Glycobiology, Vol 8, 199-205, Copyright © 1998 by Society for Glycobiology
WX Shi, R Chammas and A Varki
Sialic acids can be modified by O-acetyl esters at the 7- and/or 9-
position, altering recognition by antibodies, lectins and viruses. 9(7)-
O-acetylation is mediated by a sialic acid-specific O- acetyltransferase,
which has proven difficult to purify. Two groups have recently isolated
cDNAs possibly encoding this enzyme, by expression cloning of human
melanoma libraries in COS cells expressing the substrate ganglioside GD3.
Pursuing a similar approach, we have isolated additional clones that can
induce 9-O-acetylation. One clone present in a melanoma library encodes a
fusion protein between a bacterial tetracycline resistance gene repressor
and a sequence reported to be part of the P3 plasmid. Expression of the
open reading frame is necessary for inducing 9-O-acetylation, indicating
that this is not a reaction to the introduction of bacterial DNA. Another
clone from a rat liver cDNA library induced 9-O-acetylation on COS cells
expressing alpha2-6-linked sialic acids, and encodes an open reading frame
identical to the Vitamin D binding protein. However, truncation at the 5'
end eliminates the amino-terminal hydrophobic signal sequence, predicting
cytosolic hyperexpression of a truncated protein. Thus, diverse types of
cDNAs can indirectly induce sialic acid 9-O- acetylation in the COS cell
system, raising the possibility that the real enzyme may be composed of
multiple subunits which would not be amenable to expression cloning.
Importantly, the cDNAs we isolated are highly specific in their ability to
induce 9-O-acetylation either on alpha2-6-linked sialic acids of
glycoproteins (truncated vitamin D binding protein) or on the
alpha2-8-linked sialic acids of gangliosides (Tetrfusion protein). These
data confirm our prior suggestion that a family of O-acetyltransferases
with distinctive substrate specificities exists in mammalian systems.
ORIGINAL ARTICLES
Induction of sialic acid 9-O-acetylation by diverse gene products: implications for the expression cloning of sialic acid O- acetyltransferases
Glycobiology Program, UCSD Cancer Center, Division of Cellular and Molecular Medicine, University of California San Diego, La Jolla 92093, USA.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  A. Cariappa, H. Takematsu, H. Liu, S. Diaz, K. Haider, C. Boboila, G. Kalloo, M. Connole, H. N. Shi, N. Varki, et al. B cell antigen receptor signal strength and peripheral B cell development are regulated by a 9-O-acetyl sialic acid esterase J. Exp. Med., January 16, 2009; 206(1): 125 - 138. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. S. Houliston, H. P. Endtz, N. Yuki, J. Li, H. C. Jarrell, M. Koga, A. van Belkum, M.-F. Karwaski, W. W. Wakarchuk, and M. Gilbert Identification of a Sialate O-Acetyltransferase from Campylobacter jejuni: DEMONSTRATION OF DIRECT TRANSFER TO THE C-9 POSITION OF TERMINAL{alpha}-2, 8-LINKED SIALIC ACID J. Biol. Chem., April 28, 2006; 281(17): 11480 - 11486. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Satake, H. Y. Chen, and A. Varki Genes Modulated by Expression of GD3 Synthase in Chinese Hamster Ovary Cells. EVIDENCE THAT THE Tis21 GENE IS INVOLVED IN THE INDUCTION OF GD3 9-O-ACETYLATION J. Biol. Chem., February 28, 2003; 278(10): 7942 - 7948. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. T. Martin, J. D. Marth, A. Varki, and N. M. Varki Genetically Altered Mice with Different Sialyltransferase Deficiencies Show Tissue-specific Alterations in Sialylation and Sialic Acid 9-O-Acetylation J. Biol. Chem., August 30, 2002; 277(36): 32930 - 32938. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Zhang and Y. C. Lee Acid-catalyzed Lactonization of alpha 2,8-Linked Oligo/Polysialic Acids Studied by High Performance Anion-exchange Chromatography J. Biol. Chem., March 5, 1999; 274(10): 6183 - 6189. [Abstract] [Full Text] [PDF]
|
|