[摘要]：Caspase-12, mainly detected in endoplasmic reticulum (ER), has been suggested to play a role in ER-mediated apoptosis and inflammatory caspase activation pathway Cleavage of the prodomain by caspase-3/7 at the carboxyl terminus of Asp94 or m-calpain at the carboxyl terminus of Lys158 was reported to be a part of caspase-12-involved apoptosis We biochemically characterized the prodomain-free forms of caspase-12 and the equivalent enzymes. Delta pro1(G95-D419), rev-Delta pro1[(T319-N419)-(G95-D318), a reverse form of Delta pro1] and rev-Delta pro2[(T319-N419)-(T159-D318)]. The three variants showed comparable activities which were dependent on salt concentration and pH Auto-proteolytic cleavage was observed at two sites (carboxyl termini of Asp318 and Asp320) in Delta pro1. Constitutively active forms of caspase-12 (rev-Delta pro1 and rev-Delta pro2) could induce cell death in cells transfected with the corresponding expression vectors, but no cleavage of caspase-3, DFF45 or Bid was observed, indicating caspase-12 may mediate a distinct apoptotic pathway rather than caspase-8 or -9-mediated cell death (C) 2010 Elsevier Inc All rights reserved
