A Cellular Structure that Protects Against Amino Acid Stress

Amino acids form the basic building blocks of all life, used by cells both as fuel and in building proteins and other complex molecules. Cellular amino acid levels must be tightly controlled. Amino acid surplus is problematic and is a characteristic of many age-related diseases, including cancer and diabetes. Scientists do not yet fully understand how cells detect and respond to amino acid excess, and how this excess causes cellular damage. Research from University of Utah Health scientist Adam Hughes, PhD, and colleagues discovered a new mechanism by which cells protect themselves from the toxic effects of amino acid excess. When faced with high amino acid levels, cells generate a membrane-bound structure from mitochondria, called the mitochondrial-derived compartment (MDC). MDCs promote the breakdown of amino acids. Loss of MDCs, in combination with other systems that regulate amino acid levels, causes cells to become highly sensitive to deviations in amino acid supply, leading to cell death. These results shed light on how cells regulate nutrient metabolism, advancing our understanding of how cells maintain metabolic stability.