Figure 2.

Identified protease cleavage sites in human FL-OPN (A,B). Schematic representation of cleavage sites of thrombin, MMPs, caspases, cathepsin D, and plasmin are separately indicated by black arrows. The amino acid sequences binding to different target receptors, including integrins and syndecan-4, are shown in black, gray, white, or dashed-line boxes (A). The target receptors for each binding sequence of OPN are listed (B). Abbreviations are OPN-a, a canonical isoform of human OPN among its splicing variants; Cas-,caspase; CD, cathepsin D; P, plasmin; and SP, signal peptides. “?”, unknown.