Mitochondria share roles for energy and molecular synthesis under low-nutrient conditions, new study reveals

Researchers discovered a “division of labor” between mitochondria, with subpopulations within cells specializing in different roles when nutrients are scarce. Led by Memorial Sloan Kettering Cancer Center cell biologist Dr. Craig Thompson, the team observed that some mitochondria in nutrient-deprived cells focus on producing energy, while others turn to synthesizing molecules. necessary for cell repair and protein production. This new specialization could play an important role in how cells respond to injury and adapt to low-nutrient conditions.

Mitochondria: beyond energy production

The study was published in Nature. Mitochondria are traditionally known to produce adenosine triphosphate (ATP), the molecule that powers most cellular processes. However, they also help create amino acids, which are essential for building proteins and other vital molecules. In resource-limited environments, such as when the blood supply is reduced due to injury, mitochondria may face constraints to simultaneously support energy production and molecular synthesis. Dr. Thompson’s research team sought to understand how cells could prioritize these functions under such conditions.

Mitochondrial adaptation in mouse cells

The researchers grew mouse cells under conditions that required them to rely solely on mitochondrial ATP production, thereby limiting alternative energy sources. Unexpectedly, the mitochondria continued to produce amino acids, suggesting a specialized adaptation mechanism. A key enzyme called P5CS has been identified as playing a key role in this process. Find in certain mitochondria only, P5CS allowed the synthesis of amino acids by grouping into specific organelles. The genetic modification that prevented this clustering blocked amino acid production, revealing the essential role of P5CS in division of labor.

Implications for cancer research and cure

The study results could provide insight into how nutrient-deprived cancer cells maintain growth, as some human pancreatic cancer cells also had specialized mitochondria with P5CS clusters. Dr. Samantha Lewis, a mitochondrial biologist at the University of California, Berkeley, commented on the study, noting that it offers a model for examining mitochondrial diversity. Dr. Martin Picard, a mitochondrial psychobiologist at Columbia University, highlighted the need for further research to assess the importance of this specialization in living organisms, as this study was conducted on cultured cells.