Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Small RNA-seq of Arabidopsis pol2a mutants

ABSTRACT: DNA replication requires the faithful propagation of both genetic and epigenetic information. There is evidence that DNA polymerases play a role in transcriptional silencing, but the extent of their contribution and how it relates to heterochromatin maintenance is unclear. Analyzing a new hypomorphic pol2a mutant allele, we find that POL2A, the catalytic subunit of the DNA polymerase epsilon, maintains heterochromatin silencing and nuclear organization. We also found that POL2 inhibits DNA methylation and histone H3 lysine 9 methylation, which both correlate with 24-nucleotide small RNA accumulation. In this experiment, we sequenced small-RNA libraries generated from immature inflorescences of pol2a-10 and pol2a-12 mutants and wild-type plants.

INSTRUMENT(S): Illumina HiSeq 2500

ORGANISM(S): Arabidopsis thaliana

SUBMITTER: Pierre Bourguet

PROVIDER: E-MTAB-8938 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

Modeling cancer-associated mutations reveals an integrated role for the Pol epsilon catalytic core in replisome assembly and DNA synthesis

Project description:DNA polymerase epsilon (Pol epsilon) plays multiple roles in genome duplication and its catalytic subunit POLE suppresses tumorigenesis in humans. Despite its importance, we have limited understanding of Pol epsilon functional mechanisms and how its loss-of-function affects the evolution of cancer genomes. To address this issue, we used the budding yeast ortholog Pol2 to model cancer-associated POLE mutations that affect an uncharacterized yet highly conserved Pol2/POLE family-specific region. Analysis of pol2 mutants revealed an unexpected role for this region in the incorporation of Pol epsilon into the pre-loading complex during replisome assembly. Cellular and reconstitution experiments further identified a separate role for this region in promoting Pol epsilon polymerase activity. Unlike previously reported POLE mutations leading to hypermutation in cancer cells, the examined pol2 variants increase gross chromosomal rearrangements but not mutation rates. Our findings thus suggest that the Pol epsilon catalytic core integrates replisome assembly and DNA polymerization functions and that POLE tumor suppressive roles likely extend beyond limiting replication errors.

2020-03-29 | GSE132450 | GEO

mRNA-seq of Arabidopsis mutants : pol2a-12, cmt3-11, pol2a-12 cmt3-11, fas2-4, pol2a-12 atxr5/6

Project description:DNA replication requires the faithful propagation of both genetic and epigenetic information. There is evidence that DNA polymerases play a role in transcriptional silencing, but the extent of their contribution and how it relates to heterochromatin maintenance is unclear. To get a better understanding of the role of POL2A, the catalytic subunit of the DNA polymerase epsilon, into maintaining heterochromatin silencing, we performed mRNA-seq on Arabidopsis plants carrying a new hypomorphic pol2a mutation. We deepened our analysis by profiling transcriptomes of other silencing mutants or combinations of pol2a with other mutations.

2020-06-04 | E-MTAB-8939 | biostudies-arrayexpress

ChIP-seq of histone marks (H3K27me1, H3K27me3, H3K9me2) and of the H2A.W histone variant in Arabidopsis pol2a mutants.

Project description:DNA replication requires the faithful propagation of both genetic and epigenetic information. There is evidence that DNA polymerases play a role in transcriptional silencing, but the extent of their contribution and how it relates to heterochromatin maintenance is unclear. Analyzing a new hypomorphic pol2a mutant allele, we find that POL2A, the catalytic subunit of the DNA polymerase epsilon, maintains heterochromatin silencing and nuclear organization. We also found that POL2A inhibits DNA methylation. Using ChIP-seq in wild-type and pol2a mutants, we analyzed how this related to changes in heterochromatic histone modifications (H3K27me1, H3K27me3, H3K9me2) and H2A.W heterochromatic histone variant.

2020-10-18 | E-MTAB-9046 | biostudies-arrayexpress

BS-seq of Arabidopsis pol2a mutants, of related mutants combinations and of WT and pol2a plants treated with hydroxyurea

Project description:DNA replication requires the faithful propagation of both genetic and epigenetic information. There is evidence that DNA polymerases play a role in transcriptional silencing, but the extent of their contribution and how it relates to heterochromatin maintenance is unclear. Analyzing a new hypomorphic pol2a mutant allele, we find that POL2A, the catalytic subunit of the DNA polymerase epsilon, maintains heterochromatin silencing and nuclear organization. Here, we profiled the DNA methylation landscape using BS-seq in various pol2a mutant alleles in Arabidopsis, in combination or not with other silencing and methyltransferase mutants. We also generated methylomes of wild-type and pol2a mutants exposed to hydroxyurea, to explore the consequences of replicative stress onto DNA methylation maintenance.

2020-06-04 | E-MTAB-8940 | biostudies-arrayexpress

Genome-wide maps of DNA Polymerase pausing in asynchronously growing yeast cells

Project description:ChIP-seq of FLAG-tagged Pol2 (subunit of DNA Polymerase epsilon) was performed on two independent isolates of each of WT, isw2∆, nhp10∆, and isw2∆ nhp10∆ cells. Sample naming convention: <ChIP target>_<growth condition>_<genotype-replicate>_<strain name>

2018-10-30 | GSE112426 | GEO

Global genomic instability caused by reduced expression of DNA polymerase ε in yeast [DZP2-derived isolates]

Project description:Yeast Saccharomyces cerevisiae has been widely used as a model system for studying genome instability. Here, a heterozygous diploid S. cerevisiae strain DZP2 was generated to determine the genomic alterations induced by DNA polymerase ε. The expression of POL2 was regulated by the GAL1 promoter. In combination of a custom SNP microarray, the patterns of chromosomal instability induced by low Pol ε could be explored at a whole genome level in DZP2. Using this system, we found hundreds-fold higher rate of genomic alterations, including aneuploidy, loss of heterozygosity (LOH), and chromosomal rearrangement. DNA polymerase ε (Pol ε) is one of the three replicative eukaryotic DNA polymerases. Pol ε deficiency leads to genomic instability and multiple human diseases. Here, we explored global genomic alterations in yeast strains with reduced expression of POL2, the gene that encodes the catalytic subunit of Pol ε. Using whole-genome SNP microarray and sequencing, we found that low levels of Pol ε elevated the rates of mitotic recombination and chromosomal aneuploidy by two orders of magnitude. Strikingly, low levels of Pol ε resulted in a contraction of the number of repeats in the rDNA cluster and reduced the length of telomeres. These short telomeres led to an elevated frequency of break-induced replication, resulting in terminal loss of heterozygosity. In addition, low levels of Pol ε increased the rate of single-base mutations by 13-fold by a Pol ζ-dependent pathway. Finally, the patterns of genomic alterations caused by low levels of Pol ε were different from those observed in strains with low levels of the other replicative DNA polymerases Pol α and Pol δ, providing further insights into the different roles of the B-family DNA polymerases in maintaining genomic stability.

2021-10-07 | GSE185365 | GEO

Global genomic instability caused by reduced expression of DNA polymerase ε in yeast [DZP2-derived sectored colonies]

2021-10-07 | GSE185364 | GEO

Mrc1 and DNA polymerase ε function together in linking DNA replication and the S phase checkpoint

Project description:Yeast Mrc1, ortholog of metazoan Claspin, is both a central component of normal DNA replication forks and a mediator of the S phase checkpoint. We report that Mrc1 interacts with Pol2, the catalytic subunit of DNA polymerase ε, essential for leading strand DNA replication and for the checkpoint. In unperturbed cells, Mrc1 interacts independently with both the N-terminal and C-terminal halves of Pol2 (Pol2N and Pol2C). Strikingly, phosphorylation of Mrc1 during the S phase checkpoint abolishes Pol2N binding but not Pol2C interaction. Mrc1 is required to stabilize Pol2 at replication forks stalled in HU. The bimodal Mrc1/Pol2 interaction may identify a novel step in regulating the S phase checkpoint response to DNA damage on the leading strand. We propose that Mrc1, which also interacts with the MCMs, may modulate coupling of polymerization and unwinding at the replication fork.

2008-10-10 | GSE12138 | GEO

Asymmetric distribution of H3K9me3 at replicating DNA strands silences L1 retrotransposons during S phase

Project description:In higher eukaryotes, repetitive DNA sequences are transcriptionally silenced through histone H3 lysine 9 tri-methylation (H3K9me3). A loss of silencing of these elements leads to genome instability and human diseases, including cancer and aging1-3. While the role of H3K9me3 in the establishment and maintenance of heterochromatin and repression of DNA repeats has been extensively studied4-6, the pattern and mechanism underlying the partitioning of H3K9me3 at replicating DNA strands were unknown. Here, we report that H3K9me3 is preferentially transferred onto the leading strands of replication forks, which occurs predominantly at Long Interspersed Nuclear Element (LINE) retrotransposons that are theoretically transcribed at the head-on direction with replication fork movement. In contrast, all other modified forms of histones tested are distributed in a nearly symmetric manner at the leading and lagging strands. Mechanistically, the Human Silencing Hub (HUSH) complex interacts with the leading strand DNA polymerase Pol ε, and contributes to the asymmetric segregation of H3K9me3 during chromatin replication. Cells deficient for Pol ε (POLE3 and POLE4), the HUSH complex (MPP8 and TASOR), or cells expressing a MPP8 mutant defective of H3K9me3 binding, or TASOR mutants with reduced interaction with Pol ε, show compromised H3K9me3 asymmetry and increased LINE expression. These results reveal an unexpected mechanism whereby the HUSH complex functions with Pol ε to promote asymmetric H3K9me3 distribution at LINEs to suppress their expression during S phase.

2023-08-17 | GSE211192 | GEO

PhpNF-Y transcription factor infiltrates repressive heterochromatin to generate transcripts crucial for spliceosome-dependent small RNA production

Project description:The assembly of repressive heterochromatin domains in eukaryotic genomes is crucial for silencing lineage-inappropriate genes and repetitive DNA elements. Paradoxically, transcription of repetitive elements within constitutive heterochromatin domains is required for RNA-based mechanisms, such as the RNAi pathway, to target heterochromatin assembly proteins. However, the mechanism by which heterochromatic repeat elements are transcribed has been unclear. Using fission yeast, we show that the conserved trimeric transcription factor (TF) PhpCNF-Y complex, which includes histone fold domain proteins, can infiltrate constitutive heterochromatin to transcribe repeat elements. PhpCNF-Y collaborates with a Zn-finger containing TF to bind heterochromatic repeat promoter regions with CCAAT boxes. Mutating either the TFs or the CCAAT binding site disrupts the transcription of heterochromatic repeats. Although repeat elements are transcribed from both strands, PhpCNF-Y-dependent transcripts originate from only one strand. These TF-driven transcripts contain cryptic introns that are processed via a mechanism requiring the spliceosome to generate small interfering RNAs (siRNAs) by the RNAi machinery. Our analyses show that siRNA production by this TF-mediated transcription pathway is critical for nucleation of heterochromatin at target repeat loci. This study reveals a mechanism by which heterochromatic repeats are transcribed, initiating their own silencing by triggering a primary cascade that produces siRNAs necessary for heterochromatin nucleation.

2024-06-21 | MSV000095108 | MassIVE

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data