Mannosyl-oligosaccharide glucosidase (MOGS)

Mannosyl-oligosaccharide glucosidase (MOGS) is a membrane-bound glycoside hydrolase (EC 3.2.1.106) located in the endoplasmic reticulum of eukaryotic cells, where it catalyzes the hydrolytic removal of the terminal α-1,2-linked glucose residue from Glc​(_3)Man​(_9)GlcNAc​(_2) oligosaccharides[6]. This reaction is the first step in N-linked glycan processing during the maturation of nascent glycoproteins, prior to further glucose trimming and mannose removal[6]. Proper function of MOGS is essential for correct N-glycosylation, protein folding, and quality control, with loss-of-function mutations leading to rare congenital disorders of glycosylation that display severe multisystem involvement including neurological and immune phenotypes. Pharmacological inhibition of MOGS blocks N-glycan processing, which has been explored as an antiviral strategy for enveloped viruses and in some lysosomal storage diseases. Key attributes: - MOGS acts as glucosidase I, starting glycan trimming during N-glycosylation in the ER, crucial for proper glycoprotein maturation[6]. - Genetic defects in MOGS result in "MOGS-CDG" (Congenital Disorder of Glycosylation type IIb), characterized by developmental delay, immune deficiency, and hypogammaglobulinemia. - Inhibitors of MOGS have been studied for antiviral effects (HIV, hepatitis viruses) and in glycosphingolipid storage disorders by altering protein N-glycosylation. - Therapeutic targeting is challenged by potential toxicity due to universal importance of N-glycosylation for cell function. For clarity, this entry refers to *mannosyl-oligosaccharide glucosidase (MOGS)* and not to unrelated targets such as myelin oligodendrocyte glycoprotein (also abbreviated MOG)[6].

Other names

GCS1CWH41DER7glucosidase Iprocessing A-glucosidase ICDG2Bepididymis secretory sperm binding protein

Inhibition of glucosidase I, Interruption of N-glycan trimming, Blockage of viral glycoprotein maturation