Polymorphism in the 3'-untranslated region of TNFalpha mRNA impairs binding of the post-transcriptional regulatory protein HuR to TNFalpha mRNA.
Tumor necrosis factor alpha (TNFalpha) 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 TNFalpha mRNA as this region plays a pivotal role in post-transcriptional control of TNFalpha production. Certain stimuli, such as lipopolysaccharides, a component of the Gram-negative bacterial cell wall, have the ability to relinquish the translational suppression of TNFalpha mRNA imposed by these AREs in macrophages, thereby enabling the efficient production of the TNFalpha. In this study we show that the polymorphism (GAU trinucleotide insertional mutation) present in the regulatory 3'-UTR of TNFalpha mRNA of NZW mice results in the hindered binding of RNA-binding proteins, thereby leading to a significantly reduced production of TNFalpha protein. We also show that the binding of macrophage proteins to the main ARE is also decreased by another trinucleotide (CAU) insertion in the TNFalpha 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 TNFalpha mRNA, these results suggest that mutations in the ARE of TNFalpha mRNA decrease the production of TNFalpha protein in macrophages by hindering the binding of HuR to the ARE.
Di Marco
S
S
McGill University Health Center, McGill University, Department of Experimental Medicine, Montreal, Quebec H3G 1A4, Canada.
Hel
Z
Z
Lachance
C
C
Furneaux
H
H
Radzioch
D
D
D020413:3' Untranslated Regions / Q000235:genetics* / Q000378:metabolism*; D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D000954:Antigens, Surface; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D003609:Dactinomycin / Q000494:pharmacology; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D046911:Macromolecular Substances; D017737:Macrophages, Peritoneal / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D016254:Mutagenesis, Insertional / Q000235:genetics; D011110:Polymorphism, Genetic / Q000235:genetics*; D011485:Protein Binding / Q000187:drug effects; D015347:RNA Probes / Q000235:genetics; D016601:RNA-Binding Proteins / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics*
D020413:3' Untranslated Regions; D000954:Antigens, Surface; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; C098770:ELAVL1 protein, human; D008070:Lipopolysaccharides; D046911:Macromolecular Substances; D015347:RNA Probes; D016601:RNA-Binding Proteins; D014409:Tumor Necrosis Factor-alpha; D003609:Dactinomycin; D007371:Interferon-gamma