Does GLUT2 transport fructose?
Fourth, although all members, except GLUT5, can efficiently transport glucose, only GLUT2 and GLUT5, are capable of transporting fructose (14, 22, 23). This property allows for the uptake of fructose by liver and for transport of fructose across the basolateral membrane of epithelial cells of the small intestine.
Why is GLUT2 high in KM?
The high Km of GLUT2 allows for glucose sensing; rate of glucose entry is proportional to blood glucose levels. GLUT4 transporters are insulin sensitive, and are found in muscle and adipose tissue.
Which GLUT transfers fructose?
All three monosaccharides (glucose, galactose, and fructose) are transported from the intestinal mucosal cell into the portal circulation by GLUT2. Is a high-frequency and low-affinity isoform. Expressed mostly in neurons (where it is believed to be the main glucose transporter isoform), and in the placenta.
What is the km of GLUT2?
around 17 mM
GluT-2 have a relatively high Km value of around 17 mM, which means they do not have a high affinity for glucose and only begin to uptake glucose at high blood glucose levels (such as after carbohydrate-rich meals).
Does insulin act on GLUT2?
In pancreatic beta cells, GLUT2 is required for glucose-stimulated insulin secretion.
What type of receptor is GLUT2?
Third, GLUT2 functions as a membrane receptor of sugar. Independently of glucose metabolism, GLUT2 detects the presence of extracellular sugar and transduces a signal to modulate cell functions, including beta-cell insulin secretion, renal reabsorption, and intestinal absorption according to the sugar environment.
Why is GLUT2 low km?
GLUT2 have a lower affinity for glucose and is essential for the liver and the pancreas to regulate the blood glucose level. With a lower affinity transporter, glucose will not be taken up immediately by the liver/pancreas while reserving for the high glucose demanding organs (e.g brain, neurons, red blood cells).
What is glucokinase km?
Glucokinase: Km = 10 mM, not inhibited by glucose 6-phosphate. Present in liver and in pancreas b cells. Hexokinase: Km= 0.2 mM, inhibited by glucose 6-phosphate. Present in most cells.
Does GLUT2 need insulin?
It is the principal transporter for transfer of glucose between liver and blood Unlike GLUT4, it does not rely on insulin for facilitated diffusion.
Where are GLUT2 transporters found?
Abstract. GLUT2 is a facilitative glucose transporter located in the plasma membrane of the liver, pancreatic, intestinal, kidney cells as well as in the portal and the hypothalamus areas.