The role of N-glycosylation of GLUT1 for glucose transport activity

T. Asano, H. Katagiri, K. Takata, J. L. Lin, H. Ishihara, K. Inukai, K. Tsukuda, M. Kikuchi, H. Hirano, Y. Yazaki, Y. Oka

研究成果: Article査読

140 被引用数 (Scopus)


To elucidate a functional role of N-glycosylation in glucose transporters, we introduced oligonucleotide-directed mutagenesis in GLUT1 cDNA to remove the possible site for N-linked glycosylation. The wild-type and the mutated GLUT1 cDNAs which induced a mutation of Asn at residue 45 to Asp, Tyr, or Gln were transfected and stably expressed into Chinese hamster ovary cells. The expressed wild-type and the mutated GLUT1 was demonstrated to be a broad band of a 45-60-kDa form and a sharp band of a 38-kDa form on Western blot analysis, respectively, indicating no glycosylation in the mutated GLUT1. Although the cell surface labeling of the glucose transporters demonstrated the presence of the glycosylation-defective glucose transporters on the cells surface, photoaffinity labeling of glycosylation-defective GLUT1 with [3H]cytochalasin B and a photoreactive mannose derivative, [3H]2-N-4-(1-azi-2,2,2,trifluoroethyl)benzoyl-1,3-bis(D-mannos-4- yloxy)-2-propylamine in the membranes was observed to be 40-70 and 15-30% of that of the wild-type GLUT1, respectively. The kinetic study of 2-deoxyglucose uptake revealed that the glycosylation-defective GLUT1 had a 2-2.5-fold greater K(m) value for 2-deoxyglucose uptake compared with the wild-type GLUT1. These observations strongly suggest that 1) N-glucosylation of GLUT1 glucose transporter is only on Asn 45 and 2) N-glycosylation plays an important role in maintaining a structure of glucose transporter with high affinity for glucose, thus, with high transport activity.

ジャーナルJournal of Biological Chemistry
出版ステータスPublished - 1991

ASJC Scopus subject areas

  • 生化学
  • 分子生物学
  • 細胞生物学


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