Project description:Here, we use dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq) to conduct a target-specific and genome-wide profile of in vivo RNA secondary structure in rice (Oryza sativa). Our study presents an optimized DMS-MaPseq for probing in vivo RNA structure in rice.
Project description:Here we present dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq), which encodes DMS modifications as mismatches using a thermostable group II intron reverse transcriptase (TGIRT). DMS-MaPseq yields a high signal-to-noise ratio, can report multiple structural features for each molecule, and allows genome-wide studies as well as focused investigations of low abundance RNAs. We apply DMS-MaPseq to Drosophila melanogaster ovaries—the first experimental analysis of RNA structure in an animal tissue—and demonstrate its utility in the discovery of a functional RNA structure involved in the non-canonical GUG translation initiation of the human FXR2 mRNA. Additionally, we use DMS-MaPseq to compare the in vivo structure of messages in their pre-mRNA and mature forms. These applications illustrate DMS-MaPseq’s capacity to dramatically expand our ability to monitor RNA structure in vivo.
Project description:Telomerase is a specialized reverse transcriptase that uses an intrinsic RNA subunit as the template for telomeric DNA synthesis. Biogenesis of human telomerase requires its RNA subunit (hTR) to fold into a multi-domain architecture that includes the template-containing pseudoknot (t/PK) and the three-way junction (CR4/5). These two hTR domains bind the telomerase reverse transcriptase (hTERT) protein and are thus essential for telomerase catalytic activity. Here, we probe the structure of hTR in living cells using dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq) and ensemble deconvolution analysis. Unexpectedly, approximately 15% of the steady state population of hTR has a CR4/5 conformation lacking features required for hTERT binding. Mutagenesis demonstrates that stabilization of the alternative CR4/5 conformation is detrimental to telomerase assembly and activity. We propose that this misfolded portion of the cellular hTR pool is either slowly refolded or degraded. Thus, kinetic traps for RNA folding that have been so well-studied in vitro may also present barriers for assembly of ribonucleoprotein complexes in vivo.
Project description:While various methods exist for examining and visualizing the structure of RNA molecules, dimethyl sulfate-mutational profiling and sequencing (DMS-MaPseq) stands out for its simplicity and versatility. This technique has proven effective for studying RNA structures both in vitro and in complex biological settings. We've updated the protocol for using DMS-MaPseq, and it can also be employed to identify the binding of antisense oligonucleotides (ASOs) to RNA. By applying this updated protocol, we successfully characterized the structural ensemble of the HIV1 Rev Response Element (RRE), along with its two alternative structures. The findings align with previously published research. Additionally, we resolved the structure of the long non-coding RNA PANDA, which was previously unknown. Moreover, we used PANDA as a basis for designing ASOs and confirmed their binding through a substantial decrease in DMS-reactivities at the anticipated ASO binding locations.
Project description:Here we present dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq) prepared from leaves of adult plants in Arabidopsis. Chromatin remodeling factor 2 (CHR2) positively regulates transcription of MIR loci whereas repressing microRNA (miRNA) accumulation in vivo. CHR2 can directly bind to and unwind primary miRNAs (pri-miRNAs) and inhibit their processing; and this inhibition entails its remodeling activity in vitro and in vivo.
Project description:The goal of this set of experiments is to determine the structure of HIV-1 NL4-3 and NHG RNA structure using a novel algorithm that allows for the identification of multiple RNA folding conformations. The input data used for this algorithm is DMS-MaPseq data. We focused on two specific areas of the HIV-1 genome, the Rev Response Element (RRE) and A3 splice acceptor site, as well as probing the whole HIV-1 genome. RNA is DMS-modified in vitro and in vivo as indicated. The goal of this data set was to test the novel alternative RNA structure detecting algorithm (DREEM) using RNA molecules with known structures.
Project description:Ribosomes are among the largest folded RNAs, whose function depends on their structure. Nonetheless, in vitro studies indicate a propensity of rRNAs to misfold. We use a combination of DMS-MaPseq, structural analyses, biochemical experiments, and yeast genetics to dissect the final RNA folding steps of the small ribosomal subunit head.
Project description:Ribosomes are among the largest folded RNAs, whose function depends on their structure. Nonetheless, in vitro studies indicate a propensity of rRNAs to misfold. We use a combination of DMS-MaPseq, structural analyses, biochemical experiments, and yeast genetics to dissect the final RNA folding steps of the small ribosomal subunit head.
2022-08-31 | GSE183045 | GEO
Project description:Telomerase purification from Arabidopsis thaliana
Project description:To delineate the native structure of SF3A3 5'UTR, RNA was harvested from IMR90 human fibroblasts. Using specific primers and DMS-MaPSeq pipeline, we validated individual base pairing probabilities within the endogenous 5'UTR of SF3A3 (samples described as 'in vivo' transcribed). DMS-MaP-Seq is based on the principle that DMS is highly reactive to solvent-accessible, unpaired adenine (A) and cytosine (C) residues, but remains inert toward base-paired A and C engaged in Watson-Crick interactions (Rouskin et al., 2014). Using this methodology, we identify stable stem-loop structure (SL3) positioned within SF3A3 5'UTR. To further validate the functional importance of SL3, the structural point mutant (SF3A3 5'UTR mut: A55C and U95A) and rescue (SF3A3 5'UTR res: A55C and U95A and rescuing point mutations G61U and U100G) sequences of SF3A3 5'UTR were cloned into the reporter plasmid. For the validation of these mutate-and-rescue constructs, plasmids were in vitro transcribed and either used directly (samples described as 'in vitro') for DMS-MaP-Seq probing.