regulation of transcription by glucose

Definition

Target type: biologicalprocess

Any process involving glucose that modulates the frequency, rate or extent or transcription. [GOC:go_curators]

Glucose, a fundamental energy source for cells, plays a crucial role in regulating transcription, the process of copying genetic information from DNA to RNA. This intricate process involves a complex interplay of molecular mechanisms that sense glucose availability and trigger appropriate transcriptional responses.

The key players in glucose-mediated transcription regulation are transcription factors, proteins that bind to specific DNA sequences called promoters, which control the initiation of transcription. When glucose levels are high, cells activate pathways that promote the expression of genes required for glucose metabolism and utilization. Conversely, when glucose is scarce, cells suppress these genes and activate pathways that promote alternative energy sources, such as fatty acid oxidation.

One of the most well-studied mechanisms of glucose regulation is the **glucose-sensing pathway involving the transcription factor ChREBP (carbohydrate response element binding protein).** This pathway is activated by high glucose levels and involves the phosphorylation and activation of ChREBP, leading to its translocation to the nucleus. In the nucleus, ChREBP binds to the carbohydrate response element (ChoRE) in the promoters of genes involved in glucose metabolism, such as **glucokinase (GK), pyruvate kinase (PK), and lipogenesis-related genes.** This activation stimulates the expression of these genes, enhancing glucose uptake, glycolysis, and lipid biosynthesis.

Another important pathway involves the **AMP-activated protein kinase (AMPK), a sensor of cellular energy status.** When glucose levels are low, AMPK is activated by an increase in the AMP/ATP ratio. Activated AMPK can directly or indirectly inhibit the activity of transcription factors that promote glucose uptake and utilization, such as **sterol regulatory element binding protein 1c (SREBP1c), which regulates lipogenesis, and carbohydrate response element binding protein (ChREBP).** This suppression reduces glucose consumption and promotes the expression of genes involved in alternative energy sources, such as fatty acid oxidation.

**Furthermore, glucose levels can also impact transcription indirectly by influencing the levels of intracellular signaling molecules.** For instance, insulin, a hormone released in response to high glucose levels, activates downstream signaling pathways that involve **insulin receptor substrate (IRS) proteins and phosphatidylinositol 3-kinase (PI3K).** These pathways ultimately lead to the activation of **transcription factors like sterol regulatory element binding protein 1c (SREBP1c) and peroxisome proliferator-activated receptor γ (PPARγ),** which promote the expression of genes involved in glucose uptake, glycolysis, and lipid metabolism.

In summary, the regulation of transcription by glucose involves a complex interplay of signaling pathways, transcription factors, and metabolic intermediates. These intricate mechanisms ensure that cells can adapt to fluctuating glucose levels, maintain energy homeostasis, and respond to changes in nutrient availability.'
"

Proteins (2)

Compounds (38)