Chaperone-Mediated Autophagy (CMA) | Selection, Mechanism and Regulation

The video explains chaperone-mediated autophagy (CMA), a selective degradation process targeting proteins with a KFRQ sequence. CMA is activated during prolonged fasting and decreases with aging and certain diets. It involves chaperone proteins like HSC70 and lysosomal proteins such as lamp2A. The process is crucial for cellular health, and its dysfunction is linked to diseases like Danon disease. Lamp2C plays a role in RNA/DNA degradation independently of HSC70. The video concludes with the importance of CMA in maintaining proteostasis.

What is the primary function of the KFRQ consensus sequence in CMA?

• To enhance protein synthesis

• To select proteins for degradation

• To stabilize cellular membranes

• To promote cell division

Which chaperone protein is primarily responsible for recognizing the KFRQ sequence?

• HSP 40

• HSC 70

• Bag 1

• HSP 90

What role does HSP 90 play in the CMA process?

• It synthesizes new proteins

• It degrades proteins

• It prevents protein aggregation

• It transports proteins to the lysosome

Which lysosomal protein is crucial for acidifying the lysosome?

• Cathepsin A

• Vpas

• HSC 70

• Lamp 1

What is the primary function of cathepsins in the lysosome?

• To transport proteins

• To synthesize proteins

• To break down protein cargo

• To stabilize the lysosomal membrane

What is the rate-limiting step in the CMA process?

• Protein synthesis

• Protein translocation through lamp 2A

• Protein folding

• Protein aggregation

What disease is associated with a deficiency in lamp 2A?

• Alzheimer's disease

• Huntington's disease

• Danon disease

• Parkinson's disease

How does lamp 2C differ from lamp 2A in its function?

• It is involved in RNA and DNA degradation

• It degrades proteins

• It stabilizes the lysosomal membrane

• It transports proteins to the lysosome

Which factor is known to decrease CMA function?

• Western diet

• Exercise

• Oxidative stress

• Prolonged fasting

What percentage of soluble proteins are recycled through CMA?

• 10-20%

• 40-50%

• 20-30%

• 30-40%