Molecular cloning and expression analysis of a mouse UDP-GlcNAc:Gal(beta1-4)Glc(NAc)-R beta1,3-N-acetylglucosaminyltransferase homologous to Drosophila melanogaster Brainiac and the beta1,3-galactosyltransferase family.
We have isolated a murine cDNA coding for a beta1,3-N-acetylglucosaminyltransferase enzyme ( beta3GnT). This enzyme is similar in sequence to Drosophila melanogaster Brainiac and to the murine and human beta1,3-galactosyltransferase family of proteins. The mouse beta 3GnT protein is 397 amino acids in length and contains 7 cysteine residues that are conserved in the human orthologue. beta 3GnT is a type II membrane protein localized to the Golgi apparatus. Enzyme assays with recombinant mouse beta 3GnT reveal that it has a preference for acceptors with Gal(beta1-4)Glc(NAc) at the non-reducing termini. Proton NMR analysis of product showed incorporation of GlcNAc in beta1,3 linkage to the terminal Gal of Gal(beta1-4)Glc(beta1-O-benzyl). Northern blot analysis revealed the presence of a single 3.0[emsp4 ]kb transcript in all adult mouse and human organs tested, with highest levels in the kidney, liver, heart and placenta. The beta 3GnT gene is also expressed in a number of tumor cell lines. The human orthologue of beta 3GnT is located on chromosome 2pl5.
Egan
S
S
The Programs in Developmental Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. segan@sickkids.on.ca
Cohen
B
B
Sarkar
M
M
Ying
Y
Y
Cohen
S
S
Singh
N
N
Wang
W
W
Flock
G
G
Goh
T
T
Schachter
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics; D003001:Cloning, Molecular; D029721:Drosophila Proteins / Q000737:chemistry*; D004331:Drosophila melanogaster; D020869:Gene Expression Profiling; D006056:Golgi Apparatus / Q000201:enzymology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008565:Membrane Proteins / Q000737:chemistry*; D051379:Mice; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D029721:Drosophila Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C103963:brn protein, Drosophila; D017351:N-Acetylglucosaminyltransferases; C042261:N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase