BRCA1-associated RING domain protein 1 (BARD1)

BRCA1-associated RING domain protein 1 (BARD1) is a multifunctional tumor suppressor protein that forms an obligate, heterodimeric E3 ubiquitin ligase complex with BRCA1 via its N-terminal RING domain[3][7]. BARD1 contains additional structural features, including ankyrin repeats and BRCT (BRCA1 C-terminal) domains, which mediate extensive protein–protein interactions important for its role in the DNA damage response[2][4]. The BRCA1/BARD1 complex is essential for error-free repair of DNA double-strand breaks via homologous recombination, cell cycle checkpoint control, and maintaining genome stability by regulating ubiquitination of key substrates (such as RNA polymerase II)[3][5]. BARD1 can also induce apoptosis, in part via stabilization and interaction with p53, independently of BRCA1[2][3]. Pathogenic mutations or alternative splicing of BARD1 are implicated in hereditary and sporadic breast, ovarian, and uterine cancers[1][3][4]. No approved therapies directly target BARD1 as of 2024, but its centrality in DNA repair make it a candidate for future targeted oncology therapeutics.

Other names

BRCA1-associated RING domain 1BARD1BARD-1RING-type E3 ubiquitin transferase BARD1BRCA1-associated RING domain gene 1

Drugs targeting the BRCA1/BARD1 pathway (such as PARP inhibitors) act by exploiting synthetic lethality in cells lacking functional homologous recombination repair. Potential investigational agents would theoretically target BARD1's E3 ubiquitin ligase activity, disrupt the BRCA1-BARD1 dimer, or affect its DNA repair/scaffold functions[3][5].