title: Cloning and molecular characterization of tick kynurenine aminotransferase (HlKAT) from Haemaphysalis longicornis (Acari: Ixodidae).
abstract: A complementary DNA coding a novel kynurenine aminotransferase (KAT) molecule from Haemaphysalis longicornis tick embryo was cloned and characterized. The transcription of the HlKAT occurs at all stages during tick development as well as in the midgut, salivary glands, ovary, and synganglion of adult ticks, and protein expression levels increased during the blood-feeding course. The HlKAT gene without signal peptide was successfully expressed as a glutathione S-transferase fusion protein in soluble form, which is capable of catalyzing the transamination of kynurenine and 3-hydroxykynurenine to kynurenic acid and xanthurenic acid, respectively. The purified recombinant HlKAT showed dose-dependent inhibition effect on the growth of equine babesial parasite, Babesia caballi, in in vitro culture. All results suggested that a specific HlKAT is present in tick and HlKAT may play an important physiological role in H. longicornis. This is the first report of a member enzyme of tryptophan pathway in Chelicerata.
authors.affiliation: Laboratory of Emerging Infectious Diseases, Department of Frontier Veterinary Medicine, Kagoshima University, Korimoto 1-23-24, Kagoshima-shi, Kagoshima, 890-0065, Japan.
authors.forename: Badgar
authors.initials: B
authors.lastname: Battsetseg
authors.forename: Damdinsuren
authors.initials: D
authors.lastname: Boldbaatar
authors.forename: Banzragch
authors.initials: B
authors.lastname: Battur
authors.forename: Xuenan
authors.initials: X
authors.lastname: Xuan
authors.forename: Kozo
authors.initials: K
authors.lastname: Fujisaki
mesh_terms: D000595:Amino Acid Sequence; D000825:Animal Structures / Q000737:chemistry; D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology; D001403:Babesia / Q000187:drug effects / Q000254:growth & development; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D004795:Enzyme Stability; D020869:Gene Expression Profiling; D006863:Hydrogen-Ion Concentration; D026863:Ixodidae / Q000201:enzymology* / Q000235:genetics; D007736:Kynurenic Acid / Q000378:metabolism; D007737:Kynurenine / Q000031:analogs & derivatives / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013379:Substrate Specificity; D013696:Temperature; D000637:Transaminases / Q000096:biosynthesis* / Q000235:genetics* / Q000302:isolation & purification; D014977:Xanthurenates / Q000378:metabolism
chemical_list: D000981:Antiprotozoal Agents; D018076:DNA, Complementary; D011994:Recombinant Proteins; D014977:Xanthurenates; C005045:3-hydroxykynurenine; D007737:Kynurenine; C028330:xanthurenic acid; D000637:Transaminases; C021481:kynurenine-oxoglutarate transaminase; D007736:Kynurenic Acid