Fig. 1.

Glypican 3 structure: this represents the structural illustration of GPC-3 with 70-kDa core protein, attached to the cell surface via GPI anchor. The core protein is cleaved by furin at the Arg 358Cys 359 bond to generate two subunits: a 40-kDa N-terminal subunit and a 30-kDa C-terminal subunit with two HS side chains as appendages at S495 and S509. Both these subunits are linked to each other after cleavage by disulfide bonds. Ser560 is the cleavage site for GPI anchor and releases GPC-3 from the cell surface into the extracellular environment after cleavage by phospholipase D, a membrane-bound sheddase enzyme. GPC-3 Glypican-3, GPI glycosylphosphatidylinositol, HS heparan sulfate