Heterodimer with
BARD1. Part of the
BRCA1-associated genome surveillance complex (BASC), which contains
BRCA1,
MSH2,
MSH6,
MLH1,
ATM,
BLM,
PMS2 and the
MRE11-
RAD50-
NBN protein (MRN) complex. This association could be a dynamic process changing throughout the cell cycle and within subnuclear domains. Component of the
BRCA1-A complex, at least composed of
BRCA1,
BARD1,
UIMC1/RAP80,
ABRAXAS1,
BRCC3/
BRCC36,
BABAM2 and
BABAM1/NBA1. Interacts (via the BRCT domains) with
ABRAXAS1 (phosphorylated form); this is important for recruitment to sites of DNA damage. Can form a heterotetramer with two molecules of
ABRAXAS1 (phosphorylated form). Component of the
BRCA1-
RBBP8 complex. Interacts (via the BRCT domains) with
RBBP8 ('Ser-327' phosphorylated form); the interaction ubiquitinates
RBBP8, regulates
CHEK1 activation, and involves
RBBP8 in
BRCA1-dependent G2/M checkpoint control on DNA damage. Associates with RNA polymerase II holoenzyme. Interacts with
SMC1A, COBRA1,
DCLRE1C,
CLSPN.
CHEK1,
CHEK2,
BAP1,
BRCC3,
AURKA,
UBXN1 and
PCLAF. Interacts (via BRCT domains) with
BRIP1 (phosphorylated form). Interacts with
FANCD2 (ubiquitinated form). Interacts with
H2AFX (phosphorylated on 'Ser-140'). Interacts (via the BRCT domains) with
ACACA (phosphorylated form); the interaction prevents dephosphorylation of
ACACA. Part of a BRCA complex containing
BRCA1,
BRCA2 and
PALB2. Interacts directly with
PALB2; the interaction is essential for its function in HRR. Interacts directly with
BRCA2; the interaction occurs only in the presence of
PALB2 which serves as the bridging protein. Interacts (via the BRCT domains) with
LMO4; the interaction represses the transcriptional activity of
BRCA1. Interacts (via the BRCT domains) with
CCAR2 (via N-terminus); the interaction represses the transcriptional activator activity of
BRCA1 (By similarity). Interacts with
EXD2 (By similarity). Interacts (via C-terminus) with
DHX9; this interaction is direct and links
BRCA1 to the RNA polymerase II holoenzyme.
UniProt