title: Effect of ganglioside GM3 synthase gene knockout on the glycoprotein N-glycan profile of mouse embryonic fibroblast.
abstract: The structural and clinical significance of cellular glycoproteins and glycosphingolipids (GSLs) are often separately discussed. Considering the biosynthetic pathway of glycoconjugates, glycans of cell-surface glycoproteins and GSLs might partially share functions in maintaining cellular homeostatis. The purpose of this study is to establish a general and comprehensive glycomics protocol for cellular GSLs and N-glycans of glycoproteins. To test the feasibility of a glycoblotting-based protocol, whole glycans released both from GSLs and glycoproteins were profiled concurrently by using GM3 synthase-deficient mouse embryonic fibroblast GM3(-/-). GM3(-/-) cells did not synthesize GM3 or any downstream product of GM3 synthase. Instead, expression levels of o-series gangliosides involving GM1-b and GD1-α increased dramatically, whereas a-/b-series gangliosides were predominantly detected in wild-type (WT) cells. We also discovered that glycoprotein N-glycan profiles of GM3(-/-) cells are significantly altered as compared to WT cells, although GM3 synthase is responsible only for GSLs synthesis and is not associated with glycoprotein N-glycan biosynthesis. The present approach allows for high-throughput profiling of cellular glycomes enriched by different classes of glycoconjugates, and our results demonstrated that gene knockout of the enzymes responsible for GSL biosynthesis significantly influences the N-glycans of glycoproteins.
authors.affiliation: Graduate School of Advanced Life Science, and Frontier Research Center for the Post-Genome Science and Technology, Hokkaido University, N21, W11, Sapporo 001-0021, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Nagahori
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yamashita
authors.forename: Maho
authors.initials: M
authors.lastname: Amano
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Nishimura
mesh_terms: D000818:Animals; D002460:Cell Line; D019295:Computational Biology / Q000379:methods*; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology*; D055786:Gene Knockout Techniques; D006023:Glycoproteins / Q000737:chemistry*; D006028:Glycosphingolipids / Q000378:metabolism; D051379:Mice; D011134:Polysaccharides / Q000378:metabolism*; D012799:Sialyltransferases / Q000172:deficiency* / Q000235:genetics*
chemical_list: D006023:Glycoproteins; D006028:Glycosphingolipids; D011134:Polysaccharides; D012799:Sialyltransferases; C021343:haematoside synthetase