RESUMO
Gene expression is controlled by transcription factors (TFs) that consist of DNA-binding domains (DBDs) and activation domains (ADs). The DBDs have been well characterized, but little is known about the mechanisms by which ADs effect gene activation. Here, we report that diverse ADs form phase-separated condensates with the Mediator coactivator. For the OCT4 and GCN4 TFs, we show that the ability to form phase-separated droplets with Mediator in vitro and the ability to activate genes in vivo are dependent on the same amino acid residues. For the estrogen receptor (ER), a ligand-dependent activator, we show that estrogen enhances phase separation with Mediator, again linking phase separation with gene activation. These results suggest that diverse TFs can interact with Mediator through the phase-separating capacity of their ADs and that formation of condensates with Mediator is involved in gene activation.
Assuntos
Células-Tronco Embrionárias Murinas/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Receptores de Estrogênio/metabolismo , Ativação Transcricional/fisiologia , Animais , Células HEK293 , Humanos , Camundongos , Células-Tronco Embrionárias Murinas/citologia , Fator 3 de Transcrição de Octâmero/genética , Domínios Proteicos , Receptores de Estrogênio/genéticaRESUMO
In this issue of Molecular Cell, Yi et al. (2015) use biochemical assays and cryo-EM to determine the molecular architecture of an estrogen receptor (ERα) co-activator complex bound to DNA.