Giuseppe
Emeritus
J Virol. 2008 Nov 19. [Epub ahead of print]
Avian influenza A polymerase association with nucleoprotein, but not polymerase assembly, is impaired in human cells during the course of infection.
Rameix-Welti MA, Tomoiu A, Dos Santos Afonso E, van der Werf S, Naffakh N. - Unit? de G?n?tique Mol?culaire des Virus Respiratoires, URA CNRS 3015, EA302 Universit? Paris Diderot, Institut Pasteur, Paris, France.
Strong determinants of the host-range of influenza A viruses have been identified on the polymerase complex formed by the PB1, PB2 and PA subunits, and on the nucleoprotein (NP).
In the present study, molecular mechanisms that may involve these four core proteins and contribute to the restriction of avian influenza virus multiplication in human cells have been investigated.
The efficiencies with which the polymerase complexes of a human and an avian influenza isolate assemble and interact with the viral NP and cellular RNA polymerase II proteins were compared, in mammalian and in avian infected cells.
To this end, recombinant influenza viruses expressing either human or avian-derived core proteins with a PB2 protein fused to the One-Strep purification tag at the N- or C-terminus were generated.
Co-purification experiments performed on infected cell extracts indicate that the avian-derived polymerase is assembled and interacts physically with the cellular RNA polymerase II at least as efficiently as does the human-derived polymerase, in human as well as in avian cells.
Restricted growth of the avian isolate in human cells correlates with low levels of the core proteins in infected cell extracts, and poor association of the NP with the polymerase as compared to what is observed for the human isolate.
The NP-polymerase association is restored by a Glu to Lys substitution at residue 627 of PB2.
Overall, our data point to viral and cellular factors regulating the NP-polymerase interaction as key determinants of influenza A viruses host-range.
Recombinant viruses expressing a tagged polymerase should prove useful for further studies of the molecular interactions between viral polymerase and host factors during the infectious cycle.
PMID: 19019950 [PubMed - as supplied by publisher]
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Avian influenza A polymerase association with nucleoprotein, but not polymerase assembly, is impaired in human cells during the course of infection.
Rameix-Welti MA, Tomoiu A, Dos Santos Afonso E, van der Werf S, Naffakh N. - Unit? de G?n?tique Mol?culaire des Virus Respiratoires, URA CNRS 3015, EA302 Universit? Paris Diderot, Institut Pasteur, Paris, France.
Strong determinants of the host-range of influenza A viruses have been identified on the polymerase complex formed by the PB1, PB2 and PA subunits, and on the nucleoprotein (NP).
In the present study, molecular mechanisms that may involve these four core proteins and contribute to the restriction of avian influenza virus multiplication in human cells have been investigated.
The efficiencies with which the polymerase complexes of a human and an avian influenza isolate assemble and interact with the viral NP and cellular RNA polymerase II proteins were compared, in mammalian and in avian infected cells.
To this end, recombinant influenza viruses expressing either human or avian-derived core proteins with a PB2 protein fused to the One-Strep purification tag at the N- or C-terminus were generated.
Co-purification experiments performed on infected cell extracts indicate that the avian-derived polymerase is assembled and interacts physically with the cellular RNA polymerase II at least as efficiently as does the human-derived polymerase, in human as well as in avian cells.
Restricted growth of the avian isolate in human cells correlates with low levels of the core proteins in infected cell extracts, and poor association of the NP with the polymerase as compared to what is observed for the human isolate.
The NP-polymerase association is restored by a Glu to Lys substitution at residue 627 of PB2.
Overall, our data point to viral and cellular factors regulating the NP-polymerase interaction as key determinants of influenza A viruses host-range.
Recombinant viruses expressing a tagged polymerase should prove useful for further studies of the molecular interactions between viral polymerase and host factors during the infectious cycle.
PMID: 19019950 [PubMed - as supplied by publisher]
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