Involvement of beta-1,4-galactosyltransferase V in malignant transformation-associated changes in glycosylation.
In spite of marked changes in the glycosylation upon malignant transformation of cells, no biological significance of beta-1, 4-galactosyltransferase (beta-1,4-GalT) activities has been elucidated. When beta-1,4-GalT activities toward 1 mM GlcNAcbeta-S-pNP were determined using homogenates of NIH3T3 and its transformant, MTAg, MTAg contained 1.3 times higher activities. Northern blot analysis, however, revealed that the beta-1,4-GalT V gene expression increases by three times with a decrease in that of beta-1,4-GalT II by one-fifth and without significant changes in those of other beta-1,4-GalTs in MTAg. Analysis of beta-1,4-GalT V acceptor-specificity showed that the GlcNAcbeta1-->6Man group of the GlcNAcbeta1-->6(GlcNAbeta1-->2)Manalpha1- branch is galactosylated. These results indicate that changes in beta-1,4-GalT II and V activities are important for the altered glycosylation.
Shirane
K
K
Department of Biosignal Research, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo, 173-0015, Japan.
Sato
T
T
Segawa
K
K
Furukawa
K
K
D016475:3T3 Cells; D000818:Animals; D001665:Binding Sites; D002240:Carbohydrate Sequence; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006031:Glycosylation; D051379:Mice; D008969:Molecular Sequence Data; D009237:N-Acetyllactosamine Synthase / Q000235:genetics / Q000378:metabolism*; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity
D009844:Oligosaccharides; D009237:N-Acetyllactosamine Synthase