In vivo glycosylation of MUC1 in airway epithelial cells.
The O-glycans that decorate mucin glycoproteins contribute to the biophysical and biochemical properties of these molecules and hence their function as a barrier and lubricant on epithelial surfaces. Alterations in mucin O-glycosylation in certain diseases may contribute to pathology. It is known that both the host cell type and the amino acid sequence of the mucin tandem repeat contribute to the O-glycosylation of a mucin molecule. We expressed an epitope-tagged MUC1 mucin cDNA construct in the airway cell line 16HBE14o- and the colon carcinoma cell line Caco2 and used Fast Atom Bombardment Mass Spectrometry to evaluate the contribution of the host cell to differences in O-glycosylation of a single mucin. Many of the glycans detected on the MUC1 mucin were common to both cell types, as would be predicted from biosynthetic constraints. However, MUC1 synthesized in the airway cell line showed comparatively low levels of sialylation but carried a range of oligo-N-acetyllactosamine structures that were not seen in the colon carcinoma cell line.
Silverman
Howard S
HS
Paediatric Molecular Genetics, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK.
Sutton-Smith
Mark
M
Heal
Paul
P
Parry
Simon
S
Palmai-Pallag
Timea
T
Leir
Shih-Hsing
SH
Morris
Howard R
HR
Dell
Anne
A
Harris
Ann
A
D018938:Caco-2 Cells; D002240:Carbohydrate Sequence; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000378:metabolism*; D005786:Gene Expression Regulation; D006031:Glycosylation; D006801:Humans; D008969:Molecular Sequence Data; D018396:Mucin-1 / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012137:Respiratory System / Q000166:cytology*
D018396:Mucin-1