Organelles called mitochondria are responsible for storing energy derived from the food that we eat, in the form of molecules called ATP. Although a mitochondrion has its own genome, 99% of this organelle’s proteins
1 are encoded by nuclear genes and imported from the cytosol (the liquid part of the cytoplasm) into the mitochondrion. To function effectively, this process requires coordination and communication, and it must be able to respond to any mitochondrial dysfunction that might occur. Environmental toxins
2 and disease-causing agents
3, as well as diverse age-associated conditions, including Alzheimer’s disease
4 and Parkinson’s disease
5, are associated with mitochondrial dysfunction. Writing in
Nature, Guo
et al.
6 and Fessler
et al.
7 report a previously unknown mechanism that is used by mitochondria to send a signal of their dysfunction to the cytosol and nucleus, enabling the cell to adapt to mitochondrial stress.
