Extrinsic Pathway of Apoptosis || 4K Animation

The extrinsic pathway of apoptosis activated through Fas death
receptors. Trimeric Fas ligands on the surface of a killer lymphocyte interact with trimeric Fas receptors on the surface of the target cell, leading to clustering of several ligand-bound receptor trimers (only one
trimer is shown here for clarity). Receptor clustering activates death domains on the receptor tails, which interact with similar
domains on the adaptor protein FADD (FADD stands for Fas-associated death domain). Each FADD protein then recruits an initiator caspase (caspase-8) via a death effector domain on both FADD and
the caspase, forming a death-inducing signaling complex (DISC). Within the DISC, two adjacent initiator caspases interact and cleave one another to form an activated protease dimer, which then cleaves itself in the region linking the protease to the death effector domain. This stabilizes and releases the active caspase dimer into the cytosol, where it activates executioner caspases by cleaving them.