Distinct localization of gluts 1, 3, and 5 in human monocyte
-derived macrophages: effects of cell activation.
Malide, Daniela, Theresa M. Davies-Hill, Mark Levine, and Ian A.
Simpson.
Experimental Diabetes, Metabolism, and Nutrition Section, and
Molecular and Clinical Nutrition Section, Diabetes Branch, NIDDK,
National Institutes of Health, Bethesda, MD 20892 USA
APStracts 4:0276E, 1997.
We determined subcellular localization of GLUT1, GLUT3, and GLUT5 as
human monocytes differentiate into macrophages in culture, and
effects of the activating agents formyl-methionyl-leucyl
-phenylalanine (fMLP) and phorbol myristate acetate (PMA). Western
blot analysis demonstrated progressively increased GLUT1, rapidly
decreased GLUT3, and a delayed increase of GLUT5 expression during
differentiation. Confocal microscopy revealed that each isoform
displayed an unique subcellular distribution and cell-activation
response. GLUT1 was localized primarily to the cell surface but was
also detected in the perinuclear region, in a pattern characteristic
of recycling endosomes. GLUT3 exhibited predominantly a distinct
vesicle-like staining but was only present in monocytes. GLUT5 was
found primarily at the cell surface but was detectable
intracellularly. Activation with fMLP induced similar GLUT1 and GLUT5
redistributions from intracellular compartments towards the cell
surface. PMA elicited a similar translocation of GLUT1, but GLUT5 was
redistributed from the plasma membrane to a distinct intracellular
compartment which 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.
Received 28 August 1997; accepted in final form 10 December 1997.
APS Manuscript Number E404-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 7 January 1998