Mannosyl (Alpha-1,3-)- Glycoprotein Beta-1,2-N-Acetylglucosaminyltransferase (MGAT1)

  • Pamela Stanley
Reference work entry


Early structural studies on glycoproteins revealed bi-, tri-, and tetra-antennary N-glycans in which GlcNAc residues were linked to a conserved trimannosyl core, prompting the search for the GlcNAc-transferases that catalyzed the addition of each GlcNAc residue. Mannosyl (alpha-1,3-)-glycoprotein beta-1,2-N-acetylglucosaminyltransferase I (MGAT1), originally termed N-acetylglucosaminyltransferase I, abbreviated GlcNAc-TI, was the first N-glycan branching GlcNAc-transferase for which an assay was developed (Gottlieb et al. 1975; Stanley et al. 1975). MGAT1 catalyzes the transfer of GlcNAc from UDP-GlcNAc to the terminal α1,3-linked Man in Man5GlcNAc2Asn to initiate the synthesis of hybrid and complex N-linked glycans in multicellular organisms (reviewed in Kornfeld and Kornfeld 1985). It is not found in yeast or bacteria. The human gene MGAT1 resides on chromosome 5q35 (Kumar et al. 1992), covering 25.12 kb, from 180,242,651 to 180,217,536 (NCBI 37, August 2010) on the reverse strand (Thierry-Mieg and Thierry-Mieg 2006). The mouse gene, Mgat1, is on chromosome 11 (Pownall et al. 1992). Northern blot analyses revealed two transcripts of ˜2.9 and ˜3.3 kb present in most mammalian tissues, with the shorter transcript predominating in liver, and the longer transcript in brain (Yang et al. 1994; Yip et al. 1997). However, the human MGAT1 locus is complex with 30 introns, seven predicted alternative promoters, ten validated poly[A] addition sites >30 transcripts that encode 11 protein isoforms, with three containing the complete coding sequence (Thierry-Mieg and Thierry-Mieg 2006). The coding region is in a single exon and the Mgat1 gene is ubiquitously expressed.


GlcNAc Residue Recombinant Glycoprotein Affinity Chromatography Step Lec1 Mutant Free GlcNAc 
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  1. Akama TO, Nakagawa H, Wong NK, Sutton-Smith M, Dell A et al (2006) Essential and mutually compensatory roles of (alpha)-mannosidase II and (alpha)-mannosidase IIx in N-glycan processing in vivo in mice. Proc Natl Acad Sci USA 103:8983–8988PubMedCrossRefGoogle Scholar
  2. Batista F, Lu L, Williams SA, Stanley P (2012) Complex N-Glycans are essential, but core 1 and 2 mucin O-Glycans, O-fucose lycans, and NOTCH1 are dispensable, for mammalian spermatogenesis. Biol Reprod 86(179):1–12Google Scholar
  3. Beheshti Zavareh R, Sukhai MA, Hurren R, Gronda M, Wang X, Simpson CD, Maclean N, Zih F, Ketela T, Swallow CJ, Moffat J, Rose DR, Schachter H, Schimmer AD, Dennis JW (2012) Suppression of cancer progression by MGAT1 shRNA knockdown. PLoS One 7:e43721PubMedCentralPubMedCrossRefGoogle Scholar
  4. Boscher C, Dennis JW, Nabi IR (2011) Glycosylation, galectins and cellular signaling. Curr Opin Cell Biol 23:383–392PubMedCrossRefGoogle Scholar
  5. Campbell RM, Metzler M, Granovsky M, Dennis JW, Marth JD (1995) Complex asparagine-linked oligosaccharides in Mgat1-null embryos. Glycobiology 5:535–543PubMedCrossRefGoogle Scholar
  6. Chaney W, Stanley P (1986) Lec1A Chinese hamster ovary cell mutants appear to arise from a structural alteration in N-acetylglucosaminyltransferase I. J Biol Chem 261:10551–10557PubMedGoogle Scholar
  7. Chen W, Stanley P (2003) Five Lec1 CHO cell mutants have distinct Mgat1 gene mutations that encode truncated N-acetylglucosaminyltransferase I. Glycobiology 13:43–50PubMedCrossRefGoogle Scholar
  8. Chen S, Zhou S, Sarkar M, Spence AM, Schachter H (1999) Expression of three Caenorhabditis elegans N-acetylglucosaminyltransferase I genes during development. J Biol Chem 274:288–297PubMedCrossRefGoogle Scholar
  9. Chen W, Unligil UM, Rini JM, Stanley P (2001) Independent Lec1A CHO glycosylation mutants arise from point mutations in N-Acetylglucosaminyltransferase I that reduce affinity for both substrates. Molecular consequences based on the crystal structure of GlcNAc-TI. Biochemistry 40:8765–8772PubMedCrossRefGoogle Scholar
  10. Gordon RD, Sivarajah P, Satkunarajah M, Ma D, Tarling CA et al (2006) X-ray crystal structures of rabbit N-acetylglucosaminyltransferase I (GnT I) in complex with donor substrate analogues. J Mol Biol 360:67–79PubMedCrossRefGoogle Scholar
  11. Gottlieb C, Baenziger J, Kornfeld S (1975) Deficient uridine diphosphate-N-acetylglucosamine:glycoprotein N-acetylglucosaminyltransferase activity in a clone of Chinese hamster ovary cells with altered surface glycoproteins. J Biol Chem 250:3303–3309PubMedGoogle Scholar
  12. Grigorian A, Mkhikian H, Demetriou M (2012) Interleukin-2, Interleukin-7, T cell-mediated autoimmunity, and N-glycosylation. Ann NY Acad Sci 1253:49–57PubMedCrossRefGoogle Scholar
  13. Hassinen A, Pujol FM, Kokkonen N, Pieters C, Kihlstrom M, Korhonen K, Kellokumpu S (2011) Functional organization of Golgi N- and O-glycosylation pathways involves pH-dependent complex formation that is impaired in cancer cells. J Biol Chem 286:38329–38340PubMedCrossRefGoogle Scholar
  14. Hoe MH, Slusarewicz P, Misteli T, Watson R, Warren G (1995) Evidence for recycling of the resident medial/trans Golgi enzyme, N-acetylglucosaminyltransferase I, in ldlD cells. J Biol Chem 270:25057–25063PubMedCrossRefGoogle Scholar
  15. Ioffe E, Stanley P (1994) Mice lacking N-acetylglucosaminyltransferase I activity die at mid-gestation, revealing an essential role for complex or hybrid N-linked carbohydrates. Proc Natl Acad Sci USA 91:728–732PubMedCrossRefGoogle Scholar
  16. Ioffe E, Liu Y, Stanley P (1996) Essential role for complex N-glycans in forming an organized layer of bronchial epithelium. Proc Natl Acad Sci USA 93:11041–11046PubMedCrossRefGoogle Scholar
  17. Ioffe E, Liu Y, Stanley P (1997) Complex N-glycans in MGAT1 null preimplantation embryos arise from maternal MGAT1 RNA. Glycobiology 7:913–919PubMedCrossRefGoogle Scholar
  18. Kornfeld R, Kornfeld S (1985) Assembly of asparagine-linked oligosaccharides. Annu Rev Biochem 54:631–664PubMedCrossRefGoogle Scholar
  19. Kumar R, Yang J, Larsen RD, Stanley P (1990) Cloning and expression of N-acetylglucosaminyltransferase I, the medial Golgi transferase that initiates complex N-linked carbohydrate formation. Proc Natl Acad Sci USA 87:9948–9952PubMedCrossRefGoogle Scholar
  20. Kumar R, Yang J, Eddy RL, Byers MG, Shows TB, Stanley P (1992) Cloning and expression of the murine gene and chromosomal location of the human gene encoding N-acetylglucosaminyltransferase I. Glycobiology 2:383–393, erratum Glycobiology (1999) 9:(8):ixPubMedCrossRefGoogle Scholar
  21. Meager A, Ungkitchanukit A, Nairn R, Hughes RC (1975) Ricin resistance in baby hamster kidney cells. Nature 257:137–139PubMedCrossRefGoogle Scholar
  22. Metzler M, Gertz A, Sarkar M, Schachter H, Schrader JW, Marth JD (1994) Complex asparagine-linked oligosaccharides are required for morphogenic events during post-implantation development. EMBO J J13:2056–2065Google Scholar
  23. Mkhikian H, Grigorian A, Li CF, Chen HL, Newton B et al (2011) Genetics and the environment converge to dysregulate N-glycosylation in multiple sclerosis. Nat Commun 2(334):1–13Google Scholar
  24. Narasimhan S, Stanley P, Schachter H (1977) Control of glycoprotein synthesis. LectiN-resistant mutant containing only one of two distinct N-acetylglucosaminyltransferase activities present in wild type Chinese hamster ovary cells. J Biol Chem 252:3926–3933PubMedGoogle Scholar
  25. Nishikawa Y, Pegg W, Paulsen H, Schachter H (1988) Control of glycoprotein synthesis. Purification and characterization of rabbit liver UDP-N-acetylglucosamine:α-3-d-mannoside β-1,2-N-acetylglucosaminyltransferase I. J Biol Chem 263:8270–8281PubMedGoogle Scholar
  26. Opat AS, Puthalakath H, Burke J, Gleeson PA (1998) Genetic defect in N-acetylglucosaminyltransferase I gene of a ricin-resistant baby hamster kidney mutant. Biochem J 336:593–598PubMedGoogle Scholar
  27. Oppenheimer CL, Hill RL (1981) Purification and characterization of a rabbit liver α,1,3 mannoside β1,2 N-acetylglucosaminyltransferase. J Biol Chem 256:799–804PubMedGoogle Scholar
  28. Pownall S, Kozak CA, Schappert K, Sarkar M, Hull E, Schachter H, Marth JD (1992) Molecular cloning and characterization of the mouse UDP-N-acetylglucosamine:α-3-D-mannoside β-1,2-N-acetylglucosaminyltransferase I gene. Genomics 12:699–704PubMedCrossRefGoogle Scholar
  29. Puthalakath H, Burke J, Gleeson PA (1996) Glycosylation defect in Lec1 Chinese hamster ovary mutant is due to a point mutation in N-acetylglucosaminyltransferase I gene. J Biol Chem 271:27818–27822PubMedCrossRefGoogle Scholar
  30. Robertson MA, Etchison JR, Robertson JS, Summers DF, Stanley P (1978) Specific changes in the oligosaccharide moieties of VSV grown in different lectiN-resistant CHO cells. Cell 13:515–526PubMedCrossRefGoogle Scholar
  31. Sarkar M, Hull E, Nishikawa Y, Simpson RJ, Moritz RL, Dunn R, Schachter H (1991) Molecular cloning and expression of cDNA encoding the enzyme that controls conversion of high-mannose to hybrid and complex N-glycans: UDP-N-acetylglucosamine: α-3-d-mannoside β-1,2-N-acetylglucosaminyltransferase I. Proc Natl Acad Sci USA 88:234–238PubMedCrossRefGoogle Scholar
  32. Sarkar M, Pagny S, Unligil U, Joziasse D, Mucha J, Glossl J, Schachter H (1998) Removal of 106 amino acids from the N-terminus of UDP-GlcNAc: α-3-d- mannoside β-1,2-N-acetylglucosaminyltransferase I does not inactivate the enzyme. Glycoconj J 15:193–197PubMedCrossRefGoogle Scholar
  33. Sarkar M, Iliadi KG, Leventis PA, Schachter H, Boulianne GL (2010) Neuronal expression of Mgat1 rescues the shortened life span of Drosophila Mgat11 null mutants and increases life span. Proc Natl Acad Sci USA 107:9677–9682PubMedCrossRefGoogle Scholar
  34. Schachter H (2010) Mgat1-dependent N-glycans are essential for the normal development of both vertebrate and invertebrate metazoans. Sem Cell Dev Biol 21:609–615CrossRefGoogle Scholar
  35. Schachter H, Boulianne G (2011) Life is sweet! A novel role for N-glycans in Drosophila lifespan. Fly 5:18–24PubMedCrossRefGoogle Scholar
  36. Shi S, Williams SA, Seppo A, Kurniawan H, Chen W, Ye Z, Marth JD, Stanley P (2004) Inactivation of the Mgat1 gene in oocytes impairs oogenesis, but embryos lacking complex and hybrid N-glycans develop and implant. Mol Cell Biol 24:9920–9929PubMedCentralPubMedCrossRefGoogle Scholar
  37. Song Y, Aglipay JA, Bernstein JD, Goswami S, Stanley P (2010) The bisecting GlcNAc on N-glycans inhibits growth factor signaling and retards mammary tumor progression. Cancer Res 70:3361–3371PubMedCentralPubMedCrossRefGoogle Scholar
  38. Stanley P (1983) Selection of lectin-resistant mutants of animal cells. Methods Enzymol 96:157–184PubMedCrossRefGoogle Scholar
  39. Stanley P (1984) Glycosylation mutants of animal cells. Annu Rev Genet 18:525–552PubMedCrossRefGoogle Scholar
  40. Stanley P (1989) Chinese hamster ovary cell mutants with multiple glycosylation defects for production of glycoproteins with minimal carbohydrate heterogeneity. Mol Cell Biol 9:377–383PubMedCentralPubMedGoogle Scholar
  41. Stanley P, Narasimhan S, Siminovitch L, Schachter H (1975) Chinese hamster ovary cells selected for resistance to the cytotoxicity of phytohemagglutinin are deficient in a UDP-N-. acetylglucosamine-glycoprotein N-acetylglucosaminyltransferase activity. Proc Natl Acad Sci USA 72:3323–3327PubMedCrossRefGoogle Scholar
  42. Tabas I, Schlesinger S, Kornfeld S (1978) Processing of high mannose oligosaccharides to form complex type oligosaccharides on the newly synthesized polypeptides of the vesicular stomatitis virus G protein and the IgG heavy chain. J Biol Chem 253:716–722PubMedGoogle Scholar
  43. Thierry-Mieg D, Thierry-Mieg J (2006) AceView: a comprehensive cDNA-supported gene and transcripts annotation. Genome Biol 7(Suppl 1):S12.1–14CrossRefGoogle Scholar
  44. Unligil UM, Zhou S, Yuwaraj S, Sarkar M, Schachter H, Rini JM (2000) X-ray crystal structure of rabbit N-acetylglucosaminyltransferase I, a key enzyme in the biosynthesis of N-linked glycans. EMBO J 19:5269–5280PubMedCrossRefGoogle Scholar
  45. von Schaewen A, Sturm A, O’Neill J, Chrispeels MJ (1993) Isolation of a mutant Arabidopsis plant that lacks N-acetylglucosaminyltransferase I and is unable to synthesize Golgi-modified complex N-linked glycans. Plant Physiol 102:1109–1118CrossRefGoogle Scholar
  46. Williams SA, Stanley P (2009) Oocyte-specific deletion of complex and hybrid N-glycans leads to defects in preovulatory follicle and cumulus mass development. Reproduction 137:321–331PubMedCentralPubMedCrossRefGoogle Scholar
  47. Yang J, Bhaumik M, Liu Y, Stanley P (1994) Regulation of N-linked glycosylation. Neuronal cell-specific expression of a 5′ extended transcript from the gene encoding N-acetylglucosaminyltransferase I. Glycobiology 4:703–712PubMedCrossRefGoogle Scholar
  48. Ye Z, Marth JD (2004) N-glycan branching requirement in neuronal and post-natal viability. Glycobiology 14:547–558PubMedCrossRefGoogle Scholar
  49. Yip B, Chen SH, Mulder H, Hoppener JW, Schachter H (1997) Organization of the human b-1,2-N-acetylglucosaminyltransferase I gene (MGAT1), which controls complex and hybrid N-glycan synthesis. Biochem J 321:465–474PubMedGoogle Scholar
  50. Zhong X, Cooley C, Seth N, Juo ZS, Presman E, Resendes N, Kumar R, Allen M, Mosyak L, Stahl M, Somers W, Kriz R (2012) Engineering novel Lec1 glycosylation mutants in CHO-DUKX cells: molecular insights and effector modulation of N-acetylglucosaminyltransferase I. Biotech Bioeng 109:1723–1734CrossRefGoogle Scholar
  51. Zhu S, Hanneman A, Reinhold VN, Spence AM, Schachter H (2004) Caenorhabditis elegans triple null mutant lacking UDP-N-acetyl-d-glucosamine:alpha-3-d-mannoside beta1,2-N-acetylglucosaminyltransferase I. Biochem J 382:995–1001PubMedCrossRefGoogle Scholar

Copyright information

© Springer Japan 2014

Authors and Affiliations

  1. 1.Department of Cell BiologyAlbert Einstein College of MedicineNew YorkUSA

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