G-protein-coupled receptor kinase-interacting protein 1 (GIT1) has been shown to be critical for spine morphogenesis and synapse formation through assembling and targeting multiprotein signaling complexes, which contain important actin regulators including PIX, Rac GEF, and PAK, between the sub-cellular compartments (Zhang et al. 2003). Activation of ephrinBs (EFNBs) by EPHB receptors may lead to the phosphorylation of GIT1 on Tyr392 (in humans Tyr385, based on sequence similarity). The Src-family kinases (SFKs) recruited to EFNB expression domains are involved in this phosphorylation. Tyr392 in the N-terminal of the SLD domain is required for GIT1s binding to the SH2 domain of GRB4 (Segura et al. 2007).