TIRAP: an adapter molecule in the Toll signaling pathway.
Mammalian Toll-like receptors (TLRs) recognize conserved products of microbial metabolism and activate NF-kappa B and other signaling pathways through the adapter protein MyD88. Although some cellular responses are completely abolished in MyD88-deficient mice, TLR4, but not TLR9, can activate NF-kappa B and mitogen-activated protein kinases and induce dendritic cell maturation in the absence of MyD88. These differences suggest that another adapter must exist that can mediate MyD88-independent signaling in response to TLR4 ligation. We have identified and characterized a Toll-interleukin 1 receptor (TIR) domain-containing adapter protein (TIRAP) and have shown that it controls activation of MyD88-independent signaling pathways downstream of TLR4. We have also shown that the double-stranded RNA-binding protein kinase PKR is a component of both the TIRAP- and MyD88-dependent signaling pathways.
Horng
T
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Howard Hughes Medical Institute, Section of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA.
Barton
G M
GM
Medzhitov
R
R
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D000943:Antigens, Differentiation / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D003001:Cloning, Molecular; D018899:CpG Islands; D003713:Dendritic Cells / Q000276:immunology; D029721:Drosophila Proteins; D050956:HSP40 Heat-Shock Proteins; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D053594:Myeloid Differentiation Factor 88; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1 / Q000235:genetics* / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors; D019892:eIF-2 Kinase / Q000502:physiology
D048868:Adaptor Proteins, Signal Transducing; D000943:Antigens, Differentiation; C494651:DNAJC3 protein, human; D029721:Drosophila Proteins; D050956:HSP40 Heat-Shock Proteins; D008070:Lipopolysaccharides; C507779:MYD88 protein, human; D008562:Membrane Glycoproteins; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; C434984:TIRAP protein, human; C499045:TIRAP protein, mouse; C495345:TLR4 protein, human; C495371:TLR9 protein, human; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors; D019892:eIF-2 Kinase