At least three different glucose transport systems exist in mammalian cells. These are: (1) the constitutively active, facilitative carrier characteristic of human erythrocytes, Hep G2 (ref. 2) cells and rat brain; (2) the Na-dependent active transporter of kidney and small intestine; and (3) the facilitative carrier of rat liver (B. Thorens and H. F. Lodish, personal communication). A fourth possible glucose transport system is the insulin-dependent carrier that may be specific to muscle and adipose tissue. This transporter resides primarily in an intracellular compartment in resting cells from where it translocates to the cell surface upon cellular insulin exposure. This raises the question of whether hormonal regulation of glucose transport is conferred by virtue of a tissue-specific signalling mechanism or a tissue-specific glucose transporter. Here we present data supporting the latter concept based upon a monoclonal antibody against the fat cell glucose transporter that identifies a unique, insulin-regulatable glucose transport protein in muscle and adipose tissue.

Insulin-regulatable tissues express a unique insulin-sensitive glucose transport protein.

Insulin-stimulated translocation of glucose transporters in the isolated rat adipose cells: characterization of subcellular fractions.

http://www.jbc.org/content/264/21/12358.full.pdf

Insulin-regulated glucose uptake in rat adipocytes is mediated by two transporter isoforms present in at least two vesicle populations.

Cell surface labeling of glucose transporter isoform GLUT4 by bis-mannose photolabel. Correlation with stimulation of glucose transport in rat adipose cells by insulin and phorbol ester.

L.P. Taylor

Papers

Symmetrical kinetic parameters for 3-O-methyl-D-glucose transport in adipocytes in the presence and in the absence of insulin.

Sugar transport asymmetry in human erythrocytes--the effect of bulk haemoglobin removal and the addition of methylxanthines.