title: Sialome analysis of the cephalochordate Branchiostoma belcheri, a key organism for vertebrate evolution.
abstract: Sialic acid, a common terminal substitution of glycoconjugates, has been so far consistently identified in all vertebrates as well as in a growing number of bacterial species. It is assumed to be widely distributed among animal species of the deuterostome phylum, based on its identification in few echinoderm and all vertebrate species. However, whole sections of deuterostome, especially those intermediate species between invertebrates and vertebrates including cephalochordates, urochordates and hemichordates, are still unexplored in term of sialylation capacities. The discovery of functional sialic acid machinery in some of these species may shed new light onto the evolution of glycosylation capacities in deuterostome lineage. In a first approach, we investigated the sialylation pattern of a cephalocordate species, Branchiostoma belcheri, which occupies a strategic phylogenetic position to understand the transition of invertebrates toward vertebrates. Structural analysis of B. belcheri glycoconjugates established that this organism synthesizes large quantities of various sialic acids, some of which present rare or novel structures such as methylated sialic acids. These sialic acids were shown to be mainly associated with mono- and disialylated core 1-type O-glycans. Moreover, screening of the animal organs revealed the existence of exquisite tissue specificity in the distribution of sialic acids. Description of sialylation profiles was then correlated with the expression patterns of key enzymes involved in the biosynthesis of major forms of sialic acids, which provides the first complete overview of the sialylation patterns in cephalochordates.
authors: Université de Lille 1, Unité de Glycobiologie Structurale et Fonctionnelle, UGSF, F-59650 Villeneuve d'Ascq, France. yann.guerardel@univ-lille1.fr
authors: Yann
authors: Y
authors: Guérardel
authors: Lan-Yi
authors: LY
authors: Chang
authors: Akiko
authors: A
authors: Fujita
authors: Bernadette
authors: B
authors: Coddeville
authors: Emmanuel
authors: E
authors: Maes
authors: Chihiro
authors: C
authors: Sato
authors: Anne
authors: A
authors: Harduin-Lepers
authors: Kaoru
authors: K
authors: Kubokawa
authors: Ken
authors: K
authors: Kitajima
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002236:Carbohydrate Conformation; D002816:Chordata, Nonvertebrate / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006017:Glycolipids / Q000378:metabolism; D054794:Glycomics; D006023:Glycoproteins / Q000378:metabolism; D006031:Glycosylation; D008297:Male; D008745:Methylation; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D000216:N-Acylneuraminate Cytidylyltransferase / Q000235:genetics / Q000378:metabolism; D009928:Organ Specificity; D010053:Ovary / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D012794:Sialic Acids / Q000302:isolation & purification / Q000378:metabolism*; D012799:Sialyltransferases / Q000235:genetics / Q000378:metabolism; D013400:Sugar Acids / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D014158:Transcription, Genetic; D014714:Vertebrates / Q000235:genetics; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase
chemical_list: D006017:Glycolipids; D006023:Glycoproteins; D011134:Polysaccharides; D012794:Sialic Acids; D013400:Sugar Acids; C050008:3-deoxyglycero-galacto-nonulosonic acid; D006899:Mixed Function Oxygenases; C074383:CMPacetylneuraminate monooxygenase; D012799:Sialyltransferases; D000216:N-Acylneuraminate Cytidylyltransferase; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase