RNA polymerase II transcription compartments: from multivalent chromatin binding to liquid droplet formation?

Recent studies invoke phase separation as a mechanism underlying the formation of ‘transcriptional condensates’. However, similarities between transcriptional condensates and the previously introduced ‘transcription factories’ model raise the question of what distinguishes the two models. One crucial aspect to consider is the contribution of intrinsically disordered regions in transcription-relevant factors. Rippe and Papantonis suggest that intrinsically disordered regions in transcription-relevant factors underlie the formation of both ‘transcriptional condensates’ and ‘transcription factories’.