Glycobiology Advance Access published online on September 26, 2003
Glycobiology, doi:10.1093/glycob/cwg117
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
© 2003 Oxford University Press
ORIGINAL ARTICLES
1 INSERM U-559/UEA-3289 Université de la Méditerranée, 27 Bd. J. Moulin, 13385 Marseille Cedex 5, France Modification of Golgi glycosyltransferases, such as formation of disulfide-bonded dimers and proteolytical release from cells as a soluble form, are important processes to regulate the activity of glycosyltransferases. To better understand these processes, six glycosyltransferases were selected on the basis of the donor sugars, including two N-acetylglucosaminyltransferases, core1
Revised on August 25, 2003
Accepted on August 28, 2003
Different glycosyltransferases are differentially processed for secretion, dimerization and autoglycosylation
2 Glycobiology Program, Cancer Research Center, the Burnham Institute, La Jolla, California 92037
1,3-N-acetylglucosaminyltransferase (C1-3GnT) and core2 1,6-N-acetylglucosaminyltransferase (C2GnT-I), two fucosyltransferases, 
1,2-fucosyl-transferase-I (FucT-I) and 1,3-fucosyltransferase-VII (FucT-VII), and two sialyltransferases, 2,3-sialyltransferase-I (ST3Gal-I) and 2,6-sialyltransferase-I (ST6Gal-I). These enzymes were fused with the Enhanced Green Fluorescence Protein and stably expressed in the Chinese hamster ovary cells. Spectrofluorimetric detection and immunoblotting analyses showed that all of these glycosyltransferases except FucT-VII were secreted in the medium. By examining dimers formed in cells and culture media we found that all of the enzymes, except ST3Gal-I, form a combination of monomers and dimers in cells while the molecules released in the media are either exclusively monomers (C2GnT-I and ST6Gal-I), dimers (FucT-I) or a mixture of both (C1-3GnT). These results indicate that dimerization does not always lead to Golgi retention. Analysis of the N-glycosylation status of the enzymes revealed that the secreted proteins are generally more heavily N-glycosylated and sialylated than their membrane-associated counterparts, suggesting that the proteolytic cleavage occur before the glycosylation is completed. Using FucT-I and ST6Gal-I as a model, we also showed that these glycosyltransferases are able to perform autoglycosylation in the dimeric forms. These results indicate that different glycosyltranferases differ significantly in dimerization, proteolytic digestion and secretion, and autoglycosylation. These results strongly suggest that disulfide-bonded dimerization and secretion differentially plays a role in the processing and function of different glycosyltransferases in the Golgi apparatus.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  P. Herr, G. Korniychuk, Y. Yamamoto, K. Grubisic, and M. Oelgeschlager Regulation of TGF-{beta} signalling by N-acetylgalactosaminyltransferase-like 1 Development, May 15, 2008; 135(10): 1813 - 1822. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Schregel, S. Auerochs, R. Jochmann, K. Maurer, T. Stamminger, and M. Marschall Mapping of a self-interaction domain of the cytomegalovirus protein kinase pUL97 J. Gen. Virol., February 1, 2007; 88(2): 395 - 404. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. V. Cabrera, M. Amano, J. Mitoma, J. Chan, J. Said, M. Fukuda, and L. G. Baum Haploinsufficiency of C2GnT-I glycosyltransferase renders T lymphoma cells resistant to cell death Blood, October 1, 2006; 108(7): 2399 - 2406. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. E. Pak, P. Arnoux, S. Zhou, P. Sivarajah, M. Satkunarajah, X. Xing, and J. M. Rini X-ray Crystal Structure of Leukocyte Type Core 2 beta1,6-N-Acetylglucosaminyltransferase: EVIDENCE FOR A CONVERGENCE OF METAL ION-INDEPENDENT GLYCOSYLTRANSFERASE MECHANISM J. Biol. Chem., September 8, 2006; 281(36): 26693 - 26701. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Ma, G. F. Audette, S. Lin, M. M. Palcic, B. Hazes, and D. E. Taylor Purification, Kinetic Characterization, and Mapping of the Minimal Catalytic Domain and the Key Polar Groups of Helicobacter pylori {alpha}-(1,3/1,4)-Fucosyltransferases J. Biol. Chem., March 10, 2006; 281(10): 6385 - 6394. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. L. de Graffenried and C. R. Bertozzi The Stem Region of the Sulfotransferase GlcNAc6ST-1 Is a Determinant of Substrate Specificity J. Biol. Chem., September 17, 2004; 279(38): 40035 - 40043. [Abstract] [Full Text] [PDF]
|
|