BRD2 is a transcriptional coactivator of Smad3 in mediating TGF-β tumor suppressive responses
摘要
Transforming growth factor-β (TGF-β) is a multifunctional cytokine that regulates cell proliferation, differentiation, migration, and apoptosis. It is generally accepted that TGF-β induces cellular responses through Smad-dependent gene transcription. However, the underlying mechanisms that modulate the transcriptional activities of Smads are not yet fully understood. Here, we identify BRD2, a member of the bromodomain and extraterminal (BET) family, as a key transcriptional coactivator for Smad3. BRD2 physically interacts with Smad3 through a newly identified Smad3-binding region (SBR). This BRD2-Smad interaction enhances Smad’s association with chromatin and amplifies its transcriptional activity, playing a vital role in TGF-β transcriptional and tumor-suppressive responses. Our findings establish BRD2 as an important modulator of TGF-β signaling and suggest that it may serve as a potential target for TGF-β-related diseases.