Promotes guanine-nucleotide exchange on ARF1, ARF5 and ARF6 (PubMed:18042453, PubMed:20080746). Promotes the activation of ARF factors through replacement of GDP with GTP (PubMed:18042453). Plays an important role in membrane trafficking, during junctional remodeling and epithelial polarization, through regulation of ARF6 activity (PubMed:20080746, PubMed:29420262). Interacts with TRIM23 and CYTIP (By similarity). Interacts (via coiled-coil domain) with FRMD4A (via coiled-coil domain)(PubMed:20080746). Interacts with FRMD4B (PubMed:20080746). Found in a complex with PARD3, CYTH1 and FRMD4A (PubMed:20080746). Interacts (via N-terminal domain) with INAVA (via N-terminal domain) (By similarity). Colocalized with TJP1 during epithelial polarization (PubMed:20080746). Expressed in colon and small intestine (at protein level). Binds via its PH domain to the inositol head group of phosphatidylinositol 3,4,5-trisphosphate. Autoinhibited by its C-terminal basic region. Ubiquitinated by SCF(FBXW11) E3 ubiquitin-protein ligase complex. Ubiquitination induces proteasomal degradation.