title: Cytoplasmic domain-mediated dimerizations of toll-like receptor 4 observed by beta-lactamase enzyme fragment complementation.
abstract: Toll-like receptors (TLRs) detect the presence of microbial challenge and initiate innate immune defensive responses. In this work we have explored the mechanism and role of TLR dimerization in signal transduction using the newly developed technique of beta-lactamase protein fragment complementation, among others. We observed that TLR4 interactions with itself, with MyD88, or with TLR2 were accurately reported by the enzyme complementation technique. That technique, as well as co-immunoprecipitation, transfection-initiated cell activation, and site-directed mutagenesis all suggest an important role for TLR intracellular domains in receptor dimerization. These findings broaden our understanding of TLR self-interactions as well as heterodimer formation.
authors.affiliation: Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: Hyun-Ku
authors.initials: HK
authors.lastname: Lee
authors.forename: Stefan
authors.initials: S
authors.lastname: Dunzendorfer
authors.forename: Peter S
authors.initials: PS
authors.lastname: Tobias
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000943:Antigens, Differentiation / Q000737:chemistry / Q000378:metabolism; D002460:Cell Line; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism*; D004247:DNA / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D019281:Dimerization; D005434:Flow Cytometry; D017930:Genes, Reporter; D005816:Genetic Complementation Test; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D008164:Luminescent Proteins / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D016297:Mutagenesis, Site-Directed; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000737:chemistry*; D011971:Receptors, Immunologic / Q000737:chemistry / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014162:Transfection; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000943:Antigens, Differentiation; D018076:DNA, Complementary; D008164:Luminescent Proteins; C507779:MYD88 protein, human; D008562:Membrane Glycoproteins; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D011993:Recombinant Fusion Proteins; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D049452:Green Fluorescent Proteins; D004247:DNA; D001618:beta-Lactamases