AIIt-dependent plasminogen activation. AIIt is expressed on the cell surface of a variety of cells and functions as a plasminogen receptor. AIIt consists of 2 molecules of ANXA2 bound together by a dimer of the protein S100A10. ANXA2 contains phospholipid-binding sites that anchor S100A10 to the cell surface membrane, whereas the C-terminal lysine residue of S100A10 binds tPA and plasminogen. S100A10 has also been shown to colocalize plasminogen with the uPA/uPAR complex. S100A10-induced colocalization of plasminogen with its activators accelerates the proteolytic cleavage of plasminogen, resulting in plasmin generation and therefore enhanced fibrinolytic activity. Both ANXA2 and S100A10 bind to plasmin, protecting it from inactivation by α₂-antiplasmin.