scholarly journals Precision methylome and in vivo methylation kinetics characterization of Klebsiella pneumoniae

2020 ◽  
Author(s):  
Jing Fu ◽  
Ju Zhang ◽  
Li Yang ◽  
Nan Ding ◽  
Liya Yue ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Replication Initiation ◽  
Epigenetic Mechanism ◽  
Single Base ◽  
Genome Wide ◽  
A Genome ◽  
Intergenic Regions ◽  
Wide Scale ◽  
Single Base Resolution

Klebsiella pneumoniae (K. pneumonia) is an important pathogen that can cause severe hospital-/community-acquired infections. To panoramically analyze K. pneumoniae's methylation features, we completed the whole genome sequences of 14 K. pneumoniae strains covering various serotypes, multilocus-sequence typings (MLSTs), clonal groups (CG), viscosity/virulence and drug-resistances, and further characterized their methylomes using Pacbio-SMRT and bisulfite technologies. We identified 15 methylation motifs (13 6mA and two 5mC motifs), among which eight were novel ones. Their corresponding MTases were further validated. Additionally, we analyzed the genomic distribution of GATC and CCWGG methylation motifs shared by all strains, and identified differential distributive patterns of some hemi/un-methylated GATC motifs tending to locate in the intergenic regions (IGRs). Specifically, we characterized the in vivo methylation kinetics at single-base resolution on a genome-wide scale by simulating the dynamic processes of replication-mediated passive demethylation and MTase-catalyzed re-methylation. The slower methylation-rates of the GATC motifs in the replication origins (oriC) and IGRs suggest an epigenetic mechanism implicated in the regulation of replication-initiation and transcription. Our findings illustrate the first comprehensive dynamic methylome map of K. pneumonia at single base resolution, and provide an efficient means and important reference for a better understanding of epigenetic regulation in bacteria.

scholarly journals Timing Polymerase Pausing with TV-PRO-seq

2018 ◽  
Author(s):  
Jie Zhang ◽  
Massimo Cavallaro ◽  
Daniel Hebenstreit
Keyword(s):  
High Resolution ◽  
Human Cells ◽  
Rrna Genes ◽  
Dna Motifs ◽  
Single Base ◽  
Chromatin States ◽  
Genome Wide ◽  
A Genome ◽  
Single Base Resolution ◽  
Polymerase Pausing

Transcription of many genes in metazoans is subject to polymerase pausing, which corresponds to the transient arrest of transcriptionally engaged polymerase. It occurs mainly at promoter proximal regions and is not well understood. In particular, a genome-wide measurement of pausing times at high resolution has been lacking.We present here an extension of PRO-seq, time variant PRO-seq (TV-PRO-seq), that allowed us to estimate genome-wide pausing times at single base resolution. Its application to human cells reveals that promoter proximal pausing is surprisingly short compared to other regions and displays an intricate pattern. We also find precisely conserved pausing profiles at tRNA and rRNA genes and identified DNA motifs associated with pausing time. Finally, we show how chromatin states reflect differences in pausing times.

scholarly journals Requirement of splicing factor hnRNP A2B1 of hnRNPs for tumorigenesis of melanoma stem cells

2020 ◽  
Author(s):  
Mengqi Chu ◽  
Haitao Wan ◽  
Xiaobo Zhang
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Tumor Therapy ◽  
Cycle Arrest ◽  
Genome Wide ◽  
A Genome ◽  
Rna Immunoprecipitation ◽  
Wide Scale

Abstract Background: Cancer stem cells play essential roles in tumorigenesis, thus being the important targets for tumor therapy. The hnRNP family proteins, the important splicing factors, are found to be associated with tumor progression. However, the influence of hnRNPs on cancer stem cells has not been extensively explored.Methods: Quantitative real-time PCR and Western blot were used to examine the gene expression level. RNA immunoprecipitation assay and RNA sequencing were conducted to identify the RNAs interacted with hnRNP A2B1 on a genome-wide scale. The in vivo assays were performed in nude mice.Results: In this study, the results showed that hnRNP A2B1 of 19 hnRNPs was significantly upregulated in melanoma stem cells compared with non-stem cells, suggesting the important role of hnRNP A2B1 in cancer stem cells. The hnRNP A2B1 silencing triggered the cell cycle arrest in G2 phase, leading to apoptosis of melanoma stem cells. The results revealed that hnRNP A2B1 could bind to the precursor mRNAs of pro-apoptosis genes (DAPK1, SYT7 and RNF128) and anti-apoptosis genes (EIF3H, TPPP3 and DOCK2) to regulate the splicing of these 6 genes, thus promoting the expressions of anti-apoptosis genes and suppressing the expressions of pro-apoptosis genes. The in vivo data indicated that hnRNP A2B1 was required for tumorigenesis of melanoma stem cells in vivo by affecting the splicing of TPPP3, DOCK2, EIF3H, RNF128, DAPK1 and SYT7, thus suppressing apoptosis of melanoma stem cells.Conclusions: HnRNP A2B1 was required for tumorigenesis of melanoma stem cells. Therefore our findings presented novel molecular insights into the roles of hnRNPs in cancer stem cells.

scholarly journals The conserved elongation factor Spn1 is required for normal transcription, histone modifications, and splicing in Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Natalia I. Reim ◽  
James Chuang ◽  
Dhawal Jain ◽  
Burak H. Alver ◽  
Peter J. Park ◽  
...  
Keyword(s):  
Gene Expression ◽  
Elongation Factor ◽  
Mrna Levels ◽  
Chromatin Dynamics ◽  
Binding Partner ◽  
Genome Wide ◽  
A Genome ◽  
Highly Expressed Genes ◽  
Wide Scale

Spn1/Iws1 is a conserved protein involved in transcription and chromatin dynamics, yet its general in vivo requirement for these functions is unknown. Using a Spn1 depletion system in S. cerevisiae, we demonstrate that Spn1 broadly influences several aspects of gene expression on a genome-wide scale. We show that Spn1 is globally required for normal mRNA levels and for normal splicing of ribosomal protein transcripts. Furthermore, Spn1 maintains the localization of H3K36 and H3K4 methylation across the genome and is required for normal histone levels at highly expressed genes. Finally, we show that the association of Spn1 with the transcription machinery is strongly dependent on its binding partner, Spt6, while the association of Spt6 and Set2 with transcribed regions is partially dependent on Spn1. Taken together, our results show that Spn1 affects multiple aspects of gene expression and provide additional evidence that it functions as a histone chaperone in vivo.

scholarly journals The conserved elongation factor Spn1 is required for normal transcription, histone modifications, and splicing in Saccharomyces cerevisiae

2020 ◽  
Vol 48 (18) ◽  
pp. 10241-10258 ◽  
Author(s):  
Natalia I Reim ◽  
James Chuang ◽  
Dhawal Jain ◽  
Burak H Alver ◽  
Peter J Park ◽  
...  
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Elongation Factor ◽  
Mrna Levels ◽  
Chromatin Dynamics ◽  
Genome Wide ◽  
A Genome ◽  
Highly Expressed Genes ◽  
Wide Scale

Abstract Spn1/Iws1 is a conserved protein involved in transcription and chromatin dynamics, yet its general in vivo requirement for these functions is unknown. Using a Spn1 depletion system in Saccharomyces cerevisiae, we demonstrate that Spn1 broadly influences several aspects of gene expression on a genome-wide scale. We show that Spn1 is globally required for normal mRNA levels and for normal splicing of ribosomal protein transcripts. Furthermore, Spn1 maintains the localization of H3K36 and H3K4 methylation across the genome and is required for normal histone levels at highly expressed genes. Finally, we show that the association of Spn1 with the transcription machinery is strongly dependent on its binding partner, Spt6, while the association of Spt6 and Set2 with transcribed regions is partially dependent on Spn1. Taken together, our results show that Spn1 affects multiple aspects of gene expression and provide additional evidence that it functions as a histone chaperone in vivo.

scholarly journals Co-Overexpression of TWIST1-CSF1 Is a Common Event in Metastatic Oral Cancer and Drives Biologically Aggressive Phenotype

Cancers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 153
Author(s):  
Sabrina Daniela da Silva ◽  
Fabio Albuquerque Marchi ◽  
Jie Su ◽  
Long Yang ◽  
Ludmila Valverde ◽  
...  
Keyword(s):  
Epithelial Mesenchymal Transition ◽  
Inflammatory Cells ◽  
Rank Test ◽  
Mesenchymal Transition ◽  
Genome Wide ◽  
A Genome ◽  
Enhanced Expression ◽  
Advanced Stages

Invasive oral squamous cell carcinoma (OSCC) is often ulcerated and heavily infiltrated by pro-inflammatory cells. We conducted a genome-wide profiling of tissues from OSCC patients (early versus advanced stages) with 10 years follow-up. Co-amplification and co-overexpression of TWIST1, a transcriptional activator of epithelial-mesenchymal-transition (EMT), and colony-stimulating factor-1 (CSF1), a major chemotactic agent for tumor-associated macrophages (TAMs), were observed in metastatic OSCC cases. The overexpression of these markers strongly predicted poor patient survival (log-rank test, p = 0.0035 and p = 0.0219). Protein analysis confirmed the enhanced expression of TWIST1 and CSF1 in metastatic tissues. In preclinical models using OSCC cell lines, macrophages, and an in vivo matrigel plug assay, we demonstrated that TWIST1 gene overexpression induces the activation of CSF1 while TWIST1 gene silencing down-regulates CSF1 preventing OSCC invasion. Furthermore, excessive macrophage activation and polarization was observed in co-culture system involving OSCC cells overexpressing TWIST1. In summary, this study provides insight into the cooperation between TWIST1 transcription factor and CSF1 to promote OSCC invasiveness and opens up the potential therapeutic utility of currently developed antibodies and small molecules targeting cancer-associated macrophages.

scholarly journals F-Box Genes in the Wheat Genome and Expression Profiling in Wheat at Different Developmental Stages

Genes ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1154
Author(s):  
Min Jeong Hong ◽  
Jin-Baek Kim ◽  
Yong Weon Seo ◽  
Dae Yeon Kim
Keyword(s):  
Developmental Stages ◽  
Brachypodium Distachyon ◽  
Triticum Aestivum L ◽  
Wheat Genome ◽  
Post Translational Modification ◽  
Genome Wide ◽  
A Genome ◽  
High Sequence Homology ◽  
Wide Scale

Genes of the F-box family play specific roles in protein degradation by post-translational modification in several biological processes, including flowering, the regulation of circadian rhythms, photomorphogenesis, seed development, leaf senescence, and hormone signaling. F-box genes have not been previously investigated on a genome-wide scale; however, the establishment of the wheat (Triticum aestivum L.) reference genome sequence enabled a genome-based examination of the F-box genes to be conducted in the present study. In total, 1796 F-box genes were detected in the wheat genome and classified into various subgroups based on their functional C-terminal domain. The F-box genes were distributed among 21 chromosomes and most showed high sequence homology with F-box genes located on the homoeologous chromosomes because of allohexaploidy in the wheat genome. Additionally, a synteny analysis of wheat F-box genes was conducted in rice and Brachypodium distachyon. Transcriptome analysis during various wheat developmental stages and expression analysis by quantitative real-time PCR revealed that some F-box genes were specifically expressed in the vegetative and/or seed developmental stages. A genome-based examination and classification of F-box genes provide an opportunity to elucidate the biological functions of F-box genes in wheat.

scholarly journals Genome-wide mapping of unexplored essential regions in the Saccharomyces cerevisiae genome: evidence for hidden synthetic lethal combinations in a genetic interaction network

2014 ◽  
Vol 42 (15) ◽  
pp. 9838-9853 ◽  
Author(s):  
Saeed Kaboli ◽  
Takuya Yamakawa ◽  
Keisuke Sunada ◽  
Tao Takagaki ◽  
Yu Sasano ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Interaction ◽  
Interaction Network ◽  
Essential Genes ◽  
Genetic Interactions ◽  
Lethal Gene ◽  
Synthetic Lethal ◽  
Genome Wide ◽  
A Genome ◽  
Wide Scale

Abstract Despite systematic approaches to mapping networks of genetic interactions in Saccharomyces cerevisiae, exploration of genetic interactions on a genome-wide scale has been limited. The S. cerevisiae haploid genome has 110 regions that are longer than 10 kb but harbor only non-essential genes. Here, we attempted to delete these regions by PCR-mediated chromosomal deletion technology (PCD), which enables chromosomal segments to be deleted by a one-step transformation. Thirty-three of the 110 regions could be deleted, but the remaining 77 regions could not. To determine whether the 77 undeletable regions are essential, we successfully converted 67 of them to mini-chromosomes marked with URA3 using PCR-mediated chromosome splitting technology and conducted a mitotic loss assay of the mini-chromosomes. Fifty-six of the 67 regions were found to be essential for cell growth, and 49 of these carried co-lethal gene pair(s) that were not previously been detected by synthetic genetic array analysis. This result implies that regions harboring only non-essential genes contain unidentified synthetic lethal combinations at an unexpectedly high frequency, revealing a novel landscape of genetic interactions in the S. cerevisiae genome. Furthermore, this study indicates that segmental deletion might be exploited for not only revealing genome function but also breeding stress-tolerant strains.

Abstract 12192: MBNL1 Directly Regulates the Alternative Splicing of mRNAs That Promote Myofibroblast Differentiation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jennifer Davis ◽  
Michelle Sargent ◽  
Jianjian Shi ◽  
Lei Wei ◽  
Maurice S Swanson ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Transforming Growth Factor ◽  
Ventricular Remodeling ◽  
Cardiac Injury ◽  
Myofibroblast Differentiation ◽  
Genome Wide ◽  
A Genome

Rationale: During the cardiac injury response fibroblasts differentiate into myofibroblasts, a cell type that enhances extracellular matrix production and facilitates ventricular remodeling. To better understand the molecular mechanisms whereby myofibroblasts are generated in the heart we performed a genome-wide screen with 18,000 cDNAs, which identified the RNA-binding protein muscleblind-like splicing regulator 1 (MBNL1), suggesting a novel association between mRNA alternative splicing and the regulation of myofibroblast differentiation. Objective: To determine the mechanism whereby MBNL1 regulates myofibroblast differentiation and the cardiac fibrotic response. Methods and Results: Confirming the results from our genome wide screen, adenoviral-mediated overexpression of MBNL1 promoted transformation of rat cardiac fibroblasts and mouse embryonic fibroblasts (MEFs) into myofibroblasts, similar to the level of conversion obtained by the profibrotic agonist transforming growth factor β (TGFβ). Antithetically, Mbnl1 -/- MEFs were refractory to TGFβ-induced myofibroblast differentiation. MBNL1 expression is induced in transforming fibroblasts in response to TGFβ and angiotensin II. These results were extended in vivo by analysis of dermal wound healing, a process dependent on myofibroblast differentiation and their proper activity. By day 6 control mice had achieved 82% skin wound closure compared with only 40% in Mbnl1 -/- mice. Moreover, Mbnl1 -/- mice had reduced survival following myocardial infarction injury due to defective fibrotic scar formation and healing. High throughput RNA sequencing (RNAseq) and RNA immunoprecipitation revealed that MBNL1 directly regulates the alternative splicing of transcripts for myofibroblast signaling factors and cytoskeletal-assembly elements. Functional analysis of these factors as mediators of MBNL1 activity is also described here. Conclusions: Collectively, our data suggest that MBNL1 coordinates myofibroblast transformation by directly mediating the alternative splicing of an array of mRNAs encoding differentiation-specific signaling transcripts, which then alter the fibroblast proteome for myofibroblast structure and function.

scholarly journals Machine-learning annotation of human splicing branchpoints

2016 ◽  
Author(s):  
Bethany Signal ◽  
Brian S Gloss ◽  
Marcel E Dinger ◽  
Timothy R Mercer
Keyword(s):  
Machine Learning ◽  
Learning Algorithm ◽  
Gene Splicing ◽  
Genetic Encoding ◽  
Genome Wide ◽  
Common Genetic Variants ◽  
A Genome ◽  
Wide Scale ◽  
The Impact ◽  
Splicing Patterns

ABSTRACTBackgroundThe branchpoint element is required for the first lariat-forming reaction in splicing. However due to difficulty in experimentally mapping at a genome-wide scale, current catalogues are incomplete.ResultsWe have developed a machine-learning algorithm trained with empirical human branchpoint annotations to identify branchpoint elements from primary genome sequence alone. Using this approach, we can accurately locate branchpoints elements in 85% of introns in current gene annotations. Consistent with branchpoints as basal genetic elements, we find our annotation is unbiased towards gene type and expression levels. A major fraction of introns was found to encode multiple branchpoints raising the prospect that mutational redundancy is encoded in key genes. We also confirmed all deleterious branchpoint mutations annotated in clinical variant databases, and further identified thousands of clinical and common genetic variants with similar predicted effects.ConclusionsWe propose the broad annotation of branchpoints constitutes a valuable resource for further investigations into the genetic encoding of splicing patterns, and interpreting the impact of common- and disease-causing human genetic variation on gene splicing.

scholarly journals Emerging Technologies for Genome-Wide Profiling of DNA Breakage

2021 ◽  
Vol 11 ◽  
Author(s):  
Matthew J. Rybin ◽  
Melina Ramic ◽  
Natalie R. Ricciardi ◽  
Philipp Kapranov ◽  
Claes Wahlestedt ◽  
...  
Keyword(s):  
Genome Instability ◽  
Dna Double Strand Breaks ◽  
Single Nucleotide ◽  
Strand Breaks ◽  
Single Strand Breaks ◽  
Genome Wide ◽  
A Genome ◽  
Wide Scale ◽  
Nucleotide Resolution ◽  
Genomic Regions

Genome instability is associated with myriad human diseases and is a well-known feature of both cancer and neurodegenerative disease. Until recently, the ability to assess DNA damage—the principal driver of genome instability—was limited to relatively imprecise methods or restricted to studying predefined genomic regions. Recently, new techniques for detecting DNA double strand breaks (DSBs) and single strand breaks (SSBs) with next-generation sequencing on a genome-wide scale with single nucleotide resolution have emerged. With these new tools, efforts are underway to define the “breakome” in normal aging and disease. Here, we compare the relative strengths and weaknesses of these technologies and their potential application to studying neurodegenerative diseases.

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