title: Interspecific comparisons reveal conserved features of the Drosophila Toll protein.
abstract: The Toll gene of Drosophila melanogaster produces a transmembrane cell adhesion protein that is required to establish the dorso-ventral axis of the embryo. The Toll protein's extracellular domain contains Leu-rich repeats (LRR), implicated in intermolecular interactions, and its large intracellular domain transduces a signal that eventually reaches the nucleus. Here, we report amino-acid (aa) sequences encoded by the Toll genes of D. pseudoobscura and D. virilis, and two distinct Toll-like genes of the grasshopper, Schistocerca americana. Interspecific comparisons show a Toll-specific subfamily of LRR, and a strikingly high degree of conservation in the cytoplasmic domain. Interestingly, many aa residues conserved among the insect Toll-like cytoplasmic domains are also conserved in mammalian and avian type-I interleukin-1 receptors and the hypothetical product of a transcript, MyD88, found in murine myeloid cells. Thus, we identify a set of conserved aa in the cytoplasmic domain which might be used in a signal-transduction pathway shared by invertebrates and vertebrates.
authors.affiliation: Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110.
authors.forename: M
authors.initials: M
authors.lastname: Yamagata
authors.forename: J P
authors.initials: JP
authors.lastname: Merlie
authors.forename: J R
authors.initials: JR
authors.lastname: Sanes
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence / Q000235:genetics; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins; D017344:Genes, Insect / Q000235:genetics*; D006110:Grasshoppers / Q000235:genetics; D007301:Insect Hormones / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface / Q000235:genetics*; D016415:Sequence Alignment; D017385:Sequence Homology; D013045:Species Specificity; D051193:Toll-Like Receptors
chemical_list: D029721:Drosophila Proteins; D007301:Insect Hormones; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C068721:Tl protein, Drosophila; D051193:Toll-Like Receptors