Gene Review:
MOGS
-
mannosyl-oligosaccharide glucosidase
Homo sapiens
Synonyms:
CDG2B, CWH41, DER7, GCS1, Mannosyl-oligosaccharide glucosidase, ...
Ufficial name and symbols:
MOGS
Function
This is an enzyme in the N-glycosilation pathway; it is the first one of the 'trimming' step, right after the N-glycan sugar is attached to a nascent protein in the ER.
Proteins targeted for glycosilation are translated in the ER and modified on a target sequence (usually Asn-X-Ser/Thr) by adding a N-glycan precursor by the OST complex.
This precursor, after being attached to the nascent protein, is modified by a series of glucosidases like GCS1 and GANAB. The removal of glucoses by these enzimes is necessary for the retention of the protein in the ER, and it is a signal to indicate that the modification has occurred.
GCS1 (also known as MOGS) is the first of these glucosidases, the other one is GANAB, followed by other enzymes.
Function (from Uniprot)
Cleaves the distal alpha 1,2-linked glucose residue from the Glc3Man9GlcNAc2 oligosaccharide precursor in a highly specific manner.
Catalytic activity (from Uniprot)
Exohydrolysis of the non-reducing terminal glucose residues in the mannosyl-oligosaccharide Glc3Man9GlcNAc2.
Disease (from uniprot)
Defects in MOGS are the cause of type IIb congenital disorder of glycosylation (CDGIIb) [MIM: ]. This syndrome is also known as glucosidase I deficiency and is characterized by marked generalized hypotonia and hypomotility of the neonate, dysmorphic features, including a prominent occiput, short palpebral fissures, retrognathia, high arched palate, generalized edema, and hypoplastic genitalia. Symptoms of the infant included hepatomegaly, hypoventilation, feeding problems and seizures. The clinical course was progressive and the infant did not survive more than a few months.
Disease
All the diseases related to this gene are likely to affect both the correct protein folding for all the proteins in the secretory pathway, than the correct n-glycosilation.
High impact information on GCS1
- A human GCS1 cDNA reverted the Lec23 phenotype, whereas GCS1 cDNA carrying the lec23 mutation (S440F in human) did not [1].
- Mutations in the human GCS1 gene give rise to the congenital disorder of glycosylation termed CDG IIb [1].
- Serine at the analogous position is highly conserved in all GCS1 gene homologues [1].
References