UNIQUE SUBCELLULAR-DISTRIBUTION OF 5 ANNEXINS IN RESTING AND INSULIN-STIMULATED RAT ADIPOSE-CELLS

Several lines of evidence suggest that annexins, a family of phospholi pid-binding proteins, play a role in cellular trafficking. Five annexi ns (I, II, V, VI, VII) were detected in rat adipose cells. They were p rimarily associated with the plasma membrane in a calcium-dependent ma nner, None of them redistributed with insulin treatment of the cells, in contrast to the glucose transporter GLUT4, which moved from intrace llular membranes to the plasma membrane. Although the actual function of annexins in adipose cells remains to be determined, our data indica te that insulin-stimulated GLUT I trafficking does not rely on a chang e in subcellular location of any of the five annexins detected so far in these cells. (C) 1996 Academic Press, Inc.