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J Virol. 1995 April; 69(4): 2420–2426.
PMCID: PMC188916

Individual expression of influenza virus PA protein induces degradation of coexpressed proteins.


In the process of in vivo reconstitution of influenza virus transcriptase-replicase complex, an inhibitory effect was observed when the level of PA protein expression was increased. This inhibition was paralleled by a decrease in the accumulation of the other influenza virus core proteins. The sole expression of PA protein was sufficient to reduce the accumulation level of the proteins encoded by the coexpressed genes. The PA effect was observed upon influenza virus and non-influenza virus proteins and independently of the expression system chosen and the origin of cell line used. The expression of PA protein did not induce variations in the translation of the target proteins but did induce variations on their half-lives, which were clearly reduced. A functional PA subunit seems to be necessary to induce this negative effect, because an inactive point mutant was unable to decrease the steady-state levels or the half-lives of the reporter proteins. The PA effect was observed as early as 5 h after its expression, and continuous synthesis of proteins was not required for performance of its biological activity. The results presented represent the first biological activity of individually expressed PA polymerase subunit.

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Selected References

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  • Akkina RK, Chambers TM, Londo DR, Nayak DP. Intracellular localization of the viral polymerase proteins in cells infected with influenza virus and cells expressing PB1 protein from cloned cDNA. J Virol. 1987 Jul;61(7):2217–2224. [PMC free article] [PubMed]
  • Bárcena J, Ochoa M, de la Luna S, Melero JA, Nieto A, Ortín J, Portela A. Monoclonal antibodies against influenza virus PB2 and NP polypeptides interfere with the initiation step of viral mRNA synthesis in vitro. J Virol. 1994 Nov;68(11):6900–6909. [PMC free article] [PubMed]
  • Beloso A, Martínez C, Valcárcel J, Santarén JF, Ortín J. Degradation of cellular mRNA during influenza virus infection: its possible role in protein synthesis shutoff. J Gen Virol. 1992 Mar;73(Pt 3):575–581. [PubMed]
  • Biswas SK, Nayak DP. Mutational analysis of the conserved motifs of influenza A virus polymerase basic protein 1. J Virol. 1994 Mar;68(3):1819–1826. [PMC free article] [PubMed]
  • Blaas D, Patzelt E, Kuechler E. Identification of the cap binding protein of influenza virus. Nucleic Acids Res. 1982 Aug 11;10(15):4803–4812. [PMC free article] [PubMed]
  • Braam J, Ulmanen I, Krug RM. Molecular model of a eucaryotic transcription complex: functions and movements of influenza P proteins during capped RNA-primed transcription. Cell. 1983 Sep;34(2):609–618. [PubMed]
  • de la Luna S, Martín J, Portela A, Ortín J. Influenza virus naked RNA can be expressed upon transfection into cells co-expressing the three subunits of the polymerase and the nucleoprotein from simian virus 40 recombinant viruses. J Gen Virol. 1993 Mar;74(Pt 3):535–539. [PubMed]
  • de la Luna S, Martínez C, Ortín J. Molecular cloning and sequencing of influenza virus A/Victoria/3/75 polymerase genes: sequence evolution and prediction of possible functional domains. Virus Res. 1989 Jun;13(2):143–155. [PubMed]
  • Fuerst TR, Earl PL, Moss B. Use of a hybrid vaccinia virus-T7 RNA polymerase system for expression of target genes. Mol Cell Biol. 1987 Jul;7(7):2538–2544. [PMC free article] [PubMed]
  • Gluzman Y. SV40-transformed simian cells support the replication of early SV40 mutants. Cell. 1981 Jan;23(1):175–182. [PubMed]
  • Hay AJ, Skehel JJ, McCauley J. Characterization of influenza virus RNA complete transcripts. Virology. 1982 Jan 30;116(2):517–522. [PubMed]
  • Herz C, Stavnezer E, Krug R, Gurney T., Jr Influenza virus, an RNA virus, synthesizes its messenger RNA in the nucleus of infected cells. Cell. 1981 Nov;26(3 Pt 1):391–400. [PubMed]
  • Huang TS, Palese P, Krystal M. Determination of influenza virus proteins required for genome replication. J Virol. 1990 Nov;64(11):5669–5673. [PMC free article] [PubMed]
  • Inglis SC. Inhibition of host protein synthesis and degradation of cellular mRNAs during infection by influenza and herpes simplex virus. Mol Cell Biol. 1982 Dec;2(12):1644–1648. [PMC free article] [PubMed]
  • Jackson DA, Caton AJ, McCready SJ, Cook PR. Influenza virus RNA is synthesized at fixed sites in the nucleus. Nature. 1982 Mar 25;296(5855):366–368. [PubMed]
  • Katze MG, Krug RM. Metabolism and expression of RNA polymerase II transcripts in influenza virus-infected cells. Mol Cell Biol. 1984 Oct;4(10):2198–2206. [PMC free article] [PubMed]
  • Krug RM, Broni BA, Bouloy M. Are the 5' ends of influenza viral mRNAs synthesized in vivo donated by host mRNAs? Cell. 1979 Oct;18(2):329–334. [PubMed]
  • López-Turiso JA, Martínez C, Tanaka T, Ortín J. The synthesis of influenza virus negative-strand RNA takes place in insoluble complexes present in the nuclear matrix fraction. Virus Res. 1990 Jul;16(3):325–337. [PubMed]
  • Lozeman FJ, Litchfield DW, Piening C, Takio K, Walsh KA, Krebs EG. Isolation and characterization of human cDNA clones encoding the alpha and the alpha' subunits of casein kinase II. Biochemistry. 1990 Sep 11;29(36):8436–8447. [PubMed]
  • Luo GX, Luytjes W, Enami M, Palese P. The polyadenylation signal of influenza virus RNA involves a stretch of uridines followed by the RNA duplex of the panhandle structure. J Virol. 1991 Jun;65(6):2861–2867. [PMC free article] [PubMed]
  • Matsudaira PT, Burgess DR. SDS microslab linear gradient polyacrylamide gel electrophoresis. Anal Biochem. 1978 Jul 1;87(2):386–396. [PubMed]
  • Mena I, de la Luna S, Albo C, Martín J, Nieto A, Ortín J, Portela A. Synthesis of biologically active influenza virus core proteins using a vaccinia virus-T7 RNA polymerase expression system. J Gen Virol. 1994 Aug;75(Pt 8):2109–2114. [PubMed]
  • Nieto A, de la Luna S, Bárcena J, Portela A, Ortín J. Complex structure of the nuclear translocation signal of influenza virus polymerase PA subunit. J Gen Virol. 1994 Jan;75(Pt 1):29–36. [PubMed]
  • Nieto A, de la Luna S, Bárcena J, Portela A, Valcárcel J, Melero JA, Ortín J. Nuclear transport of influenza virus polymerase PA protein. Virus Res. 1992 Jun;24(1):65–75. [PubMed]
  • Poch O, Sauvaget I, Delarue M, Tordo N. Identification of four conserved motifs among the RNA-dependent polymerase encoding elements. EMBO J. 1989 Dec 1;8(12):3867–3874. [PubMed]
  • Robertson JS, Schubert M, Lazzarini RA. Polyadenylation sites for influenza virus mRNA. J Virol. 1981 Apr;38(1):157–163. [PMC free article] [PubMed]
  • Shapiro GI, Krug RM. Influenza virus RNA replication in vitro: synthesis of viral template RNAs and virion RNAs in the absence of an added primer. J Virol. 1988 Jul;62(7):2285–2290. [PMC free article] [PubMed]
  • Stranden AM, Staeheli P, Pavlovic J. Function of the mouse Mx1 protein is inhibited by overexpression of the PB2 protein of influenza virus. Virology. 1993 Dec;197(2):642–651. [PubMed]
  • Ulmanen I, Broni B, Krug RM. Influenza virus temperature-sensitive cap (m7GpppNm)-dependent endonuclease. J Virol. 1983 Jan;45(1):27–35. [PMC free article] [PubMed]

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