MOTS-c is a 16-residue mitochondrial-derived peptide encoded by a short open reading frame within mitochondrial 12S rRNA, whose gene symbol is MT-RNR1. Cell and mouse studies report folate/purine-pathway, AMPK, nuclear-signaling, metabolic, and muscle observations, while human evidence consists of endogenous measurements, genetic associations, and a recruiting phase 2a trial with no posted results.
MOTS-c is unusual because its coding context is mitochondrial rather than nuclear. That fact is direct identity evidence; it is not an outcome claim. The published record then branches into cell mechanisms, mouse experiments, small studies measuring endogenous MOTS-c in people, population genetics, and a newly registered human intervention. Reading those branches as one continuous proof chain overstates what is known.
- MOTS-c contains 16 residues with sequence MRWQEMGYIFYPRKLR.
- Its short open reading frame lies within mitochondrial 12S rRNA, designated MT-RNR1. MT-RNR2 is the separate 16S rRNA locus and is not the correct MOTS-c identity.
- The 2015 discovery study linked folate-cycle and de novo purine-biosynthesis changes to AICAR accumulation and AMPK activation in experimental systems.
- Mouse metabolic and physical-capacity findings do not establish a human exercise, anti-aging, weight, or treatment effect.
- Human-relevant evidence includes endogenous exercise-linked measurements and K14Q genetic associations; neither is a trial of administered MOTS-c.
- ClinicalTrials.gov lists a recruiting phase 2a study, but no results were posted at the July 23, 2026 evidence cutoff.
What Is MOTS-c?
MOTS-c stands for mitochondrial open reading frame of the 12S rRNA type-c. Lee and colleagues reported it in 2015 as a 16-amino-acid mitochondrial-derived peptide with sequence Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg, abbreviated MRWQEMGYIFYPRKLR.[1] Reviews place it within the mitochondrial-derived peptide family alongside humanin and small humanin-like peptides, while emphasizing that the family contains distinct sequences and evidence records.[2][3]
MOTS-c identity can be stated directly: 16 residues, a defined sequence, and an sORF within the mitochondrial 12S rRNA region. Identity does not establish expression level, purity of a commercial material, receptor activity, safety, or efficacy. Each of those questions needs its own method and evidence.
MOTS-c reagent identity
| Identity field | Value (source) |
|---|---|
| CAS Registry Number | 1627580-64-6 (PubChem CID 146675088) |
| Molecular formula | C101H152N28O22S2 (PubChem CID 146675088) |
| Molecular weight | 2174.6 Da average (PubChem CID 146675088); the Apex catalog records 2174.7 g/mol |
| Sequence | Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg (MRWQEMGYIFYPRKLR), 16 residues (PMID 25738459) |
| Encoding locus | Mitochondrial 12S rRNA, gene symbol MT-RNR1 (PMID 25738459) |
| Purity specification | ≥99% by HPLC with mass-spectrometric identity confirmation (Apex catalog specification; lot-specific results live in the Lab Verified archive) |
| Regulatory status | No FDA, EMA, NMPA, or other regulatory approval anywhere, and no approved indication; research-use-only reagent |
Why Is MT-RNR1 the Correct MOTS-c Locus?
The mitochondrial genome is compact, and mitochondrial-derived peptide discovery showed that short open reading frames can overlap regions historically annotated for other functions. MOTS-c was reported from a short open reading frame within mitochondrial 12S rRNA.[1] The current gene symbol for mitochondrial 12S rRNA is MT-RNR1.
MT-RNR2 is not a synonym. It designates mitochondrial 16S rRNA, a different locus. The old Apex cover placed `MT-RNR2` beside MOTS-c and is rejected for that reason. The refreshed article, visual manifest, alt text, and replacement-hero brief lock the correct `MT-RNR1` identity.
A one-character gene-symbol error changes the biological locus. It can contaminate search results, AI summaries, schema descriptions, image alt text, and downstream datasets even when the surrounding prose is accurate. The corrected symbol is therefore treated as a release-critical fact, not a cosmetic edit.
How Were MOTS-c Mechanisms Studied?
In the foundational paper, experimental work linked MOTS-c to folate-cycle and one-carbon metabolism, the tethered de novo purine-biosynthesis pathway, accumulation of the purine intermediate AICAR, and activation of AMP-activated protein kinase (AMPK).[1] This pathway description is useful when its scope is preserved: it reports what investigators measured in specified experimental systems.
It does not mean that every observed MOTS-c effect is caused by one linear pathway, that the pathway operates identically in all tissues, or that a cell finding predicts a human outcome. Reviews of mitochondrial-derived peptides summarize wider metabolic hypotheses, but a review’s integrative model does not replace the design and limits of the underlying experiments.[4]
What Does MOTS-c Nuclear Translocation Mean?
A 2019 study reported that MOTS-c can translocate to the nucleus in response to metabolic stress and interact with nuclear transcriptional programs associated with adaptive responses.[5] That work expanded the proposed role of MOTS-c beyond a local mitochondrial signal and provided a concrete route for mitochondrial-to-nuclear communication.
“Nuclear translocation” should not be turned into a general benefit claim. A localization change and associated gene-expression pattern answer mechanistic questions in the studied cells and conditions. They do not establish that administered MOTS-c reaches the same compartment in people, produces a clinical effect, or has an acceptable safety profile. Reviews describing MOTS-c as a mitochondrial-encoded regulator of the nucleus preserve that distinction when they separate mechanistic evidence from translation.[4]
What Do Cell and Mouse Studies Show?
The preclinical literature spans several questions. The discovery work reported metabolic-homeostasis observations and identified skeletal muscle as an important target in mice.[1] A later study evaluated plasma metabolites and insulin-sensitivity-related endpoints in experimental models.[6] Another reported physical-capacity and muscle-homeostasis findings across young, middle-aged, and old mice and measured endogenous MOTS-c around exercise in a small human component.[7] Separate mouse work described changes in myostatin and muscle-atrophy signaling.[8]
These studies support model-specific statements: a measured metabolite shifted, a signaling marker changed, or a defined mouse cohort performed differently under that experiment. They do not establish a human exercise-enhancement effect, “anti-aging” treatment, weight-management outcome, lifespan extension, or administration protocol. Reviews of mitochondrial-derived peptides in aging and healthspan are useful maps of hypotheses and models, not substitutes for controlled human outcomes.[9][10]
| Evidence lane | What was measured | What it can support | What it cannot support |
|---|---|---|---|
| Cellular metabolism | Pathway intermediates and AMPK-linked readouts | Mechanistic observations under stated conditions | Universal human pharmacology |
| Nuclear signaling | Stress-linked translocation and transcriptional programs | Mitochondrial-to-nuclear signaling hypothesis | Clinical benefit |
| Mouse metabolic models | Metabolites, insulin-sensitivity-related endpoints, body and tissue measures | Preclinical model effects | Human efficacy or dose |
| Mouse muscle models | Physical capacity, homeostasis, myostatin, atrophy signaling | Model-specific muscle findings | Human performance enhancement |
What Human Evidence Exists for MOTS-c?
Human-relevant evidence currently comes from three different lanes. First, small exercise studies measured endogenous MOTS-c in muscle or circulation. In the 2021 exercise and aging paper, the human component measured exercise-induced endogenous expression; it was not a randomized trial of administered MOTS-c.[7]
Second, population genetics examined an mtDNA variant that changes residue 14 from lysine to glutamine, K14Q, associated with m.1382A>C. One study reported an association with type 2 diabetes prevalence in men across analyzed cohorts.[11] Another associated the variant with muscle-fiber composition and muscular-performance phenotypes.[12] Genetic association does not prove causation and does not predict the effect of administering the reference peptide.
Third, ClinicalTrials.gov now lists MOTS-MET (`NCT07505745`), a phase 2a randomized, double-blind, placebo-controlled study in adults with prediabetes and overweight or obesity. The registry lists a February 2026 start and recruiting status, with the last update posted April 1, 2026. No results were posted at the July 23, 2026 cutoff. Registration shows that a controlled human question is being studied; it does not establish efficacy, safety, pharmacokinetics, or dose-response.
How Strong Is the MOTS-c Evidence?
MOTS-c has direct identity evidence, replicated research interest, several mechanistic and mouse-model studies, and human-relevant observational signals. Reviews published across metabolism, aging, and mitochondrial microprotein fields show that the hypothesis space is active.[13][14] The top tier remains unresolved: there is no posted controlled-human outcome record in the frozen source set.
The recruiting trial is a meaningful change from the old article’s “no human intervention” statement, but it does not yet raise the evidence tier. Until results are available and appraised, the appropriate summary is that human efficacy, safety, dose-response, and clinical utility remain unknown. “Exercise mimetic” can describe a preclinical research framing; it should not be presented as a demonstrated human effect.
Reported readouts by source
| Reported readout, with model or population | Source |
|---|---|
| Human meta-analysis (n = 27,527): men with the m.1382A>C C-allele had higher type 2 diabetes prevalence; women did not | PMID 33468709 |
| Human: 721 Japanese athletes versus 873 controls; C-allele frequency 6.5% sprint/power, 5.1% controls, 2.9% endurance | PMID 34728329 |
| Mice: physical performance enhanced at 2, 12 and 22 months of age; intermittent treatment (3×/week) initiated at 23.5 months raised physical capacity | PMID 33473109 |
| Mouse and C2C12-myotube studies: direction of effect only, with no quantitative endpoint in the published abstracts | PMID 25738459, PMID 31293078, PMID 33554779 |
| Narrative reviews and one author commentary: no quantitative endpoint reported | PMID 27216708, PMID 28574175, PMID 31131297, PMID 31378979, PMID 32910336, PMID 35499074, PMID 36677050, PMID 36833212 |
What Can Analytical Documentation Verify?
For an RUO peptide, analytical verification begins with the expected sequence and material definition. Mass spectrometry can test whether observed ions support the expected intact mass. Reversed-phase HPLC can estimate chromatographic purity under a stated method. Sequence identity, mass identity, and chromatographic purity are related but different claims.
Neither HPLC nor mass spectrometry alone establishes biological activity, cellular uptake, AMPK signaling, sterility, clinical suitability, safety, or therapeutic effect. A current lot review should include the lot identifier, date, method, expected analyte, observed result, integration basis, and limitations. The Apex guides to reading a COA and interpreting HPLC purity explain those distinctions.
Current first-party lot documentation belongs in the Lab Verified archive, not frozen into editorial artwork. For qualified laboratory projects that have independently defined an appropriate research question, the MOTS-c research reagent page is the current material record. The broader longevity and bioregulator research hub separates MOTS-c from adjacent mitochondrial, cofactor, and short-peptide research families.
Frequently Asked Questions
What is MOTS-c?
MOTS-c is a 16-residue mitochondrial-derived peptide with sequence MRWQEMGYIFYPRKLR. It was reported from a short open reading frame within mitochondrial 12S rRNA and is studied in metabolic, stress-signaling, and muscle-related experimental systems.
Which gene contains the MOTS-c reading frame?
The MOTS-c short open reading frame is within mitochondrial 12S rRNA, whose gene symbol is MT-RNR1. MT-RNR2 is the separate mitochondrial 16S rRNA locus and is not the correct MOTS-c encoding identity.
How is MOTS-c linked to AMPK?
The 2015 discovery study linked changes in folate-cycle and de novo purine-biosynthesis pathways to AICAR accumulation and AMPK activation in experimental systems. That mechanism is model-bounded and does not establish a human treatment effect.
Is MOTS-c a proven exercise mimetic in humans?
No. Mouse studies reported physical-capacity and muscle-homeostasis findings, and small human studies measured endogenous MOTS-c around exercise. Those records do not establish that administered MOTS-c improves human exercise performance.
Is there a human MOTS-c trial?
ClinicalTrials.gov lists MOTS-MET, a recruiting phase 2a randomized study in adults with prediabetes and overweight or obesity. No results were posted at the July 23, 2026 evidence cutoff, so efficacy and safety remain unresolved.
Is MOTS-c an FDA-approved drug?
The reviewed FDA and ClinicalTrials.gov sources do not identify an FDA-approved MOTS-c drug. The current U.S. registry record describes MOTS-c as an investigational intervention, and Apex material is a research-use-only reagent.
What can a MOTS-c COA establish?
A lot-specific COA can document the stated material, test methods, chromatographic purity result, and mass-identity result for that lot. It cannot establish receptor activity, human safety, clinical efficacy, or therapeutic equivalence.
References
- Lee C, et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metab. 2015;21(3):443-54. PMID: PMID 25738459.
- Lee C, et al. MOTS-c: A novel mitochondrial-derived peptide regulating muscle and fat metabolism. Free Radic Biol Med. 2016;100:182-187. PMID: PMID 27216708.
- Kim SJ, et al. Mitochondrially derived peptides as novel regulators of metabolism. J Physiol. 2017;595(21):6613-6621. PMID: PMID 28574175.
- Benayoun BA, et al. MOTS-c: A Mitochondrial-Encoded Regulator of the Nucleus. Bioessays. 2019;41(9):e1900046. PMID: PMID 31378979.
- Lee C. Nuclear transcriptional regulation by mitochondrial-encoded MOTS-c. Mol Cell Oncol. 2019;6(2):1549464. PMID: PMID 31131297.
- Kim SJ, et al. The mitochondrial-derived peptide MOTS-c is a regulator of plasma metabolites and enhances insulin sensitivity. Physiol Rep. 2019;7(13):e14171. PMID: PMID 31293078.
- Reynolds JC, et al. MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis. Nat Commun. 2021;12(1):470. PMID: PMID 33473109.
- Kumagai H, et al. MOTS-c reduces myostatin and muscle atrophy signaling. Am J Physiol Endocrinol Metab. 2021;320(4):E680-E690. PMID: PMID 33554779.
- Kim SJ, et al. Mitochondrial-derived peptides in aging and age-related diseases. Geroscience. 2021;43(3):1113-1121. PMID: PMID 32910336.
- Miller B, et al. Mitochondria-derived peptides in aging and healthspan. J Clin Invest. 2022;132(9). doi:10.1172/JCI158449. PMID: PMID 35499074.
- Zempo H, et al. A pro-diabetogenic mtDNA polymorphism in the mitochondrial-derived peptide, MOTS-c. Aging (Albany NY). 2021;13(2):1692-1717. PMID: PMID 33468709.
- Kumagai H, et al. The MOTS-c K14Q polymorphism in the mtDNA is associated with muscle fiber composition and muscular performance. Biochim Biophys Acta Gen Subj. 2022;1866(2):130048. PMID: PMID 34728329.
- Gao Y, et al. MOTS-c Functionally Prevents Metabolic Disorders. Metabolites. 2023;13(1). doi:10.3390/metabo13010125. PMID: PMID 36677050.
- Kumagai H, et al. Novel Insights into Mitochondrial DNA: Mitochondrial Microproteins and mtDNA Variants Modulate Athletic Performance and Age-Related Diseases. Genes (Basel). 2023;14(2). doi:10.3390/genes14020286. PMID: PMID 36833212.
