RP2

The RP2 locus has been implicated as one cause of X-linked retinitis pigmentosa. The predicted gene product shows homology with human cofactor C, a protein involved in the ultimate step of beta-tubulin folding. Progressive retinal degeneration may therefore be due to the accumulation of incorrectly-folded photoreceptor or neuron-specific tubulin isoforms followed by progressive cell death [provided by RefSeq, Jul 2008]

Full Name

RP2, ARL3 GTPase Activating Protein

Function

Acts as a GTPase-activating protein (GAP) involved in trafficking between the Golgi and the ciliary membrane. Involved in localization of proteins, such as NPHP3, to the cilium membrane by inducing hydrolysis of GTP ARL3, leading to the release of UNC119 (or UNC119B). Acts as a GTPase-activating protein (GAP) for tubulin in concert with tubulin-specific chaperone C, but does not enhance tubulin heterodimerization. Acts as guanine nucleotide dissociation inhibitor towards ADP-ribosylation factor-like proteins.

Biological Process

Biological Process cilium assemblyTAS:Reactome
Biological Process post-Golgi vesicle-mediated transportManual Assertion Based On ExperimentIMP:MGI
Biological Process protein foldingManual Assertion Based On ExperimentTAS:UniProtKB
Biological Process protein transportIEA:UniProtKB-KW
Biological Process visual perceptionManual Assertion Based On ExperimentTAS:ProtInc

Cellular Location

Cell membrane
Cell projection, cilium
Detected predominantly at the plasma membrane of rod and cone photoreceptors. Not detected in the nucleus.

Involvement in disease

Retinitis pigmentosa 2 (RP2):
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.

PTM

Myristoylated on Gly-2; which may be required for membrane targeting.
Palmitoylated on Cys-3; which may be required for plasma membrane targeting (Probable). Mutation of Cys-3 targets the protein to internal membranes.