Glucose deprivation induces the selective accumulation of hexose transporter protein GLUT-1 in the plasma membrane of normal rat kidney cells.
Antibody to the carboxyl-terminal of hexose transporter protein GLUT-1 was used to localize this carrier in normal rat kidney (NRK) cells during D-glucose (Glc) deprivation. Glc-deprivation of NRK cells induces increased hexose transport, inhibits the glycosylation of GLUT-1, and increases the content of both native, 55,000 apparent mol wt (Mr) and aglyco, 38,000 Mr GLUT-1 polypeptides. The distribution of GLUT-1 protein in subcellular fractions isolated from Glc-fed NRK cells shows that the 55,000 Mr polypeptide is most abundant in intracellular membrane fractions. Glc-fed cells that have been tunicamycin treated contain principally the 38,000 Mr GLUT-1 polypeptide, which is found predominantly in intracellular membrane fractions. In Glc-deprived cells the 55,000 Mr GLUT-1 polypeptide localizes predominantly in the Golgi and plasma membrane fractions, whereas the more abundant 38,000 Mr GLUT-1 polypeptide is distributed throughout all membrane fractions. In Glc-deprived but fructose-fed cells only the 55,000 Mr GLUT-1 polypeptide is detected, and it is found predominantly in the plasma membrane and Golgi fractions. The localization of GLUT-1 protein was directly and specifically visualized in NRK cells by immunofluorescence microscopy. Glc-fed cells show little labeling of cell borders and a small punctate juxtanuclear pattern suggestive of localization to the Golgi and, perhaps, endoplasmic reticulum. Glc-fed cells that have been tunicamycin treated show large punctate intracellular accumulations suggestive of localization to distended Golgi and perhaps endoplasmic reticulum. Glc-deprived cells exhibited intense labeling of cell borders as well as intracellular accumulations. Glc-deprived but fructose-fed cells show fewer intracellular accumulations, and the labeling is, in general, limited to the cell borders. Our results suggest that Glc deprivation induces the selective accumulation of GLUT-1 in the plasma membrane of NRK cells.
Haspel
H C
HC
Department of Physiology and Biophysics, State University of New York, Stony Brook 11794.
Mynarcik
D C
DC
Ortiz
P A
PA
Honkanen
R A
RA
Rosenfeld
M G
MG
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D005947:Glucose / Q000008:administration & dosage / Q000502:physiology*; D006031:Glycosylation; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007425:Intracellular Membranes / Q000378:metabolism; D007668:Kidney / Q000378:metabolism* / Q000648:ultrastructure; D008970:Molecular Weight; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D051381:Rats; D014415:Tunicamycin / Q000494:pharmacology
D009004:Monosaccharide Transport Proteins; D014415:Tunicamycin; D005947:Glucose