Project description:Understanding the targeting and spreading patterns of lncRNAs on chromatin requires a technique that can detect both high intensity binding sites and reveal genome-wide spreading patterns with high confidence. We developed an improved hybridization capture protocol to determine lncRNA localization using biotinylated LNA-containing oligonucleotides that hybridize to the target RNA and enhance capture specificity by including a protecting oligonucleotide that competitively displaces contaminating species, leading to highly specific RNA capture. This approach revealed the spreading pattern of roX2, a lncRNA involved in dosage compensation in D. melanogaster, how this pattern relates to chromatin features, and how spreading of roX2 changes upon cellular stress. Upon heat shock, roX2 displays reduced spreading on X chromosome and surprising relocalization to sites on autosomes, revealing how this improved hybridization capture approach can reveal previously uncharacterized changes in the targeting and spreading of lncRNAs on chromatin.
Project description:Schmitz2014 - RNA triplex formation
The model is parameterized using the
parameters for gene CCDC3 from Supplementary Table S1. The two
miRNAs which form the triplex together with CCDC3 are miR-551b and
miR-138.
This model is described in the article:
Cooperative gene regulation
by microRNA pairs and their identification using a
computational workflow.
Schmitz U, Lai X, Winter F,
Wolkenhauer O, Vera J, Gupta SK.
Nucleic Acids Res. 2014 Jul; 42(12):
7539-7552
Abstract:
MicroRNAs (miRNAs) are an integral part of gene regulation
at the post-transcriptional level. Recently, it has been shown
that pairs of miRNAs can repress the translation of a target
mRNA in a cooperative manner, which leads to an enhanced
effectiveness and specificity in target repression. However, it
remains unclear which miRNA pairs can synergize and which genes
are target of cooperative miRNA regulation. In this paper, we
present a computational workflow for the prediction and
analysis of cooperating miRNAs and their mutual target genes,
which we refer to as RNA triplexes. The workflow integrates
methods of miRNA target prediction; triplex structure analysis;
molecular dynamics simulations and mathematical modeling for a
reliable prediction of functional RNA triplexes and target
repression efficiency. In a case study we analyzed the human
genome and identified several thousand targets of cooperative
gene regulation. Our results suggest that miRNA cooperativity
is a frequent mechanism for an enhanced target repression by
pairs of miRNAs facilitating distinctive and fine-tuned target
gene expression patterns. Human RNA triplexes predicted and
characterized in this study are organized in a web resource at
www.sbi.uni-rostock.de/triplexrna/.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000530.
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To the extent possible under law, all copyright and related or
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Project description:Long non-coding RNAs (lncRNAs) have important regulatory roles and can function at the level of chromatin. To determine where lncRNAs bind to chromatin, we developed CHART, a hybridization-based technique that specifically enriches endogenous RNAs along with their targets from reversibly-crosslinked chromatin extracts. CHART was used to enrich the DNA and protein targets of endogenous lncRNAs from fly and human. This analysis was extended to genome-wide mapping of roX2, a well-studied ncRNA involved in dosage-compensation in Drosophila. CHART revealed that roX2 binds at specific genomic sites that coincide with the binding sites of proteins from the MSL-complex that affects dosage compensation. These results reveal the genomic targets of roX2 and demonstrate how CHART can be used to study RNAs in a manner analogous to ChIP for proteins. Examination of the binding sites of roX2 ncRNA from S2 cells using two different elution strategies compared with a sense control or input control. Processed data file 'roX2.2.peaks.bed' (for roX2 CHART RNase eluted, combined replicates) linked below as supplementary file.
Project description:CHART sequencing has been carried out in order to evaluate SCIRT target genes in MDA-MB-231 sphere derived cells. We discovered that lncRNA SCIRT binds promoter region of genes whose expression changes after SCIRT siRNA downregulation, suggesting that those are target SCIRT target genes.
Project description:Recent efforts towards the comprehensive identification of RNA-bound proteomes have revealed a large, surprisingly diverse family of candidate RNA-binding proteins (RBPs). Quantitative metrics for characterization and validation of protein-RNA interactions and their dynamic interactions have, however, proven to be analytically challenging and prone to error. Here we report a novel method termed LEAP-RBP for the selective, quantitative recovery of UV-crosslinked RNA-protein complexes. By virtue of its high specificity and yield, LEAP-RBP distinguishes RNA-bound and RNA-free protein levels and reveals common sources of experimental noise in RNA-centric RBP enrichment methods. We introduce new strategies for accurate RBP identification and signal-based metrics for quantifying protein-RNA complex enrichment, relative RNA occupancy, and method specificity. The utility of our approach is validated by comprehensive identification of RBPs whose association with mRNA is modulated in response to global mRNA translation state changes and through in-depth benchmark comparisons with current methodologies.
Project description:1. Evaluate the diagnostic value of long noncoding RNA (CCAT1) expression by RT-PCR in peripheral blood in colorectal cancer patients versus normal healthy control personal.
2. Evaluate the clinical utility of detecting long noncoding RNA (CCAT1) expression in diagnosis of colorectal cancer patients & its relation to tumor staging.
3. Evaluate the clinical utility of detecting long noncoding RNA (CCAT1) expression in precancerous colorectal diseases.
4. Compare long noncoding RNA (CCAT1) expression with traditional marker; carcinoembryonic antigen (CEA) and Carbohydrate antigen 19-9 (CA19-9) in diagnosis of colorectal cancer.
Project description:Many intergenic long noncoding RNA (lncRNA) loci regulate the expression of adjacent protein coding genes. Less clear is whether intergenic lncRNAs commonly regulate transcription by modulating chromatin at genomically distant loci. Here, we report both genomically local and distal RNA-dependent roles of Dali, a conserved central nervous system expressed intergenic lncRNA. Dali is transcribed downstream of the Pou3f3 transcription factor gene and its depletion disrupts the differentiation of neuroblastoma cells. Locally, Dali transcript regulates transcription of the Pou3f3 locus. Distally, it preferentially targets active promoters and regulates expression of neural differentiation genes, in part through physical association with the POU3F3 protein. Dali interacts with the DNMT1 DNA methyltransferase in mouse and human and regulates DNA methylation status of CpG island-associated promoters in trans. These results demonstrate, for the first time, that a single intergenic lncRNA controls the activity and methylation of genomically distal regulatory elements to modulate large-scale transcriptional programmes. The genome-wide binding profile of Dali was determined using Capture Hybridisation Analysis of RNA Targets (CHART)-Seq technique (Simon et al, Proc Natl Acad Sci U S A 108: 20497-20502, 2011) in N2A cells. Following the CHART-seq protocol, we used RNase H elution to recover genomic DNA associated with endogenous Dali transcripts. We identified Dali binding sites in comparison both to an input DNA sample from N2A cells and to DNA recovered using the control E.coli LacZ oligonucleotide. Please note that n2a_input, n2a_LacZ data was published previously [GSE52571]