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Identification of regulatory binding sites on the Glut1 glucose transporter
Author(s) -
Reyes Alejandro,
Ojeda Paola,
Pérez Alejandra,
Valenzuela Ximena,
Vera Juan C
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.699.8
Subject(s) - glut1 , mutant , xenopus , glucose transporter , cytochalasin b , transporter , biochemistry , biology , microbiology and biotechnology , chemistry , gene , cell , endocrinology , insulin
Facilitative glucose transport through plasma membrane is facilitated by GLUT1, transporter protein expressed in most cells. To identify regions on the protein involved on sensitivity towards inhibitors of transport, we identify three short sequences that show homology with typical ATP‐binding sites, as putative targets for inhibitor interaction. We probe the functional role of these regions by site directed mutagenesis and expression on Xenopus oocytes. For each mutant we analyze their kinetic properties for transport and their abilities to be affected by cytochalasin B, quercetin and tyrphostin A47. We identify mutants of exofacial orientation that suffers complete loss of sensitivity towards quercetin. Besides, we detected two groups of mutants of endofacial orientation that exhibit a decreased sensitivity to tyrphostin A47 or cytochalasin B. These data suggests that there are at least two regulatory regions, one accessible from the external side and another located on the internal surface of the protein and identify amino acid residues implied on the interaction with these ligands (Financed by FONDECYT 1060198 and FONDEF D07I1117).