RP2 (XRP2)

RP2 acts as a GTPase-activating protein (GAP) involved in trafficking between the Golgi and the ciliary membrane. RP2 is 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). RP2 acts as a GTPase-activating protein (GAP) for tubulin in concert with tubulin-specific chaperone C, but does not enhance tubulin heterodimerization. RP2 acts as guanine nucleotide dissociation inhibitor towards ADP-ribosylation factor-like proteins.

RP2 (XRP2) Alternative Names

RP2, XRP2, NME10, TBCCD2, DELXp11.3, KIAA0215

Summaries for RP2 (XRP2)

Entrez Gene summary for RP2 (XRP2):

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]

OMIM - description for RP2 (XRP2):

Retinitis pigmentosa is characterized by constriction of the visual fields, night blindness, and fundus changes, including 'bone corpuscle' lumps of pigment. RP unassociated with other abnormalities is inherited most frequently (84%) as an autosomal recessive, next as an autosomal dominant (10%), and least frequently (6%) as an X-linked recessive in the white U.S. population (Boughman et al., 1980).

Wikipedia summary for RP2 (XRP2):

In mathematics, the real projective plane is an example of a compact non-orientable two-dimensional manifold, that is, a one-sided surface. It cannot be embedded in our usual three-dimensional space without intersecting itself. It has basic applications to geometry, since the common construction of the real projective plane is as the space of lines in R3 passing through the origin.
The plane is also often described topologically, in terms of a construction based on the Möbius strip: if one could glue the (single) edge of the Möbius strip to itself in the correct direction, one would obtain the projective plane. (This cannot be done in our three-dimensional space.) Equivalently, gluing a disk along the boundary of the Möbius strip gives the projective plane. Topologically, it has Euler characteristic 1, hence a demigenus (non-orientable genus, Euler genus) of 1.
Since the Möbius strip, in turn, can be constructed from a square by gluing two of its sides together, the real projective plane can thus be represented as a unit square (that is, [0,1] × [0,1] ) with its sides identified by the following equivalence relations:
(0, y) ~ (1, 1 − y) for 0 ≤ y ≤ 1
and
(x, 0) ~ (1 − x, 1) for 0 ≤ x ≤ 1,
as in the diagram on the right.

Human RP2 (XRP2) Protein General Information

 

• Protein names: RP2
• Sequence length: 350 AA.
• Sequence similarities: Belongs to the TBCC family.
  Contains 1 C-CAP/cofactor C-like domain.
• Post-translational modification: Myristoylated on Gly-2; which may be required for membrane targeting Probable.
  Palmitoylated on Cys-3; which may be required for plasma membrane targeting Probable. Mutation of Cys-3 targets the protein to internal membranes.
• Subunit structure: 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). Interacts with ARL3; interaction is direct and stimulated with the activated GTP-bound form of ARL3.
• Subcellular location: Cell membrane; Lipid-anchor; Cytoplasmic side. Cell projection › cilium. Note: Detected predominantly to the plasma membrane of rod and cone photoreceptors. Not detected in the nucleus.
• 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).
• Involvement in disease: Defects in RP2 are the cause of retinitis pigmentosa type 2 (RP2) ; also known as X-linked retinitis pigmentosa 2 (XLRP-2). RP leads to degeneration of retinal photoreceptor cells. 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.

General information above from UniProt

Function for RP2 (XRP2) Protein

UniProtKB:

RP2 acts as a GTPase-activating protein (GAP) involved in trafficking between the Golgi and the ciliary membrane. RP2 is 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). RP2 acts as a GTPase-activating protein (GAP) for tubulin in concert with tubulin-specific chaperone C, but does not enhance tubulin heterodimerization. RP2 acts as guanine nucleotide dissociation inhibitor towards ADP-ribosylation factor-like proteins.

Genatlas:

• RP2 is involved in beta-tubulin folding
• RP2 stimulates the GTPase activity of tubulin, but does not enhance tubulin heterodimerization
• RP2 acts as guanine nucleotide dissociation inhibitor for ARL3
• RP2 is DNA-binding protein that exhibits exonuclease activity, with a preference for single-stranded or nicked DNA substrates that occur as intermediates of base excision repair pathways
• RP2 may have previously unrecognized roles as a DNA damage response factor and 3' to 5' exonuclease
• RP2 may play a role in regulating vesicle traffic and docking
• RP2 plays a role in pericentriolar vesicle trafficking and intraflagellar transport
• RP2/NSF complex may play an important role in membrane protein trafficking in photoreceptors and other cells of the retina
• RP2 may be an important regulator of ciliary function through its association with polycystin 2
• RP2 is essential for ciliary function during vertebrate development
• RP2 and PKD2 function in a common developmental process

Homology for human RP2 (XRP2)

• ortholog to rp2, Danio rerio
• ortholog to RP2, Pan troglodytes
• ortholog to Rp2, Rattus norvegicus
• ortholog to Rp2, Mus musculus

Phenotype Information for RP2 (XRP2)

• Gene/Locus: RP2
• Phenotype: Retinitis pigmentosa 2

Phenotype Information for RP2 (XRP2) from OMIM (Online Mendelian Inheritance in Man)