BRD4 bromodomain 1 (human, recombinant; GST-tagged)

Bromodomain-containing protein 4 (BRD4) is a member of the bromodomain and extra-terminal domain (BET) family.{33144} It is a ubiquitously expressed nuclear protein with roles in a variety of cellular processes, including regulation of gene transcription, cell cycle progression, and viral genome segregation.{33144,49639} BRD4 is comprised of two N-terminal bromodomains (BD1 and BD2) that can bind to acetylated lysine residues in histones, serving to couple histone acetylation marks to the transcriptional regulation of target promoters, an extra-terminal (ET) domain that facilitates protein-protein interactions, and a C-terminal motif, and can be expressed as either a long or short isoform generated via alternative splicing.{33144,49639,49640} In addition to binding acetylated lysine residues on histones, BRD4 can bind to a variety of non-histone proteins and protein complexes, including positive transcription elongation factor b (P-TEFb) and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) envelope (E) protein, a transmembrane protein involved in CoV virion assembly and pathogenesis of the related virus, SARS-CoV.{33144,55024,53462,49521} In mice, knock-down of Brd4 is embryonic lethal.{49639} Chromosomal translocations leading to the fusion of BRD4 with the nuclear protein in testis (NUT) gene and resulting in expression of BRD4-NUT fusion proteins are associated with NUT midline carcinoma (NMC).{33144,49640} Inhibition of BRD4-NUT binding to chromatin by the BET bromodomain inhibitor (+)-JQ1 (Item No. 11187) induces tumor regression and prolongs survival in NMC mouse xenograft models.{19004} Cayman’s BRD4 bromodomain 1 (human, recombinant; GST-tagged) protein can be used for ELISA, Western blot (WB), and binding assay applications.