Bromodomain-containing protein 2, 3, and 4 (BRD2, BRD3, BRD4)

Bromodomain-containing protein 2, 3, and 4 (BRD2, BRD3, BRD4) are epigenetic transcriptional regulators belonging to the BET protein family. They share a conserved structure containing tandem bromodomains (BD1 and BD2) that recognize acetylated lysine residues and an extra-terminal (ET) domain facilitating recruitment of chromatin remodeling complexes. BRD2, BRD3, and BRD4 play essential and overlapping but distinct roles in chromatin remodeling, gene transcription, cell cycle control, and immune regulation. Their aberrant activity is implicated in oncogenesis, inflammatory diseases, and metabolic dysfunction. BET proteins have become key drug targets, with several small molecule bromodomain inhibitors in clinical trials for cancer and immune disorders. BRD2 and BRD4 especially are critical for cell cycle progression, promoting G1/S transition and transcriptional elongation, while BRD3 interacts with lineage-specific transcription factors such as GATA1. Therapeutic targeting of these proteins modulates gene expression signatures central to disease pathogenesis, but clinical development is challenged by their ubiquitous roles in normal physiology and potential for on-target toxicity.[1][2][3][4][5][7]

Other names

RING3ORFXFSHRG2

Competitive inhibition of bromodomain–acetyl-lysine interaction Disruption of BET protein binding to chromatin, suppressing transcription of oncogenic, inflammatory, and pro-survival genes such as MYC, NF-kB targets, and cytokines Suppression of super-enhancer function and transcriptional elongation