Polypeptide N-acetylgalactosaminyltransferase 9 (GALNT9)

Polypeptide N-acetylgalactosaminyltransferase 9 (GALNT9) is an enzyme belonging to the GalNAc-T family that catalyzes the initial step in mucin-type O-linked glycosylation by transferring an N-acetylgalactosamine (GalNAc) residue to serine or threonine residues of target proteins, primarily in the Golgi apparatus[2][4]. GALNT9 expression is highly brain-specific, with highest levels in the cerebellum; its enzymatic activity and expression patterns are implicated in the regulation of neuronal function and brain health[1][2]. Decreased levels of GALNT9 and its glycosylation products are observed in the brains of mouse models of Parkinson's disease as well as in plasma from PD patients, suggesting GALNT9 and its activity as potential biomarkers for neurodegenerative diseases[1]. Research has also linked GALNT9 to autism spectrum disorder and Williams-Beuren syndrome, though direct causative roles and therapeutic interventions remain to be clarified[2]. GALNT9 supports cellular energy metabolism, actin cytoskeleton organization, and mitochondrial function in neuronal cells[1]. No drugs currently target GALNT9 directly, and clinical mechanisms of action or safety concerns related to drug targeting of GALNT9 have not been reported in the available literature[2][4].

Other names

GALNT9GalNAc-T9pp-GaNTase 9GALNAC-T9Polypeptide GalNAc transferase 9Protein-UDP acetylgalactosaminyltransferase 9UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 9GALNACT9