Osteopontin at the Crossroads of Inflammation and Tumor Progression

Figure 2

Main domains of OPN. The cartoon depicts the functional parts of OPN. OPN binds two different classes of receptors, integrins (in blue) and CD44 (in pink). It can also interact with calcium (green). The SVVYGLR sequence is usually masked in the full-length molecule, but it becomes available upon thrombin cleavage of OPN. OPN undergoes several posttranslational modifications including glycosylation (red and green sugars), phosphorylation (yellow dots), crosslinking mediated by transglutaminase and protease cleavage (thrombin and MMPs). Each of these modifications can alter OPN functions.