Recombinant Mouse Frizzled-7 Fc Chimera Protein, CF

Frizzled-7 is a member of the Frizzled family of unconventional G-protein-coupled glycoprotein receptors for the Wnt signaling pathway (1 ‑ 3). The Wnt genes encode a large family of glycoproteins that are essential in development and tissue maintenance (1, 2). Like other Frizzled family members, mouse Frizzled-7 contains a divergent N‑terminal signal peptide (amino acid (aa) 1 ‑ 32), a highly conserved extracellular cysteine-rich domain (CRD, aa 44 ‑ 169), a variable-length linker region (aa 170 ‑ 254), a seven-pass transmembrane region (aa 255 ‑ 547), and a variable-length C-terminal cytoplasmic domain (aa 548 ‑ 572) (1 ‑ 4). The CRD, which comprises the binding site for Wnts and other ligands such as Syndecan 4 and fibronectin, spans about 130 amino acid residues and contains ten invariant cysteine residues (2 ‑ 4). Expressed alone, it can compete with native Frizzled to inhibit Wnt canonical signaling (5). Within aa 33 ‑ 185, mouse Frizzled-7 shares ~99% aa identity with human, rat, canine and bovine Frizzled-7. Mature Frizzled-7 also shares 80% aa identity with Frizzled-1 and Frizzled-2. Roles for Frizzled-7 have been determined in both canonical Wnt/ beta-Catenin-mediated signaling and non‑canonical planar cell polarity and calcium pathways (1, 2, 5). During development, Frizzled-7 is expressed during gastrulation and in the fetal gut, kidney and lung where it is thought to influence tissue morphogenesis via non‑canonical signaling pathways (3 ‑ 6). In the adult, Frizzled-7 is expressed in skeletal muscle, especially in satellite cells that mediate muscle regeneration in response to Wnt7a (3, 4, 7). It is expressed in embryonic stem cells (ES), contributing to self-renewal signaling (8). It has been implicated in mesenchymal-to-epithelial transition in colorectal cancer (2, 9). Frizzled-7 mRNA has also been detected in adult heart and placenta (4).