Of all cells, human erythrocytes express the highest level of the Glut1 glucose transporter. However, the regulation and function of Glut1 during erythropoiesis are not known. Here, we report that glucose transport actually decreases during human erythropoiesis despite a >3-log increase in Glut1 transcripts. In contrast, Glut1-mediated transport of L-dehydroascorbic acid (DHA), an oxidized form of ascorbic acid (AA), is dramatically enhanced. We identified stomatin, an integral erythrocyte membrane protein, as regulating the switch from glucose to DHA transport. Notably though, we found that erythrocyte Glut1 and associated DHA uptake are unique traits of humans and the few other mammals that have lost the ability to synthesize AA from glucose. Accordingly, we show that mice, a species capable of synthesizing AA, express Glut4 but not Glut1 in mature erythrocytes. Thus, erythrocyte-specific coexpression of Glut1 with stomatin constitutes a compensatory mechanism in mammals that are unable to synthesize vitamin C.
Species diversity in GLUT expression and function
Montel-Hagen, A.; Kinet, S.; Manel, N.; Mongellaz, C.; Prohaska, R.; Battini, J. L.; Delaunay, J.; Sitbon, M.; Taylor, N.
2009-03-21 / vol 137 / pages 201-2
1097-4172 (Electronic) 0092-8674 (Linking)
IGMM team(s) involved in this publication
NAOMI TAYLOR / Valerie Zimmermann
Hematopoiesis and Immunotherapy
Humans; Animals; Membrane Proteins/metabolism; Transfection; Biological Transport; Mammals; Ascorbic Acid/*metabolism; Dehydroascorbic Acid/*metabolism; Erythrocytes/*metabolism; Erythropoiesis; Glucose Transporter Type 1/genetics/*metabolism; Glucose Transporter Type 4/metabolism