title: The RNA-binding protein TTP is a global post-transcriptional regulator of feedback control in inflammation.
abstract: RNA-binding proteins (RBPs) facilitate post-transcriptional control of eukaryotic gene expression at multiple levels. The RBP tristetraprolin (TTP/Zfp36) is a signal-induced phosphorylated anti-inflammatory protein guiding unstable mRNAs of pro-inflammatory proteins for degradation and preventing translation. Using iCLIP, we have identified numerous mRNA targets bound by wild-type TTP and by a non-MK2-phosphorylatable TTP mutant (TTP-AA) in 1 h LPS-stimulated macrophages and correlated their interaction with TTP to changes at the level of mRNA abundance and translation in a transcriptome-wide manner. The close similarity of the transcriptomes of TTP-deficient and TTP-expressing macrophages upon short LPS stimulation suggested an effective inactivation of TTP by MK2, whereas retained RNA-binding capacity of TTP-AA to 3'UTRs caused profound changes in the transcriptome and translatome, altered NF-κB-activation and induced cell death. Increased TTP binding to the 3'UTR of feedback inhibitor mRNAs, such as Ier3, Dusp1 or Tnfaip3, in the absence of MK2-dependent TTP neutralization resulted in a strong reduction of their protein synthesis contributing to the deregulation of the NF-κB-signaling pathway. Taken together, our study uncovers a role of TTP as a suppressor of feedback inhibitors of inflammation and highlights the importance of fine-tuned TTP activity-regulation by MK2 in order to control the pro-inflammatory response.
authors.affiliation: Institute of Physiological Chemistry, Medical School Hannover (MHH), 30625 Hannover, Germany Tiedje.Christopher@mh-hannover.de.
authors.forename: Christopher
authors.initials: C
authors.lastname: Tiedje
authors.affiliation: Lymphocyte Signalling and Development, The Babraham Institute, Cambridge CB22 3AT, UK manuel.diaz-munoz@babraham.ac.uk.
authors.forename: Manuel D
authors.initials: MD
authors.lastname: Diaz-Muñoz
authors.affiliation: Institute of Physiological Chemistry, Medical School Hannover (MHH), 30625 Hannover, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Trulley
authors.affiliation: Lymphocyte Signalling and Development, The Babraham Institute, Cambridge CB22 3AT, UK.
authors.forename: Helena
authors.initials: H
authors.lastname: Ahlfors
authors.affiliation: Institute of Physiological Chemistry, Medical School Hannover (MHH), 30625 Hannover, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Laaß
authors.affiliation: Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA; and Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Perry J
authors.initials: PJ
authors.lastname: Blackshear
authors.affiliation: Lymphocyte Signalling and Development, The Babraham Institute, Cambridge CB22 3AT, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Turner
authors.affiliation: Institute of Physiological Chemistry, Medical School Hannover (MHH), 30625 Hannover, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Gaestel
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism; D002470:Cell Survival; D003432:Cross-Linking Reagents; D016207:Cytokines / Q000235:genetics; D025461:Feedback, Physiological; D005786:Gene Expression Regulation; D057166:High-Throughput Screening Assays; D006801:Humans; D047468:Immunoprecipitation; D007249:Inflammation / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D013379:Substrate Specificity; D059467:Transcriptome; D000099190:MAP-Kinase-Activated Kinase 2
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D003432:Cross-Linking Reagents; D016207:Cytokines; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D017346:Protein Serine-Threonine Kinases; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D000099190:MAP-Kinase-Activated Kinase 2; C541099:TTP protein, mouse