What activates pfk2?
2 min read
Asked by: Grace Rossman
PFK2 is regulated by the hormones glucagon in the liver, epinephrine in muscle and by insulin. Both glucagon and epinephrine stimulate adenylate cyclase and cAMP-dependent protein kinase (PKA) in liver.
What stimulates PFK?
PFK-1 is allosterically regulated by several effectors: Fructose 2,6-bisphosphate (F2,6-BP): This effector is a “well-fed” signal that allosterically stimulates PFK-1 in the liver (Fig. 6-4). It is synthesized from F6P by PFK-2 when insulin (and glucose) levels are high.
What conditions activate PFK?
PFK1 is activated by high AMP and ADP and inhibited by high ATP levels.
Is PFK-2 activated by AMP allosterically?
PFK-2 is allosterically stimulated by inorganic phosphate, AMP, and fructose-6-phosphate and inhibited by citrate, fructose-2,6-bisphosphate, phosphoenolpyruvate, and α-glycerol phosphate.
Does phosphorylation activate PFK-2?
Phosphorylation activates PFK-2 with no effect on FBPase-2 activity.
How is PFK regulated during glycolysis?
Regulation of glycolysis
PFK is regulated by ATP, an ADP derivative called AMP, and citrate, as well as some other molecules we won’t discuss here. ATP. ATP is a negative regulator of PFK, which makes sense: if there is already plenty of ATP in the cell, glycolysis does not need to make more.
Why does glucagon inhibit PFK?
Glucagon activates protein kinase A which, in turn, shuts off the kinase activity of PFK2. This reverses any synthesis of F-2,6-BP from F6P and thus inhibits PFK1 activity.
Is PFK-1 activated when phosphorylated?
AKT also increases glycolysis by activating the enzyme phosphofructokinase-1 (PFK1) through phosphorylation of phosphofructokinase-2 (PFK2) (Deprez, Vertommen, Alessi, Hue, & Rider, 1997), which leads to allosteric activation of PFK1.
How does insulin and glucagon regulate Phosphofructokinase-1?
Insulin, alone and with glucagon, increased the Fru-2,6-P2 activation ratio. In the presence of glucagon, insulin increased Fru-2,6-P2 concentrations in hepatocytes. These effects suggest that PFK-1 is a potential regulatory point for hormones in the control of carbohydrate metabolism in the American eel liver.
Which of the following compounds are allosteric activators of phosphofructokinase PFK )?
Allosteric activators of muscle PFK-1 include adenosine monophosphate (AMP), adenosine diphosphate (ADP), fructose-6-phosphate, and inorganic phosphate (Pi); inactivators are citrate, fatty acids, and ATP.
Does PFK-2 use ATP?
Most importantly, PFK-1 activity is affected by ATP, while PFK-2 activity is not affected by ATP concentration.
