glucose transmembrane transport

Definition

Target type: biologicalprocess

The process in which glucose is transported across a membrane. [GO_REF:0000069, GOC:TermGenie, PMID:9090050]

Glucose transmembrane transport is a crucial process for cellular energy metabolism, enabling cells to take up glucose from the extracellular environment and utilize it as fuel. The transport process is facilitated by specialized membrane proteins called glucose transporters (GLUTs), which exhibit high affinity for glucose and mediate its movement across the plasma membrane.

There are multiple GLUT isoforms, each with distinct tissue distribution and kinetic properties. GLUT1 is ubiquitously expressed and serves as the primary glucose transporter in the brain and erythrocytes. GLUT2, found primarily in the liver, pancreas, and small intestine, facilitates glucose uptake and release, playing a role in blood glucose regulation. GLUT3 is highly expressed in neurons, ensuring a constant supply of glucose for neuronal activity. GLUT4 is insulin-sensitive and found in skeletal muscle, adipose tissue, and heart, mediating glucose uptake in response to insulin signaling.

Glucose transport across the plasma membrane follows a passive diffusion mechanism, meaning it does not require energy expenditure. The GLUTs act as carriers, binding to glucose molecules on the extracellular side of the membrane and facilitating their passage through the lipid bilayer. The driving force for glucose transport is the concentration gradient, with glucose moving from areas of high concentration to areas of low concentration.

The process of glucose transmembrane transport involves several key steps:

1. Glucose binding: The GLUT protein binds to a glucose molecule on the extracellular side of the membrane.
2. Conformational change: Upon glucose binding, the GLUT undergoes a conformational change, opening a channel through the membrane.
3. Glucose translocation: Glucose moves through the channel, passing from the extracellular to the intracellular environment.
4. Glucose release: Once inside the cell, glucose detaches from the GLUT protein, and the transporter reverts to its initial conformation.

The efficiency of glucose transmembrane transport is influenced by various factors, including:

* Glucose concentration gradient: A larger concentration gradient between the extracellular and intracellular compartments promotes faster transport.
* Insulin levels: Insulin promotes glucose uptake by increasing the number of GLUT4 transporters on the cell surface.
* Cellular energy demands: Cells with high energy requirements exhibit increased glucose transport activity.

Glucose transmembrane transport is essential for maintaining cellular energy homeostasis and supporting various physiological functions. Dysregulation of this process can lead to metabolic disorders, such as diabetes, where impaired glucose uptake results in hyperglycemia. Understanding the mechanisms of glucose transport is crucial for developing therapies targeting these diseases and improving human health.'
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Proteins (9)

Compounds (88)