Fig. 6: Schematic model to explain our study.
From: Truncated LKB1 nonenzymatically enhances Fas-induced apoptosis by acting as a surrogate of Smac
Upon Fas activation, caspase-8 induces MOMP by cleaving BID, and then promotes the cytoplasmic release of Smac, resulting in XIAP inactivation and apoptosis (Left part). XIAP can also be degraded in a parallel pathway independent on MOMP and Smac release. In this case, caspase-8 cleaves LKB1 within its C-terminal region to release tLKB1. tLKB1 binds to and induces proteasomal degradation of XIAP. Lowering XIAP levels releases the break imposed on caspase-3 activation and apoptosis induction (Right part).
