Q16394

EXT1(Exostosin 1) is an endoplasmic reticulum-resident type II transmembrane glycosyltransferase involved in the chain elongation step of heparan sulfate biosynthesis. EXT1 plays a crucial role in the biosynthesis of heparan sulfate, a glycosaminoglycan essential for various biological processes, including cell signaling, growth factor activity, and tissue development. By forming complexes with EXT2, EXT1 is localized in the Golgi apparatus, where EXT1 contributes to the polymerization of heparan sulfate, thereby influencing cellular interactions and the extracellular matrix. Mutations in EXT1 gene are associated with hereditary multiple exostoses, an autosomal dominant disorder characterized by the formation of cartilage-capped bony protrusions, which can lead to significant morbidity.