GLUT2 Is a High Affinity Glucosamine Transporter

FEBS Lett. 2002 Jul 31;524(1-3):199-203. doi: 10.1016/s0014-5793(02)03058-2.

Abstract

When expressed in Xenopus oocytes, GLUT1, 2 and 4 transport glucosamine with V(max) values that are three- to four-fold lower than for glucose. The K(m)s for glucosamine and glucose of GLUT1 and GLUT4 were similar. In contrast, GLUT2 had a much higher apparent affinity for glucosamine than for glucose (K(m)=0.8+/-0.1 mM vs. approximately 17-20 mM). Glucosamine transport by GLUT2 was confirmed in mammalian cells and, using hepatocytes from control or GLUT2-null mice, HgCl(2)-inhibitable glucosamine uptake by liver was shown to be exclusively through GLUT2. These data have implications for glucosamine effects on impaired glucose metabolism and for structure-function studies of transporter sugar binding sites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport
  • Cell Line
  • Glucosamine / metabolism*
  • Glucose Transporter Type 2
  • Hepatocytes / metabolism
  • Humans
  • Mice
  • Mice, Knockout
  • Monosaccharide Transport Proteins / genetics
  • Monosaccharide Transport Proteins / metabolism*
  • Oocytes
  • Transfection
  • Xenopus

Substances

  • Glucose Transporter Type 2
  • Monosaccharide Transport Proteins
  • Glucosamine