BCCIP

This gene product was isolated on the basis of its interaction with BRCA2 and p21 proteins. It is an evolutionarily conserved nuclear protein with multiple interacting domains. The N-terminal half shares moderate homology with regions of calmodulin and M-calpain, suggesting that it may also bind calcium. Functional studies indicate that this protein may be an important cofactor for BRCA2 in tumor suppression, and a modulator of CDK2 kinase activity via p21. This protein has also been implicated in the regulation of BRCA2 and RAD51 nuclear focus formation, double-strand break-induced homologous recombination, and cell cycle progression. Multiple transcript variants encoding different isoforms have been described for this gene.

Full Name

BRCA2 and CDKN1A interacting protein

Function

During interphase, required for microtubule organizing and anchoring activities. During mitosis, required for the organization and stabilization of the spindle pole (PubMed:28394342).
Isoform 2/alpha is particularly important for the regulation of microtubule anchoring, microtubule stability, spindle architecture and spindle orientation, compared to isoform 1/beta (PubMed:28394342).
May promote cell cycle arrest by enhancing the inhibition of CDK2 activity by CDKN1A. May be required for repair of DNA damage by homologous recombination in conjunction with BRCA2. May not be involved in non-homologous end joining (NHEJ).

Biological Process

DNA repair Source: UniProtKB-KW
Establishment of mitotic spindle orientation Source: UniProtKB
Microtubule anchoring Source: UniProtKB
Microtubule cytoskeleton organization Source: UniProtKB
Mitotic spindle assembly Source: UniProtKB
Mitotic spindle organization Source: UniProtKB
Neuroendocrine cell differentiation Source: UniProtKB
Regulation of cyclin-dependent protein serine/threonine kinase activity Source: MGI

Cellular Location

Centriole; Spindle pole; Nucleus. Colocalizes with BRCA2 in discrete nuclear foci (PubMed:15713648). In interphase, preferential localizes to the mother centriole (PubMed:28394342). Recruited to the spindle pole matrix and centrosome by microtubules and dynein/dynactin activity (PubMed:28394342).
Isoform 1: Centrosome; Spindle pole. Isoform 1/beta tends to be less abundant at, and less strongly associated with, centrosomes than isoform 2/alpha.
Isoform 2: Centrosome; Spindle pole. Isoform 2/alpha tends to be more abundant at, and more strongly associated with, centrosomes than isoform 1/beta.