Project description:Controlled decay of cytokine and chemokine mRNAs restrains the time and amplitude of inflammatory responses. Tristetraprolin (TTP) binds to AU-rich elements in 3´ untranslated regions of mRNA and targets the bound mRNA for degradation. We have addressed here the function of TTP in balancing the macrophage activation state by a comprehensive analysis of TTP-dependent mRNA decay in LPS-stimulated macrophages from WT and TTP-deficient mice.
Project description:Controlled decay of cytokine and chemokine mRNAs restrains the time and amplitude of inflammatory responses. Tristetraprolin (TTP) binds to AU-rich elements in 3´ untranslated regions of mRNA and targets the bound mRNA for degradation. We have addressed here the function of TTP in balancing the macrophage activation state by a comprehensive analysis of TTP-dependent mRNA decay in LPS-stimulated macrophages from WT and TTP-deficient mice. We compared mRNA stability in LPS-treated BMDMs from WT and TTP-/- mice by microarray-based measurement of the remnant mRNA after transcriptional blockade with actinomycin D (act D). To increase the sensitivity of the mRNA decay profiling we inhibited the LPS-activated p38 MAPK with the specific inhibitor SB203580 since p38 MAPK negatively regulates the mRNA-destabilizing activity of TTP. LPS stimulation was for 3h before addition of act D. RNA was harvested at 0', 45' and 90' thereafter.
Project description:Precise control of mRNA decay is fundamental for robust yet not exaggerated inflammatory responses to pathogens. Parameters determining the specificity and extent of mRNA degradation within the entire inflammation-associated transcriptome remain incompletely understood. Using transcriptome-wide high resolution occupancy assessment of the mRNA-destabilizing protein TTP, a major inflammation-limiting factor, we qualitatively and quantitatively characterize TTP binding positions and functionally relate them to TTP-dependent mRNA decay in immunostimulated macrophages. We identify pervasive TTP binding with incompletely penetrant linkage to mRNA destabilization. A necessary but not sufficient feature of TTP-mediated mRNA destabilization is binding to 3â untranslated regions (UTRs). Mapping of binding positions of the mRNA-stabilizing protein HuR in activated macrophages revealed that TTP and HuR binding sites in 3â UTRs occur mostly in different transcripts implicating only a limited co-regulation of inflammatory mRNAs by these proteins. Remarkably, we identify robust and widespread TTP binding to introns of stable transcripts. Nuclear TTP is associated with spliced-out introns and maintained in the nucleus throughout the inflammatory response. Our study establishes a functional annotation of binding positions dictating TTP-dependent mRNA decay in immunostimulated macrophages. The findings allow navigating the transcriptome-wide landscape of RNA elements controlling inflammation. RNA-Seq of RNA isolated from murine bone marrow derived macrophages (WT or TTP-deficient) stimulated for 6 h with LPS
Project description:Precise control of mRNA decay is fundamental for robust yet not exaggerated inflammatory responses to pathogens. Parameters determining the specificity and extent of mRNA degradation within the entire inflammation-associated transcriptome remain incompletely understood. Using transcriptome-wide high resolution occupancy assessment of the mRNA-destabilizing protein TTP, a major inflammation-limiting factor, we qualitatively and quantitatively characterize TTP binding positions and functionally relate them to TTP-dependent mRNA decay in immunostimulated macrophages. We identify pervasive TTP binding with incompletely penetrant linkage to mRNA destabilization. A necessary but not sufficient feature of TTP-mediated mRNA destabilization is binding to 3â?? untranslated regions (UTRs). Mapping of binding positions of the mRNA-stabilizing protein HuR in activated macrophages revealed that TTP and HuR binding sites in 3â?? UTRs occur mostly in different transcripts implicating only a limited co-regulation of inflammatory mRNAs by these proteins. Remarkably, we identify robust and widespread TTP binding to introns of stable transcripts. Nuclear TTP is associated with spliced-out introns and maintained in the nucleus throughout the inflammatory response. Our study establishes a functional annotation of binding positions dictating TTP-dependent mRNA decay in immunostimulated macrophages. The findings allow navigating the transcriptome-wide landscape of RNA elements controlling inflammation. Experiment comparing RNA decay rates in WT and TTP-/- macrophages at LPS 3 h and 6 h. Transcription was blocked with actinomycin D for 0, 45 or 90 min. Decay rates was calculated using linear model.
Project description:Precise control of mRNA decay is fundamental for robust yet not exaggerated inflammatory responses to pathogens. Parameters determining the specificity and extent of mRNA degradation within the entire inflammation-associated transcriptome remain incompletely understood. Using transcriptome-wide high resolution occupancy assessment of the mRNA-destabilizing protein TTP, a major inflammation-limiting factor, we qualitatively and quantitatively characterize TTP binding positions and functionally relate them to TTP-dependent mRNA decay in immunostimulated macrophages. We identify pervasive TTP binding with incompletely penetrant linkage to mRNA destabilization. A necessary but not sufficient feature of TTP-mediated mRNA destabilization is binding to 3â untranslated regions (UTRs). Mapping of binding positions of the mRNA-stabilizing protein HuR in activated macrophages revealed that TTP and HuR binding sites in 3â UTRs occur mostly in different transcripts implicating only a limited co-regulation of inflammatory mRNAs by these proteins. Remarkably, we identify robust and widespread TTP binding to introns of stable transcripts. Nuclear TTP is associated with spliced-out introns and maintained in the nucleus throughout the inflammatory response. Our study establishes a functional annotation of binding positions dictating TTP-dependent mRNA decay in immunostimulated macrophages. The findings allow navigating the transcriptome-wide landscape of RNA elements controlling inflammation. PAR-iCLIP for TTP (3 replicates) and for HuR (2 replicates)
Project description:Precise control of mRNA decay is fundamental for robust yet not exaggerated inflammatory responses to pathogens. Parameters determining the specificity and extent of mRNA degradation within the entire inflammation-associated transcriptome remain incompletely understood. Using transcriptome-wide high resolution occupancy assessment of the mRNA-destabilizing protein TTP, a major inflammation-limiting factor, we qualitatively and quantitatively characterize TTP binding positions and functionally relate them to TTP-dependent mRNA decay in immunostimulated macrophages. We identify pervasive TTP binding with incompletely penetrant linkage to mRNA destabilization. A necessary but not sufficient feature of TTP-mediated mRNA destabilization is binding to 3’ untranslated regions (UTRs). Mapping of binding positions of the mRNA-stabilizing protein HuR in activated macrophages revealed that TTP and HuR binding sites in 3’ UTRs occur mostly in different transcripts implicating only a limited co-regulation of inflammatory mRNAs by these proteins. Remarkably, we identify robust and widespread TTP binding to introns of stable transcripts. Nuclear TTP is associated with spliced-out introns and maintained in the nucleus throughout the inflammatory response. Our study establishes a functional annotation of binding positions dictating TTP-dependent mRNA decay in immunostimulated macrophages. The findings allow navigating the transcriptome-wide landscape of RNA elements controlling inflammation.
Project description:Precise control of mRNA decay is fundamental for robust yet not exaggerated inflammatory responses to pathogens. Parameters determining the specificity and extent of mRNA degradation within the entire inflammation-associated transcriptome remain incompletely understood. Using transcriptome-wide high resolution occupancy assessment of the mRNA-destabilizing protein TTP, a major inflammation-limiting factor, we qualitatively and quantitatively characterize TTP binding positions and functionally relate them to TTP-dependent mRNA decay in immunostimulated macrophages. We identify pervasive TTP binding with incompletely penetrant linkage to mRNA destabilization. A necessary but not sufficient feature of TTP-mediated mRNA destabilization is binding to 3’ untranslated regions (UTRs). Mapping of binding positions of the mRNA-stabilizing protein HuR in activated macrophages revealed that TTP and HuR binding sites in 3’ UTRs occur mostly in different transcripts implicating only a limited co-regulation of inflammatory mRNAs by these proteins. Remarkably, we identify robust and widespread TTP binding to introns of stable transcripts. Nuclear TTP is associated with spliced-out introns and maintained in the nucleus throughout the inflammatory response. Our study establishes a functional annotation of binding positions dictating TTP-dependent mRNA decay in immunostimulated macrophages. The findings allow navigating the transcriptome-wide landscape of RNA elements controlling inflammation.
Project description:Precise control of mRNA decay is fundamental for robust yet not exaggerated inflammatory responses to pathogens. Parameters determining the specificity and extent of mRNA degradation within the entire inflammation-associated transcriptome remain incompletely understood. Using transcriptome-wide high resolution occupancy assessment of the mRNA-destabilizing protein TTP, a major inflammation-limiting factor, we qualitatively and quantitatively characterize TTP binding positions and functionally relate them to TTP-dependent mRNA decay in immunostimulated macrophages. We identify pervasive TTP binding with incompletely penetrant linkage to mRNA destabilization. A necessary but not sufficient feature of TTP-mediated mRNA destabilization is binding to 3’ untranslated regions (UTRs). Mapping of binding positions of the mRNA-stabilizing protein HuR in activated macrophages revealed that TTP and HuR binding sites in 3’ UTRs occur mostly in different transcripts implicating only a limited co-regulation of inflammatory mRNAs by these proteins. Remarkably, we identify robust and widespread TTP binding to introns of stable transcripts. Nuclear TTP is associated with spliced-out introns and maintained in the nucleus throughout the inflammatory response. Our study establishes a functional annotation of binding positions dictating TTP-dependent mRNA decay in immunostimulated macrophages. The findings allow navigating the transcriptome-wide landscape of RNA elements controlling inflammation.
Project description: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 1h 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 transcriptome of TTP-deficient and TTP-expressing macrophages upon short LPS stimulation suggested an effective inactivation of TTP by MK2 under these conditions 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 for TTP in NF-κB-signaling and highlights the importance of fine-tuned TTP activity-regulation by MK2 in order to control feedback signaling during the inflammatory response.