Regulation of expression of the human fructose transporter (GLUT5) by cyclic AMP.
The effect of cyclic AMP on the expression of the fructose transporter, GLUT5, was studied in Caco-2 cells, a human colon cancer cell line that differentiates spontaneously in culture into cells with the properties of small intestine enterocytes. Treatment of differentiated Caco-2 cells with 50 microM forskolin, which stimulates adenylate cyclase and raises intracellular cyclic AMP levels, increased fructose uptake 2-fold and raised GLUT5 protein and mRNA levels 5- and 7-fold respectively. The increased GLUT5 mRNA levels in forskolin-treated cells are a result of stabilization of GLUT5 mRNA in these cells and increased transcription. The effect of cyclic AMP on GLUT5 transcription was assessed by measuring the activity of human GLUT5 promoter-reporter gene constructs in forskolin-treated differentiated Caco-2 cells. The results showed that forskolin stimulated the activity of the GLUT5-reporter gene constructs and this stimulatory effect was mediated by cis-acting regulatory sequences.
Mahraoui
L
L
Unité de Recherches sur la Différenciation Cellulaire Intestinale, INSERM U178, Villejuif, France.
Takeda
J
J
Mesonero
J
J
Chantret
I
I
Dussaulx
E
E
Bell
G I
GI
Brot-Laroche
E
E
D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002454:Cell Differentiation; D002460:Cell Line; D005576:Colforsin / Q000494:pharmacology; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D005632:Fructose / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D017930:Genes, Reporter; D051296:Glucose Transporter Type 5; D006801:Humans; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D017931:DNA Primers; D018076:DNA, Complementary; D051296:Glucose Transporter Type 5; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; D005576:Colforsin; D005632:Fructose; D003513:Cycloheximide; D000242:Cyclic AMP