Expression and localization of GLUT-5 in Caco-2 cells, human small intestine, and colon.
The human colon carcinoma cell line Caco-2 was used as an enterocyte model to study the expression of the facilitative glucose transporters GLUT-1 and GLUT-2, and of the putative hexose transporter GLUT-5, which are expressed specifically in the gut. Northern blots indicate that Caco-2 cells express GLUT-1 and GLUT-5 mRNAs but not the mRNA coding for the basolateral glucose transporter GLUT-2. The level of GLUT-5 mRNA is growth dependent, being detectable only in postconfluent differentiated cells. In addition, the expression of GLUT-5 increases with the number of cell passages and is approximately 10 times higher in later passages (passage 184) than in early ones (passage 26). With the use of polyclonal antibodies directed against the COOH-terminus of GLUT-5, indirect immunofluorescence and Western blotting indicate that GLUT-5 is mainly localized to the brush border of Caco-2 cells. GLUT-5 is also found to be associated with the brush border of epithelial cells from fetal and normal adult human small intestine, but is absent from the colon.
Mahraoui
L
L
Institut National de la Santé et de la Recherche Médicale, Unité 178, Villejuif, France.
Rousset
M
M
Dussaulx
E
E
Darmoul
D
D
Zweibaum
A
A
Brot-Laroche
E
E
D000328:Adult; D015153:Blotting, Western; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D002458:Cell Fractionation; D003106:Colon / Q000196:embryology / Q000378:metabolism*; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D005333:Fetus / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D051296:Glucose Transporter Type 5; D006801:Humans; D015151:Immunoblotting; D007413:Intestinal Mucosa / Q000378:metabolism; D007421:Intestine, Small / Q000196:embryology / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013194:Staining and Labeling; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
D051296:Glucose Transporter Type 5; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger