Project description:We optimized the SHAPE-MaP (selective 2'-hydroxyl acylation analyzed by primer extension and mutational profiling) assay to analyze structures of paired circular (circSHAPE-MaP) and linear (linearSHAPE-MaP) RNAs.
Project description:To refine the authentic CENP-C binding sites of lnc-CCTT and globally map lnc-CCTT secondary structure, we also performed SHAPE-MaP (selective 2’-hydroxyl acylation analyzes by primer extension and mutational profiling), which uses hydroxyl-selective electrophiles to modify the 2’-hydroxyl groups of unbound single-stranded nucleotides, in HeLa cells both ex vivo and in vivo. Lnc-CCTT secondary structure was modeled by combination SHAPE data from cell-free ex vivo with pairing probabilities. As expected, nucleotides 43-79 nt, a determinant for RNA-DNA triplex formation, exhibited a continuous single-strandedness, which may be prone to binding DNA. More importantly, only nucleotides 118-177 nt, which was folded into a stem-loop structure in the secondary structure, showed a significant reduced SHAPE reactivities in cell when comparing to cell-free state, suggesting this region could be attributed to interaction with protein components.
Project description:New regulatory roles continue to emerge for both natural and engineered noncoding RNAs, many of which have specific secondary and tertiary structures essential to their function. Thus there is a growing need to develop technologies that enable rapid characterization of structural features within complex RNA populations. We have developed a high-throughput technique, SHAPE-Seq, that can simultaneously measure quantitative, single nucleotide-resolution secondary and tertiary structural information for hundreds of RNA molecules of arbitrary sequence. SHAPE-Seq combines selective 2â²-hydroxyl acylation analyzed by primer extension (SHAPE) chemistry with multiplexed paired-end deep sequencing of primer extension products. This generates millions of sequencing reads, which are then analyzed using a fully automated data analysis pipeline, based on a rigorous maximum likelihood model of the SHAPE-Seq experiment. We demonstrate the ability of SHAPE-Seq to accurately infer secondary and tertiary structural information, detect subtle conformational changes due to single nucleotide point mutations, and simultaneously measure the structures of a complex pool of different RNA molecules. SHAPE-Seq thus represents a powerful step toward making the study of RNA secondary and tertiary structures high throughput and accessible to a wide array of scientific pursuits, from fundamental biological investigations to engineering RNA for synthetic biological systems. We sequenced in-vitro transcribed RNaseP in wild type and barcoded variants and probed them with SHAPE-Seq. Comparison to existing crystalography data and previous SHAPE experiments verified the accuracy of the technique and the absence of bias due to our multiplexiing strategy.
Project description:New regulatory roles continue to emerge for both natural and engineered noncoding RNAs, many of which have specific secondary and tertiary structures essential to their function. Thus there is a growing need to develop technologies that enable rapid characterization of structural features within complex RNA populations. We have developed a high-throughput technique, SHAPE-Seq, that can simultaneously measure quantitative, single nucleotide-resolution secondary and tertiary structural information for hundreds of RNA molecules of arbitrary sequence. SHAPE-Seq combines selective 2â²-hydroxyl acylation analyzed by primer extension (SHAPE) chemistry with multiplexed paired-end deep sequencing of primer extension products. This generates millions of sequencing reads, which are then analyzed using a fully automated data analysis pipeline, based on a rigorous maximum likelihood model of the SHAPE-Seq experiment. We demonstrate the ability of SHAPE-Seq to accurately infer secondary and tertiary structural information, detect subtle conformational changes due to single nucleotide point mutations, and simultaneously measure the structures of a complex pool of different RNA molecules. SHAPE-Seq thus represents a powerful step toward making the study of RNA secondary and tertiary structures high throughput and accessible to a wide array of scientific pursuits, from fundamental biological investigations to engineering RNA for synthetic biological systems.
Project description:Discovering the interaction mechanism and location of RNA binding proteins (RBPs) on RNA is critical for understanding gene expression regulation. Here, we apply selective 2’-hydroxyl acylation analyzed by primer extension (SHAPE) on in vivo transcripts to identify transcriptome-wide footprints (fSHAPE) on RNA when compared to protein-absent transcripts. Structural analyses indicate that fSHAPE precisely detects nucleotides whose base moieties hydrogen bond with protein and that fSHAPE patterns can predict binding sites of RBPs of interest. To illustrate, we demonstrate that fSHAPE correctly identifies known and novel iron response protein RNA elements. Furthermore, we enable selective interrogation of RNA-protein complexes by integrating SHAPE and fSHAPE with crosslinking and immunoprecipitation (eCLIP) of desired RBPs. To demonstrate, histone stem loop elements and their nucleotides that hydrogen bond with stem-loop binding protein were identified by SHAPE-eCLIP and fSHAPE-eCLIP. Together, these technologies greatly expand on strategies for understanding specific cellular RNA interactions in RNA-protein complexes.
Project description:We resolved the RNA secondary structure during zebrafish early embryogenesis based on in vivo click selective 2'-hydroxyl acylation and profiling experiment (icSHAPE). We analyzed the RNA structure dynamics among different development stages. Also, we studied which factors regulate maternal gene decay by RNA structure switch.
Project description:Spliceosomal snRNA are key components of small nuclear ribonucleoprotein particles (snRNPs), the building blocks of the spliceosome. The biogenesis of snRNPs is a complex process involving multiple cellular and subcellular compartments, the details of which are yet to be described. In short, the snRNA is exported to the cytoplasm as 3‘-end extended precursor (pre-snRNA), where it acquires a heptameric Sm ring. The SMN complex which catalyses this step, recruits Sm proteins and assembles them around the pre-snRNA at the single stranded Sm site. After additional modification, the complex is re-imported into the nucleus where the final maturation step occurs. Our modeling suggests that during the cytoplasmic stage of maturation pre-snRNA assumes a compact secondary structure containing Near Sm site Stem (NSS) which is not compattible with the formation of the Sm ring. To validate our in silico predictions we employed selective 2'-hydroxyl acylation analyzed by primer extension sequencing (SHAPE-Seq) on U2 snRNA in vivo, ex vivo and in vitro, and U4 pre-snRNA in vitro. For the in vivo experiment HeLa cells were incubated for 10 min at 37°C with NAI or DMSO to final concentration 200 mM. RNA was isolated using Trizol (Sigma) and 200 µl chloroform and precipitated with ethanol at -20°C overnight. For the ex vivo experiment, RNA was isolated from HeLa cells after Protease K treatment at room temperature for 45 min. After incubation, RNA was isolated using equilibrated phenol/chloroform/isoamyl alcohol buffered by folding buffer (110 mM HEPES pH 8.0, 110 mM KCl, 11 mM MgCl2) and cleaned on a PD-10 column according to the manufacturer’s instructions. Isolated RNA was treated with 100mM NAI or DMSO for 10 min at 37°C. For the in vitro experiment, U2WT and U4 pre-snRNA were transcribed by T7 polymerase followed by DNase I (30 min at 37 °C) and Proteinase K (30 min at 37°C) treatments. U2 snRNA was purified on 30 kDa Amicon columns, folded for 30 min at 37°C in 57 mM MgCl2 and incubated with 100 mM NAI at 37°C for 10 min. DMSO was used as a negative control. U4 pre-snRNA was purified on Superdex 200 Increase 10/300GL, folded for 30 min at 37°C in 60 mM MgCl2 and incubated with 100 mM NAI at 37°C for 10 min. DMSO was used as a negative control. All prepared RNA samples (in vitro, ex vivo, in vivo) were used for reverse transcription with the gene-specific primer 5’-CGTTCCTGGAGGTACTGCAA for U2 snRNA and 5’- AAAAATTCAGTCTCCG for U4 pre-snRNA. We used SHAPE MaP buffer (50 mM Tris-HCl pH 8.0, 75 mM KCl, 10 mM DTT, 0.5 mM dNTP, 6 mM MnCl2) and SuperScript II (Invitrogen). Amplicons for snRNAs were generated using gene-specific forward and reverse primers. Importantly, the primers include Nextera adaptors required for downstream library construction. PCR reaction products were cleaned using Monarch PCR&DNA Clean-up Kits. Remaining Illumina adaptor sequences were added using the PCR MasterMix and index primers provided in the NexteraXT DNA Library Preparation Kit (Illumina) according to the manufacturer’s protocol. Libraries were quantified using Qubit (Invitrogen) and BioAnalyzer (Agilent). Amplicons were sequenced on a NextSeq 500/550 platform using a 150 cycle mid-output kit. All sequencing data was analyzed using the ShapeMapper 2 analysis pipeline1. The ‘—amplicon’ and ‘—primers’ flags were used, along with sequences of gene-specific handles PCR primers, to ensure primer binding sites are excluded from reactivity calculations. Default read-depth thresholds of 5000x were used. Analysis of statistically significant reactivity differences between ex vivo and in vivo-determined SHAPE reactivities was performed using the DeltaSHAPE automated analysis tool and default settings2. 1. Busan, S. & Weeks, K.M. Accurate detection of chemical modifications in RNA by mutational profiling (MaP) with ShapeMapper 2. RNA 24, 143-148 (2018). 2. Smola, M.J., Rice, G.M., Busan, S., Siegfried, N.A. & Weeks, K.M. Selective 2'-hydroxyl acylation analyzed by primer extension and mutational profiling (SHAPE-MaP) for direct, versatile and accurate RNA structure analysis. Nat Protoc 10, 1643-69 (2015).
Project description:Micro (mi)RNAs are small non-coding RNAs with key regulatory functions. Recent advances in the field allowed researchers to identify their targets. However, much less is known regarding the regulation of miRNA themselves. The accumulation of these tiny regulators can be modulated at various levels during their biogenesis from the transcription of the primary transcript (pri-miRNA) to the stability of the mature miRNA. Here, we studied the importance of the pri-miRNA secondary structure for the regulation of mature miRNAs accumulation. To this end, we used the KaposiM-bM-^@M-^Ys sarcoma herpesvirus, which encodes a cluster of twelve pre-miRNAs. Using small RNA profiling and quantitative northern blot analysis, we measured the absolute amount of each mature miRNAs in different cellular context. We found that the difference in expression between the least and most expressed viral miRNA could be as high as 60-fold. Using high-throughput selective 2M-bM-^@M-^Y-hydroxyl acylation analyzed by primer extension (hSHAPE), we then determined the secondary structure of the long primary transcript. We found that highly expressed miRNAs derived from optimally structured regions within the pri-miRNA. Finally, we confirmed the importance of the local structure by swapping stem-loops for highly and lowly expressed miRNAs, which resulted in a perturbed accumulation of the mature miRNA. Examination of sRNA profiles in 3 independent B cell lines expressing KSHV miRNAs or infected with KSHV, without replicate
Project description:Micro (mi)RNAs are small non-coding RNAs with key regulatory functions. Recent advances in the field allowed researchers to identify their targets. However, much less is known regarding the regulation of miRNA themselves. The accumulation of these tiny regulators can be modulated at various levels during their biogenesis from the transcription of the primary transcript (pri-miRNA) to the stability of the mature miRNA. Here, we studied the importance of the pri-miRNA secondary structure for the regulation of mature miRNAs accumulation. To this end, we used the Kaposi’s sarcoma herpesvirus, which encodes a cluster of twelve pre-miRNAs. Using small RNA profiling and quantitative northern blot analysis, we measured the absolute amount of each mature miRNAs in different cellular context. We found that the difference in expression between the least and most expressed viral miRNA could be as high as 60-fold. Using high-throughput selective 2’-hydroxyl acylation analyzed by primer extension (hSHAPE), we then determined the secondary structure of the long primary transcript. We found that highly expressed miRNAs derived from optimally structured regions within the pri-miRNA. Finally, we confirmed the importance of the local structure by swapping stem-loops for highly and lowly expressed miRNAs, which resulted in a perturbed accumulation of the mature miRNA.
Project description:We resolved the RNA secondary structure of three cellular compartments including chromatin (ch), nucleoplasm(np) and cytoplasm(cy) in HEK293 and mES cells based on in vivo click selective 2'-hydroxyl acylation and profiling experiment (icSHAPE). We analyze the RNA structure dynamics among cellular compartments and different RNA processings. Also, we study which factors perturb the RNA structures.