fig2

Figure 2. TRAIL-Induced Apoptosis: Cross talk between the Extrinsic and Intrinsic Pathways. TRAIL binding to death receptors leads to its trimerization on the cell surface and formation of DISC. Caspase-8 gets activated in the DISC and triggers the extrinsic pathway of apoptosis. Activated caspase-8 also leads to activation of the mitochondrial pathway or intrinsic pathway of apoptosis resulting in activation of caspase-9 and executioner caspases-3 and -7. Several checkpoints of apoptosis, like increase in anti-apoptotic proteins (IAPs), Bcl-xLetc are also represented at various stages of apoptosis. ATP: Adenosine triphosphate; DISC: Death Inducing Signaling Complex; FADD: Fas-associated death domain; MOMP: mitochondrial outer membrane permeabilization.