Recombinant Mouse MESDC2 Protein, CF

Mesoderm development candidate gene 2 (MESDC2, Mesd), also known as Boca in drosophila, is a 22 kDa protein that is required for formation of the primitive streak and mesoderm during embryogenesis (1 - 3). Mature mouse MESDC2 consists of an 83 amino acid (aa) structured central domain with flexible N- and C-terminal regions (4, 5). It shares 89% and 96% aa sequence identity with human and rat MESDC2, respectively. Although Boca lacks 34 aa in the C-terminal region and is only 40% identical with mouse MESDC2, the mouse protein can functionally substitute for Boca in drosophila S2 cells (6). A C-terminal ER retention motif localizes MESDC2 and Boca to the lumen of the endoplasmic reticulum (2, 6, 7). Within the ER, MESDC2 binds to the Wnt co-receptors LRP5 and LRP6 and is required for their proper folding and cell surface expression (2, 5, 8, 9). MESDC2 is therefore important for cellular Wnt responsiveness (9). When added extracellularly, MESDC2 binds to cell surface LRP6, preventing its interaction with the Wnt antagonist Dkk-1. This binding does not, however, trigger LRP6 internalization or alteration of cytoplasmic beta-catenin levels (8). An LRP5 mutant associated with high bone mass does not interact with MESDC2 (10). MESDC2 itself can be disrupted by a chromosomal translocation occurring in the germ cell tumor, infantile sacrococcygeal teratoma (11).