Biological complexity:mitochondria helps nucleus in distress (Introduction)

by David Turell , Thursday, July 05, 2018, 22:39 (2115 days ago) @ David Turell

New research shows the mitochondria release proteins to help the nucleus during cell stress:

https://www.sciencedaily.com/releases/2018/07/180705114047.htm

"Research conducted by scientists at the USC Leonard Davis School of Gerontology is the first to show that the mitochondrial and nuclear genomes co-evolved to independently cross-regulate each other. Understanding how intracellular DNA communication is hardwired into the cell will lead more researchers to appreciate the coordination of genes encoded in both genomes and their role in aging and disease.

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"Mitochondria have their own DNA that presumably comes from ancient bacteria that joined our cells a long time ago. We didn't know that our mitochondrial DNA encoded messages to control the nucleus. In fact, the nucleus has been long thought to hold all our genetic blueprint for building and operating a cell," Lee said. "This is a fundamental discovery that integrates our two genomes as a co-evolved genetic system and may have a lasting impact for a broad range of scientific and medical fields."

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"USC researchers focused on the two parts of the cell that carry DNA: the nucleus and the mitochondria. Most genetic material resides in the nucleus, which is the largest component of the cell. Its DNA sends coded templates telling the cell what to do. Smaller mitochondria function as energy-producing factories, turning food into fuel to power the cell. But size can be misleading. The mitochondria also contain DNA, all of it inherited from the mother, and as the new study shows, they are not just taking orders from the nucleus.

"Working with human cells, the scientists discovered that when a cell is under stress and starved for nutrients, MOTS-c, a small protein encoded in the mitochondria DNA, moves into the nucleus to control genes and turn on a defensive system, including an antioxidant response."

Comment: This is only part of the obvious complexity. The mechanism of how the mitochondria recognize the cell stress is still awaiting research. It is only a tiny part of the mechanism of life remaining in equilibrium.