GTP-binding protein that recruits several effectors, such as golgins, arfaptins and Arf-GEFs to the trans-Golgi network, and modulates their functions at the Golgi complex (PubMed:9624189, PubMed:21239483, PubMed:27436755, PubMed:22679020, PubMed:27373159). Plays thereby a role in a wide range of fundamental cellular processes, including cell polarity, innate immunity, or protein secretion mediated by arfaptins, which were shown to play a role in maintaining insulin secretion from pancreatic beta cells (PubMed:22981988). The GTP-bound form interacts with GOLGA1 (By similarity). The GTP-bound form interacts with GOLGA4 and RGPD8. The GTP-bound form directly interacts with ARFIP2 (PubMed:11303027, PubMed:21239483, PubMed:22679020). Binds to SCOC, preferentially in its GTP-bound form. May interact with UNC119 (PubMed:11303027, PubMed:14580338). Interacts with ARFIP1; this interaction directs ARFIP1 to the trans-Golgi membranes (PubMed:21239483, PubMed:22981988). Interacts with ARFGEF1 (via N-terminus) (PubMed:27436755, PubMed:27373159). Detected in heart, liver, lung and liver (at protein level). Detected in fetal heart, lung, liver and kidney. Detected in adult heart, placenta, lung, liver, skeletal muscle, kidney and pancreas. Belongs to the small GTPase superfamily. Arf family.