Project description:Integrative regulatory mapping indicates that the RNA-binding protein HuR (ELAVL1) couples pre-mRNA processing and mRNA stability In this dataset, we employed two distinct experiments. 1) HuR RIP-chip to identify mRNA targets of HuR. 2) HuR knockdown to identify mRNAs whose expression are dependent on HuR. All 12 samples were normalized with PLIER using Affymetrix power tools. To identify RNA targets of HuR, HuR RIP samples were compared to Mock RIP samples. To identify RNA regulated by HuR, HuR knockdown samples were compared to mock knockdown samples.
Project description:Elavl1/HuR is a ubiquitous and conserved RNA-binding protein that binds to a U-rich RNA motif that shuttles between nucleus and cytoplasm. In epithelia, the elevated expression of HuR assumingly promotes degeneration and cancer suggesting that its generic suppression may provide clinical benefits. In this study we focused on biological and clinical functions of HuR in intestinal epithelial cells and we presented evidence that changes in HuR levels induce polarized distortions in these cells to support different pathologic outcomes. Here we study the differentiality in mRNA abundance between Control mice and mice overexpressing Elavl1 (TgATF-HuR). Control and TgATF-HuR mice were treated with Dimethylhydrazine (DMH)/Dextran Sodium Sulphate (DSS) for 60 days and tumors where dissected from large intestines; those with sizes between 10-15mm2 were pooled to generate samples with 4 tumors/sample and snap frozen. Three samples per genotype were used either for RIP analyses or total RNA extraction. Isolated RNA was used for microarray or qRT-PCR analyses.
Project description:RNA-binding proteins coordinate the fates of multiple RNAs, but the principles underlying these global interactions remain poorly understood. We elucidated regulatory mechanisms of the RNA-binding protein HuR, by integrating data from diverse high-throughput targeting technologies, specifically PAR-CLIP, RIP-chip, and whole-transcript expression profiling. The number of binding sites per transcript, degree of HuR-association, and degree of HuR-dependent RNA stabilization were positively correlated. Pre-mRNA and mature mRNA containing both intronic and 3' UTR binding sites were more highly stabilized than transcripts with only 3' UTR or only intronic binding sites, suggesting that HuR couples pre-mRNA processing with mature mRNA stability. We also observed HuR-dependent splicing changes and substantial binding of HuR in poly-pyrimidine tracts of pre-mRNAs. Comparison of the spatial patterns surrounding HuR and miRNA binding sites provided functional evidence for HuR-dependent antagonism of proximal miRNA-mediated repression. We conclude that HuR coordinates gene expression outcomes at multiple interconnected steps of RNA processing. HuR (ELAVL1) PAR-CLIP
Project description:Post-transcriptional gene regulation by miRNAs and RNA binding proteins (RBP) is important in development, physiology and disease. To examine the interplay between miRNAs and the RBP ELAVL1 (a.k.a. HuR), we mapped miRNA binding sites on a transcriptome-wide scale in WT and Elavl1 knockout murine bone marrow-derived macrophages. Proximity of ELAVL1 binding sites attenuated miRNA binding to transcripts and promoted gene expression. Transcripts that regulate angiogenesis and macrophage/ endothelial cross talk were preferentially targeted by miRNAs, suggesting that ELAVL1 promotes angiogenesis, at least in part, by antagonism of miRNA function. We found that ELAVL1 antagonized binding of miR-27 to the 3’UTR of Zfp36 mRNA and alleviated miR-27-mediated suppression of the RBP ZFP36 (a.k.a. Tristetraprolin). Thus the miR-27-regulated mechanism synchronizes the expression of ELAVL1 and ZFP36. This study provides a resource for systems-level interrogation of post-transcriptional gene regulation in macrophages, a key cell type in inflammation, angiogenesis and tissue homeostasis.
Project description:Post-transcriptional gene regulation by miRNAs and RNA binding proteins (RBP) is important in development, physiology and disease. To examine the interplay between miRNAs and the RBP ELAVL1 (a.k.a. HuR), we mapped miRNA binding sites on a transcriptome-wide scale in WT and Elavl1 knockout murine bone marrow-derived macrophages. Proximity of ELAVL1 binding sites attenuated miRNA binding to transcripts and promoted gene expression. Transcripts that regulate angiogenesis and macrophage/ endothelial cross talk were preferentially targeted by miRNAs, suggesting that ELAVL1 promotes angiogenesis, at least in part, by antagonism of miRNA function. We found that ELAVL1 antagonized binding of miR-27 to the 3’UTR of Zfp36 mRNA and alleviated miR-27-mediated suppression of the RBP ZFP36 (a.k.a. Tristetraprolin). Thus the miR-27-regulated mechanism synchronizes the expression of ELAVL1 and ZFP36. This study provides a resource for systems-level interrogation of post-transcriptional gene regulation in macrophages, a key cell type in inflammation, angiogenesis and tissue homeostasis. Bone marrow derived macrpohges mRNA profiles of 7-day cultured wild type (WT) and Elavl1l-/- mouse bone marrow cells were generated by deep sequencing, with 4 biologic duplication, using Illumina GAII.
Project description:ELAVL1 and CELF1 are two RNA-binding proteins involved in alternative splicing control. To address their functional relationships, we identify the differentially spliced mRNAs upon depletion of CELF1, ELAVL1, or both. These proteins control similar sets of genes with similar consequences on exon inclusion or skipping. The magnitude of the effect of the double depletion equals the sum of the magnitudes of the individual depletions, showing that CELF1 and ELAVL1 additively control their target RNAs. CELF1 and ELAVL1 regulated splicing events include ACSL4, WNK1, CD44, MICAL3, and JDP2. Using FRET, we find that CELF1 and ELAVL1 directly interact in cell nuclei. We demonstrate that the combined levels of CELF1 and ELAVL1 is a valuable biomarker in breast cancer, while their levels bring very limited information when taken individually. A “co-RNA splicing map” of CELF1 and ELAVL1 shows they repress alternative splice sites when bound nearby, but activate them when bound further away. Together, these data point to strong functional interactions between CELF1 and ELAVL1 to control alternative splicing with significant impacts in human pathology.
Project description:We describe an improved individual nucleotide resolution CLIP protocol (iiCLIP), which can be completed within 4 days from UV crosslinking to libraries for sequencing. For benchmarking, we directly compared PTBP1 iiCLIP libraries with the iCLIP2 protocol produced under standardised conditions with 1 million HEK293 cells, and with public eCLIP and iCLIP PTBP1 data. There are 3 PTBP1 iiCLIP libraries, 1 input iiCLIP library and 1 PTBP1 iCLIP2 library produced in this study.
Project description:Upon detection of a pathogen, the innate immune system triggers signaling events leading to the transcription of mRNAs that encode for pro-inflammatory and anti-microbial effectors. RNA-binding proteins (RBPs) interact with these functionally critical mRNAs and temporally regulate their fates at the post-transcriptional level. One such RBP is ELAVL1, which is known to bind to introns and 3’UTRs. While significant progress has been made in understanding how ELAVL1 regulates mRNAs, how its target repertoire and binding affinity changes within an immunological context remains poorly understood. Here, we overlap four distinct high-throughput approaches to define its cell-type and context-dependent targets and determine its regulatory impact during immune activation. ELAVL1 overwhelmingly binds to intronic sites in a naïve state, but during an innate immune response, ELAVL1 targets the 3’UTR binding both previously and newly expressed mRNAs. We find that ELAVL1 mediates the RNA stability of genes that regulate the pathways involved in pathogen sensing and cytokine production. Our findings reveal the importance of examining RBP regulatory impact under dynamic transcriptomic events to best understand their post-transcriptional regulatory roles within specific biological circuitries.