Distinct localization of GLUT-1, -3, and -5 in human monocyte-derived macrophages: effects of cell activation.
We determined subcellular localization of GLUT-1, GLUT-3, and GLUT-5 as human monocytes differentiate into macrophages in culture, and effects of the activating agents N-formyl-methionyl-leucyl-phenylalanine (fMLP) and phorbol myristate acetate (PMA). Western blot analysis demonstrated progressively increased GLUT-1, rapidly decreased GLUT-3, and a delayed increase of GLUT-5 expression during differentiation. Confocal microscopy revealed that each isoform displayed a unique subcellular distribution and cell-activation response. GLUT-1 was localized primarily to the cell surface but was also detected in the perinuclear region in a pattern characteristic of recycling endosomes. GLUT-3 exhibited predominantly a distinct vesicle-like staining but was present only in monocytes. GLUT-5 was found primarily at the cell surface but was detectable intracellularly. Activation with fMLP induced similar GLUT-1 and GLUT-5 redistributions from intracellular compartments toward the cell surface. PMA elicited a similar translocation of GLUT-1, but GLUT-5 was redistributed from the plasma membrane to a distinct intracellular compartment that appeared connected to the cell surface. These results suggest specific subcellular targeting of each transporter isoform and differential regulation of their trafficking pathways in cultured macrophages.
Malide
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D
Experimental Diabetes, Metabolism, and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
Davies-Hill
T M
TM
Levine
M
M
Simpson
I A
IA
D002454:Cell Differentiation; D002478:Cells, Cultured; D051272:Glucose Transporter Type 1; D051274:Glucose Transporter Type 3; D051296:Glucose Transporter Type 5; D006801:Humans; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D018613:Microscopy, Confocal; D008970:Molecular Weight; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009419:Nerve Tissue Proteins; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D051272:Glucose Transporter Type 1; D051274:Glucose Transporter Type 3; D051296:Glucose Transporter Type 5; D009004:Monosaccharide Transport Proteins; D009419:Nerve Tissue Proteins; C495677:SLC2A1 protein, human; C495687:SLC2A3 protein, human; D009240:N-Formylmethionine Leucyl-Phenylalanine; D013755:Tetradecanoylphorbol Acetate