The protein encoded by this gene is a type II membrane protein that catalyzes the transfer of sialic acid from CMP sialic acid to galactose-containing substrates. The encoded protein, which is normally found in the Golgi apparatus but which can be proteolytically processed to a soluble form, is involved in the generation of the cell surface carbohydrate determinants and differentiation antigens HB6, CDw75, and CD76. This protein is a member of glycosyltransferase family 29. Three transcript variants encoding two different isoforms have been found for this gene.
