Polypeptide N-acetylgalactosaminyltransferase 12 (GALNT12)

Polypeptide N-acetylgalactosaminyltransferase 12 (GALNT12) is an enzyme responsible for catalyzing the transfer of N-acetylgalactosamine from UDP-GalNAc to serine or threonine residues in polypeptides. This reaction is the first step in mucin-type O-glycosylation, which is essential for normal gastrointestinal function. GALNT12 is functionally unique within its family for its specificity towards densely glycosylated substrates, facilitated by coordinated interactions between its catalytic and lectin domains. Mutations in GALNT12 have been identified in subsets of patients with colorectal cancer, where they disrupt the enzyme's catalytic activity or alter substrate selectivity, implicating GALNT12 as a tumor suppressor and potential biomarker in colorectal cancer. The enzyme’s active site comprises canonical residues and is stabilized by domain interactions and specific substrate positions. It is classified as a glycosyltransferase (enzyme) involved in protein modification and signaling, with disease associations focused on cancer, particularly colorectal cancer.

Other names

GALNT12ppGaNTase-T12GLT12

For hypothetical drugs, mechanism of action would include inhibition or modulation of O-glycosylation catalyzed by GALNT12, thus affecting mucin functions and possibly cancer cell biomass and signaling. Targeting substrate binding or catalytic activity could be projected, though no agents are yet clinically validated.