Adhesion And Degranulation Promoting Adapter Protein (ADAP)

T-cell receptor signaling involves activation of the src protein-tyrosine kinases LCK and FYN, leading to the phosphorylation of various substrates including SLP76 (LCP2). Da Silva et al. (1993) identified FYB (called p120/130 by them), a 120- and 130-kD protein doublet that associates with the SH2 domain of FYN. T-cell receptor ligation led to increased tyrosine phosphorylation of FYB. Da Silva et al. (1997) showed that the 120- and 130-kD doublet is composed of 2 related isoforms of FYB. In T cells from FYN mutant mice, the phosphorylation of FYB was reduced, but not abolished, suggesting to da Silva et al. (1997) that FYB could be phosphorylated by another kinase. By screening a Jurkat T-cell line expression library with antibodies against FYB, da Silva et al. (1997) identified FYB cDNAs.