⚖️MOTS-C
Mitochondria-encoded exercise mimetic peptide. Activates AMPK via AICAR, improves insulin sensitivity and drives fat oxidation — independently of insulin receptor signalling.
MRWQEMGYIFYPRKLRWhat Is MOTS-C?
MOTS-C (Mitochondrial Open reading frame of the 12S rRNA type-c) is a 16-amino-acid peptide encoded within the mitochondrial genome — not the nuclear genome. Discovered in 2015 by Lee et al. at USC, it is a founding member of mitochondrial-derived peptides (MDPs). Its plasma levels decline with age and obesity, inversely correlating with insulin resistance and metabolic syndrome.
Key Mechanisms
- AMPK activation via AICAR — inhibits MTHFD1 in the folate cycle, accumulating AICAR (endogenous AMP-mimetic) that phosphorylates AMPK at Thr172
- Nuclear retrograde signalling — translocates to nucleus under stress to modify ARE/Nrf2 gene expression
- GLUT4 translocation — drives skeletal muscle glucose uptake independently of insulin receptor
- β-Oxidation enhancement — AMPK→ACC inhibition→CPT-1 relief→increased mitochondrial fat import
- mTORC1 suppression — via TSC2/Raptor phosphorylation — longevity-associated metabolic state
Research Applications
- Metabolic syndrome and obesity biology
- Exercise adaptation and skeletal muscle metabolism
- Insulin resistance mechanisms
- Aging and healthspan research
- Mitochondrial biology and retrograde signalling
Key References
- Lee C et al. "MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance." Cell Metab, 2015;21(3):443–454.
- Reynolds JC et al. "MOTS-c is an exercise-induced mitochondrial-encoded regulator." Nat Commun, 2021;12:470.
Frequently Asked Questions
MOTS-c is specifically encoded within the mitochondrial genome itself (from the 12S rRNA region) rather than being a nuclear-genome-encoded protein that merely acts on mitochondria — that distinction is what defines the "mitochondrial-derived peptide" (MDP) class it founded.
It works indirectly — by inhibiting MTHFD1 in the folate cycle, MOTS-c causes AICAR (an endogenous AMP-mimetic) to accumulate, and AICAR is what phosphorylates and activates AMPK at Thr172.
Circulating MOTS-c levels rise with exercise and fall with age and obesity, which is why it's studied as a candidate "exercise mimetic" — a molecule that may reproduce some of exercise's metabolic signalling effects.