Bromodomain-containing protein family (BRD) (BRD)

Bromodomains are specialized protein domains that function as epigenetic readers, identifying and binding to acetylated lysine residues on histone tails and other nuclear proteins [Filippakopoulos et al., 2012]. The human genome contains 61 bromodomains distributed across 46 different proteins, which are classified into eight distinct families based on structural similarity [Shi & Vakoc, 2014]. The most prominent therapeutic targets within this group are the Bromodomain and Extra-Terminal (BET) family members, including BRD2, BRD3, BRD4, and BRDT, which are essential for the assembly of transcriptional complexes at enhancers and promoters [Belkina & Denis, 2012]. Pan-bromodomain inhibitors, particularly those targeting the BET family, work by competitively displacing these proteins from chromatin, thereby suppressing the expression of key oncogenes such as MYC and BCL2 [Doroshow et al., 2017]. These targets are heavily implicated in various pathologies, including hematologic malignancies, solid tumors, and chronic inflammatory conditions [Alqahtani et al., 2019]. Despite their potent anti-tumor activity, clinical development of pan-BET inhibitors has faced challenges due to dose-limiting toxicities like thrombocytopenia and gastrointestinal distress, leading to a shift toward more selective or bivalent inhibitors [Stathis & Bertoni, 2018].

Other names

BET proteinsBromodomainsAcetyl-lysine readersPan-BET targets

Competitive inhibition of the acetyl-lysine binding pocket within bromodomains, which prevents the recruitment of these proteins and their associated transcriptional machinery to acetylated chromatin, thereby modulating gene expression [Filippakopoulos et al., 2010; Shi & Vakoc, 2014].