What are the differences between autophagy and apoptosis?

Question

Accepted Answer

Basis of differentiation

Autophagy

Apoptosis

Definition

Autophagy is a self-degradative process that removes dysfunctional or unnecessary components through a lysosome-dependent regulated mechanism

Apoptosis is pre-defined cell suicide, in which the cell actively destroys itself in order to maintain proper functioning in the body

Occurrence

Is caused by cellular stress (e.g. starvation)

Is caused by intracellular processes

Effect on mitochondria

Mitochondria do not become leaky

Mitochondria become leaky

Role

Autophagy balances the energy sources in the cell depending on the cellular requirements

Apoptosis balances the number of cells in a multicellular organism

Subtypes

Macrophagy, microphagy, and chaperon mediated autophagy are the subtypes

Apoptosis does not have any subtypes

Mechanism

Autophagy occurs via lysosome degradation by lysosomal hydrolases

Apoptosis occurs through caspases (which include initiator caspases and effector caspases) to degrade proteins

Regulation

Regulation of autophagy occurs by a signaling pathway mediated by tyrosine kinase

Many different proteins are involved in the regulation of apoptosis (e.g. caspases, p5 gene, Bcl-2 family of proteins, and the amyloid-B peptide)

Outcome

Autophagy forms an autophagosome, autolysosome, or chaperone bound complexes

Cells begin to condense and shrink followed by self-destruction (catalyzed by caspases)

Basis of differentiation	Autophagy	Apoptosis
Definition	Autophagy is a self-degradative process that removes dysfunctional or unnecessary components through a lysosome-dependent regulated mechanism	Apoptosis is pre-defined cell suicide, in which the cell actively destroys itself in order to maintain proper functioning in the body
Occurrence	Is caused by cellular stress (e.g. starvation)	Is caused by intracellular processes
Effect on mitochondria	Mitochondria do not become leaky	Mitochondria become leaky
Role	Autophagy balances the energy sources in the cell depending on the cellular requirements	Apoptosis balances the number of cells in a multicellular organism
Subtypes	Macrophagy, microphagy, and chaperon mediated autophagy are the subtypes	Apoptosis does not have any subtypes
Mechanism	Autophagy occurs via lysosome degradation by lysosomal hydrolases	Apoptosis occurs through caspases (which include initiator caspases and effector caspases) to degrade proteins
Regulation	Regulation of autophagy occurs by a signaling pathway mediated by tyrosine kinase	Many different proteins are involved in the regulation of apoptosis (e.g. caspases, p5 gene, Bcl-2 family of proteins, and the amyloid-B peptide)
Outcome	Autophagy forms an autophagosome, autolysosome, or chaperone bound complexes	Cells begin to condense and shrink followed by self-destruction (catalyzed by caspases)