title: Expression of a functional Drosophila melanogaster N-acetylneuraminic acid (Neu5Ac) phosphate synthase gene: evidence for endogenous sialic acid biosynthetic ability in insects.
abstract: In this study, we report the first cloning and characterization of a N-acetylneuraminic acid phosphate synthase gene from Drosophila melanogaster, an insect in the protostome lineage. The gene is ubiquitously expressed at all stages of Drosophila development and in Schneider cells. Similar to the human homologue, the gene encodes an enzyme with dual substrate specificity that can use either N-acetylmannosamine 6-phosphate or mannose 6-phosphate to generate phosphorylated forms of both the sialic acids, N-acetylneuraminic acid and 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid, respectively, when expressed in either bacterial or baculoviral expression systems. The identification of a functional sialic acid synthase in Drosophila indicates that insects have the biosynthetic capability to produce sialic acids endogenously. Although sialylation is widely distributed in organisms of the deuterstome lineage, genetic evidence concerning the presence or absence of sialic acid metabolism in organisms of the protostome lineage has been lacking. Homology searches of the Drosophila genome identified putative orthologues of other genes required for sialylation of glycoconjugates.
authors.affiliation: Department of Biology, Temple University, Philadelphia, PA 19122, USA.
authors.forename: Kildong
authors.initials: K
authors.lastname: Kim
authors.forename: Shawn M
authors.initials: SM
authors.lastname: Lawrence
authors.forename: Jung
authors.initials: J
authors.lastname: Park
authors.forename: Lee
authors.initials: L
authors.lastname: Pitts
authors.forename: Willie F
authors.initials: WF
authors.lastname: Vann
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Betenbaugh
authors.forename: Karen B
authors.initials: KB
authors.lastname: Palter
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D017931:DNA Primers / Q000737:chemistry; D004331:Drosophila melanogaster / Q000201:enzymology*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D008969:Molecular Sequence Data; D007652:Oxo-Acid-Lyases / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012794:Sialic Acids / Q000096:biosynthesis*; D013379:Substrate Specificity
chemical_list: D017931:DNA Primers; D011994:Recombinant Proteins; D012794:Sialic Acids; C018767:N-acylneuraminate-9-phosphate synthase; D007652:Oxo-Acid-Lyases