Breast Cancer Anti-Estrogen Resistance 1 (BCAR1)

BCAR1, or CAS, is an Src family kinase substrate involved in various cellular events, including migration, survival, transformation, and invasion. The predicted 870-amino acid BCAR1 protein has a calculated mass of 93 kD. BCAR1 contains an SH3 domain in its N-terminal part, multiple potential tyrosine phosphorylation sites in its central part, and a proline-rich stretch in its C-terminal part.

BCAR1 shares 91% amino acid identity with rat and mouse p130Cas. SDS-PAGE and Western blot analyses demonstrated that BCAR1 encodes a 116-kD protein; the mouse and rodent p130Cas proteins exhibit the same size. BCAR1 transcript in all tissues tested, with highest expression in testis and low expression in liver, thymus, and peripheral blood leukocytes.