Defective ALG8 does not add glucose to the N-glycan precursor

Stable Identifier
Reaction [transition]
Homo sapiens
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The probable dolichyl pyrophosphate Glc1Man9GlcNAc2 alpha-1,3-glucosyltransferase (ALG8) (Chantret et al. 2003) normally adds the second glucose moiety to the lipid-linked oligosaccharide precursor (LLO aka N-glycan precursor) which is required for subsequent N-glycosylation of proteins. Defects in ALG8 can cause congenital disorder of glycosylation 1h (ALG8-CDG, CDG-1h; MIM:608104), a multisystem disorder characterised by under-glycosylated serum glycoproteins (Chantret et al. 2003, Schollen et al. 2004). ALG8 deficiency is accompanied by an accumulation of the N-glycan precursor (Glc)1 (GlcNAc)2 (Man)9 (PP-Dol)1. Mutations that can cause ALG8-CDG include T47P, G275D, V133Sfs*3 and T138Kfs*19 (Chantret et al. 2003, Schollen et al. 2004).
Literature References
PubMed ID Title Journal Year
12480927 A deficiency in dolichyl-P-glucose:Glc1Man9GlcNAc2-PP-dolichyl alpha3-glucosyltransferase defines a new subtype of congenital disorders of glycosylation

Codogno, P, Chantret, I, Vuillaumier-Barrot, S, Oriol, R, Moore, SE, Danos, O, Bucher, S, Delenda, C, Durand, G, Seta, N, Dancourt, J, Ogier de Baulny, H, Dupré, T, Peletan, C

J. Biol. Chem. 2003
15235028 Clinical and molecular features of three patients with congenital disorders of glycosylation type Ih (CDG-Ih) (ALG8 deficiency)

Reyntjens, R, Hennet, T, Wevers, RA, Smeitink, J, Frank, CG, Matthijs, G, Keldermans, L, Winchester, BG, Grubenmann, CE, Clayton, PT, Schollen, E, Aebi, M

J Med Genet 2004
Catalyst Activity

dolichyl-phosphate-glucose-glycolipid alpha-glucosyltransferase activity of ALG8 mutants [endoplasmic reticulum membrane]

Normal reaction
Functional status

Loss of function of ALG8 mutants [endoplasmic reticulum membrane]

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