MOTS-c (mitochondrial open reading frame of the 12S rRNA type-c) is a 16-amino-acid peptide that is unusual for a simple reason: it is encoded not in the nuclear genome but inside mitochondrial DNA, within the 12S ribosomal RNA gene. It belongs to a small class called mitochondrial-derived peptides, and it has become one of the most-studied molecules in metabolic and aging research since its discovery in 2015.
What you’re reading about
MOTS-c’s sequence is MRWQEMGYIFYPRKLR. It was identified by Changhan Lee and Pinchas Cohen’s group at the University of Southern California, who were looking for additional short open reading frames in mitochondrial DNA after the earlier discovery of humanin. Circulating MOTS-c is detectable in plasma, and its levels decline with age — one reason it draws interest from longevity researchers.
Mechanism under investigation
The original work showed MOTS-c acting primarily on skeletal muscle: it inhibits the folate cycle and de novo purine synthesis, which raises AICAR and activates AMPK, the cell’s master energy sensor. Under metabolic stress the peptide translocates from mitochondria to the nucleus, where it regulates nuclear gene expression — a rare example of a mitochondrial signal directing the nuclear genome. Downstream, studies report improved glucose uptake, enhanced insulin sensitivity, brown-fat thermogenic activation via ERK signaling, and reduced inflammatory and oxidative stress markers in cardiac tissue.
Research applications
- Insulin resistance and glucose homeostasis in diet-induced and age-related models.
- Exercise physiology — endurance, physical capacity, and skeletal-muscle metabolism.
- Adipose thermogenesis and cold adaptation.
- Cardioprotection in pressure-overload heart-failure models.
- Mitochondrial-to-nuclear signaling and cellular stress adaptation.
Clinical outlook
MOTS-c has moved beyond animal work. A synthetic analog, CB4211, completed a Phase 1a/1b trial in adults with obesity and nonalcoholic fatty liver disease (NCT03998514) with reported improvements in glucose and body-weight measures. That is early-stage evidence, not proof of efficacy, but it places MOTS-c in the small group of research peptides with a human safety signal on record. The 2023 review in Frontiers in Endocrinology summarizes the field’s view: substantial preclinical promise across metabolic, cardiovascular and inflammatory models, and no established clinical application yet.
Frequently asked questions about MOTS-c
Straight answers to the questions researchers most often ask. Everything below summarizes published preclinical and clinical literature; it is not medical advice, and these compounds are supplied for laboratory research only.
What is MOTS-c?
MOTS-c is a 16-amino-acid peptide encoded in mitochondrial DNA (within the 12S rRNA gene) — one of the few known mitochondrial-derived peptides. Discovered in 2015, it is studied as a metabolic regulator that signals from mitochondria to the nucleus.
What does MOTS-c do?
In animal studies it activates AMPK, improves insulin sensitivity and glucose uptake in skeletal muscle, prevents diet-induced obesity, activates brown-fat thermogenesis, and protects the heart in pressure-overload models. Plasma levels decline with age.
How does MOTS-c work?
It inhibits the folate cycle and de novo purine synthesis, which raises AICAR and activates AMPK, the cell's energy sensor. Under metabolic stress it moves to the nucleus and regulates nuclear gene expression — a rare example of a mitochondrial signal directing the nuclear genome.
Has MOTS-c been tested in humans?
A synthetic analog, CB4211, completed a Phase 1a/1b trial in adults with obesity and nonalcoholic fatty liver disease. That is early-stage safety and signal data, not proof of efficacy, but it puts MOTS-c among the few research peptides with human trial exposure.
Is MOTS-c FDA approved?
No. MOTS-c has no approved indication and is supplied for laboratory research only.
Why is MOTS-c called an "exercise mimetic"?
Because its effects overlap with exercise — AMPK activation, improved insulin sensitivity, enhanced muscle metabolism — and because exercise itself raises MOTS-c levels in muscle and plasma. Studies in mice reported improved endurance and physical capacity.
How is MOTS-c stored?
Lyophilized MOTS-c is stable cool, dry and dark, and frozen for long-term storage; reconstituted solution is refrigerated and used within about 30 days.
References
- The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance Discovery paper: AMPK activation via folate-cycle inhibition; prevents diet-induced obesity and insulin resistance in mice.
- MOTS-c: A promising mitochondrial-derived peptide for therapeutic exploitation Review of physiology and disease applications; notes plasma levels decline with age.
- The mitochondrial-derived peptide MOTS-c relieves hyperglycemia and insulin resistance in gestational diabetes mellitus
- Mitochondrial-Derived Peptide MOTS-c Increases Adipose Thermogenic Activation to Promote Cold Adaptation Brown-fat activation and white-fat browning via ERK.
- Mitochondrial derived peptide MOTS-c prevents the development of heart failure under pressure overload conditions in mice
