Antagonistic conflict between transposon-encoded introns and guide RNAs
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1086522 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR28292630_1.fastq.gz | Fastqsanger.gz | |||
| SRR28292630_2.fastq.gz | Fastqsanger.gz | |||
| SRR28292631_1.fastq.gz | Fastqsanger.gz | |||
| SRR28292631_2.fastq.gz | Fastqsanger.gz | |||
| SRR28292632_1.fastq.gz | Fastqsanger.gz |
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Similar Datasets
Project description:Antagonistic conflict between transposon-encoded introns and guide RNAs (RIP-Seq)
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Project description:Antagonistic conflict between transposon-encoded introns and guide RNAs (RNA-Seq)
| PRJNA1086528 | ENA
Project description:TnpB nucleases represent the evolutionary precursors to CRISPR-Cas12 and are widespread in all domains of life. IS605-family TnpB homologs function in bacteria as programmable RNA-guided homing endonucleases driving transposon maintenance through DSB-stimulated homologous recombination. Here we uncover molecular mechanisms of transposition lifecycle of IS607-family elements that, remarkably, also encode group I introns. We discover molecular features for a candidate ‘IStron’ from Clostridium botulinum that allow the element to carefully control the relative levels of spliced products versus functional guide RNAs. Our results suggest that IStron transcripts have evolved a sensitive equilibrium to balance competing and mutually exclusive activities that promote transposon maintenance while limiting adverse fitness costs on the host. Collectively, this work highlights molecular innovation in the multi-functional utility of transposon-encoded noncoding RNAs.
2024-05-06 | GSE261343 | GEO
Project description:TnpB nucleases represent the evolutionary precursors to CRISPR-Cas12 and are widespread in all domains of life. IS605-family TnpB homologs function in bacteria as programmable RNA-guided homing endonucleases driving transposon maintenance through DSB-stimulated homologous recombination. Here we uncover molecular mechanisms of transposition lifecycle of IS607-family elements that, remarkably, also encode group I introns. We discover molecular features for a candidate ‘IStron’ from Clostridium botulinum that allow the element to carefully control the relative levels of spliced products versus functional guide RNAs. Our results suggest that IStron transcripts have evolved a sensitive equilibrium to balance competing and mutually exclusive activities that promote transposon maintenance while limiting adverse fitness costs on the host. Collectively, this work highlights molecular innovation in the multi-functional utility of transposon-encoded noncoding RNAs.
2024-05-06 | GSE261342 | GEO
Project description:TnpB nucleases represent the evolutionary precursors to CRISPR-Cas12 and are widespread in all domains of life, presumably due to the critical roles they play in transposon proliferation. IS605family TnpB homologs function in bacteria as programmable homing endonucleases by exploiting transposon-encoded guide RNAs to cleave vacant genomic sites, thereby driving transposon maintenance through DSB-stimulated homologous recombination. Whether this pathway is conserved in other genetic contexts, and in association with other transposases, is unknown. Here we uncover molecular mechanisms of transposition and RNA-guided DNA cleavage by IS607-family elements that, remarkably, also encode catalytic, self-splicing group I introns. After reconstituting and systematically investigating each of these biochemical activities for a candidate 'IStron' derived from Clostridium botulinum, we discovered sequence and structural features of the transposon-encoded RNA that satisfy molecular requirements of a group I intron and TnpB guide RNA, while still retaining the ability to be faithfully mobilized at the DNA level by the TnpA transposase. Strikingly, intron splicing was strongly repressed not only by TnpB, but also by the secondary structure of ωRNA alone, allowing the element to carefully control the relative levels of spliced products versus functional guide RNAs. Our results suggest that IStron transcripts have evolved a sensitive equilibrium to balance competing and mutually exclusive activities that promote transposon maintenance while limiting adverse fitness costs on the host. Collectively, this work explains how diverse enzymatic activities emerged during the selfish spread of IS607-family elements and highlights molecular innovation in the multi-functional utility of transposon-encoded noncoding RNAs.
| S-EPMC10690162 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2024-05-06 | GSE261344 | GEO
Project description:The endosperm is a reproductive tissue supporting embryo development. In most flowering plants, the initial divisions of endosperm nuclei are not succeeded by cellularization; this process occurs only after a specific number of mitotic cycles have taken place. The timing of cellularization significantly influences seed viability and size. Previous research implicated auxin as a key factor in initiating nuclear divisions and determining the timing of cellularization. Here we uncover the involvement of a family of clustered auxin response factors (cARFs) as dosage-sensitive regulators of endosperm cellularization. cARFs, maternally expressed and paternally silenced, are shown to induce cellularization, thereby restricting seed growth. Our findings align with the predictions of the parental conflict theory, suggesting that cARFs represent major molecular targets in this conflict. We further demonstrate a recurring amplification of cARFs in the Brassicaceae, suggesting an evolutionary response to parental conflict by reinforcing maternal control over endosperm cellularization. Our study highlights that antagonistic parental control on endosperm cellularization converges on auxin biosynthesis and signalling.
2024-03-22 | GSE232803 | GEO
Project description:Transposon-encoded nucleases use guide RNAs to selfishly bias their inheritance
| PRJNA925099 | ENA
Project description:Insertion sequences (IS) are compact and pervasive transposable elements found in bacteria, which encode only the genes necessary for their mobilization and maintenance. IS200/IS605 elements undergo ‘peel-and-paste’ transposition catalyzed by a TnpA transposase, but intriguingly, they also encode diverse, TnpB-family genes that are evolutionarily related to the CRISPR-associated effectors Cas9 and Cas12. Recent studies demonstrated that TnpB-family enzymes function as RNA-guided DNA endonucleases, but the broader biological role of this activity has remained enigmatic. Here we show that IscB and TnpB are essential to prevent loss of the donor IS element and potential transposon extinction as a consequence of the TnpA transposition mechanism. We first performed phylogenetic analysis of IscB/TnpB proteins and selected a family of related IS elements from Geobacillus stearothermophilus that we predicted would be mobilized by a common TnpA homolog. After reconstituting transposition using a heterologous expression system in E. coli, we found that IS elements were readily lost from the donor site due to the activity of TnpA in rejoining the flanking sequences back together upon excision. However, these IS elements also encode non-coding RNAs that guide TnpB and IscB nucleases to precisely recognize and cleave these excision products, leading either to elimination of the excision product or re-installation of the transposon through recombination. Indeed, under experimental conditions in which TnpA and TnpB-RNA complexes were co-expressed together with a genomically integrated IS element, transposon retention was significantly increased relative to conditions expressing TnpA alone. Remarkably, both TnpA and TnpB recognize the same AT-rich transposon-adjacent motif (TAM) during transposon excision and RNA-guided DNA cleavage, respectively, revealing a striking convergence in the evolution of DNA sequence specificity between transposase and nuclease. Collectively, our study reveals that RNA-guided DNA cleavage is a primal biochemical activity that arose to bias the selfish inheritance of transposable elements, which was later co-opted during the evolution of CRISPR-Cas adaptive immunity for antiviral defense.
2023-06-01 | GSE223127 | GEO