Vp165 and GLUT4 share similar vesicle pools along their trafficking pathways in rat adipose cells.
vp165 (or gp160) is an aminopeptidase that has been identified as one of the major proteins of the GLUT4-containing vesicles. In the present study we have determined the degree of co-localization between vp165 and GLUT4 in rat adipose cells and used perturbation by wortmannin to assess the exocytic and endocytic steps along the translocation and recycling pathways of GLUT4 in the absence and presence of insulin. Western blots of subcellular membrane fractions demonstrate very similar distributions of vp165 and GLUT4. Confocal microscopy of whole cells provides direct evidence that these proteins share the same vesicle populations moving both towards and from the plasma membrane. These data are consistent with the presence of a distinct insulin-sensitive compartment that sequesters both GLUT4 and vp165 and suggest similar trafficking routes through the recycling compartments.
Malide
D
D
Diabetes Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA. danielam@bdg10.niddk.nih.gov
St-Denis
J F
JF
Keller
S R
SR
Cushman
S W
SW
D000273:Adipose Tissue / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism*; D000626:Aminopeptidases / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D010122:Cystinyl Aminopeptidase; D051275:Glucose Transporter Type 4; D007425:Intracellular Membranes / Q000201:enzymology* / Q000378:metabolism*; D008297:Male; D018613:Microscopy, Confocal; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009124:Muscle Proteins; D051381:Rats; D017207:Rats, Sprague-Dawley
D051275:Glucose Transporter Type 4; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; C495694:Slc2a4 protein, rat; D000626:Aminopeptidases; D010122:Cystinyl Aminopeptidase; C105964:leucyl-cystinyl aminopeptidase