WS: Insulin Experiments:

Question 1

What is wortmanin? Potential application to insulin signalling:

Answer 1

• Fungal metabolite
• Potent inhibitor for PI3K and related enzymes
• Rapamycin: Targets mTORC2 (activation of PI3K)

Question 2

Experiments with wortmanin and rapamycin:

Answer 2

• Control: Insulin signalling results in phosphorylation and inactivation of GSK3B; GS phosphorylated and inactivated
• Rapamycin: Indistinguishable from control; adjacent leg of pathway not involved with glycogen synthesis
• Wortmanin: Activity of GS not opposed since PI3K is inhibited