Bromodomain (BRD) (BRD)

Bromodomains are evolutionarily conserved protein modules, typically consisting of approximately 110 amino acids, that function as epigenetic readers by recognizing and binding to acetylated lysine residues on histone tails and other nuclear proteins [1][2]. In the human genome, there are 61 known bromodomains found within 46 different proteins, which are organized into eight distinct families based on their structural architecture and sequence homology [2][3]. These domains play a critical role in the regulation of gene transcription by recruiting various transcriptional co-activators and chromatin-remodeling complexes to specific genomic loci [1][4]. The Bromodomain and Extra-Terminal (BET) family, comprising BRD2, BRD3, BRD4, and BRDT, is the most prominent therapeutic target due to its involvement in driving the expression of key oncogenic drivers such as MYC and BCL2 [3][5]. Small-molecule inhibitors designed to target bromodomains work by competitively binding to the hydrophobic acetyl-lysine binding pocket, thereby displacing the protein from chromatin and inhibiting the transcription of downstream target genes [5][6]. This therapeutic approach has shown significant promise in treating aggressive malignancies like NUT midline carcinoma and acute myeloid leukemia, as well as chronic inflammatory and cardiovascular diseases [4][6].

Other names

Bromodomain-containing proteinAcetyl-lysine binding proteinEpigenetic reader domainBRD

Bromodomain inhibitors function by competitively binding to the hydrophobic acetyl-lysine binding pocket of the domain [1][5]. This binding prevents the bromodomain-containing protein from associating with acetylated lysine residues on histone tails or other proteins, effectively displacing the protein from chromatin [2][6]. Consequently, the recruitment of transcriptional co-activators and the assembly of the transcriptional initiation or elongation complexes are disrupted, leading to the suppression of target gene expression, most notably oncogenes like MYC and pro-inflammatory cytokines [4][5].