The intrinsic structure of glucose transporter isoforms Glut1 and Glut3 regulates their differential distribution to detergent‐resistant membrane domains in nonpolarized mammalian cells

Abstract

The hexose transporter family, which mediates facilitated uptake in mammalian cells, consists of more than 10 members containing 12 membrane‐spanning segments with a single N‐glycosylation site. We previously demonstrated that glucose transporter 1 is organized into a raft‐like detergent‐resistant membrane domain but that glucose transporter 3 distributes to fluid membrane domains in nonpolarized mammalian cells. In this study, we further examined the structural basis responsible for the distribution by using a series of chimeric constructs. Glucose transporter 1 and glucose transporter 3 with a FLAG‐tagged N‐terminus were expressed in detergent‐resistant membranes and non‐detergent‐resistant membranes of CHO‐K1 cells, respectively. Replacement of either the C‐terminal or N‐terminal cytosolic portion of FLAG‐tagged glucose transporter 1 and glucose transporter 3 did not affect the membrane distribution. However, a critical sorting signal may exist within the N‐terminal half of the isoforms without affecting transport activity and its inhibition by cytochalasin B. Further shortening of these regions altered the critical distribution, suggesting that a large proportion or several parts of the intrinsic structure, including the N‐terminus of each isoform, are involved in the regulation.

In VitroInfection ofTrypanosoma cruziCauses Decrease in Glucose Transporter Protein-1 (GLUT1) Expression in Explants of Human Placental Villi Cultured under Normal and High Glucose Concentrations

“…On the other hand, we observed in our laboratory, that Gamma-glutamyl transpeptidase, another enzyme present in the placenta's brush border, is not affected in cells cocultured with T. cruzi [33], suggesting that the parasite affects molecules inserted in lipid microdomains of the membrane, as PLAP [42] and GLUT1 [43]. As the hyperglycemia characteristic of diabetes mellitus also affects these membrane components, we suggest that both the parasite and the high glucose conditions could have been provoking, by different ways, a lower placenta efficacy transporting glucose to fetus.…”

DNA Damage–Induced Modulation of GLUT3 Expression Is Mediated through p53-Independent Extracellular Signal-Regulated Kinase Signaling in HeLa Cells

“…and GLUT1 distribute to different microdomains in the plasma membrane, GLUT3 in a fluid domain and GLUT1 in raft-like domains (35,39).…”

“…The control plasmid pGL4.74 (Renilla luciferase reporter) was also obtained from Promega. The NH 2 terminal EGFP-GLUT3 (GFP-G3) cDNA construct was described previously (39).…”

Glucose Transporters in Sex Steroid Hormone Related Cancer

“…The localization of the GLUT1 may hinder interpretation, as high expression may be brought about by cytoplasmic straining with low membrane distribution. Furthermore, irrespective of GLUT1 content, the limiting factors in uptake maybe glycolysis, lipid raft association or post-transcriptional modifications to the transporter such as N-glycosylation [110,111].…”