Frizzled-4/CD344 Fc Chimera, CF

 Wnt signaling is involved in a variety of developmental processes including cell fate determination, cell polarity, tissue patterning and control of cell proliferation. Members of the Frizzled family of proteins serve as receptors for the Wnt signaling pathway. The founding member of this family was identified in Drosophilia based on its role in tissue polarity in the adult cuticle and named for the disorganized appearance of bristle hairs on the mutant. Mouse Frizzled-4 (mFrz-4) was originally cloned in a PCR screen to identify additional Frizzled family members in vertebrates. There are nine murine Frizzled genes and 10 human Frizzled genes identified to date. The predicted structure of Frizzled proteins is similar among all family members, containing a divergent N-terminal signal peptide, a highly conserved extracellular cysteine-rich domain, a variable-length linker region, a seven-pass transmembrane region, and a variable-length C-terminal tail. The most conserved regions of the Frizzled proteins are the extracellular cysteine-rich domain (CRD) which spans approximately 120 amino acid (aa) residues and contains 10 invariant cysteines, and the seven transmembrane domains. Mouse Frizzled-4 is 537 aa long and shows 97% and 93% aa identity to human and Xenopus Frizzled-4, respectively.