TLS Online TPP Program

#Id: 8210

#Unit 2. Cellular Organization

Autophagy (“eating oneself”)

When cells are placed under stressful conditions, they have the capacity to recycle macromolecules for use as nutrients in a process of lysosomal degradation.

TLS Online TPP Program

#Id: 8211

#Unit 2. Cellular Organization

Autophagosome, or autophagic vesicle

formation of a flattened double-membrane cup-shaped structure that envelops a region of the cytosol or an entire organelle.

TLS Online TPP Program

#Id: 8212

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 8213

#Unit 2. Cellular Organization

Autophagy occurs in the following sequence of steps:

Induction by activation of mTOR complex 1

• Nucleation of autophagosome formation by ATG9

• Closure of the membrane cup to form autophagosome

• Fusion of the autophagosome with lysosomes, catalyzed by SNAREs.

• Digestion of the inner membrane and the lumenal contents of the autophagosome

TLS Online TPP Program

#Id: 8215

#Unit 2. Cellular Organization

Autophagy can be either

• Nonselective autophagy

• Selective autophagy

TLS Online TPP Program

#Id: 8216

#Unit 2. Cellular Organization

In nonselective autophagy, a bulk portion of cytoplasm is sequestered in autophagosomes