GLUT 1 is the glucose transporter in the human red cell. The first to be characterized by molecular cloning ( 9), it consists of 492 amino acid residues (TableA^. The gene for its expression is located on chromosome 1. GLUT 1 is widely distributed in many tissues including heart, kidney, adipose cells, fibroblasts, placenta, retina, and brain, but little is expressed in muscle or liver. Since there is particularly high expression in the endothelial cells of the microvessels of the brain, it forms part of the blood-brain barrier (17). The transport process for D-glucose in the red cell is asymmetrical, as the affinity (K m) for D-glucose uptake is approximately 1 to 2 mmol/L while the Km for the exit of glucose is 20 to 30 mmol/L. This asymmetry appears to be allosterically regulated by the binding of intracellular metabolites and inhibited by adenosine triphosphate (ATP) (18). The asymmetry allows the transporter to be effective when the extracellular glucose is low and the intracellular demand high.
Was this article helpful?
I lost over 60 pounds and 4+ inches off my waist without pills, strenuous exercise, or any of the things that the diet experts tell you to do...and I did it in less than 4 months! If you have the desire, and can read through my e-book , then this is for you! I could have easily made it a lot more difficult, with stacks of information that people will never read, but why?