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Death receptor and extrinsic death signaling

13 articles

Autoimmune lymphoproliferative syndrome

Autoimmune lymphoproliferative syndrome (ALPS, Canale-Smith syndrome) is a rare genetic immune disorder caused by defective FAS-mediated apoptosis, causing chronic lymphoproliferation, autoimmune cytopenias, elevated double-negative T cells, and increased lymphoma risk.

Death Receptor Signaling

Death Receptor Signaling: apoptosis pathway from TNFRSF death receptors (TNFR1, Fas/CD95, TRAIL-R1/2, DR3, DR6) via death domains, FADD, DISC, caspase-8; also NF-kappaB survival signaling.

Death-inducing signaling complex

Death-inducing signaling complex (DISC): the Fas/CD95 and TRAIL receptor (DR4/DR5) membrane platform of FADD, caspase-8/-10, and c-FLIP that activates caspase-8 by proximity-induced dimerization to start extrinsic apoptosis; structurally a 7:5 Fas-FADD DD oligomer with DED filaments.

Decoy death receptors

Decoy death receptors are TNF receptor superfamily members, such as DcR1 and DcR2, that bind death ligands like TRAIL but cannot trigger apoptosis because they lack a functional death domain.

FADD

FADD (Fas-associated via death domain) is a 208-amino-acid adaptor protein with N-terminal DED and C-terminal DD domains that assembles the death-inducing signaling complex, recruiting caspase-8/10 to death receptors like Fas, TRAILR, and TNFR1, and also regulates cell cycle, necroptosis, and tumor immunity.

Fas ligand

Fas ligand (FasL, CD95L, CD178, FASLG) is a 40 kDa type II transmembrane TNF-family ligand binding Fas/CD95; membrane-bound form drives apoptosis, inflammation, and immune privilege, while shed soluble FasL is largely antagonistic.

NKG2D

NKG2D (natural killer group 2 member D, Klrk1) is an activating lectin-like receptor on NK and CD8+ T cells that binds MICA/B and ULBP stress ligands, costimulates TCR signaling, and is targeted in cancer immunotherapy.

Osteoprotegerin

Osteoprotegerin (OPG, TNFRSF11B, OCIF) is a secreted TNF receptor superfamily decoy receptor that binds RANKL to block osteoclast formation, protecting bone mass; mutations cause juvenile Paget's disease.

RIPK1

RIPK1 (RIP, receptor-interacting protein kinase 1) is a 74 kDa serine/threonine kinase with a death domain that decides survival NF-κB signaling versus apoptosis and necroptosis downstream of TNFR1, and a clinical drug target.

TNF signaling

TNF signaling: pathways activated when TNF-α (tumor necrosis factor alpha) binds TNFR1 or TNFR2, driving NF-κB/MAPK survival, apoptosis via complex II, or RIPK1/RIPK3 necroptosis.

TRADD

TRADD (TNFR1-associated death domain protein), a 34 kDa adaptor with N-terminal TRAF-binding and C-terminal death domains, assembles TNFR1 complex I (TRAF2, RIPK1) for NF-κB and complex II with FADD for apoptosis.

TRAIL

TRAIL (TNF-related apoptosis-inducing ligand, Apo2L, CD253, TNFSF10) is a TNF-family cytokine that selectively induces apoptosis in tumor cells via death receptors DR4/DR5, with decoy receptors, immune surveillance roles, and cancer therapies like dulanermin.

Tumor necrosis factor

Tumor necrosis factor (TNF, TNFSF2): 17 kDa trimeric macrophage cytokine signaling via death-domain TNFR1 and survival-linked TNFR2; basis of the five-blocker anti-TNF drug class (~US $30 billion sales, 2022 estimate) and RIPK1-linked necroptosis research.