TRAIL-R3 is characterized by its extracellular cysteine-rich domains that are responsible for binding TRAIL. Unlike other TRAIL receptors, TRAIL-R3 lacks an intracellular signaling domain, which means that it does not transduce an apoptosis signal upon binding to TRAIL . This unique feature classifies TRAIL-R3 as a “decoy” receptor, as it can bind to TRAIL without inducing cell death.
The primary function of TRAIL-R3 is to protect cells from TRAIL-induced apoptosis. By binding to TRAIL, TRAIL-R3 prevents TRAIL from interacting with other death receptors, such as TRAIL-R1 and TRAIL-R2, which do have the capability to induce apoptosis . This protective mechanism is crucial in regulating cell death and maintaining cellular homeostasis.
TRAIL-R3 is expressed in various tissues and has been shown to play a role in immune regulation and cancer biology. Its expression can protect normal cells from TRAIL-induced apoptosis, which is beneficial in preventing unwanted cell death. However, in the context of cancer, the overexpression of TRAIL-R3 can contribute to tumor resistance to TRAIL-based therapies .
Research on TRAIL-R3 has provided insights into its role in cancer therapy. By understanding how TRAIL-R3 interacts with TRAIL and other receptors, scientists aim to develop strategies to modulate its activity. For instance, targeting TRAIL-R3 to enhance TRAIL-induced apoptosis in cancer cells is a potential therapeutic approach .