Integrative genome-wide analysis reveals cooperative regulation of alternative splicing by hnRNP proteins (CLIP-Seq)
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ABSTRACT: Understanding how RNA binding proteins control the splicing code is fundamental to human biology and disease. Here we present a comprehensive study to elucidate how heterogeneous nuclear ribonucleoparticle (hnRNP) proteins, among the most abundant RNA binding proteins, coordinate to regulate alternative pre-mRNA splicing (AS) in human cells. Using splicing-sensitive microarrays, cross-linking and immunoprecipitation coupled with high-throughput sequencing, and cDNA sequencing, we find that more than half of all AS events are regulated by multiple hnRNP proteins, and that some combinations of hnRNP proteins exhibit significant synergy, whereas others act antagonistically. Our analyses reveal position-dependent RNA splicing maps, in vivo consensus binding sites, a surprising level of cross- and auto-regulation among hnRNP proteins, and the coordinated regulation by hnRNP proteins of dozens of other RNA binding proteins and genes associated with cancer. Our findings define an unprecedented degree of complexity and compensatory relationships among hnRNP proteins and their splicing targets that likely confer robustness to cells. CLIPseq for hnRNP A1, hnRNP A2/B1, hnRNP F, hnRNP M, and hnRNP U in human 293T cells
Project description:This SuperSeries is composed of the following subset Series: GSE34992: Integrative genome-wide analysis reveals cooperative regulation of alternative splicing by hnRNP proteins (splice array) GSE34993: Integrative genome-wide analysis reveals cooperative regulation of alternative splicing by hnRNP proteins (CLIP-Seq) GSE34995: Integrative genome-wide analysis reveals cooperative regulation of alternative splicing by hnRNP proteins (RNA-Seq) Refer to individual Series
Project description:Understanding how RNA binding proteins control the splicing code is fundamental to human biology and disease. Here we present a comprehensive study to elucidate how heterogeneous nuclear ribonucleoparticle (hnRNP) proteins, among the most abundant RNA binding proteins, coordinate to regulate alternative pre-mRNA splicing (AS) in human cells. Using splicing-sensitive microarrays, cross-linking and immunoprecipitation coupled with high-throughput sequencing, and cDNA sequencing, we find that more than half of all AS events are regulated by multiple hnRNP proteins, and that some combinations of hnRNP proteins exhibit significant synergy, whereas others act antagonistically. Our analyses reveal position-dependent RNA splicing maps, in vivo consensus binding sites, a surprising level of cross- and auto-regulation among hnRNP proteins, and the coordinated regulation by hnRNP proteins of dozens of other RNA binding proteins and genes associated with cancer. Our findings define an unprecedented degree of complexity and compensatory relationships among hnRNP proteins and their splicing targets that likely confer robustness to cells. In triplicate, polyA-selected RNA was extracted from control, hnRNP A1, hnRNP A2/B1, hnRNP H1, hnRNP F, hnRNP M, and hnRNP U siRNA treated human 293T cells, and hybridized to custom splice-junction arrays
Project description:Understanding how RNA binding proteins control the splicing code is fundamental to human biology and disease. Here we present a comprehensive study to elucidate how heterogeneous nuclear ribonucleoparticle (hnRNP) proteins, among the most abundant RNA binding proteins, coordinate to regulate alternative pre-mRNA splicing (AS) in human cells. Using splicing-sensitive microarrays, cross-linking and immunoprecipitation coupled with high-throughput sequencing, and cDNA sequencing, we find that more than half of all AS events are regulated by multiple hnRNP proteins, and that some combinations of hnRNP proteins exhibit significant synergy, whereas others act antagonistically. Our analyses reveal position-dependent RNA splicing maps, in vivo consensus binding sites, a surprising level of cross- and auto-regulation among hnRNP proteins, and the coordinated regulation by hnRNP proteins of dozens of other RNA binding proteins and genes associated with cancer. Our findings define an unprecedented degree of complexity and compensatory relationships among hnRNP proteins and their splicing targets that likely confer robustness to cells. RNAseq for control, hnRNP A1, hnRNP A2/B1, hnRNP H1, hnRNP F, hnRNP M, and hnRNP U siRNA treated human 293T cells
Project description:The hnRNP A1 and A2 proteins regulate processes such as alternative pre-mRNA splicing and mRNA stability. Here, we report that a reduction in the levels of hnRNP A1 and A2 by RNA interference or their cytoplasmic retention by osmotic stress drastically increases the transcription of a reporter gene. Based on previous work, we propose that this effect may be linked to a decrease in the activity of the transcription elongation factor P-TEFb. Consistent with this hypothesis, the transcription of the reporter gene was stimulated when the catalytic component of P-TEFb, CDK9, was inhibited with DRB. While low levels of A1/A2 stimulated the association of RNA polymerase II with the reporter gene, they also increased the association of CDK9 with the repressor 7SK RNA, and compromised the recovery of promoter-distal transcription on the Kitlg gene after the release of pausing. Transcriptome analysis revealed that more than 50% of the genes whose expression was affected by the siRNA-mediated depletion of A1/A2 were also affected by DRB. RNA polymerase II-chromatin immunoprecipitation assays on DRB-treated and A1/A2-depleted cells identified a common set of repressed genes displaying increased occupancy of polymerases at promoter-proximal locations, consistent with pausing. Overall, our results suggest that lowering the levels of hnRNP A1/A2 elicits defective transcription elongation on a fraction of P-TEFb-dependent genes, hence favoring the transcription of P-TEFb-independent genes. two treatements and one control
Project description:This experiment identifies hnRNP A1 binding sites transcriptome-wide in Hela cells. HeLa cells with inducible expression of T7-tagged hnRNP A1 were grown to approximately 90% confluence and then subject to iCLIP analysis (following the protocol from Huppertz et al. 2014 (iCLIP: protein-RNA interactions at nucleotide resolution)). The iCLIP library was sequenced using Illumina's HighSeq 1500
Project description:The goals of this study were to identify LIN28 downstream gene targets in breast cancer cells. We use a subclone of the MCF-7 breast cancer cell line, MCF-7M as our model system. Methods: mRNA profiles from MCF-7M breast cancer cells treated with siRNA against non-targeting control (NT), LIN28, hnRNP A1, LIN28 and hnRNPA1 (LIN28A1) for 72 hrs were generated by deep sequencing, in duplicate, using Illumina HiSeq 2000. The sequence reads that passed quality filters were analyzed at the transcript isoform level with two methods: Burrows–Wheeler Aligner (BWA) followed by ANOVA (ANOVA) and TopHat followed by Cufflinks. qRT–PCR validation was performed using TaqMan and SYBR Green assays Results: Using an optimized data analysis workflow, we mapped over 200 million sequence reads per sample to the human genome (build h19). Each of the four groups had two biological replicates. We developed a custom method to identify alternative splicing events and identified 111 genes with significant (FDR<0.05) differential splicing for LIN28 depleted cells compared to non-targeting siRNA control, as well as 249 and 182 genes for hnRNP A1 and LIN28A1 respectively. RNA-seq data were validated with by qRT–PCR analysis of a subset of genes. Conclusions: Results reveal that LIN28 regulates alternative splicing and steady state mRNA expression of genes implicated in aspects of breast cancer biology. Notably, cells lacking LIN28 undergo significant isoform switching of the ENAH gene, resulting in a decrease in the expression of ENAH exon 11a isoform. Expression of ENAH isoform 11a has been shown to be elevated in breast cancers that express HER2. mRNA profiles of MCF-7M cells treated with siRNA for NT control, LIN28, hnRNP A1, and LIN28 plus hnRNP A1 (A1) (LIN28A1) were generated by deep sequencing, in duplicate, using Illumina HiSeq 2000
Project description:iCLIP experiment to assess the binding of the highly abundant nuclear RNA-binding protein hnRNP C and core splicing factor U2AF65 on a genomic scale. To investigate how both proteins compete for binding at a subset of sites, U2AF65 iCLIP experiments were performed from both HNRNPC knockdown and control HeLa cells.
Project description:Through alternative splicing, most human genes express multiple isoforms that may have distinct or even antagonistic functions. To infer isoform regulation based on data from high-throughput sequencing of cDNA fragments (RNA-Seq), we have developed MISO, a computational model that estimates the expression level of alternatively spliced exons and mRNA isoforms and provides intuitive measures of con?dence in these estimates. Incorporation of the length distribution of inserted cDNA fragments in paired-end RNA-Seq analysis in MISO enables dramatic improvements in estimation of alternative splicing levels relative to previous methods. We show that one lane of paired-end RNA-Seq data can provide far more information about splicing than two lanes of single-end data, depending critically on properties of the distribution of cDNA fragment lengths in the sequenced library. MISO also leads to an intuitive method to detect di?erentially regulated exons or isoforms. Application of this method implicates the RNA splicing factor hnRNP H in regulation of alternative cleavage and polyadenylation, a role that is supported by UV crosslinking/immunoprecipitation/high-throughput sequencing (CLIP-Seq) analysis. Together, our results provide a probabilistic framework for RNA-Seq analysis, derive functional insights into pre-mRNA processing, and yield guidelines for the optimal design of RNA-Seq experiments for studies of gene and isoform expression. CLIPseq of hnRNP H in HEK 293T cells. RNAseq of polyA+ RNA from C2C12 mouse myoblasts stably expressing an empty vector or a vector containing an shRNA against CUGBP1. Libraries of two different insert lengths were created and examined.
Project description:The nuclear matrix associated hnRNP U/SAF-A protein has been implicated in diverse pathways from transcriptional regulation to telomere length control to X inactivation, but the precise mechanism underlying each of these processes has remained elusive. Here, we report hnRNP U as a regulator of SMN2 splicing from a custom RNAi screen. Genome-wide analysis by CLIP-seq reveals that hnRNP U binds virtually to all classes of regulatory non-coding RNAs, including all snRNAs required for splicing of both major and minor classes of introns, leading to the discovery that hnRNP U regulates U2 snRNP maturation and Cajal body morphology in the nucleus. Global analysis of hnRNP U-dependent splicing by RNA-seq coupled with bioinformatic analysis of associated splicing signals suggests a general rule for splice site selection through modulating the core splicing machinery. These findings exemplify hnRNP U/SAF-A as a potent regulator of nuclear ribonucleoprotein particles in diverse gene expression pathways. Examination of hnRNP U regulated splicing in Hela cells with CLIP-seq (two biological replicates) and paired-end RNA-seq (control and hnRNP U knockdown)
Project description:Neurons critically rely on the functions of RNA-binding proteins to maintain their polarity and resistance to neurotoxic stresses. HnRNP R has a diverse range of post-transcriptional regulatory functions and is important for neuronal development by regulating axon growth. Hnrnpr pre-mRNA undergoes alternative splicing to produce transcripts encoding two isoforms: a full-length protein and a shorter form lacking the N-terminal acidic domain. While the neuronal defects produced by total hnRNP R depletion have been investigated before, the individual functions of each hnRNP R isoforms are unknown. We generated a Hnrnpr knockout mouse (Hnrnprtm1a/tm1a) showing selective loss of the full-length hnRNP R isoform. Motoneurons cultured from Hnrnprtm1a/tm1a mice did not show any axonal growth defects. However, they show an accumulation of double-strand breaks and an impaired DNA damage response. Proteomic analysis of the hnRNP R interactome revealed the multifunctional protein Yb1 as a top interactor. Yb1 depleted motoneurons also exhibit defects in DNA damage repair. We show that Yb1 is recruited to chromatin upon DNA damage, a mechanism that is dependent on full-length hnRNP R. Our findings thus suggest a novel role of hnRNP R in maintaining genomic integrity and highlight the function of its Nterminal acidic domain in this context.