Reconstitution in vitro of the GDP-fucose biosynthetic pathways of Caenorhabditis elegans and Drosophila melanogaster.
The deoxyhexose sugar fucose has an important fine-tuning role in regulating the functions of glycoconjugates in disease and development in mammals. The two genetic model organisms Caenorhabditis elegans and Drosophila melanogaster also express a range of fucosylated glycans, and the nematode particularly has a number of novel forms. For the synthesis of such glycans, the formation of GDP-fucose, which is generated from GDP-mannose in three steps catalysed by two enzymes, is required. By homology we have identified and cloned cDNAs encoding these two proteins, GDP-mannose dehydratase (GMD; EC 4.2.1.47) and GDP-keto-6-deoxymannose 3,5-epimerase/4-reductase (GER or FX protein; EC 1.1.1.271), from both Caenorhabditis and Drosophila. Whereas the nematode has two genes encoding forms of GMD (gmd-1 and gmd-2) and one GER-encoding gene (ger-1), the insect has, like mammalian species, only one homologue of each (gmd and gmer). This compares to the presence of two forms of both enzymes in Arabidopsis thaliana. All corresponding cDNAs from Caenorhabditis and Drosophila, as well as the previously uncharacterized Arabidopsis GER2, were separately expressed, and the encoded proteins found to have the predicted activity. The biochemical characterization of these enzymes is complementary to strategies aimed at manipulating the expression of fucosylated glycans in these organisms.
Rhomberg
Simone
S
Department für Chemie, Universität für Bodenkultur, Vienna, Austria.
Fuchsluger
Christina
C
Rendić
Dubravko
D
Paschinger
Katharina
K
Jantsch
Verena
V
Kosma
Paul
P
Wilson
Iain B H
IB
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000201:enzymology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D002238:Carbohydrate Epimerases / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D006154:Guanosine Diphosphate Fucose / Q000737:chemistry / Q000378:metabolism*; D006155:Guanosine Diphosphate Mannose / Q000031:analogs & derivatives / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
D029681:Arabidopsis Proteins; D029742:Caenorhabditis elegans Proteins; D018076:DNA, Complementary; D029721:Drosophila Proteins; D020033:Protein Isoforms; D006154:Guanosine Diphosphate Fucose; C054686:GDP-4-keto-6-deoxymannose; D006155:Guanosine Diphosphate Mannose; D006836:Hydro-Lyases; C044971:GDPmannose 4,6-dehydratase; D002238:Carbohydrate Epimerases; C407922:GER1 protein, Arabidopsis