Transcriptional regulation of the interferon-gamma-inducible tryptophanyl-tRNA synthetase includes alternative splicing.
We have investigated the transcriptional control elements of the human interferon (IFN)-gamma-induced tryptophanyl-tRNA synthetase (hWRS) gene and characterized the transcripts. Transcription leads to a series of mRNAs with different combinations of the first exons. The full-length mRNA codes for a 55-kDa protein (hWRS), but a mRNA lacking exon II is present in almost as high amounts as the full-length transcript. This alternatively spliced mRNA is probably translated into a 48-kDa protein starting from Met48 in exon III. The predicted 48-kDa protein corresponds exactly to an IFN-gamma-inducible protein previously detected by two-dimensional gel electrophoresis. By isolation of genomic clones and construction of plasmids containing hWRS promoter fragments fused to the secreted alkaline phosphatase reporter gene we have mapped a promoter region essential for IFN-mediated gene activation. This region contains IFN-stimulated response elements (ISRE) as well as a Y-box and a gamma-activated sequence (GAS) element. IFN-gamma inducibility of hWRS depends on ongoing protein synthesis, suggesting that so far undescribed transcription factors apart from the latent GAS-binding protein p91 contribute to gene activation. This could be interferon-regulatory factor-1, which binds ISRE elements.
Tolstrup
A B
AB
Department of Molecular Biology, University of Aarhus, Denmark.
Bejder
A
A
Fleckner
J
J
Justesen
J
J
D000469:Alkaline Phosphatase / Q000235:genetics; D017398:Alternative Splicing; D001483:Base Sequence; D003001:Cloning, Molecular; D004790:Enzyme Induction; D006367:HeLa Cells; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic; D014162:Transfection; D014369:Tryptophan-tRNA Ligase / Q000096:biosynthesis / Q000235:genetics*
D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D007371:Interferon-gamma; D000469:Alkaline Phosphatase; D014369:Tryptophan-tRNA Ligase