Project description:PUF proteins have become a leading scaffold for designing RNA-binding proteins to contact and control RNAs at will. We analyze the effects of that reengineering across the transcriptome in vivo for the first time. We show, by HITS-CLIP and PAR-CLIP, that S. cerevisiae Puf2p, a non-canonical PUF protein, binds more than 1000 mRNA targets. Puf2p binds multiple UAAU elements, unlike canonical PUF proteins. We also perform CLIP-seq on truncations of the Puf2p, showing that its prion domain is dispensable for WT binding. We design a modified Puf2p to bind UAAG rather than UAAU, which allows us to align the protein with the binding site. In vivo, the redesigned protein binds UAAG sites. Its altered specificity redistributes the protein away from 3âUTRs, such that the protein tracks with its sites, binds throughout the mRNA. We use RNA-seq to determine that R1 SNE Puf2p represses a novel RNA network. CLIP-seq was performed in BY4742 S. cerevisiae grown in log phase, and using 2 replicates of TAP-tagged proteins.
Project description:PUF proteins have become a leading scaffold for designing RNA-binding proteins to contact and control RNAs at will. We analyze the effects of that reengineering across the transcriptome in vivo for the first time. We show, by HITS-CLIP and PAR-CLIP, that S. cerevisiae Puf2p, a non-canonical PUF protein, binds more than 1000 mRNA targets. Puf2p binds multiple UAAU elements, unlike canonical PUF proteins. We also perform CLIP-seq on truncations of Puf2p, showing that its prion domain is dispensable for WT binding. We design a modified Puf2p to bind UAAG rather than UAAU, which allows us to align the protein with the binding site. In vivo, the redesigned protein binds UAAG sites. Its altered specificity redistributes the protein away from 3âUTRs, such that the protein tracks with its sites and binds throughout the mRNA. We use RNA-seq to determine that R1 SNE Puf2p represses a novel RNA network. CLIP-seq was performed in BY4742 S. cerevisiae grown in log phase, and using 2 replicates of TAP-tagged proteins. RNA-seq was performed to determine the regulatory effect of WT or mutant Puf2p, using 4 replicates of the control (no Puf2p), 3 of WT Puf2p and 4 of R1 SNE Puf2p.
Project description:TAF15, an RNA binding protein was recently implicated in Amyotrophic Lateral Sclerosis (ALS). ALS is a fatal neurodegenerative disease. We report the identification of the conserved neuronal RNA targets of TAF15 and the assessment of the impact of TAF15 depletion on the neuronal transcriptome. Our study uncovers regulation of splicing of sets of neuronal RNAs encoding proteins with essential roles in synaptic activities including glutamergic receptors such as zeta-1 subunit of the glutamate N-methyl-D-aspartate (NMDA) receptor (Grin1). Identification of TAF15 neuronal targets using normal human brain samples and mouse neurons. Mouse background: E14Tg2a.4 wildtype cells derived from 129P2/OlaHsd.
Project description:FUS, an RNA binding protein was recently implicated in Amyotrophic Lateral Sclerosis (ALS). ALS is a fatal neurodegenerative disease. We report the identification of the conserved neuronal RNA targets of FUS and the assessment of the impact of FUS depletion on the neuronal transcriptome. We identified that FUS regulates splicing of conserved intron containing transcripts. FUS retains or excludes the conserved intron by binding to them. Identification of FUS neuronal targets using normal human brain samples and mouse neurons
Project description:The regulation of translation elongation plays a vital role in protein folding; an adequate translational pause provides time and cellular environments for the co-translational folding of nascent peptides. However, the genomic landscape, sequence determinants, and molecular consequences of translational pausing remain mostly unknown. In this study, we performed disome-seq that sequenced mRNA fragments protected by two consecutive ribosomes – a product of severe translational pauses during which the upstream ribosome collides into the paused one. We detected severe translational pauses on ~75% of yeast genes. These pauses were often explained by one of the three mechanisms: 1) slow ribosome releasing at stop codons, 2) slow peptide formation from proline, glycine, asparagine, and cysteine, and 3) slow leaving of polylysine from the exit tunnel of ribosomes. Notably, these amino acids also terminate the α-helical conformation. Such dual roles of amino acids establish an inborn coupling between the synthetic completion of a structural motif and a translational pause. Furthermore, paused ribosomes often recruit chaperones to assist protein folding. As a consequence, emergent protein structures during evolution should be ready to be correctly folded. Collectively, our study shows widespread translational pauses and sheds lights on a better understanding of the regulation of co-translational protein folding.
Project description:Expression, crosslinking and immunoprecipitation of tagged HNRPA2B1 (variant A2) to identify bound RNA sequences RNA molecules that are immunoprecipitated are sequenced followed purification under denaturing conditions
Project description:Human brain samples from control and advanced Alzheimer's Diseased subjects were subjected to HITS-CLIP to monitor nELAVL binding changes during AD progression Human brain samples were obtained from the Mount Sinai Brain Bank; samples were UV-irradiated and subjected to nELAVL HITS-CLIP (detailed desription in accompanying paper)
Project description:Validation of physiologic miRNA targets has been met with significant challenges. We employed HITS-CLIP to identify which miRNAs participate in liver regeneration, and to identify their target mRNAs. miRNA recruitment to the RISC is highly dynamic, changing more than five-fold for several miRNAs. miRNA recruitment to the RISC did not correlate with changes in overall miRNA expression for these dynamically recruited miRNAs, emphasizing the necessity to determine miRNA recruitment to the RISC in order to fully assess the impact of miRNA regulation. We incorporated RNAseq quantification of total mRNA to identify expression-weighted Ago footprints, and developed a microRNA regulatory element (MRE) prediction algorithm that represents a greater than 20-fold refinement over computational methods. These high confidence MREs were used to generate candidate competing endogenous RNA (ceRNA) networks. Conclusion: HITS-CLIP analysis provide novel insights into global miRNA:mRNA relationships in the regenerating liver .
Project description:The Kaposi's sarcoma associated herpesvirus (KSHV) is an oncogenic virus that causes Kaposi's sarcoma, primary effusion lymphoma (PEL), and some forms of multicentric Castleman's disease. The KSHV ORF57 protein is a conserved posttranscriptional regulator of gene expression that is essential for virus replication. ORF57 is multifunctional, but most of its activities are directly linked to its ability to bind RNA. We globally identified virus and host RNAs bound by ORF57 during lytic reactivation in PEL cells using high-throughput sequencing of RNA isolated by crosslinking immunoprecipitation (HITS-CLIP). As expected, ORF57-bound RNA fragments mapped throughout the KSHV genome, including the known ORF57 ligand PAN RNA. In agreement with previously published ChIP results, we observed that ORF57 bound RNAs near the oriLyt regions of the genome. Examination of the host RNA fragments revealed that a subset of the ORF57-bound RNAs was derived from transcript 5´ ends. The position of these 5´-bound fragments correlated closely with the 5´-most exonintron junction of the pre-mRNA. We selected four candidates (BTG1, EGR1, ZFP36, and TNFSF9) and analyzed their pre-mRNA and mRNA levels during lytic phase. Analysis of both steady-state and newly made RNAs revealed that these candidate ORF57-bound pre-mRNAs persisted for longer periods of time throughout infection than control RNAs, consistent with a role for ORF57 in pre-mRNA metabolism. In addition, exogenous expression of ORF57 was sufficient to increase the pre-mRNA levels and, in one case, the mRNA levels of the putative ORF57 targets. These results demonstrate that ORF57 interacts with specific host pre-mRNAs during lytic reactivation and alters their processing, likely by stabilizing pre-mRNAs. These data suggest that ORF57 is involved in modulating host gene expression in addition to KSHV gene expression during lytic reactivation. HITS-CLIP was performed on TREx BCBL-Rta cells 20 hpi using antibodies against ORF57. Three biological replicates were performed.