Cell Stress Police

Mitochondria are a cell’s power source. This organelle is also pivotal in the cell life cycle. There are multiple signaling pathways between a mitochondrion and various organelles.

The number of mitochondria in a cell varies widely by organism and tissue type. Some cells sport only a single mitochondrion, while others may have several thousand. However numerous or sparse, mitochondrial health is crucial to cell well-being.

Unsurprisingly, given the organelle’s criticality, mitochondria are watchful monitors of cell stress level. “Mitochondria act as a first line of defense in sensing stress. The mitochondria tell the rest of the cell,” said American cytologist Gerald Shadel.


Ishi Nobu, Spokes 1: The Science of Existence, BookBaby (2019).

Zheng Wu et al, “Mitochondrial DNA stress signalling protects the nuclear genome,” Nature Metabolism 1: 1209-1118 (9 December 2019).

Mitochondria are the ‘canary in the coal mine’ for cellular stress,” ScienceDaily (14 December 2019).

Mitochondrion photo courtesy of Gerald Shadel.