scholarly journals A semi-supervised approach uncovers thousands of intragenic enhancers differentially activated in human cells

2015 ◽  
Author(s):  
Juan Gonzalez-Vallinas ◽  
Amadís Pagès ◽  
Babita Singh ◽  
Eduardo Eyras
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Positional Distribution ◽  
Human Cells ◽  
Host Gene ◽  
Cell Type ◽  
Related Factors ◽  
Transcriptional Enhancers ◽  
Gm12878 Cell ◽  
Host Genes

Background Transcriptional enhancers are generally known to regulate gene transcription from afar. Their activation involves a series of changes in chromatin marks and recruitment of protein factors. These enhancers may also occur inside genes, but how many may be active in human cells and their effects on the regulation of the host gene remains unclear. Results We describe a novel semi-supervised method based on the relative enrichment of chromatin signals between 2 conditions to predict active enhancers. We applied this method to the tumoral K562 and the normal GM12878 cell lines to predict enhancers that are differentially active in one cell type. These predictions show enhancer-like properties according to positional distribution, correlation with gene expression and production of enhancer RNAs. Using this model, we predict 10,365 and 9,777 intragenic active enhancers in K562 and GM12878, respectively, and relate the differential activation of these enhancers to expression and splicing differences of the host genes. Conclusions We propose that the activation or silencing of intragenic transcriptional enhancers modulate the regulation of the host gene by means of a local change of the chromatin and the recruitment of enhancer-related factors that may interact with the RNA directly or through the interaction with RNA binding proteins. Predicted enhancers are available at http://regulatorygenomics.upf.edu/Projects/enhancers.html

scholarly journals Deep analysis of RNA N6-adenosine methylation (m6A) patterns in human cells

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Jun Wang ◽  
Liangjiang Wang
Keyword(s):  
Rna Binding ◽  
Data Transfer ◽  
Rna Binding Proteins ◽  
Consensus Sequence ◽  
Model Performance ◽  
Cell Types ◽  
Human Cells ◽  
Rna Modification ◽  
Cell Type ◽  
Cell Type Specific

Abstract N6-adenosine methylation (m6A) is the most abundant internal RNA modification in eukaryotes, and affects RNA metabolism and non-coding RNA function. Previous studies suggest that m6A modifications in mammals occur on the consensus sequence DRACH (D = A/G/U, R = A/G, H = A/C/U). However, only about 10% of such adenosines can be m6A-methylated, and the underlying sequence determinants are still unclear. Notably, the regulation of m6A modifications can be cell-type-specific. In this study, we have developed a deep learning model, called TDm6A, to predict RNA m6A modifications in human cells. For cell types with limited availability of m6A data, transfer learning may be used to enhance TDm6A model performance. We show that TDm6A can learn common and cell-type-specific motifs, some of which are associated with RNA-binding proteins previously reported to be m6A readers or anti-readers. In addition, we have used TDm6A to predict m6A sites on human long non-coding RNAs (lncRNAs) for selection of candidates with high levels of m6A modifications. The results provide new insights into m6A modifications on human protein-coding and non-coding transcripts.

scholarly journals Alternative polyadenylation: methods, mechanism, function, and role in cancer

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Yi Zhang ◽  
Lian Liu ◽  
Qiongzi Qiu ◽  
Qing Zhou ◽  
Jinwang Ding ◽  
...  
Keyword(s):  
Gene Regulation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Single Gene ◽  
Alternative Polyadenylation ◽  
Length Change ◽  
Suppressor Gene ◽  
Gene Expressions ◽  
Related Factors ◽  
Mrna Maturation

AbstractOccurring in over 60% of human genes, alternative polyadenylation (APA) results in numerous transcripts with differing 3’ends, thus greatly expanding the diversity of mRNAs and of proteins derived from a single gene. As a key molecular mechanism, APA is involved in various gene regulation steps including mRNA maturation, mRNA stability, cellular RNA decay, and protein diversification. APA is frequently dysregulated in cancers leading to changes in oncogenes and tumor suppressor gene expressions. Recent studies have revealed various APA regulatory mechanisms that promote the development and progression of a number of human diseases, including cancer. Here, we provide an overview of four types of APA and their impacts on gene regulation. We focus particularly on the interaction of APA with microRNAs, RNA binding proteins and other related factors, the core pre-mRNA 3’end processing complex, and 3’UTR length change. We also describe next-generation sequencing methods and computational tools for use in poly(A) signal detection and APA repositories and databases. Finally, we summarize the current understanding of APA in cancer and provide our vision for future APA related research.

P5398CircRNAs deregulation in heart failure patients

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Greco ◽  
A Made' ◽  
M Longo ◽  
R Tikhomirov ◽  
S Castelvecchio ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Functional Characterization ◽  
Enrichment Analysis ◽  
Host Gene ◽  
Circular Rnas ◽  
Amplification Efficiency ◽  
Rna Seq ◽  
Bioinformatics Pipeline

Abstract Background Circular RNAs (circRNAs) are an emerging class of noncoding RNAs stemming from the splicing and circularization of pre-mRNAs exons. CircRNAs can regulate transcription and splicing, sequester microRNAs acting as “sponge” and inducing the respective targets, and bind to RNA binding proteins. Recently, they have been found deregulated in dilated cardiomyopathies (DCM), one of the cardiovascular diseases with the worst rate of morbidity and mortality, and whose molecular mechanisms are only partially known. Purpose Therein, we will evaluate in ischemic DCM patients the modulation of 17 circRNAs, 14 out of them obtained from literature data on DCM ischemic or not, while the other 3 were circRNAs not characterized in the heart previously. The study aims to identify circRNAs candidates for further functional characterization in DCM. In addition, as differential expression (DE) analysis is not easily performed for circRNAs in RNA-seq datasets, the validated circRNAs will be used to set up the most specific and sensitive bioinformatics pipeline for circRNA-DE analysis. Methods We designed divergent and convergent specific primers for 17 circRNAs and their host gene, respectively, and their amplification efficiency was measured by RT-qPCR. Transcripts expression was measured in left ventricle biopsies of 12 patients affected by non end-stage ischemic HF and of 12 matched controls. Results We identified cPVT1, cANKRD17, cBPTF as DE, and validated the modulation of 5 out of the 14 DCM-related circRNAs (cHIPK3, cALPK2, cPCMTD1, cNEBL, cSLC8A1), while cPDRM5, cTTN1 showed opposite modulation, which may be due to the specific disease condition. All of them were modulated differently from the respective host gene. CircRNA/miRNA interactions were predicted using Starbase 3.0. Next, mRNAs-targets of the identified miRNAs were predicted by mirDIP 4.1 and intersected with gene expression datasets of the same patients, previously obtained by microarray analysis. We found that cBPTF and cANKRD17 might sponge 12 and 2 miRNAs, respectively. Enrichment analysis of the relevant targets identified several important pathways implicated in DCM, such as MAPK, FoxO, EGFR, VEGF and Insulin/IGF pathways. In addition, deep RNA-Seq analysis that is currently ongoing and the validated circRNAs will be used to optimize the bioinformatics pipeline for circRNA DE analysis. Conclusions We identified a subset of circRNAs deregulated in ischemic HF potentially implicated in HF pathogenesis.

scholarly journals Regulation and Function of RNA Pseudouridylation in Human Cells

2020 ◽  
Vol 54 (1) ◽  
pp. 309-336
Author(s):  
Erin K. Borchardt ◽  
Nicole M. Martinez ◽  
Wendy V. Gilbert
Keyword(s):  
Messenger Rna ◽  
Noncoding Rna ◽  
Protein Production ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Human Cells ◽  
Rna Sequences ◽  
Rna Targets ◽  
Pseudouridine Synthases ◽  
And Function

Recent advances in pseudouridine detection reveal a complex pseudouridine landscape that includes messenger RNA and diverse classes of noncoding RNA in human cells. The known molecular functions of pseudouridine, which include stabilizing RNA conformations and destabilizing interactions with varied RNA-binding proteins, suggest that RNA pseudouridylation could have widespread effects on RNA metabolism and gene expression. Here, we emphasize how much remains to be learned about the RNA targets of human pseudouridine synthases, their basis for recognizing distinct RNA sequences, and the mechanisms responsible for regulated RNA pseudouridylation. We also examine the roles of noncoding RNA pseudouridylation in splicing and translation and point out the potential effects of mRNA pseudouridylation on protein production, including in the context of therapeutic mRNAs.

scholarly journals Systematic discovery of regulated and conserved alternative exons in the mammalian brain reveals NMD modulating chromatin regulators

2015 ◽  
Vol 112 (11) ◽  
pp. 3445-3450 ◽  
Author(s):  
Qinghong Yan ◽  
Sebastien M. Weyn-Vanhentenryck ◽  
Jie Wu ◽  
Steven A. Sloan ◽  
Ye Zhang ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Splice Variants ◽  
Mammalian Brain ◽  
Cell Type ◽  
Evolutionary Selection ◽  
Chromatin Regulators ◽  
Brain Transcriptome ◽  
Cell Type Specific ◽  
Specific Regulation

Alternative splicing (AS) dramatically expands the complexity of the mammalian brain transcriptome, but its atlas remains incomplete. Here we performed deep mRNA sequencing of mouse cortex to discover and characterize alternative exons with potential functional significance. Our analysis expands the list of AS events over 10-fold compared with previous annotations, demonstrating that 72% of multiexon genes express multiple splice variants in this single tissue. To evaluate functionality of the newly discovered AS events, we conducted comprehensive analyses on central nervous system (CNS) cell type-specific splicing, targets of tissue- or cell type-specific RNA binding proteins (RBPs), evolutionary selection pressure, and coupling of AS with nonsense-mediated decay (AS-NMD). We show that newly discovered events account for 23–42% of all cassette exons under tissue- or cell type-specific regulation. Furthermore, over 7,000 cassette exons are under evolutionary selection for regulated AS in mammals, 70% of which are new. Among these are 3,058 highly conserved cassette exons, including 1,014 NMD exons that may function directly to control gene expression levels. These NMD exons are particularly enriched in RBPs including splicing factors and interestingly also regulators for other steps of RNA metabolism. Unexpectedly, a second group of NMD exons reside in genes encoding chromatin regulators. Although the conservation of NMD exons in RBPs frequently extends into lower vertebrates, NMD exons in chromatin regulators are introduced later into the mammalian lineage, implying the emergence of a novel mechanism coupling AS and epigenetics. Our results highlight previously uncharacterized complexity and evolution in the mammalian brain transcriptome.

scholarly journals Nuclear role for human Argonaute-1 as an estrogen-dependent transcription coactivator

2020 ◽  
Vol 219 (9) ◽  
Author(s):  
Luciana I. Gómez Acuña ◽  
Ezequiel Nazer ◽  
Santiago A. Rodríguez-Seguí ◽  
Berta Pozzi ◽  
Valeria Buggiano ◽  
...  
Keyword(s):  
Small Rna ◽  
Transcriptional Activation ◽  
Rna Binding ◽  
Estrogen Receptor Α ◽  
Human Cells ◽  
Transcriptional Gene Silencing ◽  
Transcriptional Enhancers ◽  
Mammary Gland Cells ◽  
Target Promoters

In mammals, argonaute (AGO) proteins have been characterized for their roles in small RNA–mediated posttranscriptional and also in transcriptional gene silencing. Here, we report a different role for AGO1 in estradiol-triggered transcriptional activation in human cells. We show that in MCF-7 mammary gland cells, AGO1 associates with transcriptional enhancers of estrogen receptor α (ERα) and that this association is up-regulated by treating the cells with estrogen (E2), displaying a positive correlation with the activation of these enhancers. Moreover, we show that AGO1 interacts with ERα and that this interaction is also increased by E2 treatment, but occurs in the absence of RNA. We show that AGO1 acts positively as a coactivator in estradiol-triggered transcription regulation by promoting ERα binding to its enhancers. Consistently, AGO1 depletion decreases long-range contacts between ERα enhancers and their target promoters. Our results point to a role of AGO1 in transcriptional regulation in human cells that is independent from small RNA binding.

scholarly journals GC content shapes mRNA decay and storage in human cells

2018 ◽  
Author(s):  
Maïté Courel ◽  
Yves Clément ◽  
Dominika Foretek ◽  
Olivia Vidal Cruchez ◽  
Zhou Yi ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Mrna Decay ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Gc Content ◽  
Mrna Translation ◽  
Human Cells ◽  
Protein Yield ◽  
Fine Tuning ◽  
Rnp Granules

SummaryControl of protein expression results from the fine tuning of mRNA synthesis, decay and translation. These processes, which are controlled by a large number of RNA-binding proteins and by localization in RNP granules such as P-bodies, appear often intimately linked although the rules of this interplay are not well understood. In this study, we combined our recent P-body transcriptome with various transcriptomes obtained following silencing of broadly acting mRNA decay and repression factors. This analysis revealed the central role of GC content in mRNA fate, in terms of P-body localization, mRNA translation and mRNA decay. It also rationalized why PBs mRNAs have a strikingly low protein yield. We report too the existence of distinct mRNA decay pathways with preference for AU-rich or GC-rich transcripts. Compared to this impact of the GC content, sequence-specific RBPs and miRNAs appeared to have only modest additional effects on their bulk targets. Altogether, these results lead to an integrated view of post-transcriptional control in human cells where most regulation at the level of translation is dedicated to AU-rich mRNAs, which have a limiting protein yield, whereas regulation at the level of 5’ decay applies to GC-rich mRNAs, whose translation is optimal.

scholarly journals Regulation of RNA editing by RNA-binding proteins in human cells

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Giovanni Quinones-Valdez ◽  
Stephen S. Tran ◽  
Hyun-Ik Jun ◽  
Jae Hoon Bahn ◽  
Ei-Wen Yang ◽  
...  
Keyword(s):  
Rna Editing ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Human Cells

scholarly journals Dr. Jekyll and Mr. Hyde? Physiology and Pathology of Neuronal Stress Granules

2021 ◽  
Vol 9 ◽  
Author(s):  
Pureum Jeon ◽  
Jin A. Lee
Keyword(s):  
Adaptive Response ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Mrna Translation ◽  
Stress Granules ◽  
Cell Type ◽  
Therapeutic Approaches ◽  
Lateral Sclerosis ◽  
Neuronal Stress

Stress granules (SGs) are membraneless cytosolic granules containing dense aggregations of RNA-binding proteins and RNAs. They appear in the cytosol under stress conditions and inhibit the initiation of mRNA translation. SGs are dynamically assembled under stressful conditions and rapidly disassembled after stress removal. They are heterogeneous in their RNA and protein content and are cell type- and stress-specific. In post-mitotic neurons, which do not divide, the dynamics of neuronal SGs are tightly regulated, implying that their dysregulation leads to neurodegeneration. Mutations in RNA-binding proteins are associated with SGs. SG components accumulate in cytosolic inclusions in many neurodegenerative diseases, such as frontotemporal dementia and amyotrophic lateral sclerosis. Although SGs primarily mediate a pro-survival adaptive response to cellular stress, abnormal persistent SGs might develop into aggregates and link to the pathogenesis of diseases. In this review, we present recent advances in the study of neuronal SGs in physiology and pathology, and discuss potential therapeutic approaches to remove abnormal, persistent SGs associated with neurodegeneration.

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