Facilitative glucose transporter

GLUT stands for Glucose Transport Facilitators. Glucose Transporters... 

Phay, J. E., H. B. Hussain, and J. F. Moley. Cloning and expression analysis of a novel member of the facilitative glucose transporter family, SLC2A9 (GLUT9). Genomics 2000, 66, 217-220. 

Olson, A. L. and J. E. Pessin. Structure, function, and regulation of the mammalian facilitative glucose transporter gene family. Annu. Rev. Nutr. 1996, 36, 235-256. 

Hruz, P. W. and M. M. Mueckler. Structural analysis of the GLUT1 facilitative glucose transporter. Mol. Membr. Biol. 2001, 38, 183-193. 

Immunohistochemical study ND not determined GLUT1 facilitative glucose transporter MCT1 monocarboxylate transporter CRT creatine transporter LAT1 L-type amino acid transporter TAUT taurine transporter ENT equilibrative nucleoside transporter Oatp organic anion-transporting polypeptide PAH p-aminohippuric acid RUI retinal uptake index TR-iBRB rat retinal capillary endothelial cells. 

Thorens, B. 1993. Facilitated glucose transporters in epithelial cells. Ann Rev Physiol 55 591. 

Kahn BB (1992), Facilitative glucose transporters. Regulatory mechanisms and deregulation in diabetes, J. Clin. Invest. 89 1367-1374. 

Pessin JE, Bell GI (1992), Mammalian facilitative glucose transporter family. Structure and molecular regulation, Annu. Rev. Physiol. 54 911-930. 

Catalysis of Glucose Transport by Facilitative Glucose Transporters 72... 

Structural Requirements of Glucose Binding to Facilitative Glucose Transporters 74... 

Kinetic Differences Among Facilitative Glucose Transporters 77... 

Figure 1. Models for the orientation of A.) Members of the facilitative glucose transporter family (CLUT1 to GLUT7), and B.) the sodium-dependent glucose transporter (SGLT1). The branched structure is at the site of glycosylation for both transporters. In A, the open residues represent amino acids which are identical in GLUT1 through GLUT5.

Mueckler and colleagues achieved the molecular cloning of the GLUTI isoform of facilitative glucose transporters by using an expression library. In this technique, cDNA was prepared from a human hepatoma cell line known to express large... 

Among the facilitative glucose transporters, there is a strong conservation of sequences between species with greater than 85% identity at the amino acid level from rodent to man. This suggests that an array of glucose transporters with different characteristics are important to proper maintenance of glucose homeostasis in mammals. 

CATALYSIS OF GLUCOSE TRANSPORT BY FACILITATIVE GLUCOSE TRANSPORTERS... 

Figure 5. Space filling model of -D-glucopyranose in the chair conformation which is thought to be the preferred conformation for transport. The carbon atoms numbered 1,3, and 6 are thought to be most important for proper interaction with the facilitative glucose transporters.

Figure 6. Schematic representation of glucose in the pore of the facilitative glucose transporter. The amphipathic a-helices of the membrane spanning domains are thought to form a hydrophilic pore through which glucose moves via hydrogen bonding to amino acids. The importance of the hydrogen bonds at positions 1,3, and 6 of the glucose molecule for efficient transport (see text) is shown.

The primary, secondary, and presumably tertiary, and higher, structure of the family of facilitative glucose transporters are similar. It is beginning to be understood which domains of these transporters are important for substrate and inhibitor binding and for subcellular localization. Future work will undoubtably uncover the molecular mechanism by which the facilitative transporters catalyze the translocation of sugars across the membrane. 

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