Poly [ADP-ribose] polymerase 1 (PARP1)–Bromodomain-containing protein 4 (BRD4) complex (PARP1–BRD4 complex)

The PARP1–BRD4 induced protein–protein complex is a functional molecular assembly formed between Poly [ADP-ribose] polymerase 1 (PARP1) and Bromodomain-containing protein 4 (BRD4). This complex is typically induced under conditions of cellular stress, particularly DNA damage, where PARP1 undergoes auto-poly(ADP-ribosyl)ation (PARylation), creating a scaffold that recruits BRD4 via its PAR-binding motifs or through direct protein-protein interactions. Biologically, this complex bridges the DNA damage response with transcriptional regulation, allowing BRD4 to modulate the expression of genes involved in repair, cell cycle progression, and oncogenesis, such as the MYC oncogene. In many cancers, including prostate and triple-negative breast cancer, the PARP1–BRD4 interaction is upregulated and contributes to therapy resistance and tumor progression. Consequently, the complex has become a high-interest therapeutic target, with researchers developing dual-acting inhibitors that simultaneously block PARP1 enzymatic activity and BRD4 bromodomain binding. These dual inhibitors aim to provide superior efficacy over monotherapies by synergistically inducing DNA damage and suppressing compensatory survival pathways, thereby overcoming resistance in aggressive malignancies.

Other names

PARP1-BRD4 interactionPARP1-BRD4 assemblyPARylated PARP1-BRD4 complexPARP1-BRD4 induced protein-protein complex

Simultaneous inhibition of PARP1 catalytic activity and BRD4 bromodomain binding, disruption of the PARylation-dependent recruitment of BRD4 to DNA damage sites, and suppression of MYC-mediated oncogenic signaling.