Transcription condensates are promoter hubs that enhance transcriptional bursts - PubMed
4 hours ago
- #transcription condensates
- #chromatin organization
- #super-resolution microscopy
- Transcription in eukaryotic genes by RNA Polymerase II occurs in bursts and spatial clusters, regulated by various transcription factors, coactivators, and histone marks.
- Pol II clusters act as promoter chromatin hubs with a continuous spectrum of sizes, and show a layered regulatory chromatin organization: H3K27ac and H3K4me3 are central, while H3K4me1 is peripheral.
- Super-resolution microscopy reveals that cohesin loop extrusion, not condensate-driven interactions, primarily forms the active chromatin scaffold for transcription assemblies.
- Transcriptional burst size and number increase with Pol II cluster size, indicating cooperative benefits of organization in promoter hubs as a functional consequence of chromatin structure.