A non-canonical function of eukaryotic elongation factor 1A1: Regulation of interleukin-6 expression |
| |
Authors: | Ingo Schulz Claudia Engel André J Niestroj Astrid Kehlen Jens-Ulrich Rahfeld Martin Kleinschmidt Karola Lehmann Steffen Roßner Hans-Ulrich Demuth |
| |
Institution: | 1. Probiodrug AG, Weinbergweg 22, Halle/Saale 06120, Germany;2. Fraunhofer Institute of Cell Therapy and Immunology (IZI) Leipzig, c/o Department of Drug Design and Target Validation (MWT) Halle, Biocenter, Weinbergweg 22, 06120 Halle (Saale), Germany;3. Proteome Factory AG, Magnusstrasse 11, 12489 Berlin, Germany;4. Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, Leipzig 04109, Germany |
| |
Abstract: | Interleukin-6 is one of the most prominent triggers of inflammatory processes. We have shown recently that heteroarylketones (HAKs) interfere with stimulated interleukin-6 expression in astrocytes by suppression of STAT3 phosphorylation at serine 727. Surprisingly, this effect is not based on the inhibition of STAT3-relevant kinases. Therefore, we here used the structurally modified HAK compound biotin-HAK-3 in a reverse chemical approach to identify the relevant molecular target in UV-mediated cross-linking experiments. Employing streptavidin-specific 2D-immunoblotting followed by mass spectrometry we identified nine proteins putatively interacting with biotin-HAK-3. After co-immunoprecipitation, co-immunofluorescence, surface plasmon resonance analyses and RNAi-mediated knock-down, the eukaryotic elongation factor 1A1 (eEF1A1) was verified as the relevant target of HAK bioactivity. eEF1A1 forms complexes with STAT3 and PKCδ, which are crucial for STAT3S727 phosphorylation and for NF-κB/STAT3-enhanced interleukin-6 expression. Furthermore, the intracellular HAK accumulation is strongly dependent on eEF1A1 expression. Taken together, the results reveal a novel molecular mechanism for a non-canonical role of eEF1A1 in signal transduction via direct modulation of kinase-dependent phosphorylation events. |
| |
Keywords: | OSM oncostatin M HAK heteroarylketone SPR surface plasmon resonance RNAi RNA interference UV ultraviolet IEF isoelectric focusing LC&ndash ESI-MS/MS liquid chromatography&ndash electrospray ionization/multi-stage mass spectrometry HPLC high-performance liquid chromatography 2D-PAGE two-dimensional polyacrylamide gel electrophoresis |
本文献已被 ScienceDirect 等数据库收录! |
|