FYN-binding protein 1 (FYB1), also known as ADAP or SLAP, is an adapter protein in beta 1 integrin signalling and T lymphocyte migration []. It has been found to co-localise with F-actin in membrane ruffles, adhesion plaques/podosomes and phagocytic cups [, ]. In activated T cells, Fyb/SLAP associates with Ena/VASP family proteins and may link T cell signalling to the actin cytoskeleton remodelling []. FYB1 also interacts with mammalian actin binding protein 1 (mAbp1) that affects F-actin dynamics [].The SH3 domain of FYB adopts an altered fold referred to as a helically extended SH3 (hSH3) domain characterised by clusters of positive charges. The hSH3 domain can no longer bind conventional proline-rich peptides; instead, it functions as a novel lipid interaction domain and can bind acidic lipids such as phosphatidylserine, phosphatidylinositol, phosphatidic acid, and polyphosphoinositides [, , ].
