Bromodomain Containing Protein 4 (BRD4)

Bromodomain Containing Protein 4 (BRD4) is a protein that in humans is encoded by the BRD4 gene. BRD4 is a member of the BET (bromodomain and extra terminal domain) family, which also includes BRD2, BRD3, and BRDT. BRD4, similar to other BET family members, contains two bromodomains that recognize acetylated lysine residues. BRD4 also has an extended C-terminal domain with little sequence homology to other BET family members. The two bromodomains in BRD4, termed BD1 and BD2, consist of 4 alpha-helices linked by 2 loops. The ET domain structure is made up of 3 alpha-helices and a loop. The C-terminal domain of BRD4 has been implicated in promoting gene transcription through interaction with the transcription elongation factor P-TEFb and RNA polymerase II.