Familial exudative vitreoretinopathy (FEVR) is a disease state characterized by aberrant retinal angiogenesis. Norrin-induced activation of Frizzled-4 (Fz4) has a major role in regulating beta-catenin levels in the eye that, in turn, modulate the blood retina barrier (BRB). Here we gain insight on the basis of the pathology of a FEVR implicated F328S Fz4 mutant by study. The receptor exhibits a substantially reduced ability to activate Lef/Tcf-dependent transcription. This impaired activation correlates with a decreased ability to stabilize and recruit Dishevelled-2 (Dvl2) to the cell surface. Aromaticity at position 328 of the intracellular loop 2 (iloop2) is revealed similarly as a prerequisite for Dvl2 recruitment to the Fz4. This aromaticity at 328 enables normal Norrin-induced canonical activation. The corresponding position in iloop2 of other Frizzleds likely functions in Dvl recruitment.
Keyphrases
- cell surface
- high glucose
- transcription factor
- diabetic rats
- endothelial cells
- diabetic retinopathy
- early onset
- age related macular degeneration
- epithelial mesenchymal transition
- optical coherence tomography
- drug induced
- reactive oxygen species
- single cell
- optic nerve
- cell proliferation
- oxidative stress
- vascular endothelial growth factor
- sensitive detection
- binding protein
- stress induced