Core 1 synthase, glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1 (C1GALT1)

Core 1 synthase, glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1 (C1GALT1), also known as T-synthase, is a crucial glycosyltransferase enzyme responsible for catalyzing the transfer of galactose from UDP-galactose to N-acetylgalactosamine-alpha-Ser/Thr, forming the core 1 O-glycan structure (T antigen), a precursor for many mucin-type O-glycans on secreted and cell-surface glycoproteins. C1GALT1 is a type II transmembrane protein localized mainly to the Golgi apparatus, essential for the elongation of O-glycans and required for normal development, platelet production, kidney function, and maintenance of mucosal barriers. Its activity depends on the chaperone protein Cosmc (C1GALT1C1), which prevents misfolding and degradation. Abnormal expression or mutation of C1GALT1 (or Cosmc deficiency) leads to truncated O-glycans (Tn antigen accumulation), contributing to cancer progression, immune system disorders (including IgA nephropathy), and developmental defects. As a critical regulator of post-translational O-glycosylation, C1GALT1 is emerging as a potential therapeutic target and biomarker, especially in various cancers and immune diseases.

Other names

T-synthaseCore 1 β1,3-galactosyltransferaseCore 1 O-glycan T-synthaseB3Gal-T8Core 1 beta3-Gal-T1Glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1core 1 UDP-galactose:N-acetylgalactosamine-alpha-R beta 1,3-galactosyltransferase 1Epididymis secretory sperm binding protein

Drugs or molecules targeting C1GALT1 would inhibit or modulate O-glycosylation by blocking or altering the transfer of galactose to GalNAc residues (key for T/Tn antigen and mucin-type O-glycan formation)