GLUT2

GLUT 2 is a transmembrane carrier protein and gene which is involved in passive glucose transport.

Locations
It is found in cellular membranes of:
 * liver
 * pancreatic beta cells
 * hypothalamus
 * basolateral membrane of small intestine
 * basolateral membrane of renal tubular cells

Function
It has high capacity but low affinity (high Km, ca. 5 mM) part of "the glucose sensor" in pancreatic ß-cells. It is a very efficient carrier for glucose. This receptor is insulin-independent.

It may also carry glucosamine, suspected because mouse embryos lacking this glucose carrier protein/gene- and its suspected capacity to transport glucosamine- soon die. According to genetics researchers in neonatal and maternal-fetal medicine at Harvard University Medical School and Beth-Israel Deaconess Hospital Medical Center, this creates a problem for diabetic pregnancies in which glucose levels in the woman are uncontrolled, exposing her fetus to the possibility of neural tube and cardiac defects in the early-developing brain, spine, and heart.