our field may finally be cracking the puzzle of cohesin loop extrusion's role in enhancer! Careful biophysical measurements, engineered loci, and first-principle biophysical thinking are a powerful combo.
An overview of Nora/Mirny lab's preprint+important context by @lucagiorgetti.bsky.social
Beautiful new study from @elphegenoralab.bsky.social and Leonid Mirny's lab:
Cohesin-bridged encounters mediate enhancer-promoter communication, predicting how enhancer effect scales with genomic distance and - for the first time - how CTCF sites modulate enhancer-promoter communciation!
🧵 below
2/ This is very much in line with and extends our recent discovery that loop extrusion creates rare, but long-lived cohesin-mediated encounters that lasting longer than random contacts and provide support for E-P communication:
👉https://www.biorxiv.org/content/10.1101/2025.09.24.678119v1.full
7/ Our studies thus converge on the idea that long-range enhancer-promoter communication depends on long-lived, cohesin-bridged, loop-extrusion-driven encounters mediated by cohesins that land in specific genomic regions depending on whether or not there are CTCF sites, and where they are located:
3/ Cohesin bridges in @elphegenoralab.bsky.social & Leonid Mirny's new study identify with the loop-extrusion-driven long-lived encounters that we recently discovered using polymer simulations and super-high resolution live imaging: