PROTEOSTASIS AND AUTOPHAGY

Question 1

Describe proteostasis

Answer 1

Dynamic regulation of proteins in cell

Question 2

Describe autophagy

Answer 2

Process in which cytoplasmic material is delivered to the lysosome inside a double-membraned vesicles for degradation

Question 3

Three types of autophagy

Answer 3

Chaperone-mediated autophagy
Micro autophagy
Macro autophagy

Question 4

What is an autophagosome?

Answer 4

A unique organelle that mediates autophagy

Starts with phagophore which engulfs

Question 5

Principles of macroautophagy

Answer 5

A double membrane structure sequesters random cell material (e.g. organelles, soluble cytosolic proteins, protein aggregates) for degradation.
This structure is designated the autophagosome.
Subsequently, the outer membrane of the autophagosome lysosome containing hydrolases releases its contents into AP for degradation

Question 6

Autophagosome formation:

Initiation key players

Answer 6

MTORC1 complex
ATG1/ULK1/2 complex
Class III P13K complex

Question 7

Nucleation key players

Answer 7

PI3P recruits and activates other proteins

Question 8

Elongation and closure key players

Answer 8

Atg complex recruited - elongation

Activates LC3-PE binding - closure