Small GTP-binding protein which cycles between an inactive GDP-bound and an active GTP-bound form, and the rate of cycling is regulated by guanine nucleotide exchange factors (GEF) and GTPase-activating proteins (GAP) (PubMed:16525022, PubMed:18588884). Required for normal cytokinesis and cilia signaling (PubMed:22085962). Requires assistance from GTPase-activating proteins (GAPs) like RP2 and PDE6D, in order to cycle between inactive GDP-bound and active GTP-bound forms. Required for targeting proteins to the cilium, including myristoylated NPHP3 and prenylated INPP5E (PubMed:30269812). Targets NPHP3 to the ciliary membrane by releasing myristoylated NPHP3 from UNC119B cargo adapter into the cilium (PubMed:22085962). Required for PKD1:PKD2 complex targeting from the trans-Golgi network to the cilium (By similarity). Found in a complex with ARL3, RP2 and UNC119 (or UNC119B); RP2 induces hydrolysis of GTP ARL3 in the complex, leading to the release of UNC119 (or UNC119B) (PubMed:11303027, PubMed:11847227, PubMed:18588884). Interacts with RP2; interaction is direct and stimulated with the activated GTP-bound form of ARL3 (PubMed:16472755). Interacts with SYS1 (PubMed:11303027, PubMed:11847227, PubMed:15077113). The GTP-bound form interacts with ARL2BP and PDE6D (PubMed:11303027, PubMed:11847227). Microtubule-associated protein (PubMed:11303027, PubMed:16525022). May interact with GOLGA4 (PubMed:11303027). Interacts with GGA1; the interaction recruits PKD1:PKD2 complex to trans-Golgi network and is required for ciliary targeting of PKD1:PKD2 complex (By similarity). Interacts with DNAAF9 (PubMed:22085962). Detected predominantly in the photoreceptor connecting cilium. Present on the mitotic spindle. Centrosome-associated throughout the cell cycle. Not detected to interphase microtubules. Expressed in the retina. Strongly expressed in connecting cilium, the myoid region of the inner segments (IS) and in cone photoreceptors (at protein level). The disease is caused by variants affecting the gene represented in this entry. The disease may be caused by variants affecting the gene represented in this entry. Belongs to the small GTPase superfamily. Arf family.