| Abstract: |
Tumor necrosis factor α (TNFα) acts as a beneficial mediator in the process of host defence. In recent years major interest has focused on the AU-rich elements (AREs) present in the 3′-untranslated region (3′-UTR) of TNFα mRNA as this region plays a pivotal role in post-transcriptional control of TNFα production. Certain stimuli, such as lipopolysaccharides, a component of the Gram-negative bacterial cell wall, have the ability to relinquish the translational suppression of TNFα mRNA imposed by these AREs in macrophages, thereby enabling the efficient production of the TNFα. In this study we show that the polymorphism (GAU trinucleotide insertional mutation) present in the regulatory 3′-UTR of TNFα mRNA of NZW mice results in the hindered binding of RNA-binding proteins, thereby leading to a significantly reduced production of TNFα protein. We also show that the binding of macrophage proteins to the main ARE is also decreased by another trinucleotide (CAU) insertion in the TNFα 3′-UTR. One of the proteins affected by the GAU trinucleotide insertional mutation was identified as HuR, a nucleo-cytoplasmic shuttling protein previously shown to play a prominent role in the stability and translatability of mRNA containing AREs. Since binding of this protein most likely modulates the stability, translational efficiency and transport of TNFα mRNA, these results suggest that mutations in the ARE of TNFα mRNA decrease the production of TNFα protein in macrophages by hindering the binding of HuR to the ARE. |
| Keywords: |
controlled study; gene mutation; genetics; nonhuman; animal cell; mouse; animal; metabolism; animals; mice; nuclear protein; cell protein; cell line; animal experiment; animal model; protein binding; genetic transcription; drug effect; bacteria (microorganisms); enzyme linked immunosorbent assay; animalia; mice, inbred strains; rna binding protein; gene expression regulation; rna-binding proteins; membrane antigen; biosynthesis; tumor necrosis factor alpha; tumor necrosis factor-alpha; gamma interferon; messenger rna; guanine; protein synthesis; nucleotide sequence; protein transport; dactinomycin; rna translation; cytoplasm; active transport, cell nucleus; genetic stability; base sequence; binding site; lipopolysaccharide; binding sites; 3' untranslated region; cell nucleus; mouse strain; enzyme-linked immunosorbent assay; macrophage; polymorphism, genetic; antigens, surface; mutagenesis, insertional; genetic polymorphism; regulator protein; 3' untranslated regions; macromolecule; macromolecular substances; adenine; rna probe; rna probes; uracil; cytosine; lipopolysaccharides; interferon type ii; hur protein; gene insertion sequence; peritoneum macrophage; cytoplasm protein; negibacteria; active transport; trinucleotide repeat; trinucleotide; male; female; priority journal; article; elav-like protein 1; macrophages, peritoneal
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