scholarly journals Herpesvirus infection reduces Pol II occupancy of host promoters but spares viral promoters

2019 ◽  
Author(s):  
Ella N Hartenian ◽  
Britt A Glaunsinger
Keyword(s):  
Rna Polymerase Ii ◽  
Transcriptional Repression ◽  
Mammalian Cells ◽  
Mrna Decay ◽  
Viral Transcript ◽  
Pol Ii ◽  
Murine Gammaherpesvirus ◽  
A Genome ◽  
Viral Promoters ◽  
Gammaherpesvirus 68

AbstractIn mammalian cells, widespread acceleration of cytoplasmic mRNA degradation is linked to impaired RNA polymerase II (Pol II) transcription. This mRNA decay-induced transcriptional repression occurs during infection with gammaherpesviruses including Kaposi’s sarcoma-associated herpesvirus (KSHV) and murine gammaherpesvirus 68 (MHV68), which encode an mRNA endonuclease that initiates widespread RNA decay. Here, we show that MHV68-induced mRNA decay leads to a genome-wide reduction of Pol II occupancy at mammalian promoters. Viral genes, despite the fact that they require Pol II for transcription, escape this transcriptional repression. Protection is not governed by viral promoter sequences; instead, location on the viral genome is both necessary and sufficient to escape the transcriptional repression effects of mRNA decay. We hypothesize that the ability to escape from transcriptional repression is linked to the localization of viral DNA in replication compartments, providing a means for these viruses to counteract decay-induced viral transcript loss.

Mediator dynamics during heat shock in budding yeast

2021 ◽  
pp. gr.275750.121
Author(s):  
Debasish Sarkar ◽  
Z. Iris Zhu ◽  
Elisabeth R. Knoll ◽  
Emily Paul ◽  
David Landsman ◽  
...  
Keyword(s):  
Heat Shock ◽  
Rna Polymerase Ii ◽  
Budding Yeast ◽  
Core Promoter ◽  
Growth Conditions ◽  
Promoter Regions ◽  
Pol Ii ◽  
A Genome ◽  
Wide Scale ◽  
Stable Association

The Mediator complex is central to transcription by RNA polymerase II (Pol II) in eukaryotes. In budding yeast (Saccharomyces cerevisiae), Mediator is recruited by activators and associates with core promoter regions, where it facilitates pre-initiation complex (PIC) assembly, only transiently prior to Pol II escape. Interruption of the transcription cycle by inactivation or depletion of Kin28 inhibits Pol II escape and stabilizes this association. However, Mediator occupancy and dynamics have not been examined on a genome-wide scale in yeast grown in nonstandard conditions. Here we investigate Mediator occupancy following heat shock or CdCl2 exposure, with and without depletion of Kin28. We find that Pol II occupancy exhibits similar dependence on Mediator under normal and heat shock conditions. However, while Mediator association increases at many genes upon Kin28 depletion under standard growth conditions, little or no increase is observed at most genes upon heat shock, indicating a more stable association of Mediator after heat shock. Mediator remains associated upstream of the core promoter at genes repressed by heat shock or CdCl2 exposure whether or not Kin28 is depleted, suggesting that Mediator is recruited by activators but is unable to engage PIC components at these repressed targets. This persistent association is strongest at promoters that bind the HMGB family member Hmo1, and is reduced but not eliminated in hmo1∆ yeast. Finally, we show a reduced dependence on PIC components for Mediator occupancy at promoters after heat shock, further supporting altered dynamics or stronger engagement with activators under these conditions.

scholarly journals The Rpb7p subunit of yeast RNA polymerase II plays roles in the two major cytoplasmic mRNA decay mechanisms

2007 ◽  
Vol 178 (7) ◽  
pp. 1133-1143 ◽  
Author(s):  
Rona Lotan ◽  
Vicky Goler-Baron ◽  
Lea Duek ◽  
Gal Haimovich ◽  
Mordechai Choder
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Active Component ◽  
Mrna Decay ◽  
State Level ◽  
Mrna Levels ◽  
Exonuclease Activity ◽  
Steady State Level ◽  
Pol Ii ◽  
P Bodies

The steady-state level of mRNAs is determined by the balance between their synthesis by RNA polymerase II (Pol II) and their decay. In the cytoplasm, mRNAs are degraded by two major pathways; one requires decapping and 5′ to 3′ exonuclease activity and the other involves 3′ to 5′ degradation. Rpb7p is a Pol II subunit that shuttles between the nucleus and the cytoplasm. Here, we show that Rpb7p is involved in the two mRNA decay pathways and possibly couples them. Rpb7p stimulates the deadenylation stage required for execution of both pathways. Additionally, Rpb7p is both an active component of the P bodies, where decapping and 5′ to 3′ degradation occur, and is capable of affecting the P bodies function. Moreover, Rpb7p interacts with the decapping regulator Pat1p in a manner important for the mRNA decay machinery. Rpb7p is also involved in the second pathway, as it stimulates 3′ to 5′ degradation. Our genetic analyses suggest that Rpb7p plays two distinct roles in mRNA decay, which can both be uncoupled from Rpb7p's role in transcription. Thus, Rpb7p plays pivotal roles in determining mRNA levels.

scholarly journals RNA Polymerase II Accumulation in the Promoter-Proximal Region of the Dihydrofolate Reductase and γ-Actin Genes

2003 ◽  
Vol 23 (6) ◽  
pp. 1961-1967 ◽  
Author(s):  
Chonghui Cheng ◽  
Phillip A. Sharp
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Dihydrofolate Reductase ◽  
Mammalian Cells ◽  
Proximal Region ◽  
Heptad Repeat ◽  
Pol Ii ◽  
Actin Genes ◽  
Carboxyl Terminal ◽  
Promoter Proximal Region

ABSTRACT The carboxyl-terminal domain (CTD) of RNA polymerase II (Pol II) can be phosphorylated at serine 2 (Ser-2) and serine 5 (Ser-5) of the CTD heptad repeat YSPTSPS, and this phosphorylation is important in coupling transcription to RNA processing, including 5′ capping, splicing, and polyadenylation. The mammalian endogenous dihydrofolate reductase and γ-actin genes have been used to study the association of Pol II with different regions of transcribed genes (promoter-proximal compared to distal regions) and the phosphorylation status of its CTD. For both genes, Pol II is more concentrated in the promoter-proximal regions than in the interior regions. Moreover, different phosphorylation forms of Pol II are associated with distinct regions. Ser-5 phosphorylation of Pol II is concentrated near the promoter, while Ser-2 phosphorylation is observed throughout the gene. These results suggest that the accumulation of paused Pol II in promoter-proximal regions may be a common feature of gene regulation in mammalian cells.

scholarly journals Transcriptional repression by FACT is linked to regulation of chromatin accessibility at the promoter of ES cells

2018 ◽  
Author(s):  
Constantine Mylonas ◽  
Peter Tessarz
Keyword(s):  
Rna Polymerase Ii ◽  
Cell Fate ◽  
Transcriptional Repression ◽  
Mammalian Cells ◽  
Es Cells ◽  
Embryonic Stem ◽  
Antisense Transcription ◽  
Chromatin Accessibility ◽  
Promoter Architecture ◽  
Neuronal Lineage

The conserved and essential histone chaperone FACT (Facilitates Chromatin Transcription) reorganizes nucleosomes during DNA transcription, replication and repair and ensures both, efficient elongation of RNA Pol II and nucleosome integrity. In mammalian cells, FACT is a heterodimer, consisting of SSRP1 and SUPT16. Here, we show that in contrast to yeast, FACT accumulates at the transcription start site of genes reminiscent of RNA Polymerase II profile. Depletion of FACT in mouse embryonic stem cells leads to up-regulation of pro-proliferative genes and key pluripotency factors concomitant with hyper-proliferation of mES cells. Using MNase-, ATAC-, and Nascent Elongating Transcript Sequencing (NET-seq) we show that up-regulation of genes coincides with loss of nucleosomes upstream of the TSS and concomitant increase in antisense transcription, indicating that FACT impacts the promoter architecture to regulate expression of these genes. Finally, we demonstrate a role for FACT in cell fate determination and show that FACT depletion primes ES cells for the neuronal lineage.

scholarly journals Live-cell single particle imaging reveals the role of RNA polymerase II in histone H2A.Z eviction

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Anand Ranjan ◽  
Vu Q Nguyen ◽  
Sheng Liu ◽  
Jan Wisniewski ◽  
Jee Min Kim ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Single Molecule ◽  
Transcription Initiation ◽  
General Mechanism ◽  
Pol Ii ◽  
Promoter Escape ◽  
Genome Wide ◽  
A Genome ◽  
Particle Imaging

The H2A.Z histone variant, a genome-wide hallmark of permissive chromatin, is enriched near transcription start sites in all eukaryotes. H2A.Z is deposited by the SWR1 chromatin remodeler and evicted by unclear mechanisms. We tracked H2A.Z in living yeast at single-molecule resolution, and found that H2A.Z eviction is dependent on RNA Polymerase II (Pol II) and the Kin28/Cdk7 kinase, which phosphorylates Serine 5 of heptapeptide repeats on the carboxy-terminal domain of the largest Pol II subunit Rpb1. These findings link H2A.Z eviction to transcription initiation, promoter escape and early elongation activities of Pol II. Because passage of Pol II through +1 nucleosomes genome-wide would obligate H2A.Z turnover, we propose that global transcription at yeast promoters is responsible for eviction of H2A.Z. Such usage of yeast Pol II suggests a general mechanism coupling eukaryotic transcription to erasure of the H2A.Z epigenetic signal.

scholarly journals Artificial Recruitment of TFIID, but Not RNA Polymerase II Holoenzyme, Activates Transcription in Mammalian Cells

2000 ◽  
Vol 20 (12) ◽  
pp. 4350-4358 ◽  
Author(s):  
David R. Dorris ◽  
Kevin Struhl
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Activation ◽  
Mammalian Cells ◽  
Yeast Cells ◽  
Pol Ii ◽  
Activation Domains ◽  
Synergistic Activation ◽  
The One ◽  
Rna Polymerase Ii Holoenzyme

ABSTRACT In yeast cells, transcriptional activation occurs when the RNA polymerase II (Pol II) machinery is artificially recruited to a promoter by fusing individual components of this machinery to a DNA-binding domain. Here, we show that artificial recruitment of components of the TFIID complex can activate transcription in mammalian cells. Surprisingly, artificial recruitment of TATA-binding protein (TBP) activates transiently transfected and chromosomally integrated promoters with equal efficiency, whereas artificial recruitment of TBP-associated factors activates only chromosomal reporters. In contrast, artificial recruitment of various components of the mammalian Pol II holoenzyme does not confer transcriptional activation, nor does it result in synergistic activation in combination with natural activation domains. In the one case examined in more detail, the Srb7 fusion failed to activate despite being associated with the Pol II holoenzyme and being directly recruited to the promoter. Interestingly, some acidic activation domains are less effective when the promoter is chromosomally integrated rather than transiently transfected, whereas the Sp1 glutamine-rich activation domain is more effective on integrated reporters. Thus, yeast and mammalian cells differ with respect to transcriptional activation by artificial recruitment of the Pol II holoenzyme.

Abstract 138: Inhibition of Stress-inducible Genes That Distinguish Pathological Cardiac Hypertrophy via Targeting Acidic Nuclear Protein 32e

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Hyewon Shin ◽  
Zhi Yang ◽  
Minzhen He ◽  
Danish Sayed ◽  
Maha Abdellatif
Keyword(s):  
Cardiac Hypertrophy ◽  
Rna Polymerase Ii ◽  
Nuclear Protein ◽  
De Novo ◽  
Transcriptional Start Site ◽  
Pressure Overload ◽  
Release Mechanism ◽  
Pol Ii ◽  
A Genome ◽  
Inducible Genes

Cardiac hypertrophy is a manifestation of an increase in the workload imposed on the heart. The cause, duration, and extent of the workload dictate the physiological vs. pathological nature of the hypertrophy and its likelihood to transition into cardiac failure. Our goal is to identify differences between these 2 forms of hypertrophy by examining the binding patterns of key basic transcription factors and regulators in a genome-wide fashion. Our data show that a pause-release mechanism of RNA polymerase II (pol II) bound to the transcriptional start site (TSS) induces housekeeping/essential genes (~ 63% of expressed genes), in a synchronous and incremental fashion that is proportional to the increase in myocyte size and does not require de novo pol II binding. This mechanism is responsible for the increase in cell size and mass that constitute hypertrophy in both physiological and pathological forms. Superimposed on this is a second and critical group of genes (~3.5%) that are stress-induced in the pathological form of hypertrophy but are minimally, if at all, expressed in the postnatal and adult heart (e.g. Acta1, Ankrd1, Xirp2, Nppa, Col1a1 ..etc). In contrast to the housekeeping genes, these genes require de novo pol II recruitment and exhibit a robust increase in expression. To further identify the transcriptional mechanisms that distinguish these sets of genes, we performed chromatin immunoprecipitation-deep sequencing (ChIP-Seq) analysis for cyclin-dependent kinase 9 (Cdk9) and histone H2A.z. The results reveal an increase in Cdk9 at the TSS of paused genes vs. an increase at TSS and throughout the gene body of inducible genes. In contrast, H2A.z levels remained constant. However, we found that Acidic Nuclear Protein 32e (Anp32e), a nuclear protein phosphatase 2A (PP2A) inhibitor, interacted with H2A.z and regulated phosphorylation of Cdk9. Interestingly, knockdown of Anp32e during pressure overload hypertrophy resulted in 70-90% inhibition of stress-inducible genes, but only an incremental inhibition of the increase in cardiac size. Thus, we propose that targeting Anp32e may partially revert pathological hypertrophy to a more physiological form via specifically inhibiting the stress-induced genes while preserving the increase in cardiac mass.

scholarly journals Multi-step regulation of transcription kinetics explains the non-linear relation between RNA polymerase II density and mRNA expression in Dosage Compensation

2017 ◽  
Author(s):  
Pouria Dasmeh
Keyword(s):  
Rna Polymerase ◽  
Mrna Expression ◽  
Rna Polymerase Ii ◽  
Dosage Compensation ◽  
Mammalian Cells ◽  
Experimental Studies ◽  
Regulation Of Transcription ◽  
Pol Ii ◽  
Non Linear

AbstractIn heterogametic organisms, expression of unequal number of X chromosomes in males and females is balanced by a process called dosage compensation. In Drosophila and mammals, dosage compensation involves nearly two-fold up-regulation of the X chromosome mediated by dosage compensation complex (DCC). Experimental studies on the role of DCC on RNA polymerase II (Pol II) transcription in mammals disclosed a non-linear relationship between Pol II densities at different transcription steps and mRNA expression. An ~20-30% increase in Pol II densities corresponds to a rough 200% increase in mRNA expression and two-fold up-regulation. Here, using a simple kinetic model of Pol II transcription calibrated by in vivo measured rate constants of different transcription steps in mammalian cells, we demonstrate how this non-linearity can be explained by multi-step transcriptional regulation. Moreover, we show how multi-step enhancement of Pol II transcription can increase mRNA production while leaving Pol II densities unaffected. Our theoretical analysis not only recapitulates experimentally observed Pol II densities upon two-fold up-regulation but also points to a limitation of inferences based on Pol II profiles from chromatin immunoprecipitation sequencing (ChIP-seq) or global run-on assays.

scholarly journals Xrn1 influence on gene transcription results from the combination of general effects on elongating RNA pol II and gene-specific chromatin configuration

2020 ◽  
Author(s):  
Victoria Begley ◽  
Antonio Jordán-Pla ◽  
Xenia Peñate ◽  
Ana I. Garrido-Godino ◽  
Drice Challal ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase Ii ◽  
Mrna Decay ◽  
Transcription Elongation ◽  
General Mechanism ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Chromatin Configuration ◽  
Polyadenylation Sites ◽  
Nucleosome Mapping

AbstractmRNA homeostasis is favored by crosstalk between transcription and degradation machineries. Both the Ccr4-Not and the Xrn1-decaysome complexes have been described to influence transcription. While Ccr4-Not has been shown to directly stimulate transcription elongation, the information available on how Xrn1 influences transcription is scarce and contradictory. In this study we have addressed this issue by mapping RNA polymerase II (RNA pol II) at high resolution, using CRAC and BioGRO-seq techniques in Saccharomyces cerevisiae. We found significant effects of Xrn1 perturbation on RNA pol II profiles across the genome. RNA pol II profiles at 5’ exhibited significant alterations that were compatible with decreased elongation rates in the absence of Xrn1. Nucleosome mapping detected altered chromatin configuration in the gene bodies. We also detected accumulation of RNA pol II shortly upstream of polyadenylation sites by CRAC, although not by BioGRO-seq, suggesting higher frequency of backtracking before pre-mRNA cleavage. This phenomenon was particularly linked to genes with poorly positioned nucleosomes at this position. Accumulation of RNA pol II at 3’ was also detected in other mRNA decay mutants. According to these and other pieces of evidence, Xrn1 seems to influence transcription elongation at least in two ways: by directly favoring elongation rates and by a more general mechanism that connects mRNA decay to late elongation.

scholarly journals Hyperosmotic stress induces downstream-of-gene transcription and alters the RNA Polymerase II interactome despite widespread transcriptional repression

2020 ◽  
Author(s):  
Nicolle A. Rosa-Mercado ◽  
Joshua T. Zimmer ◽  
Maria Apostolidi ◽  
Jesse Rinehart ◽  
Matthew D. Simon ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Repression ◽  
Transcriptional Response ◽  
Hyperosmotic Stress ◽  
Transcriptional Level ◽  
List Type ◽  
Upstream Gene ◽  
Pol Ii ◽  
Transcription Profiles

SummaryStress-induced readthrough transcription results in the synthesis of thousands of downstream-of-gene (DoG) containing transcripts. The mechanisms underlying DoG formation during cellular stress remain unknown. Nascent transcription profiles during DoG induction in human cell lines using TT-TimeLapse-seq revealed that hyperosmotic stress induces widespread transcriptional repression. Yet, DoGs are produced regardless of the transcriptional level of their upstream genes. ChIP-seq confirmed that the stress-induced redistribution of RNA Polymerase (Pol) II correlates with the transcriptional output of genes. Stress-induced alterations in the Pol II interactome are observed by mass spectrometry. While subunits of the cleavage and polyadenylation machinery remained Pol II-associated, Integrator complex subunits dissociated from Pol II under stress conditions. Depleting the catalytic subunit of the Integrator complex, Int11, using siRNAs induces hundreds of readthrough transcripts, whose parental genes partially overlap those of stress-induced DoGs. Our results provide insights into the mechanisms underlying DoG production and how Integrator activity influences DoG transcription.In briefRosa-Mercado et al. report that hyperosmotic stress causes widespread transcriptional repression in human cells, yet DoGs arise regardless of the transcriptional response of their upstream genes. They find that the interaction between Pol II and Integrator is disrupted by hypertonicity and that knocking down the Integrator nuclease leads to DoG production.HighlightsHyperosmotic stress triggers transcriptional repression of many genes.DoG RNAs arise independent of the transcriptional level of their upstream gene.The interaction between Pol II and Integrator subunits decreases after salt stress.Depletion of the Int11 nuclease subunit induces the production of hundreds of DoGs.

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