title: Functional expression of influenza A viral nucleoprotein in cells transformed with cloned DNA.
abstract: Simian cells permissive for influenza A virus infection were stably transformed with a full-length cloned influenza A nucleoprotein gene under the control of an inducible metallothionein promoter and linked to a dihydrofolate reductase gene to facilitate cell selection. Transformed cells synthesized a virus-specific nucleoprotein which was indistinguishable from the nucleoprotein synthesized in virus-infected cells with respect to molecular weight and intracellular localization. It was estimated that transformed cells produced only 1% of the amount of nucleoprotein synthesized in simian cells infected with influenza A virus. Nonetheless, when transformed cells were infected with influenza virus mutants which synthesized temperature-sensitive nucleoprotein, protein expressed by the cloned gene was able to complement the synthesis of plus-strand and minus-strand viral RNA for one mutant and only plus-strand synthesis for another mutant. This indicated that the influenza A nucleoprotein expressed in the transformed cells exhibited functional activity.
mesh_terms: D000818:Animals; D002451:Cell Compartmentation; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics*; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D009980:Influenza A virus / Q000235:genetics*; D008970:Molecular Weight; D009698:Nucleoproteins / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics*; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D009698:Nucleoproteins; D012367:RNA, Viral; D014764:Viral Proteins