title: Serine/threonine kinase PKR: a sentinel kinase that discriminates a signaling pathway mediated by TLR4 from those mediated by TLR3 and TLR9.
abstract: Cells of the innate immune system discriminate between "noninfectious self" and "infectious nonself" via pattern recognition receptors known as Toll-like receptors (TLRs). Though TLRs and the related interleukin 1 receptors share considerable homology in their cytoplasmic domains and adaptor molecules, signaling cascades may substantially differ from one another depending on the adaptor proteins recruited. Here we show that ectopic overexpression of catalytically inactive dominant-negative PKR expression system suppressed NF- kappa B activation mediated by TLR3, TLR9, TNF receptor 1 and 2 (TNF-R 1/2), but not by TLR4. Physiological relevance of the observations described here are discussed.
authors.affiliation: Department of Anesthesiology, Aichi Medical University, Nagoya, Japan. yasakura@aichi-med-u.ac.jp
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Asakura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Naoko
authors.initials: N
authors.lastname: Kato
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sato
authors.forename: Toru
authors.initials: T
authors.lastname: Komatsu
mesh_terms: D000818:Animals; D002460:Cell Line; D005786:Gene Expression Regulation; D017930:Genes, Reporter / Q000235:genetics; D008024:Ligands; D051379:Mice; D015398:Signal Transduction; D051196:Toll-Like Receptor 3 / Q000378:metabolism*; D051197:Toll-Like Receptor 4 / Q000378:metabolism*; D051217:Toll-Like Receptor 9 / Q000378:metabolism*; D019892:eIF-2 Kinase / Q000235:genetics / Q000378:metabolism*
chemical_list: D008024:Ligands; D051196:Toll-Like Receptor 3; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9; D019892:eIF-2 Kinase