title: Sweet Tooth, a novel receptor protein-tyrosine kinase with C-type lectin-like extracellular domains.
abstract: A gene encoding a novel type of receptor protein-tyrosine kinase was identified in Hydra vulgaris. The extracellular portion of this receptor (which we have named Sweet Tooth) contains four C-type lectin-like domains (CTLDs). Comparison of the sequences of these domains with the sequences of the carbohydrate recognition domains of various vertebrate C-type lectins shows that Sweet Tooth CTLD1 and CTLD4 have amino acids in common with those shown to be involved in carbohydrate binding by the lectins. Comparison of sequences encoding CTLD1 from the Sweet Tooth genes from different species of Hydra shows variation in some of the conserved residues that participate in carbohydrate binding in C-type lectins. The Sweet Tooth gene is expressed widely in the Hydra polyp, and expression is particularly high in the endoderm of the tentacles. Treatment of polyps with peptides corresponding to sequences in the Sweet Tooth CTLDs results in the disintegration of the animal. These same peptides do not block adhesion or morphogenesis of Hydra cell aggregates.
authors.affiliation: Department of Biological Chemistry and the Developmental Biology Center, University of California, Irvine, California 92697-1700, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Reidling
authors.forename: M A
authors.initials: MA
authors.lastname: Miller
authors.forename: R E
authors.initials: RE
authors.lastname: Steele
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D019040:E-Selectin / Q000737:chemistry; D006829:Hydra / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D017403:In Situ Hybridization; D037102:Lectins / Q000737:chemistry; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000494:pharmacology; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D019040:E-Selectin; D037102:Lectins; D010446:Peptide Fragments; D020794:Receptor Protein-Tyrosine Kinases; C407344:sweet tooth protein, Hydra vulgaris