tetano
Editor, Senior Moderator
J Immunol. 2016 Mar 25. pii: 1502303. [Epub ahead of print]
[h=1]Defining Viral Defective Ribosomal Products: Standard and Alternative Translation Initiation Events Generate a Common Peptide from Influenza A Virus M2 and M1 mRNAs.[/h] Yang N[SUP]1[/SUP], Gibbs JS[SUP]1[/SUP], Hickman HD[SUP]1[/SUP], Reynoso GV[SUP]1[/SUP], Ghosh AK[SUP]2[/SUP], Bennink JR[SUP]1[/SUP], Yewdell JW[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Influenza A virus gene segment 7 encodes two proteins: the M1 protein translated from unspliced mRNA and the M2 protein produced by mRNA splicing and largely encoded by the M1 +1 reading frame. To better understand the generation of defective ribosomal products relevant to MHC class I Ag presentation, we engineered influenza A virus gene segment 7 to encode the model H-2 K[SUP]b[/SUP]class I peptide ligand SIINFEKL at the M2 protein C terminus. Remarkably, after treating virus-infected cells with the RNA splicing inhibitor spliceostatin A to prevent M2 mRNA generation, K[SUP]b[/SUP]-SIINFEKL complexes were still presented on the cell surface at levels ≤60% of untreated cells. Three key findings indicate that SIINFEKL is produced by cytoplasmic translation of unspliced M1 mRNA initiating at CUG codons within the +1 reading frame: 1) synonymous mutation of CUG codons in the M2-reading frame reduced K[SUP]b[/SUP]-SIINFEKL generation; 2) K[SUP]b[/SUP]-SIINFEKL generation was not affected by drug-mediated inhibition of AUG-initiated M1 synthesis; and 3) K[SUP]b[/SUP]-SIINFEKL was generated in vitro and in vivo from mRNA synthesized in the cytoplasm by vaccinia virus, and hence cannot be spliced. These findings define a viral defective ribosomal product generated by cytoplasmic noncanonical translation and demonstrate the participation of CUG-codon-based translation initiation in pathogen immunosurveillance.
Copyright ? 2016 by The American Association of Immunologists, Inc.
PMID: 27016602 [PubMed - as supplied by publisher]
[h=1]Defining Viral Defective Ribosomal Products: Standard and Alternative Translation Initiation Events Generate a Common Peptide from Influenza A Virus M2 and M1 mRNAs.[/h] Yang N[SUP]1[/SUP], Gibbs JS[SUP]1[/SUP], Hickman HD[SUP]1[/SUP], Reynoso GV[SUP]1[/SUP], Ghosh AK[SUP]2[/SUP], Bennink JR[SUP]1[/SUP], Yewdell JW[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Influenza A virus gene segment 7 encodes two proteins: the M1 protein translated from unspliced mRNA and the M2 protein produced by mRNA splicing and largely encoded by the M1 +1 reading frame. To better understand the generation of defective ribosomal products relevant to MHC class I Ag presentation, we engineered influenza A virus gene segment 7 to encode the model H-2 K[SUP]b[/SUP]class I peptide ligand SIINFEKL at the M2 protein C terminus. Remarkably, after treating virus-infected cells with the RNA splicing inhibitor spliceostatin A to prevent M2 mRNA generation, K[SUP]b[/SUP]-SIINFEKL complexes were still presented on the cell surface at levels ≤60% of untreated cells. Three key findings indicate that SIINFEKL is produced by cytoplasmic translation of unspliced M1 mRNA initiating at CUG codons within the +1 reading frame: 1) synonymous mutation of CUG codons in the M2-reading frame reduced K[SUP]b[/SUP]-SIINFEKL generation; 2) K[SUP]b[/SUP]-SIINFEKL generation was not affected by drug-mediated inhibition of AUG-initiated M1 synthesis; and 3) K[SUP]b[/SUP]-SIINFEKL was generated in vitro and in vivo from mRNA synthesized in the cytoplasm by vaccinia virus, and hence cannot be spliced. These findings define a viral defective ribosomal product generated by cytoplasmic noncanonical translation and demonstrate the participation of CUG-codon-based translation initiation in pathogen immunosurveillance.
Copyright ? 2016 by The American Association of Immunologists, Inc.
PMID: 27016602 [PubMed - as supplied by publisher]