Characterization of human glucose transporter (GLUT) 11 (encoded by SLC2A11), a novel sugar-transport facilitator specifically expressed in heart and skeletal muscle.
Human GLUT11 (encoded by the solute carrier 2A11 gene, SLC2A11) is a novel sugar transporter which exhibits significant sequence similarity with the members of the GLUT family. The amino acid sequence deduced from its cDNAs predicts 12 putative membrane-spanning helices and all the motifs (sugar-transporter signatures) that have previously been shown to be essential for sugar-transport activity. The closest relative of GLUT11 is the fructose transporter GLUT5 (sharing 41.7% amino acid identity with GLUT11). The human GLUT11 gene (SLC2A11) consists of 12 exons and is located on chromosome 22q11.2. In human tissues, a 7.2 kb transcript of GLUT11 was detected exclusively in heart and skeletal muscle. Transfection of COS-7 cells with GLUT11 cDNA significantly increased the glucose-transport activity reconstituted from membrane extracts as well as the specific binding of the sugar-transporter ligand cytochalasin B. In contrast to that of GLUT4, the glucose-transport activity of GLUT11 was markedly inhibited by fructose. It is concluded that GLUT11 is a novel, muscle-specific transport facilitator that is a member of the extended GLUT family of sugar/polyol-transport facilitators.
Doege
H
H
Institut für Pharmakologie und Toxikologie, Medizinische Fakultät der RWTH Aachen, Wendlingweg 2, D-52057 Aachen, Germany.
Bocianski
A
A
Scheepers
A
A
Axer
H
H
Eckel
J
J
Joost
H G
HG
Schürmann
A
A
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D003001:Cloning, Molecular; D003571:Cytochalasin B / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D005091:Exons; D015870:Gene Expression; D015894:Genome, Human; D051246:Glucose Transport Proteins, Facilitative; D006801:Humans; D066298:In Vitro Techniques; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D018076:DNA, Complementary; D051246:Glucose Transport Proteins, Facilitative; D009004:Monosaccharide Transport Proteins; D011994:Recombinant Proteins; C439386:SLC2A11 protein, human; D003571:Cytochalasin B