Molecular cloning and expression of a novel human beta-Gal-3-O-sulfotransferase that acts preferentially on N-acetyllactosamine in N- and O-glycans.
A novel cDNA-encoding galactose 3-O-sulfotransferase was cloned by screening the expressed sequence tag data base using the previously cloned cDNA encoding a galactosyl ceramide 3-O-sulfotransferase, which we term Gal3ST-1. The newly isolated cDNA encodes a novel 3-O-sulfotransferase, termed Gal3ST-3, that acts exclusively on N-acetyllactosamine present in N-glycans and core2-branched O-glycans. These conclusions were confirmed by analyzing CD43 chimeric proteins in Chinese hamster ovary cells expressing core2 beta1,6-N-acetylglucosaminyltransferase. The acceptor specificity of Gal3ST-3 contrasts with that of the recently cloned galactose 3-O-sulfotransferase (Honke, K., Tsuda, M., Koyota, S., Wada, Y., Iida-Tanaka, N., Ishizuka, I., Nakayama, J., and Taniguchi, N. (2001) J. Biol. Chem. 276, 267-274), which we term Gal3ST-2 in the present study because the latter enzyme can also act on core1 O-glycan and type 1 oligosaccharides, Galbeta1-->3GlcNAc. Moreover, Gal3ST-3 but not Gal3ST-2 can act on Galbeta1-->4(sulfo-->6)GlcNAc, indicating that disulfated sulfo-->3Galbeta1-->4(sulfo-->6) GlcNAc-->R may be formed by Gal3ST-3 in combination with GlcNAc 6-O-sulfotransferase. Although both Gal3ST-2 and Gal3ST-3 do not act on galactosyl ceramide, Gal3ST-3 is only moderately more homologous to Gal3ST-2 (40.1%) than to Gal3ST-1 (38.0%) at the amino acid level. Northern blot analysis demonstrated that transcripts for Gal3ST-3 are predominantly expressed in the brain, kidney, and thyroid where the presence of 3'-sulfation of N-acetyllactosamine has been reported. These results indicate that the newly cloned Gal3ST-3 plays a critical role in 3'-sulfation of N-acetyllactosamine in both O- and N-glycans.
Suzuki
A
A
Glycobiology Program, Cancer Research Center, The Burnham Institute, La Jolla, California 92037, USA.
Hiraoka
N
N
Suzuki
M
M
Angata
K
K
Misra
A K
AK
McAuliffe
J
J
Hindsgaul
O
O
Fukuda
M
M
D000595:Amino Acid Sequence; D000606:Amino Sugars / Q000378:metabolism*; D000818:Animals; D015703:Antigens, CD; D001483:Base Sequence; D001921:Brain / Q000201:enzymology; D016466:CHO Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D006801:Humans; D007668:Kidney / Q000201:enzymology; D051917:Leukosialin; D008969:Molecular Sequence Data; D019006:Neural Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012795:Sialoglycoproteins / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D013431:Sulfates / Q000378:metabolism; D015238:Sulfotransferases / Q000235:genetics* / Q000378:metabolism; D013466:Sulfurtransferases / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D013961:Thyroid Gland / Q000201:enzymology; D014158:Transcription, Genetic
D000606:Amino Sugars; D015703:Antigens, CD; D051917:Leukosialin; D019006:Neural Cell Adhesion Molecules; D011134:Polysaccharides; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C465014:SPN protein, human; D012795:Sialoglycoproteins; D013431:Sulfates; C000458:N-acetyllactosamine; D013466:Sulfurtransferases; C432419:GAL3ST2 protein, human; D015238:Sulfotransferases; C097036:galactose 3-O-sulfotransferase