MOTS-c (Mitochondrial Open Reading Frame of the 12S rRNA-c) is a 16-amino-acid peptide (sequence: MRWQEMGYIFYPRKLR) encoded within the 12S ribosomal RNA gene of mitochondrial DNA. First identified by Changhan Lee and colleagues at the University of Southern California and published in Nature Medicine in 2015, it belongs to a rare class of bioactive peptides encoded in mitochondrial, rather than nuclear, DNA.
Under conditions of metabolic stress (including nutrient excess, folate stress, and reactive oxygen species accumulation) MOTS-c translocates from the mitochondrial matrix to the nucleus. There it regulates gene expression linked to glucose homeostasis, lipid oxidation, and cellular stress adaptation. This retrograde communication from mitochondria to nucleus makes MOTS-c structurally and functionally unlike any nuclear-encoded peptide in current research.
Key mechanismMOTS-c activates the AMPK pathway, which promotes GLUT4 translocation to the cell membrane, increases glucose uptake independent of insulin, and shifts fuel utilisation toward fatty acid oxidation. These downstream effects form the basis of its metabolic and insulin-sensitivity research interest.