Week 3 - Regulating Metabolism

Question 1

What is mTOR?

Answer 1

Mechanistic Target of Rapamycin
- protein kinase
- involved in cell growth / proliferation / survival
- stop autography (cell recycling)

Question 2

What is AMPK?

Answer 2

• AMP-activated Protein Kinase
• energy sensor
• maintains energy during low ATP conditions
• stress signalling

Question 3

Why is agmatinase important to regulate the mTOR pathway?

Answer 3

• breaks down arginine
• arginine would activate mTORC1
• signalling pathway can be down regulated
• this is essential to stop growth but no stress is present to stop it
• maintains cycle and balance of the two responses

Question 4

How is AMPK activated?

Answer 4

• ATP on γ-subunit replaced by ADP/AMP
• Thr residue in activation loop of kinase domain is phosphorylated
• fold activation
• ATP displacement at a second site in the same subunit
• further tenfold allosteric activation