Transcription-coupled changes in higher-order genomic structure and transcription hub viscosity prolong enhancer-promoter connectivity

The orchestration of our genes heavily relies on a coordinated communication between enhancers and promoters, yet how this dynamic interplay remains elusive while transcription is active. Here, we investigated enhancer-promoter (E-P) interactions and relative to transcriptional bursting in mouse embryonic stem cells using sequential DNA/RNA/immunofluorescence (IF)-FISH analyses and computational simulations. Our data reveal that the active state of specific genes is characterized by higher-order genomic structures and local condensates of transcriptional regulatory factors, leading to an elevation in local viscosity that highly stabilizes the duration of E-P interactions. Our study underscores the pivotal role of viscosity in transcriptional dynamics and paves the way for a more nuanced understanding of gene-specific regulatory mechanisms.