Abstract
Chimeric constructs of glucose transporters GLUT2 and GLUT4 were transiently expressed in COS-7 cells in order to determine regions of the proteins responsible for their differences in activity and ligand binding. Exchange of the C-terminal tail (aa 479-509) of GLUT4 failed to affect glucose transport activity assayed at 1 mM glucose or ligand binding (cytochalasin B, IAPS-forskolin). In contrast, exchange of the C-terminal half of GLUT4 (aa 222-509) for that of GLUT2 markedly reduced ligand binding (K(d)) of cytochalasin B binding 1.88 ± 0.2 μM vs. 0.21 ± 0.06 in the wild-type GLUT4), and moderately (25%) reduced glucose transport activity. These data support the conclusion that the domains determining differences in Ligand binding between GLUT4 and GLUT2 are located in the C-terminal half of the glucose transporters.
Original language | English |
---|---|
Pages (from-to) | 56-62 |
Number of pages | 7 |
Journal | Biochimica et Biophysica Acta - Biomembranes |
Volume | 1284 |
Issue number | 1 |
DOIs | |
State | Published - 2 Oct 1996 |
Externally published | Yes |
Keywords
- 3-[I]Ioda-4-azidophenetylamido-7-O-succinyldeacetyl-forskolin
- Cytochalasin B
- Glucose transport
- Insulin-regulated glucose transporter GLUT4