N-Acetylgalactosaminyltransferase 1

N-Acetylgalactosaminyltransferase 1 (GALNT1) is a glycosyltransferase that initiates mucin-type O-glycosylation by transferring α-GalNAc from UDP-GalNAc to serine (Ser) or threonine (Thr) residues in proteins. Overexpression of N-Acetylgalactosaminyltransferase 1 in gastric cancer enhances the aberrant O-glycosylation of CD44, activating the Wnt/β-catenin signaling pathway and influencing the malignant behavior of gastric cancer cells. This enzyme plays a crucial role in cancer progression and metastasis by modifying the O-glycosylation of various glycoproteins such as mucin (MUC1), osteopontin (OPN), matrix metalloproteinase-14 (MMP14), and integrin α3.