Isolation of Plasma Membrane Vesicles from Fat Cells of Epididymal Fat Pads of the Rat by Aqueous Two-Phase Partition
The responses of fat cells to insulin involve potentially important membrane alterations. There is now considerable evidence to support the concept that insulin stimulates glucose transport by inducing a rapid and reversible translocation of glucose transporters from an intracellular membrane pool to the plasma membrane [1–4]. However, little is known about the cellular mechanism of insulin and the process or biochemical events whereby glucose transporter levels at the cell surface may be modulated. Initial efforts  to better characterise the glucose transport system involved use of a sensitive silver staining method to visualise membrane proteins in two-dimensional gel electrophoretograms in conjunction with computerised scanning and quantification. A 90 kDa protein was lost from the plasma membranes upon incubation of fat cells with insulin and calcium. We are investigating the dynamics and identity of the 90 kDa protein in the fat cell, and especially the mechanism whereby the protein is dissociated from the plasma membrane as well as its fate and function in relation to the oncoming glucose transporter vesicles from the cytoplasm.
KeywordsAdenosine Triphosphatase Plasma Membrane Vesicle Insulin Stimulate Glucose Transport Glucose Transport System Purify Plasma Membrane
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- 11.S. Kasiwampta, S. Goto, R. Samba and F. Suzuki, Inhibition by bilirubin of (Na+-K+)-activated adenosine triphosphatase and K+-activated p-nitrophenylphosphatase activities of Na+-treated microsomes from young rat cerebrum, J. Biol. Chem. 254:4577 (1979)Google Scholar
- 13.O.H. Lowry, N.J. Rosebrough, A.L. Farr and R.J. Randall, Protein measurement with the Folin phenol reagent, J. Biol. Chem. 293:265 (1951)Google Scholar