Proteolytic cleavage of beta-catenin by caspases: an in vitro analysis

Cleavage of structural proteins by caspases has been associated with the se vere morphological changes occurring during the apoptotic process. One of t he proteins regulating the connection of the actin filament with cadherins in a cell-cell adhesion complex is beta-catenin, During apoptosis, both an N-terminal and a small C-terminal part are removed from beta-catenin, Remov al of the N-terminal part may result in a disconnection of the actin filame nt from a cadherin cell-cell adhesion complex. We demonstrate that caspase- 8, -3 and -6 directly proteolyse beta-catenin in vitro, However, the beta-c atenin cleavage products generated by caspase-8 mere different from those g enerated by caspase-3 or caspase-6. Caspase-1, -2, -4/11 and -7 did not or only very inefficiently cleave beta-catenin. These data suggest that activa tion of procaspase-3, -6 or -8 by different stimuli in the cell might resul t in a differential proteolysis of beta-catenin, (C) 1999 Federation of Eur opean Biochemical Societies.