ID:NDP_HUMAN DESCRIPTION: RecName: Full=Norrin; AltName: Full=Norrie disease protein; AltName: Full=X-linked exudative vitreoretinopathy 2 protein; Flags: Precursor; FUNCTION: Activates the canonical Wnt signaling pathway through FZD4 and LRP5 coreceptor. Plays a central role in retinal vascularization by acting as a ligand for FZD4 that signals via stabilizing beta-catenin (CTNNB1) and activating LEF/TCF-mediated transcriptional programs. Acts in concert with TSPAN12 to activate FZD4 independently of the Wnt-dependent activation of FZD4, suggesting the existence of a Wnt-independent signaling that also promote accumulation the beta-catenin (CTNNB1). May be involved in a pathway that regulates neural cell differentiation and proliferation. Possible role in neuroectodermal cell-cell interaction. SUBUNIT: Interacts with FZD4. Component of a complex, at least composed of TSPAN12, FZD4 and norrin (NDP) (By similarity). Oligomer; disulfide-linked. SUBCELLULAR LOCATION: Secreted. TISSUE SPECIFICITY: Expressed in the outer nuclear, inner nuclear and ganglion cell layers of the retina, and in fetal and adult brain. DISEASE: Defects in NDP are the cause of Norrie disease (ND) [MIM:310600]; also known as atrophia bulborum hereditaria or Episkopi blindness. ND is a recessive disorder characterized by very early childhood blindness due to degenerative and proliferative changes of the neuroretina. Approximately 50% of patients show some form of progressive mental disorder, often with psychotic features, and about one-third of patients develop sensorineural deafness in the second decade. In addition, some patients have more complex phenotypes, including growth failure and seizure. DISEASE: Defects in NDP are the cause of vitreoretinopathy exudative type 2 (EVR2) [MIM:305390]. EVR2 is a disorder of the retinal vasculature characterized by an abrupt cessation of growth of peripheral capillaries, leading to an avascular peripheral retina. This may lead to compensatory retinal neovascularization, which is thought to be induced by hypoxia from the initial avascular insult. New vessels are prone to leakage and rupture causing exudates and bleeding, followed by scarring, retinal detachment and blindness. Clinical features can be highly variable, even within the same family. Patients with mild forms of the disease are asymptomatic, and their only disease related abnormality is an arc of avascular retina in the extreme temporal periphery. SIMILARITY: Contains 1 CTCK (C-terminal cystine knot-like) domain. WEB RESOURCE: Name=Mutations of the NDP gene; Note=Retina International's Scientific Newsletter; URL="http://www.retina-international.org/files/sci-news/ndgmut.htm"; WEB RESOURCE: Name=GeneReviews; URL="http://www.ncbi.nlm.nih.gov/sites/GeneTests/lab/gene/NDP";
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on Q00604
Front
Top
Side
The pictures above may be empty if there is no ModBase structure for the protein. The ModBase structure frequently covers just a fragment of the protein. You may be asked to log onto ModBase the first time you click on the pictures. It is simplest after logging in to just click on the picture again to get to the specific info on that model.
Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
US Server
Sequence and Links to Tools and Databases 
Common Gene Haplotype Alleles 
