| Abstract: |
Cytokine stimulation of human DLD-1 cells resulted in a marked expression of nitric-oxide synthase (NOS) II mRNA and protein accompanied by only a moderate increase in transcriptional activity. Also, there was a basal transcription of the NOS II gene, which did not result in measurable NOS II expression. The 3'-untranslated region (3'-UTR) of the NOS II mRNA contains four AUUUA motifs and one AUUUUA motif, known to destabilize the mRNAs of proto-oncogenes, nuclear transcription factors, and cytokines. Luciferase reporter gene constructs containing the NOS II 3'-UTR showed a significantly reduced luciferase activity. The embryonic lethal abnormal vision (ELAV)-like protein HuR was found to bind with high affinity to the adenylate/uridylate-rich elements of the NOS II 3'-UTR. Inhibition of HuR with antisense constructs reduced the cytokine-induced NOS II mRNA, whereas overexpression of HuR potentiated the cytokine-induced NOS II expression. This provides evidence that NOS II expression is regulated at the transcriptional and post-transcriptional level. Binding of HuR to the 3'-UTR of the NOS II mRNA seems to play an essential role in the stabilization of this mRNA. |
| Keywords: |
protein expression; human cell; sequence analysis; binding affinity; transcription, genetic; rna-binding proteins; transcription regulation; molecular sequence data; protein processing, post-translational; messenger rna; rna, messenger; nucleotide sequence; base sequence; mutagenesis, site-directed; 3' untranslated region; cell stimulation; luciferases; molecular weight; nitric oxide synthase; antigens, surface; enzyme induction; 3' untranslated regions; nitric oxide synthase type ii; adenosine phosphate; gene expression regulation, enzymologic; enzyme stability; humans; human; priority journal; article; uridine phosphate
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