Breast cancer type 2 susceptibility protein (IPR015525)

Short name: BRCA2

Overlapping homologous superfamilies


Family relationships



The breast cancer type 2 susceptibility protein (BRCA2) is a breast tumour suppressor involved in double-strand break repair and/or homologous recombination [PMID: 12442171]. BRCA2 gene expression is regulated in a cell-cycle dependent manner and peak expression of BRCA2 mRNA occurring in S phase, suggesting BRCA2 may participate in regulating cell proliferation. BRCA2, and related protein BRCA1, have transcriptional activation potential and the two proteins are associated with the activation of double-strand break repair and/or homologous recombination. The two proteins have been shown to coexist and colocalize in a biochemical complex. BRCA2 has a number of 39 amino acid repeats [PMID: 8673099] that are critical for binding to RAD51 (a key protein in DNA recombinational repair) and resistance to methyl methanesulphonate treatment [PMID: 9405383, PMID: 9560268, PMID: 9811893]. There are eight repeats in BRCA2 designated as BRC1 to BRC8. BRC1, BRC2, BRC3, BRC4, BRC7, and BRC8 have high sequence identity and bind to Rad51, whereas BRC5 and BRC6 are less well conserved and are unable to bind Rad51 [PMID: 10551859]. It has been suggested that BRCA2 plays a role in positioning Rad51 at the site of DNA repair or in removing Rad51 from DNA once repair has been completed.

Mutations in BRCA1 and BRCA2 have been linked to an elevated risk of young onset breast cancer and confer a high risk of the disease through a dominantly inherited fashion [PMID: 20513136]. BRCA2 mutations are typically microdeletions.

Homologues exist in plants: the BRCA2A and BRCA2B proteins from Arabidopsis thaliana are required for repair of breaks in double-stranded DNA and homologous recombination and in the prophase stage of meiosis are required for formation of RAD51 and DMC1 foci in males [PMID: 22077663].

GO terms

Biological Process

GO:0006281 DNA repair
GO:0000724 double-strand break repair via homologous recombination

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.