After APC/C-mediated degradation of PTTG1 (securin), ESPL1 (separin i.e. separase) is rapidly autocatalytically cleaved after arginine residues at positions 1506 and 1535. The N-terminal and C-terminal fragments remain bound to each other after cleavage. It has not been examined what happens with the short middle fragment of ESPL1, so it is annotated as a part of the autocleaved ESPL1 complex. The autocatalytic cleavage of ESPL1 is not a prerequisite for the subsequent cleavage of the cohesin subunit RAD21 (Waizenegger et al. 2002).