Fachbereich Veterinärmedizin



    Mitogen-activated Protein Kinase-activated Protein Kinase 2 Regulates Tumor Necrosis Factor mRNA Stability and Translation mainly by altering Tristetraprolin Expression, Stability, and Binding to Adenine/Uridine-rich Element (2006)

    Zeitschriftenartikel / wissenschaftlicher Beitrag
    Hitti, Edward
    Iakovleva, Tatiana
    Brook, Matthew
    Deppenmeier, Stefanie
    Gruber, Achim D
    Radzioch, Danuta
    Clark, Andrew R
    Blackshear, Perry J
    Kotlyarov, Alexey
    Gaestel, Matthias
    Molecular and Cellular Biology; 26(6) — S. 2399–2407
    ISSN: 0270-7306
    Pubmed: 16508014
    Institut für Tierpathologie

    Robert-von-Ostertag-Str. 15
    Gebäude 12
    14163 Berlin
    +49 30 838 62450

    Abstract / Zusammenfassung

    The mitogen-activated protein kinase (MAPK) p38/MAPK-activated protein kinase 2 (MK2) signaling pathway plays an important role in the posttranscriptional regulation of tumor necrosis factor (TNF), which is dependent on the adenine/uridine-rich element (ARE) in the 3' untranslated region of TNF mRNA. After lipopolysaccharide (LPS) stimulation, MK2-deficient macrophages show a 90% reduction in TNF production compared to the wild type. Tristetraprolin (TTP), a protein induced by LPS, binds ARE and destabilizes TNF mRNA. Accordingly, macrophages lacking TTP produce large amounts of TNF. Here, we generated MK2/TTP double knockout mice and show that, after LPS stimulation, bone marrow-derived macrophages produce TNF mRNA and protein levels comparable to those of TTP knockout cells, indicating that in the regulation of TNF biosynthesis TTP is genetically downstream of MK2. In addition, we show that MK2 is essential for the stabilization of TTP mRNA, and phosphorylation by MK2 leads to increased TTP protein stability but reduced ARE affinity. These data suggest that MK2 inhibits the mRNA destabilizing activity of TTP and, in parallel, codegradation of TTP together, with the target mRNA resulting in increased cellular levels of TTP.