ARL3

ADP-ribosylation factor-like 3 is a member of the ADP-ribosylation factor family of GTP-binding proteins. ARL3 binds guanine nucleotides but lacks ADP-ribosylation factor activity.

Full Name

ADP Ribosylation Factor Like GTPase 3

Function

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).

Biological Process

Cilium assembly Source: UniProtKB
Golgi to plasma membrane transport Source: UniProtKB
Intraciliary transport Source: Ensembl
Kidney development Source: UniProtKB
Mitotic cytokinesis Source: UniProtKB
Photoreceptor cell development Source: UniProtKB
Positive regulation of microtubule polymerization Source: InterPro
Post-Golgi vesicle-mediated transport Source: MGI
Protein localization to ciliary membrane Source: UniProtKB
Protein localization to cilium Source: UniProtKB
Small GTPase mediated signal transduction Source: UniProtKB
Smoothened signaling pathway Source: Ensembl

Cellular Location

Spindle; Centrosome; Golgi apparatus membrane; Cytoplasm; Nucleus; Cilium. Detected predominantly in the photoreceptor connecting cilium. Present on the mitotic spindle. Centrosome-associated throughout the cell cycle. Not detected to interphase microtubules.

Involvement in disease

Joubert syndrome 35 (JBTS35): A form of Joubert syndrome, a disorder presenting with cerebellar ataxia, oculomotor apraxia, hypotonia, neonatal breathing abnormalities and psychomotor delay. Neuroradiologically, it is characterized by cerebellar vermian hypoplasia/aplasia, thickened and reoriented superior cerebellar peduncles, and an abnormally large interpeduncular fossa, giving the appearance of a molar tooth on transaxial slices (molar tooth sign). Additional variable features include retinal dystrophy, renal disease, liver fibrosis, and polydactyly. JBTS35 inheritance is autosomal recessive.
Retinitis pigmentosa 83 (RP83): An autosomal dominant form of retinitis pigmentosa, a retinal dystrophy belonging to the group of pigmentary retinopathies. Retinitis pigmentosa is characterized by retinal pigment deposits visible on fundus examination and primary loss of rod photoreceptor cells followed by secondary loss of cone photoreceptors. Patients typically have night vision blindness and loss of midperipheral visual field. As their condition progresses, they lose their far peripheral visual field and eventually central vision as well.