ST6GALNAC5

The protein encoded by this gene is a Golgi type II transmembrane glycosyltransferase. The encoded protein catalyzes the transfer of sialic acid to cell surface proteins to modulate cell-cell interactions. Several transcript variants encoding different isoforms have been found for this gene.

Full Name

ST6 N-Acetylgalactosaminide Alpha-2,6-Sialyltransferase 5

Function

Predominantly catalyzes the biosynthesis of ganglioside GD1alpha from GM1b in the brain, by transferring the sialyl group (N-acetyl-alpha-neuraminyl or NeuAc) from CMP-NeuAc to the GalNAc residue on the NeuAc-alpha-2,3-Gal-beta-1,3-GalNAc sequence of GM1b (PubMed:12668675).
GD1alpha is a critical molecule in the communication and interaction between neuronal cells and their supportive cells, particularly in brain tissues, and functions as an adhesion molecule in the process of metastasis (By similarity).
Also shows activity towards sialyl Lc4Cer (N-acetyl-alpha-neuraminosyl-(2->3)-beta-D-galactosyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->3)-beta-D-galactosyl-(1->4)-beta-D-glucosyl-(1<->1')-N-acyl-sphing-4-enine) generating disialyl Lc4Cer, which can lead to the synthesis of disialyl Lewis a (Le(a)), suggested to be a cancer-associated antigen (PubMed:12668675).

Biological Process

Biological Process ganglioside biosynthetic processManual Assertion Based On ExperimentIBA:GO_Central
Biological Process glycosphingolipid biosynthetic processISS:BHF-UCL
Biological Process oligosaccharide biosynthetic processBy SimilarityISS:BHF-UCL
Biological Process oligosaccharide metabolic processManual Assertion Based On ExperimentIBA:GO_Central
Biological Process protein glycosylationIEA:InterPro

Cellular Location

Golgi apparatus membrane

Topology

Cytoplasmic: 1-8
Helical: 9-29
Lumenal: 30-336