The beta 1,3-galactosyltransferase beta 3GalT-V is a stage-specific embryonic antigen-3 (SSEA-3) synthase.

Abstract

We have previously reported the molecular cloning of beta1, 3-galactosyltransferase-V (beta3GalT-V), which catalyzes the transfer of Gal to GlcNAc-based acceptors with a preference for the core3 O-linked glycan GlcNAc(beta1,3)GalNAc structure. Further characterization indicated that the recombinant beta3GalT-V enzyme expressed in Sf9 insect cells also utilized the glycolipid Lc3Cer as an efficient acceptor. Surprisingly, we also found that beta3GalT-V catalyzes the transfer of Gal to the terminal GalNAc unit of the globoside Gb4, thereby synthesizing the glycolipid Gb5, also known as the stage-specific embryonic antigen-3 (SSEA-3). The SSEA-3 synthase activity of beta3GalT-V was confirmed in vivo by stable expression of the human beta3GalT-V gene in F9 mouse teratocarcinoma cells, as detected with the monoclonal antibody MC-631 by flow cytometry analysis and immunostaining of extracted glycolipids. The biological relation between SSEA-3 formation and beta3GalT-V was further documented by showing that F9 cells treated with the differentiation-inducing agent retinoic acid induced the expression of both the SSEA-3 epitope and the endogenous mouse beta3GalT-V gene. This study represents the first example of a glycosyltransferase, which utilizes two kinds of sugar acceptor substrates without requiring any additional modifier molecule.

• Authors: D Zhou, T R Henion, F B Jungalwala, E G Berger, T Hennet
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 275 Issue 30 Pg. 22631-4 (Jul 28 2000) ISSN: 0021-9258 [Print] United States
• PMID: 10837462 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antigens, Tumor-Associated, Carbohydrate
• DNA Primers
• Glycosphingolipids
• Stage-Specific Embryonic Antigens
• stage-specific embryonic antigen-3
• Galactosyltransferases
• UDP-galactose N-acetylglucosaminyl-1-3-N-acetylgalactosamine beta-1,3-galactosyltransferase

Topics

• Animals
• Antigens, Tumor-Associated, Carbohydrate
• Base Sequence
• DNA Primers
• Galactosyltransferases (genetics, metabolism)
• Glycosphingolipids (metabolism)
• Humans
• Mice
• Molecular Sequence Data
• Stage-Specific Embryonic Antigens
• Substrate Specificity
• Tumor Cells, Cultured