title: UDP-N-acetylglucosamine transporter (SLC35A3) regulates biosynthesis of highly branched N-glycans and keratan sulfate.
abstract: SLC35A3 is considered the main UDP-N-acetylglucosamine transporter (NGT) in mammals. Detailed analysis of NGT is restricted because mammalian mutant cells defective in this activity have not been isolated. Therefore, using the siRNA approach, we developed and characterized several NGT-deficient mammalian cell lines. CHO, CHO-Lec8, and HeLa cells deficient in NGT activity displayed a decrease in the amount of highly branched tri- and tetraantennary N-glycans, whereas monoantennary and diantennary ones remained unchanged or even were accumulated. Silencing the expression of NGT in Madin-Darby canine kidney II cells resulted in a dramatic decrease in the keratan sulfate content, whereas no changes in biosynthesis of heparan sulfate were observed. We also demonstrated for the first time close proximity between NGT and mannosyl (α-1,6-)-glycoprotein β-1,6-N-acetylglucosaminyltransferase (Mgat5) in the Golgi membrane. We conclude that NGT may be important for the biosynthesis of highly branched, multiantennary complex N-glycans and keratan sulfate. We hypothesize that NGT may specifically supply β-1,3-N-acetylglucosaminyl-transferase 7 (β3GnT7), Mgat5, and possibly mannosyl (α-1,3-)-glycoprotein β-1,4-N-acetylglucosaminyltransferase (Mgat4) with UDP-GlcNAc.
authors.affiliation: Laboratory of Biochemistry, Faculty of Biotechnology, University of Wrocław, 2 Tamka Street, 50-137 Wrocław, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Maszczak-Seneczko
authors.forename: Paulina
authors.initials: P
authors.lastname: Sosicka
authors.forename: Teresa
authors.initials: T
authors.lastname: Olczak
authors.forename: Piotr
authors.initials: P
authors.lastname: Jakimowicz
authors.forename: Michał
authors.initials: M
authors.lastname: Majkowski
authors.forename: Mariusz
authors.initials: M
authors.lastname: Olczak
mesh_terms: D000818:Animals; D001483:Base Sequence; D001692:Biological Transport; D016466:CHO Cells; D002460:Cell Line; D045744:Cell Line, Tumor; D006224:Cricetinae; D003412:Cricetulus; D004285:Dogs; D031541:Fluorescence Resonance Energy Transfer; D005700:Galactosyltransferases / Q000235:genetics / Q000378:metabolism; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007632:Keratan Sulfate / Q000096:biosynthesis*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism; D011134:Polysaccharides / Q000096:biosynthesis*; D034622:RNA Interference; D017422:Sequence Analysis, DNA; D014539:Uridine Diphosphate Sugars / Q000378:metabolism; D000099237:UDP-Galactose Translocators
chemical_list: D005700:Galactosyltransferases; D016695:Glycosyltransferases; D007632:Keratan Sulfate; D026901:Membrane Transport Proteins; D009004:Monosaccharide Transport Proteins; D017351:N-Acetylglucosaminyltransferases; D011134:Polysaccharides; D014539:Uridine Diphosphate Sugars; D000099237:UDP-Galactose Translocators; C423446:UDP-N-acetylfucosamine; C121945:UDP-N-acetylglucosamine transporter; C111678:beta-1,4-galactosyltransferase IV; C052254:alpha-1,6-mannosylglycoprotein beta 1,6-N-acetylglucosaminyltransferase
keywords: Branched N-Glycans; Glycosylation; Glycosyltransferases; Golgi; Keratan; Proteoglycan; UDP-N-Acetylglucosamine Transporter