Human Fas/CD95 Protein, ECD (Extracellular Domain), Fc-fusion, Recombinant

Description :
Fas, also known as APO-1 and CD95, is a single-pass, type I transmembrane glycoprotein in the TNF receptor superfamily (TNFRSF6). Fas is highly expressed on epithelial cells, hepatocytes, activated mature lymphocytes, virus­transformed lymphocytes and tumor cells. Fas contains an extracellular domain (ECD) with three cysteine­rich repeats that mediates the interaction with Fas ligand (FasL) or TNFSF6, a type II transmembrane protein expressed on activated T cells, NK cells and other immune cells. The cytoplasmic region of Fas contains a death domain (DD), which is required for transducing apoptotic signals. Fas is also involved in the activation of NF-κB, ERK, JNK, and alternate pathways for T cell-mediated cytotoxicity. Fas is implicated in the pathogenesis of various malignancies and diseases of the immune system. Multiple Fas isoforms are derived from alternative splicing. For example, a soluble form that lacks the transmembrane domain is secreted by resting lymphocytes. Alternate shorter isoforms that lack the DD and have substitutions for cysteine-rich repeats are less prominently expressed. These isoforms can block the extrinsic apoptosis pathway induced by FasL. Fas is an essential mediator in the activation-induced death of T cells that terminates the immune reaction. In immune-privileged tissues, infiltrating Fas-bearing lymphocytes and inflammatory cells are killed by FasL engagement. Both humans and animals with genetic defects in Fas accumulate abnormal lymphocytes and develop systemic autoimmunity. Mutations in Fas are associated with autoimmune lymphoproliferative syndrome 1A (ALPS1A).