Recombinant Mouse Wnt-9a Protein

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Wnt-9a (Wingless integration region 9a; also Wnt-14) is a cysteine-rich member of the Wnt family of secreted glycoproteins (1-4).  This family is rather large at 19 members, and although it is most often associated with embryogenesis, the Wnt family is now known to be also important in a number of related processes, including angiogenesis, wound healing, tissue remodeling, and cancer (2, 5-8). Wnt-9a represents a paralog (common ancestor; different function) to Wnt-9b/Wnt-14b which, in the mouse, are found on the same chromosome (2, 4). The mouse Wnt-9a precursor is 365 amino acids (aa) in length. It contains a 29 aa signal sequence coupled to a 336 aa mature region (aa 30-365) that is characterized by the presence of 24 Cys residues, two palmitoylation sites (Cys93 and Ser221), and one presumably utilized glycosylation site at Asn103 (4, 9). The glycosylation and palmitoylation appear essential for secretion and activity. Based on studies with other Wnts, the palmitic acid at Cys93 is essential for frizzled/FZD4, 7 and 9, WIF-1 activation, while Ser221 is necessary for secretion (10). Although the exact mechanism(s) for secretion is unclear, it would appear that Wnt-9a initially binds to a select GPCR (Evi) in the Golgi. As a complex, it is transported to the plasma membrane in where it is inserted, internalized, and budded-off in a microvesicle that returns to the cell membrane for release as an exosome (11). Over the mature region, mouse Wnt-9a is identical in aa sequence to rat Wnt-9a and shares 98% aa sequence identity with human Wnt-9a (12). With respect to its paralog (Wnt-9b), mouse Wnt-9a and -9b share only 65% aa sequence identity in the mature region (4, 13). Cells known to express Wnt-9a, either inducibly or constitutively, include skeletal muscle (14, 15), limb-bud mesenchyme (16), mammary epithelium (17, 18), embryonic hepatic stellate/Ito and sinusoidal endothelial cells (19), and cranial osteoblasts (20). There are an extraordinary number of receptors/binding proteins that have been identified for members of the Wnt family (1, 21, 22). To date, Wnt-9a has been reported to bind to Fzd4, 7 and 9 (19), WIF-1 (16), and MuSK in conjunction with LRP4 (15). Functionally, Wnt-9a is best known for its participation in joint formation (but not initiation). During the formation of cartilaginous tissue, Wnt-9a contributes to the process of cavitation where chondrogenic tissue undergoes apoptosis and remodeling to create a functional space (interzone; precursor to a joint) (23). Elsewhere in the embryo, Wnt-9a is posited to induce hepatocyte proliferation and promote the generation of glycogen through enzyme activity regulation (19). In addition, Wnt-9a is reported to induce acetylcholine receptor clustering in newly formed myotubes (15).

Array 8148-WN

• Wnt-9a Antibodies
• Wnt-9a Lysate
• Wnt-9a Proteins and Enzymes