Involved in membrane protein trafficking at the base of the ciliary organelle. Mediates recruitment onto plasma membrane of the BBSome complex which would constitute a coat complex required for sorting of specific membrane proteins to the primary cilia. May regulate cilia assembly and disassembly and subsequent ciliary signaling events such as the Wnt signaling cascade. Isoform 2 may be required for proper retinal function and organization.
Involvement in disease
Defects in ARL6 are a cause of Bardet-Biedl syndrome type 3 (BBS3) [MIM:209900]. Bardet-Biedl syndrome (BBS) is a genetically heterogeneous disorder characterized by usually severe pigmentary retinopathy, early onset obesity, polydactyly, hypogenitalism, renal malformation and mental retardation. Secondary features include diabetes mellitus, hypertension and congenital heart disease. Defects in ARL6 are the cause of retinitis pigmentosa type 55 (RP55) [MIM:613575]. RP55 is 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.
Belongs to the small GTPase superfamily. Arf family.
Cell projection > cilium membrane. Cytoplasm > cytoskeleton > cilium axoneme. Cytoplasm > cytoskeleton > cilium basal body. Appears in a pattern of punctae flanking the microtubule axoneme that likely correspond to small membrane-associated patches. Localizes to the so-called ciliary gate where vesicles carrying ciliary cargo fuse with the membrane.