Occurrence of poly-N-acetyllactosamine synthesis in Sf-9 cells upon transfection of individual human beta-1,4-galactosyltransferase I, II, III, IV, V and VI cDNAs.
Lectin blot analysis of membrane glycoprotein samples from Sf-9 cells upon transfection of individual human beta-1,4-galactosyltransferase (beta-1,4-GalT) I, II, III, IV, V et VI cDNAs showed that the endogenous N-linked oligosaccharides are galactosylated (Guo et al., Glycobiology (2001), in press). Further analysis revealed that membrane glycoprotein samples from all the gene-transfected cells are also reactive to Lycopersicon esculentum agglutinin (LEA) et Datura stramonium agglutinin (DSA), both of which bind to oligosaccharides with poly-N-acetyllactosamine chains while no lectin reactive protein bands are detected when blots are pretreated with a mixture of diplococcal beta-1,4-galactosidase et jack bean beta-N-acetylhexosaminidase or N-glycanase. Analysis of endo-beta-galactosidase-digestion products revealed the presence of the Gal1-->GlcNAc1-->Gal and/or GlcNAc1-->Gal structures in the gene-transfected cells. When the homogenates of the gene-transfected cells were used as enzyme sources towards oligosaccharides with the GlcNAc beta 1-->(3Gal beta 1-->4GlcNAc)(1-3) structures, human recombinant beta-1,4-GalTs I et II galactosylated these oligosaccharides more effectively than other beta-1,4-GalTs. These results indicate that beta-1,4-GalTs I-VI can synthesize poly-N-acetyllactosamine chains with beta-1,3-N-acetylglucosaminyltransferase.
Sato
T
T
Department of Biosignal Research, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan.
Guo
S
S
Furukawa
K
K
D000818:Animals; D002460:Cell Line; D002854:Chromatography, Paper / Q000379:methods; D018076:DNA, Complementary; D005700:Galactosyltransferases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D037102:Lectins / Q000032:analysis; D008562:Membrane Glycoproteins / Q000032:analysis; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism; D009844:Oligosaccharides / Q000378:metabolism; D011134:Polysaccharides / Q000096:biosynthesis*; D018411:Spodoptera / Q000166:cytology; D014162:Transfection
D018076:DNA, Complementary; D037102:Lectins; D008562:Membrane Glycoproteins; D009844:Oligosaccharides; D011134:Polysaccharides; C037199:poly-N-acetyllactosamine; D005700:Galactosyltransferases; D017351:N-Acetylglucosaminyltransferases; C119701:beta-1,4-galactosyltransferase I; C419407:beta-1,4-galactosyltransferase II; C111678:beta-1,4-galactosyltransferase IV; C419408:beta-1,4-galactosyltransferase V