May be involved in B-cell and macrophage adhesion processes. In B-cells, may act by coupling the B-cell receptor (BCR) to integrin activation. May play a role in src signaling pathway. Interacts with LAT, GRB2, PTK2B and PRAM1 (By similarity). Homodimer. Interacts with FYB1, which is required for SKAP2 protein stability. Interacts with PTPNS1. Part of a complex consisting of SKAP2, FYB1 and PTPNS1. Part of a complex consisting of SKAP2, FYB1 and LILRB3. May interact with actin. May interact with FYN, HCK and LYN. Interacts with FASLG (By similarity). Membrane ruffles of macrophages. Perikarya and dendrites from neurons. Expressed in kidney, lung, liver, spleen, bone marrow and testis. Present in T-cells, B-cells, and all cells of the myelomonocytic lineage. Present in all brain regions, with highest levels in neurons from the Purkinje cell layer, hippocampal gyrus, cortex and substantia nigra (at protein level). By IL-6 in myeloid cells. The SH3 domain interacts with FYB1 and PTK2B. Dephosphorylated on Tyr-75 by PTPN22 (By similarity). Phosphorylated by FYN on Tyr-260. In case of infection with Y.pseudotuberculosis, dephosphorylated by bacterial phosphatase yopH. Mice are healthy and do not display any obvious abnormality. They have normal T-cell, platelet and macrophage function, but show reduced levels of spontaneous immunoglobulins in the serum, and defects in B-cell proliferation. Belongs to the SKAP family.