RRC ID 67401
Author Togayachi A, Akashima T, Ookubo R, Kudo T, Nishihara S, Iwasaki H, Natsume A, Mio H, Inokuchi J, Irimura T, Sasaki K, Narimatsu H.
Title Molecular cloning and characterization of UDP-GlcNAc:lactosylceramide beta 1,3-N-acetylglucosaminyltransferase (beta 3Gn-T5), an essential enzyme for the expression of HNK-1 and Lewis X epitopes on glycolipids.
Journal J Biol Chem
Abstract A new member of the UDP-N-acetylglucosamine:beta-galactose beta1,3-N-acetylglucosaminyltransferase (beta3Gn-T) family having the beta3Gn-T motifs was cloned from rat and human cDNA libraries and named beta3Gn-T5 based on its position in a phylogenetic tree. We concluded that beta3Gn-T5 is the most feasible candidate for lactotriaosylceramide (Lc(3)Cer) synthase, an important enzyme which plays a key role in the synthesis of lacto- or neolacto-series carbohydrate chains on glycolipids. beta3Gn-T5 exhibited strong activity to transfer GlcNAc to glycolipid substrates, such as lactosylceramide (LacCer) and neolactotetraosylceramide (nLc(4)Cer; paragloboside), resulting in the synthesis of Lc(3)Cer and neolactopentaosylceramide (nLc(5)Cer), respectively. A marked decrease in LacCer and increase in nLc(4)Cer was detected in Namalwa cells stably expressing beta3Gn-T5. This indicated that beta3Gn-T5 exerted activity to synthesize Lc(3)Cer and decrease LacCer, followed by conversion to nLc(4)Cer via endogenous galactosylation. The following four findings further supported that beta3Gn-T5 is Lc(3)Cer synthase. 1) The beta3Gn-T5 transcript levels in various cells were consistent with the activity levels of Lc(3)Cer synthase in those cells. 2) The beta3Gn-T5 transcript was presented in various tissues and cultured cells. 3) The beta3Gn-T5 expression was up-regulated by stimulation with retinoic acid and down-regulated with 12-O-tetradecanoylphorbol-13-acetate in HL-60 cells. 4) The changes in beta3Gn-T5 transcript levels during the rat brain development were determined. Points 2, 3, and 4 were consistent with the Lc(3)Cer synthase activity reported previously.
Volume 276(25)
Pages 22032-40
Published 2001-6-22
DOI 10.1074/jbc.M011369200
PII S0021-9258(20)78469-3
PMID 11283017
MeSH Amino Acid Sequence Animals Base Sequence Cloning, Molecular DNA, Complementary Epitopes / chemistry* Glycolipids / chemistry* Humans Lewis X Antigen / chemistry* Molecular Sequence Data N-Acetylglucosaminyltransferases / chemistry N-Acetylglucosaminyltransferases / genetics* N-Acetylglucosaminyltransferases / metabolism Phylogeny Rats Recombinant Proteins / chemistry Recombinant Proteins / genetics Recombinant Proteins / metabolism Sequence Homology, Amino Acid Tumor Cells, Cultured
IF 4.238
Human and Animal Cells EBC-1(RCB1965) MKN1(RCB1003) MKN7(RCB0999) MKN45(RCB1001)