BCAP (E1U9X) Rabbit mAb #63633

B cell adaptor for PI3K (BCAP) is a multidomain-containing signaling adaptor that is expressed by myeloid cells, B cells, and NK cells (1,2). Two major BCAP protein isoforms that differ significantly in size, BCAP-L and BCAP-S, have been shown to be expressed by macrophages, B cells, and NK cells (1,2). Although it remains unclear if there is a differential function for these isoforms, both BCAP-L and BCAP-S undergo robust tyrosine phosphorylation by multiple tyrosine kinases in response to B cell receptor and Toll-like receptor engagement, which promotes association of BCAP with multiple SH2- and SH3-domain-containing proteins (1,3,4). In the context of B cells, research studies have demonstrated that phosphorylation of the YXXM motifs within BCAP are critical for the recruitment and activation of PI3K to drive B cell proliferation (4,5). Macrophages, however, utilize the BCAP/PI3K signaling module to restrain proinflammatory functions in response to infection (3,6).