Defective ALG12 does not add mannose to the N-glycan precursor

Stable Identifier
R-HSA-4720497
Type
Reaction [transition]
Species
Homo sapiens
Compartment
endoplasmic reticulum membrane, lumenal side of endoplasmic reticulum membrane
ReviewStatus
5/5
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Defective ALG12 does not add mannose to the N-glycan precursor
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Dol-P-Man:Man(7)GlcNAc(2)-PP-Dol alpha-1,6-mannosyltransferase (ALG12) (Chantret et al. 2002) normally tranfers the 8th mannose moiety to the lipid-linked oligosaccharide (LLO aka N-glycan precursor) which is required for subsequent N-glycosylation of proteins. Defects in ALG12 are associated with congenital disorder of glycosylation 1g (ALG12-CDG, CDG1g; MIM:607143), a multisystem disorder caused by a defect in glycoprotein biosynthesis and characterised by under-glycosylated serum glycoproteins (Chantret et al. 2002, Grubenmann et al. 2002). CDG type 1 diseases result in a wide variety of clinical features, such as defects in the nervous system development, psychomotor retardation, dysmorphic features, hypotonia, coagulation disorders, and immunodeficiency. Point mutations that can cause ALG12-CDG are F142V, T67M, R146Q, G101R, L158P and Y414* (Chantret et al. 2002, Grubenmann et al. 2002).
Literature References
PubMed ID Title Journal Year
11983712 Congenital disorders of glycosylation type Ig is defined by a deficiency in dolichyl-P-mannose:Man7GlcNAc2-PP-dolichyl mannosyltransferase

Chantret, I, Dupré, T, Delenda, C, Bucher, S, Dancourt, J, Barnier, A, Charollais, A, Heron, D, Bader-Meunier, B, Danos, O, Seta, N, Durand, G, Oriol, R, Codogno, P, Moore, SE

J Biol Chem 2002
12217961 ALG12 mannosyltransferase defect in congenital disorder of glycosylation type lg

Grubenmann, CE, Frank, CG, Kjaergaard, S, Berger, EG, Aebi, M, Hennet, T

Hum. Mol. Genet. 2002
Participants
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as an event of
Catalyst Activity

mannosyltransferase activity of ALG12 mutants [endoplasmic reticulum membrane]

Physical Entity
ALG12 mutants [endoplasmic reticulum membrane] (Homo sapiens)
Activity
mannosyltransferase activity (GO:0000030)
Normal reaction
ALG12 transfers Man to N-glycan precursor (GlcNAc)2 (Man)7 (PP-Dol)1 (Homo sapiens)
Functional status

Loss of function of ALG12 mutants [endoplasmic reticulum membrane]

Normal Entity
Disease Entity
Status
Disease
Cross References
Mondo
Authored
Jassal, B  (2013-10-21)
Reviewed
Belaya, K  (2014-10-31)
Created
Jassal, B  (2013-10-21)
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