fructose 2,6-bisphosphate metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving fructose 2,6-bisphosphate. The D enantiomer is an important regulator of the glycolytic and gluconeogenic pathways. It inhibits fructose 1,6-bisphosphatase and activates phosphofructokinase. [ISBN:0198506732]

Fructose 2,6-bisphosphate (F2,6BP) is a potent regulator of carbohydrate metabolism, playing a critical role in the control of glycolysis and gluconeogenesis. This molecule acts as an allosteric activator of phosphofructokinase 1 (PFK1), the key regulatory enzyme in glycolysis, and as an inhibitor of fructose 1,6-bisphosphatase (FBPase-1), the key regulatory enzyme in gluconeogenesis.

The synthesis and degradation of F2,6BP are catalyzed by two distinct enzymes: 6-phosphofructo-2-kinase (PFK-2) and fructose 2,6-bisphosphatase (FBPase-2). PFK-2 is responsible for the synthesis of F2,6BP, while FBPase-2 catalyzes its degradation. These two enzymes are often encoded by the same gene, and their activity is regulated by a variety of mechanisms, including phosphorylation, allosteric regulation, and hormonal control.

**In the presence of high glucose levels**:

1. **Increased Insulin Signaling**: Insulin promotes the dephosphorylation of PFK-2, converting it to the active kinase form. This leads to an increase in the production of F2,6BP.
2. **Activation of PFK1**: Elevated levels of F2,6BP activate PFK1, stimulating the glycolytic pathway and promoting glucose utilization for energy production.
3. **Inhibition of FBPase-1**: F2,6BP inhibits FBPase-1, reducing gluconeogenesis and preventing the unnecessary synthesis of glucose.

**In the presence of low glucose levels**:

1. **Increased Glucagon Signaling**: Glucagon promotes the phosphorylation of PFK-2, converting it to the inactive kinase form. This leads to a decrease in the production of F2,6BP.
2. **Inhibition of PFK1**: Reduced levels of F2,6BP decrease the activity of PFK1, slowing down glycolysis.
3. **Activation of FBPase-1**: The lowered concentration of F2,6BP allows FBPase-1 to be active, promoting gluconeogenesis and the production of glucose to maintain blood glucose levels.

In summary, the F2,6BP metabolic process plays a crucial role in the fine-tuning of glucose metabolism, ensuring the appropriate balance between glycolysis and gluconeogenesis depending on the physiological state and energy demands of the organism.'
"

Proteins (1)

Compounds (3)