 2b are minor structural proteins. The M and GP 5 proteins occur in virus particles as disulfide-linked heterodimers while the GP 4 , GP 3 , and GP 2b proteins are incorporated into virions as a heterotrimeric complex. Here, we studied the effect on virus assembly of inactivating the structural protein genes one by one in the context of a (full-length) EAV cDNA clone. It appeared that the three major structural proteins are essential for particle formation, while the other four virion proteins are dispensable. When one of the GP 2b , GP 3 , or GP 4 proteins was missing, the incorporation of the remaining two minor envelope glycoproteins was completely blocked while that of the E protein was greatly reduced. The absence of E entirely prevented the incorporation of the GP 2b , GP 3 , and GP 4 proteins into viral particles. EAV particles lacking GP 2b , GP 3 , GP 4 , and E did not markedly differ from wild-type virions in buoyant density, major structural protein composition, electron microscopic appearance, and genomic RNA content. On the basis of these results, we propose a model for the EAV particle in which the GP 2b /GP 3 /GP 4 heterotrimers are positioned, in association with a defined number of E molecules, above the vertices of the putatively icosahedral nucleocapsid. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|