Core2 O-glycan structure is essential for the cell surface expression of sucrase isomaltase and dipeptidyl peptidase-IV during intestinal cell differentiation.

TitleCore2 O-glycan structure is essential for the cell surface expression of sucrase isomaltase and dipeptidyl peptidase-IV during intestinal cell differentiation.
Publication TypeJournal Article
Year of Publication2010
AuthorsLee SHo, Yu S-Y, Nakayama J, Khoo K-H, Stone EL, Fukuda MN, Marth JD, Fukuda M
JournalJ Biol Chem
Volume285
Issue48
Pagination37683-92
Date Published2010 Nov 26
ISSN1083-351X
KeywordsAnimals, Caco-2 Cells, Cell Differentiation, Dipeptidyl Peptidase 4, Gene Expression Regulation, Enzymologic, Glycosylation, HT29 Cells, Humans, Intestines, Mice, Mice, Knockout, N-Acetylglucosaminyltransferases, Sucrase-Isomaltase Complex
Abstract

Alterations in glycosylation play an important role during intestinal cell differentiation. Here, we compared expression of mucin-type O-glycan synthases from proliferating and differentiated HT-29 and Caco-2 cells. Mucin-type O-glycan structures were analyzed at both stages by mass spectrometry. Core2 β1,6-N-acetylglucosaminyltransferase-2 (C2GnT-2) was markedly increased in differentiated HT-29 and Caco-2 cells, but the core3 structure was hardly detectable. To determine whether such differential expression of mucin-type O-glycan structures has physiological significance in intestinal cell differentiation, expression of sucrase isomaltase (SI) and dipeptidyl-peptidase IV (DPP-IV), two well known intestinal differentiation markers, was examined. Interestingly, the fully glycosylated mature form of SI was decreased in C2GnT-2 knock-out mice but not in core2 N-acetylglucosaminyltransferase-3 (C2GnT-3) nulls. In addition, expression of SI and DPP-IV was dramatically reduced in C2GnT-1-3 triple knock-out mice. These patterns were confirmed by RNAi analysis; C2GnT-2 knockdown significantly reduced cell surface expression of SI and DPP-IV in Caco-2 cells. Similarly, overexpression of the core3 structure in HT-29 cells attenuated cell surface expression of both enzymes. These findings indicate that core3 O-glycan structure regulates cell surface expression of SI and DPP-IV and that core2 O-glycan is presumably an essential mucin-type O-glycan structure found in both molecules in vivo. Finally, goblet cells in the upper part of the crypt showed impaired maturation in the core2 O-glycan-deficient mice. These studies are the first to clearly identify functional mucin-type O-glycan structures modulating cell surface expression of SI and DPP-IV during the intestinal cell differentiation.

DOI10.1074/jbc.M110.162735
Alternate JournalJ. Biol. Chem.
PubMed ID20841351
PubMed Central IDPMC2988373
Grant ListCA33000 / CA / NCI NIH HHS / United States
P01 CA71932 / CA / NCI NIH HHS / United States
P30 CA030199 / CA / NCI NIH HHS / United States