Recombinant Mouse FZD4

Frizzled-4 (FZD4), also known as CD344 and EVR1, is a transmembrane glycoprotein of the Frizzled family within the G-protein coupled receptor superfamily. Members of this family encode seven transmembrane domain proteins that function as receptors for Wnt proteins. They can activate canonical Wnt/beta-catenin signaling as well as planar cell polarity and calcium flux pathways (1). FZD4 is particularly important in angiogenic Wnt pathway signaling and it is expressed in a variety of tissues (1). FZD4 is unusual in that it binds to Norrin, a non-wnt ligand, in addition to binding Wnt ligands (2). Mutations producing loss of function of either FZD4 or Norrin, result in blindness due to familial exudative vitreoretinopathy (FEVR). FZD4 also functions as a ligand-receptor pair to control vascular development in the retina and inner ear (3). FZD4 expression may play a critical role in responses to Wnt signaling in the tumor microenvironment (4).