Bromodomain-containing protein 2, Bromodomain-containing protein 4, and Bromodomain testis-specific protein (BRD2, BRD4, and BRDT)

Bromodomain-containing protein 2, Bromodomain-containing protein 4, and Bromodomain testis-specific protein (BRDT) are mammalian BET family members characterized by two tandem bromodomains and an extra-terminal (ET) domain[6][3][2]. These proteins act as chromatin readers, recognizing acetylated lysine residues on histones, which enables them to regulate gene transcription and organize higher-order chromatin structure. BRD2 and BRD4 are ubiquitously expressed and regulate key processes in cell cycle progression, inflammatory responses, and cancer biology, while BRDT is primarily expressed in germ cells and essential for spermatogenesis[7][8][3][6]. Aberrant activity or expression of BET proteins is implicated in oncogenesis, inflammatory diseases, and metabolic disorders. Small molecule inhibitors of BET proteins, such as JQ1 and I-BET151, block their activity by competing for acetyl-lysine binding, resulting in downregulation of oncogenes (like MYC) and suppression of growth and inflammatory mutations. BRD4 is particularly notable for its role in super-enhancer function and transcriptional elongation, while BRD2 actively regulates cell cycle and boundary formation in gene transcription[2][3][7][1][5]. These proteins are important emerging drug targets across oncology, immunology, and virology, but clinical use is associated with hematological toxicity and risks of immunosuppression[6][1].

Other names

RING3FSRG1RNF3FSHD6S113EMCAPHUNK1FSRC4BRD6CT9SPGF21

Inhibition of bromodomains: blocks BET proteins binding to acetylated lysines on histones, disrupting transcription of pro-proliferative and inflammatory genes (e.g., MYC, NF-κB); Suppression of oncogene transcription and proliferation; Modulation of cytokine production and immune cell function