Biological complexity: how mitochondria call for help: (Introduction)

by David Turell , Thursday, March 05, 2020, 22:01 (1506 days ago) @ David Turell

They always need help from the whole cell:

https://phys.org/news/2020-03-mitochondrial-distress-pathway-revealed.html

"This unbiased genome-wide screening procedure revealed two mitochondrial key factors that are essential for the ability of the mitochondria to activate the cellular stress response. One of these is the enzyme OMA1, which can cleave target proteins, and the other is a barely studied protein called DELE1," Jae explains.

When mitochondria are exposed to stress, OMA1 becomes activated and induces the cleavage of the DELE1 protein into a shorter fragment. This fragment is then redistributed to the cytosol, where it binds to another enzyme called HRI, which in turn triggers the ISR. "HRI was thus far believed to be primarily required for the formation of red blood cells," says Jae. "Our study has now shown that it can also be activated by DELE1 in the context of mitochondrial perturbation."

Comment: As usual the reaction involves very specialized proteins and complex enzymes. Could not have developed by chance.