Question - What does the glut4 do?

Answered by: Helen Hughes  |  Category: General  |  Last Updated: 28-06-2022  |  Views: 1057  |  Total Questions: 14

GLUT4 is an insulin-regulated glucose transporter that is responsible for insulin-regulated glucose uptake into fat and muscle cells. In the absence of insulin, GLUT4 is mainly found in intracellular vesicles referred to as GLUT4 storage vesicles (GSVs). Skeletal muscle both stores glucose as glycogen and oxidizes it to produce energy following the transport step. The principal glucose transporter protein that mediates this uptake is GLUT4, which plays a key role in regulating whole body glucose homeostasis. GLUT4 is Essential for Glucose Homeostasis GLUT4 in muscle and adipose tissue is indispensable for glucose homeostasis. Interestingly, these mice also display dysregulated glucose metabolism in adipose and liver. During periods in which insulin is low, GLUT4 is found in intracellular vesicles among adipose and muscle cells. Once translocation occurs and GLUT4 is inserted into the plasma membrane, glucose absorption in the cell is increased. Facilitated diffusion of glucose down its concentration gradient into the cell occurs. GLUT2 is insulin independent (Liver and pancreas), GLUT4 is insulin dependent (on muscle, adipose, heart). GLUT2 has a higher Km and so transport is not maximally active at low concentrations. Postprandially when blood glucose is higher than the km transport into liver and pancreas will be high.

https://en.wikipedia.org/wiki/GLUT4

Glucose transporter type 4 (GLUT-4), also known as solute carrier family 2, facilitated glucose transporter member 4, is a protein encoded, in humans, by the SLC2A4 gene. GLUT4 is the insulin-regulated glucose transporter found primarily in adipose tissues and striated muscle (skeletal and cardiac).

https://www.ncbi.nlm.nih.gov/pubmed/23899560

Exercise training is the most potent stimulus to increase skeletal muscle GLUT4 expression, an effect that may partly contribute to improved insulin action and glucose disposal and enhanced muscle glycogen storage following exercise training in health and disease.

https://www.khanacademy.org/test-prep/mcat/cells/transport-across-a-cell-membrane/a/passive-transpor

Insulin triggers GLUT4 to insert into the membranes of these cells so that glucose can be taken in from the blood. Since this is a passive mechanism, the amount of sugar entering our cells is proportional to how much sugar we consume, up to the point that all our channels are being used (saturation).

https://www.ebi.ac.uk/interpro/entry/IPR002945

GLUT3 is the most prominent glucose transporter isoform expressed in adult brain, where it tends to be preferentially located in neurones, rather than in other cell types, such as glia or endothelial cells. It is also widely distributed in other human tissues, having been detected in the liver, kidney and placenta.

https://www.news-medical.net/health/What-is-Insulin.aspx

Insulin is a protein chain or peptide hormone. There are 51 amino acids in an insulin molecule. It has a molecular weight of 5808 Da. Insulin is produced in the islets of Langerhans in the pancreas.

https://www.webmd.com/diabetes/glucose-diabetes

Glucose comes from the Greek word for "sweet. " It's a type of sugar you get from foods you eat, and your body uses it for energy. As it travels through your bloodstream to your cells, it's called blood glucose or blood sugar. Insulin is a hormone that moves glucose from your blood into the cells for energy and storage.

https://www.yourhormones.info/hormones/insulin/

Without insulin, cells are unable to use glucose as fuel and they will start malfunctioning. Extra glucose that is not used by the cells will be converted and stored as fat so it can be used to provide energy when glucose levels are too low.

https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/glut1

GLUT1 is highly abundant in the mammalian erythrocyte membrane where it can rapidly equilibrate glucose between the cytoplasm of the erythrocyte and the blood plasma. GLUT1 is also found in brain tissues.

https://www.endocrineweb.com/conditions/type-1-diabetes/what-insulin

Insulin is a hormone made by the pancreas that allows your body to use sugar (glucose) from carbohydrates in the food that you eat for energy or to store glucose for future use. Insulin helps keeps your blood sugar level from getting too high (hyperglycemia) or too low (hypoglycemia).

https://www.webmd.com/diabetes/type-2-diabetes

Type 2 diabetes is a lifelong disease that keeps your body from using insulin the way it should. People with type 2 diabetes are said to have insulin resistance. People who are middle-aged or older are most likely to get this kind of diabetes, so it used to be called adult-onset diabetes.

https://en.wikipedia.org/wiki/Glucose_transporter

Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose across the plasma membrane. Because glucose is a vital source of energy for all life, these transporters are present in all phyla. GLUT is a type of uniporter transporter protein.

https://www.nih.gov/news-events/news-releases/nih-study-shows-how-insulin-stimulates-fat-cells-take-

Cells obtain energy from glucose or convert it to fat for long-term storage. Like a key fits into a lock, insulin binds to receptors on the cell's surface, causing GLUT4 molecules to come to the cell's surface. The vesicles transported GLUT4 to the cell membrane and merged with the membrane, a process known as fusion.

https://www.webmd.com/diabetes/qa/what-are-insulin-receptors

What are insulin receptors? Insulin receptors are areas on the outer part of a cell that allow insulin in the blood to join or bind with the cell. When the cell and insulin bind together, the cell can take glucose from the blood and use it for energy.