First Author | Xu Q | Year | 2004 |
Journal | Cell | Volume | 116 |
Issue | 6 | Pages | 883-95 |
PubMed ID | 15035989 | Mgi Jnum | J:107732 |
Mgi Id | MGI:3621833 | Doi | 10.1016/s0092-8674(04)00216-8 |
Citation | Xu Q, et al. (2004) Vascular development in the retina and inner ear: control by Norrin and Frizzled-4, a high-affinity ligand-receptor pair. Cell 116(6):883-95 |
abstractText | Incomplete retinal vascularization occurs in both Norrie disease and familial exudative vitreoretinopathy (FEVR). Norrin, the protein product of the Norrie disease gene, is a secreted protein of unknown biochemical function. One form of FEVR is caused by defects in Frizzled-4 (Fz4), a presumptive Wnt receptor. We show here that Norrin and Fz4 function as a ligand-receptor pair based on (1) the similarity in vascular phenotypes caused by Norrin and Fz4 mutations in humans and mice, (2) the specificity and high affinity of Norrin-Fz4 binding, (3) the high efficiency with which Norrin induces Fz4- and Lrp-dependent activation of the classical Wnt pathway, and (4) the signaling defects displayed by disease-associated variants of Norrin and Fz4. These data define a Norrin-Fz4 signaling system that plays a central role in vascular development in the eye and ear, and they indicate that ligands unrelated to Wnts can act through Fz receptors. |