Core 2 β-1,6-N-acetylglucosaminyltransferase (C2GnT (or C2GlcNAcT; both are widely used, but C2GnT is more common in the literature))

Core 2 β-1,6-N-acetylglucosaminyltransferase (C2GnT) is a key **glycosyltransferase enzyme** located in the Golgi apparatus that catalyzes the addition of N-acetylglucosamine in a β1-6 linkage to the core 1 O-glycan structure, resulting in the formation of the core 2 branch[1][3][4]. This modification is essential for producing functional selectin ligands, such as those found on P-selectin glycoprotein ligand 1 (PSGL-1), which regulate **cell-cell adhesion and immune cell trafficking**[1][3]. Multiple isoforms exist (e.g., C2GnT-I, -II, and -III) with overlapping and tissue-specific activity, and regulation occurs at the transcriptional, post-translational, and developmental levels[4][5]. Dysregulation or altered expression is implicated in various **cancers, immune disorders, and inflammatory conditions**, often through changes in glycosylation affecting cell interactions and migration[3][4][5]. The enzyme’s activity is regulated by glycosylation and can be altered experimentally by inhibitors, though no clinically approved drugs target it directly[2]. Its products serve as biomarkers in oncology and immunology research, especially for monitoring glycan branching and selectin ligand status. Caveats: - There is no commonly approved drug that directly targets or inhibits this enzyme in clinical settings to date[2]. - The core 2 β-1,6-N-acetylglucosaminyltransferase family includes multiple isoforms, so specificity in biomarker assays and research is essential[1][3][6].

Other names

Core 2 GlcNAc-TC2GnTC2GlcNAcTβ-1,6-N-acetylglucosaminyltransferaseCore 2 branching enzymeGCNT1, GCNT3 (gene names for isoenzymes)

Drugs targeting this enzyme would act as *glycosyltransferase inhibitors*, blocking the formation of core 2 O-glycans, thereby altering selectin ligand display and the downstream processes of immune cell trafficking and adhesion[1][2].