Oligomerization of the influenza virus polymerase complex in vivo.
The influenza virus polymerase is a heterotrimer formed by the PB1, PB2 and PA subunits and is responsible for virus transcription and replication. We have expressed the virus polymerase complex by co-transfection of the subunit cDNAs, one of which was tandem affinity purification (TAP)-tagged, into human cells. The intracellular polymerase complexes were purified by the TAP approach, involving two affinity chromatography steps, IgG-Sepharose and calmodulin-agarose. Gel-filtration analysis indicated that, although most of the purified polymerase behaved as a heterotrimer, a significant proportion of the purified material migrated as polymerase dimers, trimers and higher oligomers. Co-purification of polymerase complexes alternatively tagged in the same subunit confirmed that the polymerase complex might form oligomers intracellularly. The implications of this observation for virus infection are discussed.
Jorba
Núria
N
Centro Nacional de Biotecnología (CSIC), Darwin 3, Campus de Cantoblanco, 28049 Madrid, Spain.
Area
Estela
E
Centro Nacional de Biotecnología (CSIC), Darwin 3, Campus de Cantoblanco, 28049 Madrid, Spain.
Ortín
Juan
J
Centro Nacional de Biotecnología (CSIC), Darwin 3, Campus de Cantoblanco, 28049 Madrid, Spain.
D002460:Cell Line; D006801:Humans; D009975:Orthomyxoviridae / Q000201:enzymology* / Q000276:immunology; D011108:Polymers; D011487:Protein Conformation; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry*; D014764:Viral Proteins / Q000737:chemistry*
C057027:PB2 protein, Influenzavirus A; D011108:Polymers; D021122:Protein Subunits; D014764:Viral Proteins; C077346:influenza virus polymerase basic protein 1; D012324:RNA-Dependent RNA Polymerase