RESUMO
The nucleus contains diverse phase-separated condensates that compartmentalize and concentrate biomolecules with distinct physicochemical properties. Here, we investigated whether condensates concentrate small-molecule cancer therapeutics such that their pharmacodynamic properties are altered. We found that antineoplastic drugs become concentrated in specific protein condensates in vitro and that this occurs through physicochemical properties independent of the drug target. This behavior was also observed in tumor cells, where drug partitioning influenced drug activity. Altering the properties of the condensate was found to affect the concentration and activity of drugs. These results suggest that selective partitioning and concentration of small molecules within condensates contributes to drug pharmacodynamics and that further understanding of this phenomenon may facilitate advances in disease therapy.
Assuntos
Antineoplásicos/farmacologia , Núcleo Celular/metabolismo , Resistencia a Medicamentos Antineoplásicos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Antineoplásicos/uso terapêutico , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Homólogo 5 da Proteína Cromobox , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Subunidade 1 do Complexo Mediador/genética , Subunidade 1 do Complexo Mediador/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Nucleofosmina , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
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.