Defective MGAT2 does not transfer GlcNAc to N-glycans

Stable Identifier
Reaction [transition]
Homo sapiens
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Alpha-1,6-mannosyl-glycoprotein 2-beta-N-acetylglucosaminyltransferase (MGAT2) normally catalyses the transfer of a GlcNAc moiety onto the alpha,1,6 mannose of an alpha,1,4 branch of oligomannose N-glycans to form complex N-glycans (Tan et al. 1995). Defects in MGAT2 are associated with congenital disorder of glycosylation type IIa (MGAT2-CDG, CDG-2a; MIM:212066), a multisystem disorder caused by a defect in glycoprotein biosynthesis and characterised by under-glycosylated serum glycoproteins. Mutations that can cause MGAT2-CDG are S290F, H262R, C339*, N318D and K237N (Tan et al. 1996, Cormier-Daire et al. 2000, Alkuraya 2010, Alazami et al. 2012).

Literature References
PubMed ID Title Journal Year
22105986 Congenital disorder of glycosylation IIa: the trouble with diagnosing a dysmorphic inborn error of metabolism

Salih, MA, Hashem, M, Alzahrani, F, Alazami, AM, Meyer, BF, Monies, D, Alkuraya, FS

Am. J. Med. Genet. A 2012
8808595 Mutations in the MGAT2 gene controlling complex N-glycan synthesis cause carbohydrate-deficient glycoprotein syndrome type II, an autosomal recessive disease with defective brain development

Schachter, H, Dunn, J, Tan, J, Jaeken, J

Am J Hum Genet 1996
20684000 Mental retardation, growth retardation, unusual nose, and open mouth: an autosomal recessive entity

Alkuraya, FS

Am. J. Med. Genet. A 2010
7635144 The human UDP-N-acetylglucosamine: alpha-6-D-mannoside-beta-1,2- N-acetylglucosaminyltransferase II gene (MGAT2). Cloning of genomic DNA, localization to chromosome 14q21, expression in insect cells and purification of the recombinant protein

Leong, P, Squire, JA, D'Agostaro, AF, Schachter, H, Sarkar, M, Tan, J, Bendiak, B, Reck, F

Eur J Biochem 1995
11228641 Congenital disorders of glycosylation IIa cause growth retardation, mental retardation, and facial dysmorphism

Seta, N, Tan, J, Le Merrer, M, Durand, G, Vuillaumier-Barrot, S, Amiel, J, Munnich, A, Cormier-Daire, V

J. Med. Genet. 2000
Catalyst Activity

alpha-1,6-mannosylglycoprotein 2-beta-N-acetylglucosaminyltransferase activity of MGAT2 mutants [Golgi membrane]

Normal reaction
Functional status

Loss of function of MGAT2 mutants [Golgi membrane]

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