Two forms of VP7 are involved in assembly of SA11 rotavirus in endoplasmic reticulum.
AUTOR(ES)
Kabcenell, A K
RESUMO
Two pools of the glycoprotein VP7 were detected in the endoplasmic reticulum (ER) of SA11 rotavirus-infected cells. One portion of the newly synthesized protein with VP3 composed the virus outer capsid, while the rest remained associated with the membrane. The two populations could be separated biochemically by fluorocarbon extraction or by immunological methods which used two classes of antibodies. A monoclonal antibody with neutralizing activity recognized VP7 only as displayed on intact virus particles, while a polyclonal antiserum precipitated predominantly the unassembled ER form of the protein and precipitated virus-assembled VP7 poorly. Virus-associated VP7 was localized by immunofluorescence to small punctate structures, presumably corresponding to accumulated virus particles, and to regions of the ER surrounding viroplasmic inclusions, whereas the membrane-associated molecules were distributed in an arborizing reticular pattern throughout the ER. VP3 and the nonstructural glycoprotein NCVP5 displayed a localization similar to that of virus-associated VP7. Intracellular virus particles were isolated from infected cells to determine the kinetics of assembly of VP7 and of the other structural proteins into virions. It was found that incorporation of the inner capsid proteins into single-shelled particles occurred rapidly, while VP7 and VP3 appeared in mature double-shelled particles with a lag time of 10 to 15 min. In addition, the alpha-mannosidase processing kinetics of virus-associated VP7 oligosaccharides showed a 15-min lag compared with that of the membrane-associated form, suggesting that the latter is the precursor to virion VP7. This lag may represent the time required for virus budding and outer capsid assembly.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=253731Documentos Relacionados
- Location of sequences within rotavirus SA11 glycoprotein VP7 which direct it to the endoplasmic reticulum.
- Expression of the rotavirus SA11 protein VP7 in the simple eukaryote Dictyostelium discoideum.
- Vaccinia virus recombinants expressing the SA11 rotavirus VP7 glycoprotein gene induce serotype-specific neutralizing antibodies.
- Production of reassortant viruses containing human rotavirus VP4 and SA11 VP7 for measuring neutralizing antibody following natural infection.
- Production of Reassortant Viruses Containing Human Rotavirus VP4 and SA11 VP7 for Measuring Neutralizing Antibody following Natural Infection