What type of transporter is GLUT2?

What type of transporter is GLUT2?

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.

What is a high affinity transporter?

Typically, high-affinity transporters are expressed when substrate is scarce and low-affinity ones when it is abundant. The benefit of using low instead of high-affinity transporters remains unclear, especially when additional nutrient sensors are present. Here, we investigate two hypotheses.

What type of transporter is glucose?

There are two types of glucose transporters in the brain: the glucose transporter proteins (GLUTs) that transport glucose through facilitative diffusion (a form of passive transport), and sodium-dependent glucose transporters (SGLTs) that use an energy-coupled mechanism (active transport).

What is Antiport transport?

The antiport (exchange), which involves transport of a solute from one side in exchange for a second solute from the opposite side of the membrane, and. iii. The symport (cotransport), which involves transport of two solutes in the same direction across the membrane.

What is low affinity transporter?

Many organisms have several similar transporters for the same nutrient, which differ in their affinity. Typically, high affinity transporters are expressed when substrate is scarce and low affinity ones when substrate is more abundant. This might explain the abundance of glucose transporters in yeast.

How many types of glucose transporter are there?

There are five known Class III glucose facilitative transporters, namely, GLUT6, GLUT8, GLUT10, GLUT12 and GLUT13 (HMIT). The glycosylation site in the transporters of this class is located on loop 9, in contrast to Class I and II transporters in which it is located on loop 1 (Asano et al. 1991).

Does GLUT2 have a high capacity for glucose?

GLUT2 has high capacity for glucose but low affinity (high Km, ca. 15-20 mM) and thus functions as part of the “glucose sensor” in the pancreatic β-cells of rodents, though in human β-cells the role of GLUT2 seems to be a minor one. It is a very efficient carrier for glucose. GLUT2 also carries glucosamine.

Is the glucose transporter a high or low affinity isoform?

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. Is a high-affinity isoform, allowing it to transport even in times of low glucose concentrations.

Which is a Class I facilitative glucose transporter?

The GLUTs transport glucose across the plasma membrane by means of a facilitated diffusion mechanism. Class I facilitative glucose transporters Class I facilitative glucose transportors are represented by GLUT1 to GLUT4, among which GLUT2 is expressed mainly in beta cells of the pancreas, liver and kidney.

Where does glucose transporter type 2 take place?

Glucose transporter type 2 (GLUT2) predominates in the liver (and pancreatic beta cells) and has a high K m (≈15 to 20 mmol/L); consequently, the free glucose concentration in hepatocytes increases in direct proportion to the increase in plasma glucose concentration.

Which is the main glucose transporter in the kidney?

SGLT2, which is the main glucose transporter in kidney tubules, reabsorbs glucose from glomerular filtrate. In individuals with a genetic defect in the SGLT2 gene this reabsorption of glucose is impaired, leading to he excretion of high concentrations of glucose in urine.