Promotes guanine-nucleotide exchange on ARF1 and ARF3. Promotes the activation of ARF1/ARF3 through replacement of GDP with GTP. Involved in vesicular trafficking. Required for the maintenance of Golgi structure; the function may be independent of its GEF activity. Required for the maturaion of integrin beta-1 in the Golgi. Involved in the establishment and persistence of cell polarity during directed cell movement in wound healing. Proposed to act as A kinase-anchoring protein (AKAP) and may mediate crosstalk between Arf and PKA pathways. Inhibits GAP activity of MYO9B probably through competitive RhoA binding. The function in the nucleus remains to be determined (By similarity). Inhibited by brefeldin A. Homodimer. Interacts with ARFGEF2/BIG2; both proteins are probably part of the same or very similar macromolecular complexes. Interacts with FKBP2. Interacts with MYO9B. Interacts with PRKAR1A and PRKAR2A. Interacts with PPP1CC. Interacts with NCL, FBL, NUP62 and U3 small nucleolar RNA. Interacts with DPY30. Interacts with PDE3A. Interacts with KANK1. Interacts with TBC1D22A and TBC1D22B. Translocates from cytoplasm to membranes and nucleus upon cAMP treatment (By similarity). PRKAR1B. Phosphorylated. In vitro phosphorylated by PKA reducing its GEF activity and dephosphorylated by phosphatase PP1 (By similarity).