Plays a role in the generation of neuronal polarity formation and axon growth (PubMed:24720729). Implicated in the formation of a single axon by developing neurons (PubMed:24720729). May inhibit the formation of additional axons by inhibition of PI3K in minor neuronal processes (By similarity). Plays a role in the formation of F-actin-enriched protrusive structures at the cell periphery (By similarity). Plays a role in cytoskeletal organization by regulating the subcellular localization of FSCN1 and DBN1 at axonal growth cones (PubMed:24720729). Promotes gastric cancer cell migration and invasion in a PAK1-dependent manner (By similarity). Interacts (via N-terminus) with FSCN1; this interaction induces neuron axon development (PubMed:24720729). Interacts with DBN1 (PubMed:24720729). Interacts with PAK1 (By similarity). Interacts (via C-terminus) with Ras-related Rab-5 proteins (By similarity). Interacts (via C-terminus) with Ras-related Rap-2 proteins (By similarity). Interacts with PIK3CA and PIK3R1 (By similarity). Accumulates in axon growth cones in a F-actin-dependent manner (PubMed:24720729). Colocalized with FSCN1 and F-actin at filipodia and lamellipodia of axonal growth cones (PubMed:24720729). Colocalized with DBN1 and F-actin at transitional domain of the axonal growth cone (PubMed:24720729). Colocalizes with PAK1, F-actin, myosins and integrins in invadopodia at the cell periphery (By similarity). Colocalized with Ras-related Rab-5 proteins in cytoplasmic vesicles (By similarity). Expressed in brain (at protein level) (PubMed:24720729). Expressed during the embryonic brain development from 11.5 dpc, onwards (PubMed:24720729). Expressed in the upper layers of the cortex at 11.5 dpc (PubMed:24720729). Expressed in the intermediate zone to the cortical plate of the cortex at 18.5 dpc (PubMed:24720729). Expressed in neurons (at protein level) (PubMed:24720729). Phosphorylated by PAK1. Isoform 1 is partially phosphorylated.