🧵 I’m very happy to share a new preprint from the @samuzambrano.bsky.social group and ours — a project driven by @emabiong.bsky.social, a PhD student bold enough to tackle a question at the interface of our two expertises: how the biological oscillators p53 and NF-κB talk to each other.

Really excited to share our latest work led by @mattiaubertini.bsky.social and @nesslfy.bsky.social: we report that cohesin loop extrusion creates rare but long-lived encounters between genomic sequences which underlie efficient enhancer-promoter communication.
www.biorxiv.org/content/10.1...
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Chromatin Dynamics are Highly Subdiffusive Across Seven Orders of Magnitude Chromatin dynamics control the timescales of essential biological processes including DNA damage repair and activation of gene promoters by distal enhancers. Prior chromatin dynamics studies have repo...

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This was a true team effort with @domenicnarducci.bsky.social, Simon Grosse-Holz,
@jessematthias.bsky.social & @andersshansen.bsky.social. I’m grateful and proud to have worked together. Huge thanks to AICF for their fellowship support. Check out the preprint:
www.biorxiv.org/content/10.1...

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However, as distance increases search times become progressively more challenging. At ~1µm (1-3 Mb), EP can take ~5-24 h to randomly find each other – potentially too long for a cell cycle → distant EP need help (e.g. loop extrusion)

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We ran simulations to estimate EP search times based on 1) measured subdiffusion, 2) physical/genomic distance. Within 300nm (~<200 kb), a gene can find 1000s of enhancers in minutes. Such encounters can’t be selective → EP selectivity needs other mechanisms, e.g. biochemical

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Such fast and long chromatin tracking is key to understanding how distal genomic elements (e.g. enhancers and promoters – EP) find each other. We found chromatin is highly subdiffusive (α ~ 0.3) -> loci are great at exploring the neighborhoods but rarely reach distant regions

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Super excited to share my first preprint from @andersshansen.bsky.social Lab! We used MINFLUX to track chromatin (H2B-Halo and Fbn2 locus) at an unprecedented 200 μs, then combined it with SPT to span μs-minutes (H2B) or SPT & Super-Res Live-Cell Imaging (SRLCI) to span μs-hours (Fbn2)