Polypeptide N-acetylgalactosaminyltransferase 1 (GALNT1)

Polypeptide N-acetylgalactosaminyltransferase 1 (GALNT1) is a type II membrane-bound glycosyltransferase enzyme essential for catalyzing the first step in mucin-type O-linked glycosylation in the Golgi apparatus, specifically the transfer of an N-acetyl-D-galactosamine (GalNAc) residue to serine or threonine residues on extracellular and cell-surface proteins[2][3][5]. This process is critical for proper protein function, signaling, and extracellular matrix composition. GALNT1 is structurally characterized by an N-terminal transmembrane region, a stem, a catalytic domain, and a C-terminal lectin-like domain[2][3]. It has a broad substrate specificity, acting on mucin-derived peptides such as MUC1, MUC2, and MUC5AC[2]. Loss of GALNT1 activity leads to abnormal heart valve development, altered cell proliferation, and changes in extracellular matrix structure, and has been implicated in congenital heart disease and cancer (via the Tn-antigen biomarker)[1][4]. As of current literature, no drugs directly target GALNT1, but its central role in O-glycosylation and disease involvement mark it as a potential target for future therapeutic investigation[2][4].

Other names

GalNAc-T1pp-GaNTase 1polypeptide GalNAc transferase 1protein-UDP acetylgalactosaminyltransferase 1UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 1GALNAC-T1GALNT1

Not directly targeted by drugs for approved therapies as of current knowledge; mechanisms would involve inhibition or modulation of mucin-type O-glycosylation if targeted