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 re cycling pathways of GLUT4 in the absence and presence of insulin, West ern blots of subcellular membrane fractions demonstrate very similar d istributions of vp165 and GLUT4, Confocal microscopy of whole cells pr ovides direct evidence that these proteins share the same vesicle popu lations moving both towards and from the plasma membrane. These data a re consistent with the presence of a distinct insulin-sensitive compar tment that sequesters both GLUT4 and vp165 and suggest similar traffic king routes through the recycling compartments. (C) 1997 Federation of European Biochemical Societies.