AMPK

Question 1

What is AMPK activated by? Inhibited by?

Answer 1

Activated- AMP (high AMP:ATP ratio) and ADP

Inhibited- ATP

Question 2

What does AMPK stand for?

Answer 2

AMP-activated Protein Kinase (so it’s an enzyme that phosphorylates)

Question 3

Give a general overview of what AMPK does

Answer 3

Promotes ATP production by increasing the activity or expression of proteins involved in catabolism while conserving ATP by switching off biosynthetic pathways

Question 4

What are the two general mechanisms in which AMPK is activated, or how it senses intracellular energy changes?

Answer 4

• Calcium-dependent pathway (eg: when work out and muscles release calcium)
• AMP-dependent pathway (AMP:ATP ratio raises)

**result is phosphorylation of AMPK, activating it

Question 5

AMPK activation changes local and whole body energy utilization from _______ to ______

Answer 5

FROM: an energy-consuming state (convert ATP to ADP to AMP)

TO: an energy-producing state (convert ADP/AMP to ATP) in order to restore energy balance

Question 6

Describe how AMPK can aid in glucose regulation. Where does this happen?

Answer 6

In skeletal muscles, AMPK is phosphorylated during exercise, which phosphyorylates protein AS160 to release grip and let GLUT4 move to plasma membrane

Question 7

Describe how AMPK can suppress gluconeogenesis. Where does this happen?

Answer 7

AMPK activation phosphorylates CREB co-activator, preventing it from entering the nucleus and activating CREB

• CREB is transcription factor that upregulates PEPCK and glucose-6-phosphatase (rate limiting enzymes in gluconeogenesis pathway)
• Result is gluconeogenesis suppression and increased glucose uptake in adipose and skeletal cells

Question 8

How does AMPK promote fatty acid uptake? Where does it happen?

Answer 8

In HEART MUSCLES, AMPK activation triggers translocation of FA TRANSPORTER to the plasma membrane, allowing a lot of FAs to enter into the cell

Question 9

How does AMPK promote fatty acid oxidation? Where does this happen?

Answer 9

AMPK phosphorylates acetyl-CoA carboxylase (ACC), lowering malonyl-CoA (

Question 10

How does AMPK suppress protein synthesis and promote autophagy?

Answer 10

By inhibiting mTOR pathway

Question 11

List the overall CHO, Lipid, and PRO effects of AMPK and briefly describe how it does so for each.

Answer 11

CARB:
• Enhance peripheral glucose uptake (promoting Glut4 translocation)
• Suppress gluconeogenesis (inhibiting PEPCK and glucose-6-phosphatase gene expression)

LIPID:
• Increase FA oxidation (suppressing ACC, alleviating CPT-1 inhibition)
• Increase FA uptake (promoting FA transporter translocation)

PROTEIN:
• Activates autophagy (inhibiting mTOR)
• Inhibits protein synthesis (inhibiting mTOR)

Question 12

Name three ways AMPK-based medication could benefit diabetes patients

Answer 12

• Suppresses gluconeogenesis (inhibiting PEPCK and glucose-6-phosphatase)
• Enhances peripheral glucose uptake by promoting Glut4 translocation (inuslin-independent glucose uptake)
• Promotes FA oxidation via suppressing ACC, alleviating CPT-1 inhibition