May play a role in semaphorin signaling (By similarity). Functions as guanine nucleotide exchange factor for RAC1. Plays a role in the assembly and disassembly of dendritic filopodia, the formation of dendritic spines, regulation of dendrite length and ultimately the formation of synapses. Interacts with CADM1. Interacts with RAC1. Recruited to the cell membrane via interaction with CADM1. Detected in forbrain (at protein level). Highly expressed in forebrain during the first 15 days after birth, a period of intense synaptogenesis. Intramolecular interaction between the DH domain and the PH domains can stabilize the protein in an autoinhibited conformation.