title: Molecular fingerprinting of carbohydrate structure phenotypes of three porifera proteoglycan-like glyconectins.
abstract: Glyconectins (GNs) represent a new class of proteoglycan-like cell adhesion and recognition molecules found in several Porifera species. Physico-chemical properties of GN carbohydrate moieties, such as size, composition, and resistance to most glycosaminoglycan-degrading enzymes, distinguish them from any other type of known glycoproteins. The molecular mechanism of GN-mediated self/non-self discrimination function is based on highly species-specific and Ca(2+)-dependent GN to GN associations that approach the selectivity of the evolutionarily advanced immunoglobulin superfamily. Carbohydrates of glyconectins 1, 2, and 3 are essential for species-specific auto-aggregation properties in three respective Porifera species. To obtain a structural insight into the molecular mechanisms, we performed carbohydrate structural analyses of glyconectins isolated from the three sponge model systems, Microciona prolifera (GN1), Halichondria panicea (GN2), and Cliona celata (GN3). The glycan content of all three GNs ranged between 40 and 60% of their total mass. Our approach using sequential and selective chemical degradation of GN glycans and subsequent mass spectrometric and NMR analyses revealed that each glyconectin presents novel and highly species-specific carbohydrate sequences. All three GNs include distinct acid-resistant and acid-labile carbohydrate domains, the latter composed of novel repetitive units. We have sequenced four short sulfated and one pyruvilated unit in GN1, eight larger and branched pyruvilated oligosaccharides in GN2, which represent a heterogeneous but related family of structures, and four sulfated units in GN3.
authors.affiliation: Laboratoire des Processus Intégratifs Cellulaires, UMR 6037 CNRS, Faculté des Sciences et Techniques de Rouen, 76821 Mont St Aignan Cedex, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Guerardel
authors.forename: Xavier
authors.initials: X
authors.lastname: Czeszak
authors.forename: Lazar T
authors.initials: LT
authors.lastname: Sumanovski
authors.forename: Yannis
authors.initials: Y
authors.lastname: Karamanos
authors.forename: Octavian
authors.initials: O
authors.lastname: Popescu
authors.forename: Gerard
authors.initials: G
authors.lastname: Strecker
authors.forename: Gradimir N
authors.initials: GN
authors.lastname: Misevic
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000737:chemistry*; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D000431:Ethanol / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010641:Phenotype; D011134:Polysaccharides / Q000737:chemistry*; D011161:Porifera; D011485:Protein Binding; D011509:Proteoglycans / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002241:Carbohydrates; D015815:Cell Adhesion Molecules; D011134:Polysaccharides; D011509:Proteoglycans; D000431:Ethanol; D002118:Calcium