RP2
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 a guanine nucleotide dissociation inhibitor towards ADP-ribosylation factor-like proteins.
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.
None
The disease is caused by variants affecting the gene represented in this entry.
Post-translational modifications
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.
Sequence Similarities
Belongs to the TBCC family.
Tissue Specificity
Ubiquitous. Expressed in the rod and cone photoreceptors, extending from the tips of the outer segment (OS) through the inner segment (IS) and outer nuclear layer (ONL) and into the synaptic terminals of the outer plexiform layer (ONL). Also detected in the bipolar, horizontal and amacrine cells in the inner nuclear layer (INL), extending to the inner plexiform layer (IPL) and though the ganglion cell layer (GCL) and into the nerve fiber layer (NFL) (at protein level).
Cellular localization
- Cell membrane
- Lipid-anchor
- Cytoplasmic side
- Cell projection
- Cilium
- Detected predominantly at the plasma membrane of rod and cone photoreceptors. Not detected in the nucleus.
Alternative names
Protein XRP2, RP2