title: Oligomerization of the influenza virus polymerase complex in vivo.
abstract: 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.
authors.affiliation: Centro Nacional de Biotecnología (CSIC), Darwin 3, Campus de Cantoblanco, 28049 Madrid, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Jorba
authors.affiliation: Centro Nacional de Biotecnología (CSIC), Darwin 3, Campus de Cantoblanco, 28049 Madrid, Spain.
authors.forename: Estela
authors.initials: E
authors.lastname: Area
authors.affiliation: Centro Nacional de Biotecnología (CSIC), Darwin 3, Campus de Cantoblanco, 28049 Madrid, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Ortín
mesh_terms: 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*
chemical_list: 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