Description
Death receptor-6 (DR6), also known as TNFRSF21, is a type I transmembrane protein and member of the death domain-containing TNFR superfamily. DR6 is expressed in most human tissues and the highest levels were detected in heart, brain, placenta, pancreas, thymus, lymph node and several non-lymphoid cancer cell lines. It functions as a regulatory receptor for mediating CD4(+) T cell activation and maintaining proper immune responses (1). DR6 interacts with the adaptor protein TRADD and mediates signal transduction through its death domain, and expression of DR6 in mammalian cells induces activation of both NF-κB and JNK and cell apoptosis (2). In addition, DR6 is uniquely cleaved from the cell surface of tumor cell lines by MMP-14, which is associated with tumor malignancy. The ligand for DR6 has not been identified