Human Smc5/6 recognizes transcription-generated positive DNA supercoils
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ABSTRACT:
PROVIDER: PRJNA963774 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Beyond its essential roles in ensuring faithful chromosome segregation and genomic stability, the human Smc5/6 complex acts as an antiviral factor. It binds to and impedes the transcription of extrachromosomal DNA templates; an ability which is lost upon chromosomal DNA integration. How the complex distinguishes among different DNA templates is unknown. Here we show that, in human cells, Smc5/6 preferentially binds to circular rather than linear extrachromosomal DNA. We further show that this binding is unlikely due to differences in the chromatin composition. Instead, the transcriptional process, per se, and more specifically the accumulation of DNA secondary structures known to be substrates for topoisomerases, is responsible for Smc5/6 recruitment. Those findings, in conjunction with our genome-wide Smc5/6 binding analysis showing that Smc5/6 localises at few but highly transcribe chromosome loci, reveal a previously unforeseen role of Smc5/6 in DNA topology management during transcription.
2024-06-10 | GSE231328 | GEO
Project description:Loop-extruding Smc5/6 organizes transcription-induced positive DNA supercoils.
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Project description:Loop-extruding Smc5/6 organizes transcription-induced positive DNA supercoils [ChIP-seq]
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Project description:Loop-extruding Smc5/6 organizes transcription-induced positive DNA supercoils [Hi-C]
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Project description:Loop-extruding Smc5/6 organizes transcription-induced positive DNA supercoils [RNA-seq]
| PRJNA986465 | ENA
Project description:The Structural Maintenance of Chromosome (SMC) protein complexes cohesin, condensin and the Smc5/6 complex (Smc5/6) are essential for chromosome function. At the molecular level, these complexes fold DNA by loop extrusion. Accordingly, cohesin creates chromosome loops in interphase, and condensin compacts mitotic chromosomes. However, the role of Smc5/6’s recently discovered DNA loop extrusion activity is unknown. Here, we uncover that Smc5/6 controls the spatial organization of supercoiled chromosomal regions. The results show that Smc5/6 associates with transcription-induced positively supercoiled chromosomal DNA at cohesin-dependent chromosome loop boundaries. Mechanistically, single-molecule imaging reveals that dimers of Smc5/6 specifically recognize the tip of positively supercoiled DNA plectonemes, and efficiently initiates loop extrusion to gather the supercoiled DNA into a large plectonemic loop. Finally, Hi-C analysis shows that Smc5/6 links chromosomal regions containing transcription-induced positive supercoiling in cis. Altogether, our findings indicate that Smc5/6 controls the three-dimensional organization of chromosomes by recognizing and initiating loop extrusion on positively supercoiled DNA.
2024-01-30 | GSE235559 | GEO
Project description:The Structural Maintenance of Chromosome (SMC) protein complexes cohesin, condensin and the Smc5/6 complex (Smc5/6) are essential for chromosome function. At the molecular level, these complexes fold DNA by loop extrusion. Accordingly, cohesin creates chromosome loops in interphase, and condensin compacts mitotic chromosomes. However, the role of Smc5/6’s recently discovered DNA loop extrusion activity is unknown. Here, we uncover that Smc5/6 controls the spatial organization of supercoiled chromosomal regions. The results show that Smc5/6 associates with transcription-induced positively supercoiled chromosomal DNA at cohesin-dependent chromosome loop boundaries. Mechanistically, single-molecule imaging reveals that dimers of Smc5/6 specifically recognize the tip of positively supercoiled DNA plectonemes, and efficiently initiates loop extrusion to gather the supercoiled DNA into a large plectonemic loop. Finally, Hi-C analysis shows that Smc5/6 links chromosomal regions containing transcription-induced positive supercoiling in cis. Altogether, our findings indicate that Smc5/6 controls the three-dimensional organization of chromosomes by recognizing and initiating loop extrusion on positively supercoiled DNA.
2024-01-30 | GSE235558 | GEO
Project description:The Structural Maintenance of Chromosome (SMC) protein complexes cohesin, condensin and the Smc5/6 complex (Smc5/6) are essential for chromosome function. At the molecular level, these complexes fold DNA by loop extrusion. Accordingly, cohesin creates chromosome loops in interphase, and condensin compacts mitotic chromosomes. However, the role of Smc5/6’s recently discovered DNA loop extrusion activity is unknown. Here, we uncover that Smc5/6 controls the spatial organization of supercoiled chromosomal regions. The results show that Smc5/6 associates with transcription-induced positively supercoiled chromosomal DNA at cohesin-dependent chromosome loop boundaries. Mechanistically, single-molecule imaging reveals that dimers of Smc5/6 specifically recognize the tip of positively supercoiled DNA plectonemes, and efficiently initiates loop extrusion to gather the supercoiled DNA into a large plectonemic loop. Finally, Hi-C analysis shows that Smc5/6 links chromosomal regions containing transcription-induced positive supercoiling in cis. Altogether, our findings indicate that Smc5/6 controls the three-dimensional organization of chromosomes by recognizing and initiating loop extrusion on positively supercoiled DNA.
2024-01-30 | GSE235557 | GEO
Project description:The twin supercoiled domain model posits that, as RNA Polymerase II (Pol II) transcribes a gene, it generates negative and positive supercoils upstream and downstream respectively, but little is known about the functional consequence in vivo of the resulting torsional strain. Here we provide a method for high resolution mapping of DNA supercoils using next-generation sequencing, and show that the level of supercoiling is correlated with gene expression in Drosophila cells. Inhibition of topoisomerases, enzymes that relieve torsional strain, leads to accumulation of supercoils surrounding gene bodies and of Pol II at the transcription start sites. Topoisomerase I inhibition results in increased nascent RNA transcripts with Topoisomerase II inhibition shows little change in nascent RNA levels. Despite these different effects on transcription, inhibition of either enzyme results in increased nucleosome turnover within gene bodies, suggesting that torsional stress contributes to destabilizing nucleosomes ahead of Pol II. 12 paired-end samples and 8 single-end samples were sequenced and analyzed.
2013-10-31 | E-GEOD-47795 | biostudies-arrayexpress
Project description:The twin supercoiled domain model posits that, as RNA Polymerase II (Pol II) transcribes a gene, it generates negative and positive supercoils upstream and downstream respectively, but little is known about the functional consequence in vivo of the resulting torsional strain. Here we provide a method for high resolution mapping of DNA supercoils using next-generation sequencing, and show that the level of supercoiling is correlated with gene expression in Drosophila cells. Inhibition of topoisomerases, enzymes that relieve torsional strain, leads to accumulation of supercoils surrounding gene bodies and of Pol II at the transcription start sites. Topoisomerase I inhibition results in increased nascent RNA transcripts with Topoisomerase II inhibition shows little change in nascent RNA levels. Despite these different effects on transcription, inhibition of either enzyme results in increased nucleosome turnover within gene bodies, suggesting that torsional stress contributes to destabilizing nucleosomes ahead of Pol II.
2013-10-31 | GSE47795 | GEO