Novel induction of alpha-lactalbumin-mediated lacdiNAc-R expression in vivo.
alpha-Lactalbumin (alpha-LA) is a regulatory protein by which the mammalian beta1,4-galactosyltransferase (beta1,4-galT) is induced to utilize glucose as an acceptor instead of N-acetylglucosamine (GlcNAc) during lactose synthesis in mammary gland. alpha-LA can also modulate beta1,4-galT to utilize UDP-N-acetylgalactosamine (UDP-GalNAc) as a donor towards GlcNAc acceptor substrate with high efficiency in vitro [Do, Do and Cummings (1995) J. Biol. Chem. 270, 18447-18451]. In the present study we transfected cDNA encoding bovine alpha-LA into Lec8 cells and examined whether nucleotide sugar switching of UDP-galactose (UDP-Gal) into UDP-GalNAc occurred in vivo and whether the neo-glycosylation of GalNAcbeta1,4GlcNAc-R structure was synthesized in alpha-LA-stable transfectants. Our studies demonstrate that the stable expression of alpha-LA in Lec8 cells induces the formation of GalNAcbeta1,4GlcNAc-R in vivo through the nucleotide sugar switching of beta1,4-galT.
Do
S I
SI
Korea Research Institute of Bioscience and Biotechnology (KRIBB), Glycobiology Division, Animal Cell and Medical Glycobiology Laboratory, Republic of Korea. sido@kribb4680.kribb.re.kr
Lee
K Y
KY
Kim
H N
HN
D000581:Amidohydrolases / Q000378:metabolism; D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism; D016466:CHO Cells; D002417:Cattle; D002478:Cells, Cultured; D006224:Cricetinae; D004187:Disaccharides / Q000378:metabolism*; D005944:Glucosamine / Q000378:metabolism; D006020:Glycopeptides / Q000032:analysis; D015151:Immunoblotting; D007768:Lactalbumin / Q000235:genetics / Q000378:metabolism*; D007785:Lactose / Q000031:analogs & derivatives* / Q000378:metabolism; D017350:N-Acetylgalactosaminyltransferases; D009842:Oligopeptides / Q000378:metabolism; D009844:Oligosaccharides / Q000378:metabolism; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014316:Tritium
D014408:Biomarkers, Tumor; D004187:Disaccharides; D006020:Glycopeptides; D009842:Oligopeptides; D009844:Oligosaccharides; D014316:Tritium; C093701:N-acetylgalactosaminyl-1-4-N-acetylglucosamine; D007768:Lactalbumin; D017350:N-Acetylgalactosaminyltransferases; C023220:(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D007785:Lactose; D005944:Glucosamine