GLUT1

Structure

spinqualitylabelsall models Crystal structure 4PYP from PDB Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D The GLUT1 is an insulin-independent glucose transporter expressed by all cells in the body to maintain adequate baseline glucose uptake. Tissues that express GLUT1 at high concentrations include (but are not limited to): the placenta and fetal tissues, epithelial cells of the retina and mammary gland, and the brain. The GLUT1 transporter works synergistically with the GLUT3 transporter in the brain. Astrocytes and endothelial cells of brain capillaries primarily express GLUT1 and neurons primarily express GLUT3. GLUT1 has a relatively high Km and is upregulated in times of hypoglycemia in the brain to ensure adequate glucose uptake. GLUT3 has a low Km to ensure a steady supply of glucose for neurons even when extracellular glucose concentrations are low. Structural highlights The GLUT1 transporter has one known N-linked glycosylation site at Asn 45. This glycosylation site is thought to be important for glucose binding to the extracellular portion of the transporter. Mutations in the GLUT1 transporter from Asn 45 to an Asp, Tyr, or Gln residue have been shown to decrease the Km of the enzyme.

References

Asano T, Katagiri H, Takata K, Lin JL, Ishihara H, Inukai K, Tsukuda K, Kikuchi M, Hirano H, Yazaki Y, et al. The role of N-glycosylation of GLUT1 for glucose transport activity. J Biol Chem. 1991 Dec 25;266(36):24632-6. PMID: 1761560.

Koepsell H. Glucose transporters in brain in health and disease. Pflugers Arch. 2020 Sep;472(9):1299-1343. doi: 10.1007/s00424-020-02441-x. Epub 2020 Aug 13. PMID: 32789766; PMCID: PMC7462931.

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