Unaltered prion protein cleavage in plasminogen-deficient mice

In normal brains and cultured cells, cellular prion. protein (PrPC) is partially found as N-terminally truncated fragments, designated C1 and C2. The cleavage of recombinant PrP to a fragment corresponding to CI can be mediated by the protease plasmin (PIn) in vitro, suggesting that plasmin might be responsible for the generation of the CI fragment in vivo as well. The cleavage pattern of PrPC found in both brain lysates and other tissues plasminogen knock-out mice, however, is unaltered. The presence of Cl fragment in homogenates from plasminogen-deficient mice in a comparable ratio with full-length PrPC as can be found in wildtype animals indicates that other proteases in addition to plasmin are responsible for PrPC cleavage in vivo. NeuroReport 17:527-530 (c) 2006 Lippincott Williams & Wilkins.