1ncf
A NEW PARADIGM FOR TUMOR NECROSIS FACTOR SIGNALLINGA NEW PARADIGM FOR TUMOR NECROSIS FACTOR SIGNALLING
Structural highlights
DiseaseTNR1A_HUMAN Defects in TNFRSF1A are the cause of familial hibernian fever (FHF) [MIM:142680; also known as tumor necrosis factor receptor-associated periodic syndrome (TRAPS). FHF is a hereditary periodic fever syndrome characterized by recurrent fever, abdominal pain, localized tender skin lesions and myalgia. Reactive amyloidosis is the main complication and occurs in 25% of cases.[1] [2] [3] [4] [5] Genetic variation in TNFRSF1A is associated with susceptibility to multiple sclerosis 5 (MS5) [MIM:614810. A multifactorial, inflammatory, demyelinating disease of the central nervous system. Sclerotic lesions are characterized by perivascular infiltration of monocytes and lymphocytes and appear as indurated areas in pathologic specimens (sclerosis in plaques). The pathological mechanism is regarded as an autoimmune attack of the myelin sheat, mediated by both cellular and humoral immunity. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia and bladder dysfunction. Genetic and environmental factors influence susceptibility to the disease. Note=An intronic mutation affecting alternative splicing and skipping of exon 6 directs increased expression of isoform 4 a transcript encoding a C-terminally truncated protein which is secreted and may function as a TNF antagonist.[6] FunctionTNR1A_HUMAN Receptor for TNFSF2/TNF-alpha and homotrimeric TNFSF1/lymphotoxin-alpha. The adapter molecule FADD recruits caspase-8 to the activated receptor. The resulting death-inducing signaling complex (DISC) performs caspase-8 proteolytic activation which initiates the subsequent cascade of caspases (aspartate-specific cysteine proteases) mediating apoptosis. Contributes to the induction of non-cytocidal TNF effects including anti-viral state and activation of the acid sphingomyelinase. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedActivation of the cell surface receptors for tumor necrosis factor (TNF) is effected by the aggregation of cytoplasmic domains that occurs when the extracellular domains of two or three receptors bind to trimeric TNF alpha or TNF beta. The structure of the type I TNF receptor extracellular domain (sTNF-R1), crystallized in the absence of TNF, has now been determined at 2.25-A resolution. The receptor itself is an elongated molecule comprising four disulfide-rich domains in a nearly linear array. Contrary to expectations, the unliganded domains are found to associate into dimers of two distinct types, in which monomers are related by local two-fold axes of symmetry. In one case, the receptors are antiparallel to each other and associate through an interface that overlaps the TNF binding site. If intact receptors were capable of such an association, their cytoplasmic domains would be separated by over 100 A. This interaction could inhibit signaling in the absence of TNF. Parallel dimers are also observed in which the dimer interface is well separated from the TNF binding site. Associations among TNF-bound parallel dimers could cause receptor clustering. Both dimers bury substantial areas of protein surface and are formed by polar and non-polar interactions. Crystallographic evidence for dimerization of unliganded tumor necrosis factor receptor.,Naismith JH, Devine TQ, Brandhuber BJ, Sprang SR J Biol Chem. 1995 Jun 2;270(22):13303-7. PMID:7768931[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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