Evidence that modulation of glucose transporter intrinsic activity is the mechanism involved in the allose-mediated depression of hexose transport in mammalian cells.
In serum starved V79 Chinese hamster lung fibroblast cells, replacement of D-glucose with D-allose resulted in a significant 38 +/- 18% (P < 0.05) reduction of 2-deoxy-D-glucose (2-DG) transport. Similarly, in a respiration-deficient mutant cell line (V79-G14), which has elevated 2-DG transport activity, D-allose reduced 2-DG transport by 59 +/- 18% (P < 0.05). [3H]D-allose uptake by V79 cells occurred slowly and was not inhibited by cytochalasin B, suggesting diffusion as the mode of D-allose entry. Western blot analysis using a rabbit polyclonal antibody to the human erythrocyte glucose transporter (GT) demonstrated that, in both cell lines, GT content and GT subcellular distribution were not significantly different in D-glucose vs. D-allose-treated cells. delta-Antibody, which has been shown to bind to exofacial epitopes of the GT (Harrison et al., 1990, J. Biol. Chem., 265:5793-5801), did not demonstrate any differences in surface binding to D-glucose vs. D-allose-treated intact V79 cells. D-allose treatment of 3T3 fibroblasts resulted in a similar decrease (72%) of 2-DG transport, however D-allose had no apparent effect on basal sugar transport in 3T3 adipocytes. These results suggest that D-allose reduces sugar transport through a modulation of the intrinsic activity of the GT, and that D-allose may act in a tissue-specific manner.
Pratt
S E
SE
Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada.
Colby-Germinario
S
S
Manuel
S
S
Germinario
R J
RJ
D016475:3T3 Cells; D017667:Adipocytes / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D005347:Fibroblasts / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D006601:Hexoses / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*
D006601:Hexoses; D009004:Monosaccharide Transport Proteins; C002055:allose; D005947:Glucose