Acts as a guanine-nucleotide exchange factor (GEF). Promotes guanine-nucleotide exchange on ARF1, ARF3 and ARF6. Activates ARF factors through replacement of GDP with GTP (By similarity). The cell membrane form, in association with ARL4 proteins, recruits ARF6 to the plasma membrane . Involved in neurite growth (By similarity).
Subcellular locations: Cell membrane, Cytoplasm, Cell projection, Cell projection, Growth cone, Cell junction, Tight junction, Cell junction, Adherens junction
Both isoform 1 and isoform 2 are recruited to the cell membrane through its association with ARL4A, ARL4C and ARL4D. They require also interaction with phosphoinositides for targeting to plasma membrane . In differentiating neuroblastoma cells, colocalizes with CCDC120 in both neurite shaft and growth cone areas.
Widely expressed.