Molecular interactions and trafficking of influenza A virus polymerase proteins analyzed by specific monoclonal antibodies.
The influenza polymerase complex composed of PA, PB1 and PB2, plays a key role in viral replication and pathogenicity. Newly synthesized components must be translocated to the nucleus, where replication and transcription of viral genomes take place. Previous studies suggest that while PB2 is translocated to the nucleus independently, PA and PB1 subunits could not localize to the nucleus unless in a PA-PB1 complex. To further determine the molecular interactions between the components, we created a panel of 16 hybridoma cell lines, which produce monoclonal antibodies (mAbs) against each polymerase component. We showed that, although PB1 interacts with both PA and PB2 individually, nuclear localization of PB1 is enhanced only when co-expressed with PA. Interestingly, one of the anti-PA mAbs reacted much more strongly with PA when co-expressed with PB1. These results suggest that PA-PB1 interactions induce a conformational change in PA, which could be required for its nuclear translocation.
Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA.
Leslie A
LA
MacDonald
Shilpa
S
Aggarwal
Kendra A
KA
Bussey
Emily A
EA
Desmet
Baek
B
Kim
Toru
T
Takimoto
D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis / Q000276:immunology; D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry / Q000821:virology; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D007251:Influenza, Human / Q000821:virology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011485:Protein Binding; D021381:Protein Transport; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; C061290:PA protein, influenza viruses; C502893:PB2 protein, influenza virus; D014764:Viral Proteins; C077346:influenza virus polymerase basic protein 1; D012324:RNA-Dependent RNA Polymerase