C-terminal mutations that alter the turnover number for 3-O-methylglucose transport by GLUT1 and GLUT4.

Turnover numbers for 3-O-methylglucose transport by the homologous glucose transporters GLUT1 and GLUT4 were compared to those for truncated and chimeric transporters expressed in Xenopus oocytes to assess potential regulatory properties of the C-terminal domain. The ability of high intracellular sugar concentrations to increase the turnover number for sugar entry ("accelerated exchange") by GLUT1 and not by GLUT4 was maintained in oocytes. Replacing the GLUT1 C terminus with that of GLUT4 stimulated turnover 1.