SKAP1 (also known as SKAP55) is an immune cell-specific adaptor protein that plays an important role in T-cell adhesion, migration, and integrin clustering. It is expressed exclusively in T-lymphocytes, mast cells, and macrophages []. Binding partners include ADAP (adhesion and degranulation-promoting adaptor protein), Fyn, Riam, RapL, and RasGRP [, , ]. It contains a pleckstrin homology (PH) domain, a C-terminal SH3 domain, and several tyrosine phosphorylation sites. The SH3 domain of SKAP1 is necessary for its ability to regulate T-cell conjugation with antigen-presenting cells and the formation of LFA-1 clusters. SKAP1 binds primarily to a proline-rich region of ADAP through its SH3 domain; its degradation is regulated by ADAP. A secondary interaction occurs via the ADAP SH3 domain and the RKxxYxxY motif in SKAP1 [, ].This entry represents the SH3 domain of SKAP1.
This entry represents the SKAP (Src kinase-associated phosphoprotein) family, whose members include SKAP1 and SKAP2. They are adaptor proteins that have been implicated in cell adhesion through their association to integrins and cytoplasmic actin []. They contain an N-terminal coiled-coil conformation, a central PH domain and a C-terminal SH3 domain [].SKAP1 (also known as SKAP55) is required for microcluster persistence and movement, junctional stabilization, and integrin-independent adhesion via the T cell receptor (TCR). It interacts with RAPL and RIAM via its N-termianl dimerization (DM) domain. The K152 and D120 within the PH domain of SKAP55 regulate plasma membrane targeting and TCR-mediated activation of LFA-1 (lymphocyte function-associated antigen 1) [].SKAP2 (also known as RA70) is required for beta2 integrin-mediated neutrophil recruitment and functions [].
