fig1

Figure 1. Structure of TRAIL receptors. TRAIL binds to death receptors DR4 (TRAIL-R1) and DR5 (TRAIL-R2) at the extracellular domains. The death domains (DD) on the cytoplasmic side lead to recruitment of other DD containing proteins that lead to apoptosis. TRAIL decoy receptors lack the cytoplasmic DD or have a truncated DD which fails to trigger apoptosis. OPG is a soluble receptor of TRAIL with low affinity.