Enzymatic activity of a developmentally regulated member of the sialyltransferase family (STX): evidence for alpha 2,8-sialyltransferase activity toward N-linked oligosaccharides.
We have detected sialyltransferase activity of recombinant mouse STX, which was cloned from rat brain as a new member of the sialyltransferase family, but sialyltransferase activity of which had not been detected previously [Livingston and Paulson, J. Biol. Chem. (1993) 268, 11504-11507]. The activity of mouse STX was specific toward sialylated glycoproteins. N-Glycanase treatment and linkage-specific sialidase treatment of glycoproteins revealed that STX transfers sialic acids through alpha 2,8-linkages to only N-linked oligosaccharides of glycoproteins. However, polymerase activity for polysialic acid synthesis was not detected for this sialyltransferase. Since this alpha 2,8-sialyltransferase gene is highly restricted in fetal and newborn brain, it may be involved in the polysialylation of glycoproteins, especially of N-CAM.
Kojima
N
N
Frontier Research Program, Institute of Physical and Chemical Research (RIKEN), Saitama, Japan.
Yoshida
Y
Y
Kurosawa
N
N
Lee
Y C
YC
Tsuji
S
S
D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D015971:Gene Expression Regulation, Enzymologic; D051379:Mice; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000378:metabolism*; D012799:Sialyltransferases / Q000235:genetics / Q000378:metabolism*
D018076:DNA, Complementary; D009844:Oligosaccharides; D012799:Sialyltransferases