ST6GAL2

ST6GAL2, or beta-galactoside alpha-2,6-sialyltransferase 2, is a human gene encoding a Golgi-resident glycosyltransferase that catalyzes the transfer of sialic acid to galactose residues in alpha-2,6 linkage on N- and O-glycans and glycolipids. The enzyme uses CMP-Neu5Ac as the donor substrate and contributes to the biosynthesis of sialylated glycoconjugates that shape the cell surface glycome. ST6GAL2 is categorized in the GT29 family of glycosyltransferases and is closely related to ST6GAL1, another alpha-2,6-sialyltransferase.

Protein structure and localization: ST6GAL2 is a type II membrane protein with a short cytoplasmic N-terminus, a single transmembrane segment, and a luminal catalytic domain. In the Golgi apparatus, it accesses glycoprotein and glycolipid substrates destined for sialylation.

Expression and function: ST6GAL2 transcripts have been detected in various tissues, with expression patterns that differ from ST6GAL1. The enzyme contributes to the diversity of cell-surface sialylation, influencing protein folding, receptor binding, cell adhesion, and immune recognition.

Clinical and research relevance: Altered ST6GAL2 expression has been reported in certain cancers and inflammatory conditions, consistent with a broader role for sialylation changes in disease. Ongoing studies seek to define substrate specificity and the physiological consequences of ST6GAL2-mediated alpha-2,6-sialylation.