I examine the enzyme Phosphofructokinase 2 (PFK2) in wildtype and mutant animals

Question

I examine the enzyme Phosphofructokinase 2 (PFK2) in wildtype and mutant animals. I find that in the presence of Glucagon, the wildtype PFK2 is phosphorylated, whereas the mutant is not. When treated with Insulin, both the wildtype and mutant PFK2 are non-phosphorylated. cAMP levels in wildtype and mutant cells are indistinguishable in all conditions. A schematic of Glucagon signaling is shown alongside. Low Blood Glucose Glucagon secretion by Pancreas Glucagon receptors on Liver Activation of Adenylate cyclase Activation of Protein KinaseA Phosphorylation of Pyruvate kinase Phosphorylation of PFK2

Explanation / Answer

Phosphofructokinase regulate the glycolysis and gluconeogenesis in the human body. Normally, glucagon inhibits PFK2 activity by activating protein kinase A. Thus according to decription given, presence of glucagon will cause PFK2 to gets phosphorylated. It also means phosphorylation inhibits PFK2. But in presence of insulin, PFK2 gets activated. Insulin activates protein phosphatses, that dephosphorylates PFK2, and thus activation. So, mutant types is activated in presence of glucagon as well as in presence of insulin.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.