Effects of insulin and GTPγS on the subcellular distribution of Rab proteins in 3T3-L1 adipocytes. 3T3-L1 adipocytes were stimulated with GTPγS (100 μM) or insulin (1 μM) for 15 min and subjected to subcellular fractionation as outlined in MATERIALS AND METHODS. Aliquots (10 μg of protein) of isolated plasma membrane (PM) and low-density microsomes (LDM) were separated by SDS PAGE, transferred to nitrocellulose, and immunoblotted with antibodies against vp165, GLUT4, Rab4, Rab5, Rab7, or Rab11 and Syntaxin 4 as indicated. Shown are representative immunoblots from three experiments of this type. Quantification of this data is presented in B.