BRCA1-A complex subunit RAP80 (RAP80)

BRCA1-A complex subunit RAP80 (abbreviated as RAP80; gene: UIMC1) is a nuclear adaptor protein characterized by two N-terminal ubiquitin-interacting motifs (UIMs)[1][3]. RAP80 is a core component of the BRCA1-A complex, which also includes BRCC36, BRE, and MERIT40[4]. RAP80 recognizes Lys63-linked polyubiquitin chains at DNA double-strand break sites through its UIM domains, facilitating recruitment of the BRCA1-A complex to DNA damage-induced nuclear foci[5][6]. This process enables BRCA1 localization to sites of DNA damage for error-free homologous recombination (HR) repair but also plays a regulatory role in limiting BRCA1's recombination activity, likely shifting the balance between HR and non-homologous end joining (NHEJ)[2][3][4]. Loss or mutation of RAP80 impairs the recruitment of BRCA1 and associates with increased genomic instability, defective DNA repair, and cancer predisposition[1][2][4]. RAP80 itself is not a direct therapeutic target or traditional receptor/enzyme; rather, its role is as an essential mediator of genome maintenance and a potential indirect influencer in cancer etiology and therapy sensitivity.

Other names

UIMC1RXRIP110Receptor-associated protein 80Retinoid X receptor-interacting protein 110Ubiquitin interaction motif-containing protein 1X2HRIP110