Defective MAN1B1 does not hydrolyse a second 1,2-linked mannose (a branch)

Stable Identifier
R-HSA-9036008
Type
Reaction [transition]
Species
Homo sapiens
Compartment
endoplasmic reticulum quality control compartment
ReviewStatus
5/5
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Defective MAN1B1 does not hydrolyse a second 1,2-linked mannose (a branch)
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Endoplasmic reticulum mannosyl-oligosaccharide 1,2-alpha-mannosidase (MAN1B1) normally trims single mannose residues from misfolded glycoproteins, targeting them for degradation and thus providing a quality control process for N-glycosylated proteins. Defects in MAN1B1 can cause mental retardation, autosomal recessive 15 (MRT15; MIM:614202), a disorder resulting in nonsyndromic moderate to severe mental retardation. It is characterised by significantly below average intellectual functioning associated with impaired adaptative behaviour during the developmental period (Rafiq et al. 2010, Rafiq et al. 2011). Mutations that can cause MRT15 are E397K, W473* and R334C (Rafiq et al. 2010, Rafiq et al. 2011).
Literature References
PubMed ID Title Journal Year
21763484 Mutations in the alpha 1,2-mannosidase gene, MAN1B1, cause autosomal-recessive intellectual disability

Ullmann, R, Mahmood, K, Ramiah, A, Ropers, HH, Ishak, GE, Garshasbi, M, Ansar, M, Puettmann, L, Weksberg, R, Xiang, Y, Ayub, M, Kahrizi, K, Kuss, AW, Vincent, JB, Khan, MA, Hu, H, Moremen, KW, Tzschach, A, Kerio, NA, Naeem, F, Najmabadi, H, Noor, A, Ali, G, Rafiq, MA

Am. J. Hum. Genet. 2011
20345473 Mapping of three novel loci for non-syndromic autosomal recessive mental retardation (NS-ARMR) in consanguineous families from Pakistan

Shaheen, N, Noor, A, Scherer, SW, Amin-ud-Din, M, Ansar, M, Khan, MA, Mowjoodi, A, Rafiq, MA, Marshall, CR, Ali, G, Vincent, JB, Feuk, L

Clin. Genet. 2010
Participants
Input
Participates
as an event of
Catalyst Activity

mannosyl-oligosaccharide 1,2-alpha-mannosidase activity of MAN1B1 mutants [endoplasmic reticulum quality control compartment]

Physical Entity
MAN1B1 mutants [endoplasmic reticulum quality control compartment] (Homo sapiens)
Activity
mannosyl-oligosaccharide 1,2-alpha-mannosidase activity (GO:0004571)
Normal reaction
MAN1B1 hydrolyses a second 1,2-linked mannose (a branch) (Homo sapiens)
Functional status

Loss of function of MAN1B1 mutants [endoplasmic reticulum quality control compartment]

Normal Entity
Disease Entity
Status
Disease
Authored
Jassal, B  (2013-07-29)
Reviewed
Belaya, K  (2014-10-31)
Created
Jassal, B  (2013-10-29)
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