Roles of intrinsically disordered protein regions in transcriptional regulation and genome organization.

Eukaryotic transcription is a complex process regulated by transcription factors (TFs), coactivators, and RNA polymerase machineries, many of which contain sizable intrinsically disordered regions (IDRs). Many TFs activate transcription through multivalent IDR-IDR interactions. Optimal levels of such multivalent interactions associated with appropriate IDR concentrations, interaction strengths, or interaction valencies are required for effective transcriptional activation. The interaction selectivity of IDRs is crucial for the precise regulation of transcription, and this selectivity is dependent on the IDR sequences. Furthermore, IDRs modulate gene expression by bringing chromatin sites together to form transcriptionally active chromatin hubs. Mutations in IDRs may cause dysregulation of their multivalent interactions, contributing to diseases, including cancers and neurodegenerative disorders. Understanding the effects of IDR-related mutations on transcription control and genome organization opens new opportunities for developing targeted therapeutic strategies. In this review, we discuss recent reports documenting important functions of IDRs in transcriptional regulation and their implications for human health and disease.