Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit (DDOST) (OST48)

Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit (DDOST), also known as OST48, is a critical non-catalytic subunit of the oligosaccharyltransferase (OST) complex located in the endoplasmic reticulum membrane (UniProt: P39656). Its primary biological function is to facilitate the transfer of a high-mannose oligosaccharide from a dolichol-linked donor to specific asparagine residues on nascent polypeptides, a process known as N-linked glycosylation (PubMed: 25524443). This modification is essential for proper protein folding, stability, and intracellular trafficking. Beyond its role in glycosylation, OST48 (as AGER1) is involved in the clearance of advanced glycation end-products (AGEs), which are linked to inflammatory and oxidative stress pathways in diabetes and kidney disease (PubMed: 21832108). Mutations in the DDOST gene lead to congenital disorder of glycosylation type Ih (DDOST-CDG), characterized by multi-systemic clinical features including developmental delay and hypotonia (OMIM: 602202). While not a common target for current clinical therapeutics, the OST complex is a subject of research for its potential in treating certain cancers and viral infections where glycosylation is a key factor in pathogenesis, with small molecules like NGI-1 serving as experimental inhibitors (PubMed: 28234446).

Other names

DDOSTOligosaccharyltransferase 48 kDa subunitAGER1Advanced glycation end-product receptor 1WBP1 homologOST48

Inhibition of the oligosaccharyltransferase (OST) complex, thereby preventing the N-linked glycosylation of nascent proteins in the endoplasmic reticulum (PubMed: 28234446).