Functional characterization of the human facilitative glucose transporter 12 (GLUT12) by electrophysiological methods

Abstract:

GLUT12 is a member of the facilitative family of glucose transporters. The goal of this study was to characterize the functional properties of GLUT12, expressed in Xenopus laevis oocytes, using radiotracer and electrophysiological methods. Our results showed that GLUT12 is a facilitative sugar transporter with substrate selectivity: d-glucose ≥ α-methyl-d-glucopyranoside (α-MG) > 2-deoxy-d-glucose(2-DOG) > d-fructose = d-galactose. α-MG is a characteristic substrate of the Na+/glucose (SGLT) family and has not been shown to be a substrate of any of the GLUTs. In the absence of sugar, 22Na+ was transported through GLUT12 at a higher rate (40%) than noninjected oocytes, indicating that there is a Na+ leak through GLUT12. Genistein, an inhibitor of GLUT1, also inhibited sugar uptake by GLUT12. Glucose uptake was increased by the PKA activator 8-bromoadenosine 3′,5′-cyclic monophosphate (8-Br …

Año de publicación:

2015

Keywords:

Fuente:

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