GLUT4 is an insulin-regulated glucose transporter responsible for insulin-regulated glucose uptake into fat and muscle cells. GLUT4 translocates from intracellular stores to the cell surface, from an inactive site to an active one in order to enhance glucose uptake.GLUT4 is expressed mainly in adipose tissue and skeletal muscle. It is also detected in brain, kidney and intestine.There is no evidence for mutation in GLUT4 that is linked to metabolic disease in humans. However, GLUT4 polymorphisms are rare and equally common in normoglycaemic individuals and type 2 diabetics. General decrease in GLUT4 levels show signs of diabetes, while a disruption in GLUT4 expression in muscle or adipose tissue might contribute to the development of whole-body insulin resistance in humans.
