Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Nascent transcription defined by RNA polymerase IV in Zea mays

ABSTRACT: Maize RNA Polymerase D1 (RPD1), the largest subunit of RNA polymerase IV (Pol IV), is required for normal plant development, repression of transposable elements (TEs), and for the regulation of specific alleles associated with TEs. Here, we define the nascent transcriptomes of rpd1 mutant and wild-type (WT) seedlings using global run-on sequencing (GRO-seq) to identify the broader targets of RPD1-based transcriptional regulation. Surprisingly, although TE-like sequences comprise >85% of the maize genome, most TEs are not transcribed at the seedling stage, even in rpd1 mutants. Profile comparisons identify the global set of genes and TEs whose transcription is altered in the absence of RPD1, in some cases in antisense orientation. These results indicate that maize Pol IV specifies Pol II-based transcriptional regulation for certain regions of the maize genome.

ORGANISM(S): Zea mays

PROVIDER: GSE54166 | GEO | 2015/02/04

SECONDARY ACCESSION(S): PRJNA235320

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Nascent transcription defined by RNA polymerase IV in Zea mays

Project description:Maize RNA Polymerase D1 (RPD1), the largest subunit of RNA polymerase IV (Pol IV), is required for normal plant development, repression of transposable elements (TEs), and for the regulation of specific alleles associated with TEs. Here, we define the nascent transcriptomes of rpd1 mutant and wild-type (WT) seedlings using global run-on sequencing (GRO-seq) to identify the broader targets of RPD1-based transcriptional regulation. Surprisingly, although TE-like sequences comprise >85% of the maize genome, most TEs are not transcribed at the seedling stage, even in rpd1 mutants. Profile comparisons identify the global set of genes and TEs whose transcription is altered in the absence of RPD1, in some cases in antisense orientation. These results indicate that maize Pol IV specifies Pol II-based transcriptional regulation for certain regions of the maize genome. Nuclei isolated from 10 wild-type and 10 rpd1 mutant seedlings were pooled and used to make two global run-on sequencing libraries.

2015-02-04 | E-GEOD-54166 | biostudies-arrayexpress

Investigating CLSY proteins and Pol-IV complex interaction in controlling DNA methylation patterns in Arabidopsis thaliana

Project description:Eukaryotes must balance the need for gene transcription by RNA polymerase II (Pol II) against the danger of mutations caused by transposable element (TE) proliferation. In plants, these gene expression and TE silencing activities are divided between different RNA polymerases. Specifically, RNA polymerase IV (Pol IV), which evolved from Pol II, transcribes TEs to generate small interfering RNAs (siRNAs) that guide DNA methylation and block TE transcription by Pol II. While the Pol IV complex is recruited to TEs via SNF2-like CLASSY (CLSY) proteins, how Pol IV partners with the CLSYs remains unknown. Here we identified a conserved CYC-YPMF motif that is specific to Pol IV and is positioned on the complex exterior. Furthermore, we found that this motif is essential for the co-purification of all four CLSYs with Pol IV, but that only one CLSY is present in any given Pol IV complex. These findings support a “one CLSY per Pol IV” model where the CYC-YPMF motif acts as a CLSY-docking site. Indeed, mutations in and around this motif phenocopy pol iv null mutants. Together, these findings provide structural and functional insights into a critical protein feature that distinguishes Pol IV from other RNA polymerases, allowing it to promote genome stability by targeting TEs for silencing.

2024-10-01 | GSE278181 | GEO

CLSY docking to Pol IV requires a conserved domain critical for small RNA biogenesis and transposon silencing.

Project description:Eukaryotes must balance the need for gene transcription by RNA polymerase II (Pol II) against the danger of mutations caused by transposable element (TE) proliferation. In plants, these gene expression and TE silencing activities are divided between different RNA polymerases. Specifically, RNA polymerase IV (Pol IV), which evolved from Pol II, transcribes TEs to generate small interfering RNAs (siRNAs) that guide DNA methylation and block TE transcription by Pol II. While the Pol IV complex is recruited to TEs via SNF2-like CLASSY (CLSY) proteins, how Pol IV partners with the CLSYs remains unknown. Here we identified a conserved CYC-YPMF motif that is specific to Pol IV and is positioned on the complex exterior. Furthermore, we found that this motif is essential for the co-purification of all four CLSYs with Pol IV, but that only one CLSY is present in any given Pol IV complex. These findings support a “one CLSY per Pol IV” model where the CYC-YPMF motif acts as a CLSY-docking site. Indeed, mutations in and around this motif phenocopy pol iv null and clsy quadruple mutants. Together, these findings provide structural and functional insights into a critical protein feature that distinguishes Pol IV from other RNA polymerases, allowing it to promote genome stability by targeting TEs for silencing.

2024-08-22 | GSE242191 | GEO

CLSY docking to Pol IV requires a conserved domain critical for small RNA biogenesis and transposon silencing

Project description:RNA polymerase IV (Pol IV) transcribes transposable elements (TEs) into precursors for small interfering RNAs (siRNAs) that guide DNA methylation to silence these potentially dangerious mobile elements in plants. Pol IV is recruited to TEs via SNF2-like CLASSY (CLSY) proteins. How Pol IV evolved to partner with the CLSYs is unknown. Using phylogenetics, we identified a conserved CYC-YPMF motif that is specific to Pol IV’s largest subunit. Modeling predicts that this motif coordinates a zinc ion and is exposed near Pol IV’s surface in a domain contacting downstream DNA. Via immunoprecipitation and mass spectrometry we found that this motif is essential for the association of all four CLSYs with Pol IV and hereby designate it as a CLSY-docking motif. Consistent with these biochemical results, mutations in the CLSY-docking motif or in neighboring sites of the Pol IV clamp domain, phenocopy pol iv null mutants and display a near-total loss of siRNA biogenesis, resulting in defects in DNA methylation and TE silencing. Together, our findings provide structural and functional insights into a critical protein feature that distinguishes Pol IV from other RNA polymerases, allowing Pol IV to target, transcribe and limit the expression of TE regions, thereby protecting genome integrity.

2024-11-28 | PXD047743 | Pride

Polymerase IV Plays a Crucial Role in Pollen Development in Capsella

Project description:In Arabidopsis thaliana, DNA-dependent RNA polymerase IV (Pol IV) is required for the formation of transposable element (TE)-derived small RNA (sRNA) transcripts. These transcripts are processed by DICER-LIKE3 into 24-nt small interfering RNAs (siRNAs) that guide RNA-directed DNA methylation. In the pollen grain, Pol IV is also required for the accumulation of 21/22-nt epigenetically activated siRNAs (easiRNAs), which likely silence TEs via post-transcriptional mechanisms. Despite this proposed role of Pol IV, its loss of function in Arabidopsis does not cause a discernable pollen defect. Here, we show that the knockout of NRPD1, encoding the largest subunit of Pol IV in the Brassicaceae species Capsella rubella, caused post-meiotic arrest of pollen development at the microspore stage. As in Arabidopsis, all TE-derived siRNAs were 2 depleted in Capsella nrpd1 microspores. In the wild-type background, the same TEs produced 21/22-nt and 24-nt siRNAs; these processes required Pol IV activity. Arrest of Capsella nrpd1 microspores was accompanied by the deregulation of genes targeted by Pol IV-dependent siRNAs. TEs were much closer to genes in Capsella rubella compared to Arabidopsis thaliana, perhaps explaining the essential role of Pol IV in pollen development in Capsella. Our discovery that Pol IV is functionally required in Capsella microspores emphasizes the relevance of investigating different plant models.

2020-01-23 | GSE136847 | GEO

Arabidopsis RNA Polymerase IV generates 21-22 nucleotide small RNAs that can participate in RNA-directed DNA methylation and may regulate genes

Project description:Canonically, Arabidopsis RNA Polymerase IV (Pol IV) is known to produce heterochromatic small RNAs (typically 23-24 nucleotide in length) that maintain silencing of transposable elements (TEs). In contrast, when TEs are transcriptionally activated and produce Pol II transcripts, these transcripts are degraded into 21-22 nt small RNAs (sRNAs) known to participate in post transcriptional gene silencing. Recently, it was reported that Pol IV can also produce 21-22 nt sRNAs in pollen. We investigated the mechanism of Pol IV dependent 21-22 nt sRNAs and show that this mechanism is not specific to pollen. Additionally, we show that these 21-22 nt sRNAs can participate in RNA-directed DNA methylation, are incorporated into ARGONAUTE 1 (AGO1) and may guide AGO1 to cleave genic mRNAs to regulate their expression.

2020-02-24 | GSE133618 | GEO

Locus-specific paramutation in Zea mays is maintained by a chromodomain helicase DNA-binding 3 protein controlling development and male gametophyte function

Project description:Paramutations represent directed and meiotically-heritable changes in gene regulation leading to apparent violations of Mendelian inheritance. Although the mechanism and evolutionary importance of paramutation behaviors remain largely unknown, genetic screens in maize (Zea mays) identify five components affecting 24 nucleotide RNA biogenesis as required to maintain repression of a paramutant purple plant1 (pl1) allele. Currently, the RNA polymerase IV largest subunit represents the only component also specifying proper development. Here we identify a chromodomain helicase DNA-binding 3 (CHD3) protein orthologous to Arabidopsis (Arabidopsis thaliana) PICKLE as a second component maintaining both pl1 paramutation, and normal somatic development. In addition, genetic tests show this protein contributes to proper male gametophyte function. The similar mutant phenotypes documented in Arabidopsis and maize implicate some evolutionarily-conserved gene regulation while developmental defects associated with the two paramutation mutants are largely distinct. Our results show that a CHD3 protein responsible for normal plant ontogeny and sperm transmission also maintains meiotically-heritable epigenetic regulatory variation for specific alleles. This finding implicates an intersection of RNA polymerase IV function and nucleosome positioning in the paramutation process.

2020-11-24 | GSE158990 | GEO

Epigenomic profiles of Brachypodium distachyon mutants deficient in RNA polymerase IV (Pol IV)

Project description:Monocot grass species (Poaceae) express a diverse set of multisubunit RNA polymerase enzymes, including Pol II, Pol IV and Pol V. To better understand this functional diversity, we have charted Pol IV function in the model Brachypodium distachyon. Intriguingly, pol IV null mutations in Poaceae crops disrupt growth, reproductive development and seed set. In order to investigate how Pol IV controls vegetative growth and TE activity in these grasses, we have isolated B. distachyon mutant alleles for Pol IV’s largest subunit, NRPD1. We obtained the germplasm in which to screen for these pol IV mutations from the B. distachyon community's sodium azide (NaN) and T-DNA insertion collections.

2024-03-04 | GSE243693 | GEO

Three groups of transposable elements with contrasting copy number dynamics and host responses in the maize (Zea mays ssp. mays) genome

Project description:Most angiosperm nuclear DNA is repetitive and derived from silenced transposable elements (TEs). TE silencing requires substantial resources from the plant host, including the production of small interfering RNAs (siRNAs). Thus, the interaction between TEs and siRNAs is a critical aspect of both the function and the evolution of plant genomes. Yet the co-evolutionary dynamics between these two entities remains poorly characterized. Here we studied the organization of TEs within the maize (Zea mays ssp mays) genome, documenting that TEs fall within three groups based on the class and copy numbers. These groups included DNA elements, low copy RNA elements and higher copy RNA elements. The three groups varied statistically in characteristics that included length, location, age, siRNA expression and 24:22 nucleotide (nt) siRNA targeting ratios. In addition, the low copy retroelements encompassed a set of TEs that had previously been shown to decrease expression within a 24 nt siRNA biogenesis mutant (mop1). To investigate the evolutionary dynamics of the three groups, we estimated their abundance in two landraces, one with a genome similar in size to that of the maize reference and the other with a 30% larger genome. For all three accessions, we assessed TE abundance as well as 22 nt and 24 nt siRNA content within leaves. The high copy number retroelements are under targeted similarly by siRNAs among accessions, appear to be born of a rapid bust of activity, and may be currently transpositionally dead or limited. In contrast, the lower copy number group of retrolements are targeted more dynamically and have had a long and ongoing history of transposition in the maize genome We compared TE abundances and siRNA profiles among B73 (maize inbred line) and two additional maize landraces, Palomero Toluqueño (PT) and Olote Colorado (OAXA) using HTS

2014-03-11 | E-GEOD-55730 | biostudies-arrayexpress

RNA Polymerase IV sensitizes the chromatin via histone modifications modulating protein coding genes [Degradome]

Project description:Knock down of RNA polymerase IV in rice caused pleiotropic reproductive defects. We investigated the molecular effects of loss of pol IV in different rice tissues by profiling sRNA and mRNA transcriptomes, DNA methylomes, histone modifications and degradome sequencing. These analyses revealed the multifaceted roles of RNA polymerase IV in bringing about regulation of protein coding genes.

2023-02-28 | GSE180312 | GEO

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