FAM175A (Abraxas)丝氨酸残基S406的DNA损伤无关磷酸化形成pS-X-X-F (phospho- ser - x - phe)基序，结合BRCA1的BRCT重复序列。BRCA1癌症易感突变M1775R (Met1775Arg)抑制了BRCA1与FAM175A的结合。FAM175A与UIMC1 (RAP80)的相互作用使BRCA1能够募集到DNA双链断裂(DSBs) (Wang et al. 2007)。除了BRCA1, FAM175A还与BRCC3 (BRCC36) (Wang et al. 2007, Hu et al. 2011)和BABAM1 (MERIT40, NBA1) (Vikrant et al. 2014)相互作用。BABAM1同时与BRE相互作用(BRCC45) (Hu et al. 2011)。BRCA1、BARD1、UIMC1、FAM175A、BRCC36、BRE和BABAM1一起在DNA dsb形成所谓的BRCA1- a复合物(Wang et al. 2009)。