Alpha-1,2-mannosyltransferase ALG9 (ALG9)

Alpha-1,2-mannosyltransferase ALG9 (ALG9) is an endoplasmic reticulum membrane enzyme critical for N-linked glycosylation of proteins. It catalyzes the addition of mannose residues to lipid-linked oligosaccharides, which are precursors necessary for proper protein folding and cellular quality control. Mutations in ALG9 cause congenital disorders of glycosylation type IL (CDG-IL), associated with multi-organ dysfunction, and have recently been linked to polycystic kidney and liver diseases. The enzyme’s activity is fundamental for glycoprotein biosynthesis, and its absence or dysfunction leads to defective N-glycosylation, accumulated misfolded proteins, and pathological organ morphology. ALG9 is essential and currently no therapeutics target its function directly, though genetic diagnosis informs patient care in relevant syndromes.

Other names

Asparagine-linked glycosylation protein 9 homologDisrupted in bipolar disorder protein 1DIBD1Dol-P-Man:Man(6)GlcNAc(2)-PP-Dol alpha-1,2-mannosyltransferaseDol-P-Man:Man(8)GlcNAc(2)-PP-Dol alpha-1,2-mannosyltransferaseLoss of heterozygosity, 11, chromosomal region 1 gene J productGillessen-Kaesbach-Nishimura syndrome geneCDG1LLOH11CR1JGIKANISEC 2.4.1.259EC 2.4.1.261