Sergei Rudnizky
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nucleosomezky.bsky.social
Sergei Rudnizky
@nucleosomezky.bsky.social
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HFSP postdoc @BostonChildrens @harvardmed w/ @Taekjip Ha. Past:@EMBO fellow, @JohnsHopkins. Phd w/ @Ariel Kaplan & @Philippa Melamed @Technion. I ❤️ #chromatin
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Reposted by Sergei Rudnizky
teiflab.bsky.social
Ultrastable and versatile multimeric ensembles of FoxP3 on microsatellites www.cell.com/molecular-ce...
▶️FoxP3 recognizes a variety of TnG repeat microsatellites
▶️FoxP3 multimers are ultrastable, can bridge 2–4 DNA duplexes
▶️Nucleosomes can facilitate FoxP3 assembly by inducing local DNA bending
Microsatellites are essential genomic components increasingly linked to transcriptional regulation. FoxP3, a transcription factor critical for regulatory T cell (Treg) development, recognizes TTTG repeat microsatellites by forming multimers along DNA. However, FoxP3 also binds a broader range of TnG repeats (n = 2–5), often at the edges of accessible chromatin regions. This raises questions about how FoxP3 adapts to sequence variability and the potential role of nucleosomes. Using cryoelectron microscopy and single-molecule analyses, we show that murine FoxP3 assembles into various distinct supramolecular structures, depending on DNA sequence. This structural plasticity enables FoxP3 to bridge 2–4 DNA duplexes, forming ultrastable structures that coordinate multiple genomic loci. Nucleosomes further facilitate FoxP3 assembly by inducing local DNA bending, creating a nucleus that recruits distal DNA elements through multiway bridging. Our findings thus reveal FoxP3’s unusual ability to shapeshift to accommodate evolutionarily dynamic microsatellites and its potential to reinforce chromatin boundaries and three-dimensional genomic architecture.
April 5, 2025 at 9:54 PM
Reposted by Sergei Rudnizky
albertomarin.bsky.social
1/n
Really excited to share our latest pre-print on the role of cohesin in homology search, now available on bioRxiv!
www.biorxiv.org/content/10.1...
Cohesin drives chromatin scanning during the RAD51-mediated homology search.
Cohesin folds genomes into chromatin loops, whose roles are under debate. We report that double strand breaks (DSB) induce de novo formation of chromatin loops, with the break positioned at the loop b...
www.biorxiv.org
February 13, 2025 at 1:16 AM
Reposted by Sergei Rudnizky
teiflab.bsky.social
The yeast genome is globally accessible in living cells [new from the group of David Clark] www.nature.com/articles/s41...
▶️Measured DNA accessibility in living budding yeast by inducible expression of methyltransferases
▶️The genome is globally accessible in living cells, unlike in isolated nuclei
The yeast genome is globally accessible in living cells - Nature Structural & Molecular Biology
The authors measure the accessibility of the yeast genome using DNA methylases. They show that the genome is globally accessible in living cells, except for centromeres and silenced loci, unlike in is...
www.nature.com
November 28, 2024 at 9:03 PM