Recombinant Human Glypican 2 Protein, CF

The glypicans (GPC) constitute a family of heparan sulfate proteoglycans that are attached to the cell surface by a glycosylphosphatidylinositol (GPI) anchor. Six members of this family have been identified in mammals (GPC1-GPC6). All glypican core proteins contain an N-terminal signal peptide, a large globular cysteine-rich domain (CRD) with 14 invariant cysteine residues, a stalk-like region containing the heparan sulfate attachment sites, and a C-terminal GPI attachment site. Based on the degree of their amino acid sequence similarity, two subfamilies of glypicans have been defined. One subfamily (sharing from 35-63% sequence homology) includes GPC1, 2, 4, and 6, while the second subfamily (sharing 54% sequence identity) includes GPC3 and 5. Proteins between the two subfamilies also share 17-25% sequence similarity (1-4). Glypicans are widely expressed in adult and fetal tissues. During embryonic development, the expression level of the various glypicans changes in a stage and tissue specific manner. GPC2, also known as cerebroglycan, is primarily expressed in developing neuronal tissues including the brain, spinal cord, dorsal root ganglia, and cranial nerves. It is found on the tracts of actively growing axons (5). Cell surface GPC2 binds midkine, indicating midkine-GPC2 interaction may participate in neuronal cell migration and neurite outgrowth (6).