🧬 Aging Wiki

mots-c

Properties1
aliasesMitochondrial Open Reading Frame of the 12S rRNA-c, MOTSc, mitochondrial-derived peptide, MDP, MOTS c

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MOTS-c

A 16-amino-acid peptide encoded by a short open reading frame within the mitochondrial 12S rRNA gene — making it unusual among biologically active peptides in being encoded by the mitochondrial genome rather than the nuclear genome 1. Discovered in 2015 by the Cohen lab (USC), MOTS-c regulates glucose and lipid metabolism primarily in skeletal muscle, acts as a circulating “mitokine” whose levels respond to exercise and metabolic state, and declines with age. It represents the best-characterized member of the growing mitochondrial-derived peptide (MDP) class 2.

Identity and discovery

PropertyValue
Full nameMitochondrial Open Reading Frame of the 12S rRNA-c
Length16 amino acids
Mitochondrial geneMT-RNR1 (12S rRNA)
EncodingShort ORF within the 12S rRNA gene region of mtDNA
Discovery year2015
Discovery paperLee et al. Cell Metabolism 2015 1
PubChem CID146675088 (verified; sequence MRWQEMGYIFYPRKLR, MW 2174.6 Da)
Molecular weight2174.6 Da (average; PubChem CID 146675088; consistent with calculated MW for MRWQEMGYIFYPRKLR)

What makes MDPs unusual: Most biologically active peptides are encoded by nuclear genes and synthesised on cytosolic or ER-associated ribosomes. MOTS-c is translated from a small open reading frame embedded within the mitochondrial 12S rRNA transcript — a gene conventionally regarded as a structural non-coding RNA. This places MOTS-c within a small but expanding class of mitochondrial-derived peptides (MDPs) that includes humanin (HN, also encoded by 12S rRNA) and the SHLP1–6 family (encoded by 16S rRNA). The existence of peptide-coding ORFs within rRNA genes is mechanistically surprising and suggests mitochondria actively participate in intercellular signalling beyond their classical role as energy producers 2.

MDP class context (as of 2026-05-09): At least eight MDPs have been characterised with bioactivity data. MOTS-c is the most-studied for metabolic and aging phenotypes. All known MDPs are small (<25 aa) and circulate in plasma. Levels of humanin, MOTS-c, and SHLP2 are reduced in obese and diabetic states 3.

Mechanism of action

Primary mechanism: folate-methionine cycle disruption → AICAR → AMPK

MOTS-c’s metabolic effects arise from inhibition of the folate-methionine cycle in skeletal muscle cells 1. The chain:

  1. MOTS-c enters cells (mechanism of uptake not fully resolved no-mechanism) and disrupts the folate-methionine metabolic cycle.
  2. This disruption reduces methylene-tetrahydrofolate availability for purine biosynthesis.
  3. Consequently, AICAR (5-aminoimidazole-4-carboxamide ribonucleotide) accumulates — a natural intermediate in the de novo purine synthesis pathway that also serves as a direct AMPK activator.
  4. Elevated AICAR → AMPK activation → downstream metabolic reprogramming 4.

This is a non-canonical route to AMPK activation distinct from the direct AMP/ADP-sensing mechanism that is engaged by exercise-induced energy depletion. The folate-cycle input is the key distinguishing feature of MOTS-c’s mechanism vs. other AMPK activators (metformin, which operates via complex-I inhibition; AICAR administered directly). Supporting papers: Lee 2015 (discovery), Gao 2023 (mechanism review), Yin 2020 (LPS model) 5.

Verification note: The folate-AICAR mechanism was demonstrated primarily in cell culture experiments in Lee 2015. In vivo confirmation of the folate-cycle step (as opposed to alternative AMPK-activating mechanisms) is less direct. needs-replication

Nuclear translocation and gene regulation

Under metabolic stress, MOTS-c translocates from the cytoplasm to the nucleus, where it regulates transcription of metabolic and proteostatic genes 6. This places MOTS-c in a rare category of peptides that function both as circulating hormones and as intracellular transcription modulators. Specific nuclear target genes include those involved in glucose transport (GLUT4), inflammatory signalling (STAT3, IL-10), and stress response 4. The nuclear translocation mechanism is not fully characterised. no-mechanism

Downstream metabolic effects

EffectEvidence levelNotes
Insulin sensitisation (skeletal muscle)Rodent in vivoLee 2015 — prevented age-dependent and HFD-induced insulin resistance 1
Glucose uptake in muscleIn vitro + rodentAMPK → GLUT4 translocation
Inhibition of de novo lipogenesisRodent HFD modelLee 2015 1
Reduced obesity on HFDRodentLee 2015 1
Anti-inflammatory signallingIn vivo (LPS model)Yin 2020 5
Mitochondrial quality improvementIn vitro (aged MSCs)Yu 2021 7
Physical capacity enhancement (aged mice)Rodent late-life interventionReynolds 2021 6

Exercise induction in humans and animals

MOTS-c is classified as an exercise-inducible mitokine. Key evidence:

  • Reynolds et al. 2021 (Nat Commun): Exercise induces endogenous MOTS-c expression in skeletal muscle (11.9-fold) and in circulation in humans 6 (n=10 healthy young male volunteers, 24.5 ± 3.7 years). The paper demonstrated that MOTS-c translocates to the nucleus in response to metabolic stress and regulates metabolic + proteostasis genes — establishing MOTS-c as a mediator of exercise-adaptive gene expression. In aged C57BL/6N mice (23.5 months), late-life intermittent MOTS-c treatment (15 mg/kg/day IP, 3×/week, initiated at ~24 months) improved grip strength, gait, walking capacity, and blood glucose maintenance; lifespan trended toward increase (median 912 vs 970 days) but did not reach significance (P=0.05 until 31.8 months). needs-replication (single cohort; lifespan result marginal).
  • Woodhead et al. 2021 (BBA Gen Subj): Acute high-intensity exercise increases humanin and MOTS-c concentrations in both muscle and plasma; MOTS-c treatment produces adaptations similar to physical activity 8.
  • Yoon 2022 (Diabetes Metab J): MOTS-c expression increases in skeletal muscle and circulation during exercise; systemic administration increases exercise performance by boosting skeletal muscle stress responses 9.

The exercise-inducible profile positions MOTS-c as part of the “exerkine” / “mitokine” class — endogenous factors released during exercise that transduce metabolic benefits to distant tissues. Whether MOTS-c is causally responsible for any component of exercise’s aging benefits (vs. being a correlated marker) is not established. no-mechanism

Plasma levels decline with age: Multiple groups have reported reduced circulating MOTS-c in older vs. younger individuals and in metabolic disease states 10. A study in healthy aging men (D’Souza et al. 2020) found skeletal muscle MOTS-c increased 1.5-fold in older versus young men — paradoxically inversely correlated with circulating levels — and was associated with slow-type muscle fibre composition, suggesting compartment-specific regulation [PMID 32182209; not yet in wiki studies/].

Aging relevance

MOTS-c is encoded in the mitochondrial genome and its expression reflects mitochondrial transcriptional activity. Aging-associated mtDNA mutations and declining mitochondrial biogenesis impair the mitochondrial transcriptional programme, plausibly reducing MOTS-c output. Exogenous MOTS-c treatment in aged human mesenchymal stem cells in vitro restored mitochondrial morphology, reduced ROS production, reduced lipid accumulation, and reversed several aged-cell phenotypes toward youthful states 7. This is consistent with MOTS-c as both a reporter of mitochondrial function and a mediator of mitochondrial quality.

MOTS-c activates AMPK — the canonical energy sensor that is dysregulated with aging (reduced AMPKα1/2 protein expression, reduced activation in response to energy stress). AMPK activates autophagy, suppresses mTOR-driven protein synthesis, and promotes mitochondrial biogenesis. Via AMPK, MOTS-c sits at the intersection of nutrient-sensing deregulation and mitochondrial dysfunction. The folate-AICAR-AMPK mechanism is mechanistically orthogonal to canonical AMPK activators like metformin, potentially allowing additive effects if combined. needs-replication

Longevity genetics: the m.1382A>C polymorphism

A natural mtDNA variant (m.1382A>C, rs111033358), specific to East Asian populations (haplogroup D4b2), encodes a K14Q substitution in MOTS-c that reduces its insulin-sensitising efficacy both in vitro and in vivo 11. Meta-analysis across three Japanese cohorts (J-MICC, MEC, TMM; total n=27,527) showed males with the C allele had significantly higher T2D prevalence (pooled OR 1.34, 95% CI 1.14–1.54; p<0.01); this association was absent in females. The C allele effect was driven by sedentary males: in the J-MICC cohort, C-allele men in the lowest physical-activity tertile had a 65% greater T2D prevalence than A-allele counterparts (A-allele 11.2% vs C-allele 18.5%; p=0.014), whereas higher activity negated the difference — a kinesio-genomic interaction. Contrary to a prior small-sample report (n=96 centenarians suggesting enrichment), Zempo 2021 found no association with longevity in an expanded centenarian cohort (n=736): C-allele frequencies were 7.7% in centenarians vs 7.5% in controls, leading the authors to conclude the m.1382A>C variant “is unlikely to be involved with exceptional longevity.” contradictory-evidence (earlier n=96 claim superseded). Cautionary note: mtDNA population genetics are subject to selection confounds and linkage disequilibrium with other mtDNA variants.

Preclinical evidence summary

ModelInterventionOutcomeSource
CD-1 (outbred) mice, HFDMOTS-c IP 0.5 mg/kg/day × 8 weeksPrevented diet-induced obesity and insulin resistanceLee 2015 1
C57BL/6J mice, aged (12 months)MOTS-c IP 5 mg/kg/day × 7 daysReversed age-dependent insulin resistance in soleus muscleLee 2015 1
C57BL/6N mice, 12 and 22 monthsMOTS-c IP 15 mg/kg/day × 2 weeksImproved treadmill performance in middle-aged and old miceReynolds 2021 6
C57BL/6N mice, ~24 months (late-life)MOTS-c IP 15 mg/kg/day, 3×/week, late-life initiatedImproved grip, gait, walking; lifespan trend (ns); healthspan improvedReynolds 2021 6
Aged hPD-MSCs (in vitro)MOTS-c 0.5 μMActivated AMPK, inhibited mTORC1, improved mitochondrial morphology, reduced ROSYu 2021 7
BALB/c mice, LPS-induced lung injuryMOTS-c IPReduced inflammatory cytokines; improved lung pathologyYin 2020 5
D-galactose accelerated aging mouse modelExogenous MOTS-cPrevented abnormal lipid accumulation, improved mitochondrial dynamicsLi 2019 [PMID 30967270]

needs-human-replication — all intervention evidence is rodent or in vitro as of 2026-05-09. No interventional human trial of MOTS-c administration has been published.

Human evidence

Observational / biomarker data (indirect):

  • Plasma MOTS-c declines with aging and metabolic disease in multiple cohort samples 10.
  • The m.1382A>C mtDNA variant that reduces MOTS-c activity is associated with elevated T2D risk in sedentary Japanese men 11; an earlier small-sample report (n=96) suggested centenarian enrichment but a larger cohort (n=736) found no association with longevity 11.
  • MOTS-c is induced by acute exercise in healthy humans 6, and the magnitude of induction correlates with muscle metabolic adaptations.

Interventional human data: None. One active trial (NCT03878706) measures MOTS-c as a plasma biomarker in T2D patients receiving GLP-1 agonists or SGLT2 inhibitors — it is not a MOTS-c intervention trial.

Extrapolation quality:

DimensionStatus
AMPK pathway conserved in humans?Yes
Metabolic phenotype conserved?Partial — T2D reversal shown in rodents; human metabolic effects not yet tested interventionally
Replicated in humans (interventional)?No — biomarker data only

Delivery challenges and clinical development barriers

MOTS-c’s slow clinical translation reflects common peptide-therapeutic development problems:

  1. Peptide stability: Short peptides are rapidly degraded by circulating serine and metalloproteinases. MOTS-c has no disulfide bridge or cyclisation to protect it. Half-life in plasma is presumed short (no formal human PK study published as of 2026-05-09). long-term-unknown
  2. Route of administration: Oral bioavailability of unmodified peptides is negligible. Subcutaneous or IV injection is required — a practical barrier for chronic anti-aging use. Peptide modification strategies (PEGylation, cyclisation, protease-resistant analogues, liposomal encapsulation) are under exploration but no candidate has advanced to clinical testing.
  3. Endogenous production vs. exogenous dosing: The dose-response relationship between exogenous MOTS-c administration and plasma levels is not characterised in humans. Rodent studies used 0.5 mg/kg IP — a route not usable in humans. dose-response-unclear
  4. Regulatory category: MOTS-c occupies an ambiguous space — it is endogenously produced (not a foreign molecule) but is currently investigational with no IND-enabling package in the public domain as of 2026-05-09.
  5. Senescence-paradox concern: Mendelsohn & Larrick 2018 proposed that MOTS-c may promote cellular senescence in some contexts (possibly via metabolic stress signalling) and suggested co-administration with senolytics to offset this risk [PMID 30058454]. This has not been systematically tested and the primary evidence is interpretive/speculative — flag as a concern pending further study. contradictory-evidence

Limitations and knowledge gaps

  • PubChem CID 146675088 verified — sequence MRWQEMGYIFYPRKLR (16 aa), MW 2174.6 Da confirmed correct. No remaining canonical-ID gap.
  • needs-human-replication — No interventional human trial of MOTS-c has been published or registered as of 2026-05-09.
  • dose-response-unclear — Effective dose, route, and frequency in humans entirely unknown.
  • no-mechanism — Nuclear translocation mechanism not characterised; precise receptor or uptake mechanism not identified.
  • long-term-unknown — No long-term safety data in any organism for chronic MOTS-c administration.
  • needs-replication — Folate-cycle disruption as the primary AMPK-activating mechanism was demonstrated primarily in cell culture; in vivo confirmation needs independent replication.
  • ampk — primary pathway target; MOTS-c canonical mechanism converges here
  • mitochondrial-dysfunction — hallmark; MOTS-c is an MDP whose expression reflects mtDNA/mitochondrial transcriptional capacity
  • deregulated-nutrient-sensing — hallmark; MOTS-c → AMPK → nutrient-sensing normalisation
  • insulin-igf1 — pathway; MOTS-c improves insulin sensitivity via AMPK; intersects IIS
  • disabled-macroautophagy — downstream; AMPK activation de-represses autophagy (ULK1)
  • autophagy — downstream process (stub needed if not seeded)
  • exercise — MOTS-c as an exerkine/mitokine released during exercise; relevant exercise-induction context
  • elamipretide — sister compound in the mitochondria-targeted peptide class (different mechanism: cardiolipin stabilizer, not AMPK activator)
  • metformin — functional analogue at the AMPK level; mechanistic comparison relevant

Implicit stubs created by this page:

  • [[folate-cycle]] — no page exists; should be created as a process or pathway page
  • [[interventions/pharmacological/exercise-mimetics]] — referenced from exercise.md as a planned stub

Footnotes

Footnotes

  1. doi:10.1016/j.cmet.2015.02.009 · Lee C, Zeng J, Drew BG, Sallam T, Martin-Montalvo A, Wan J, Kim SJ, Mehta H, Hevener AL, de Cabo R, Cohen P · Cell Metabolism 2015;21(3):443–454 · in-vivo (mouse) + in-vitro · model: C57BL/6 mice on HFD and aged mice; cultured skeletal muscle cells · Identified 16-aa MOTS-c from mt-12S rRNA ORF; demonstrated MOTS-c prevents HFD-induced obesity and age-dependent insulin resistance via folate-cycle disruption → AICAR → AMPK activation · local PDF confirmed in a local paper archive (692 citations; impact percentile 100) ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8

  2. doi:10.1172/JCI158449 · Miller B, Kim SJ, Kumagai H, Mehta HH, Xiang W, Liu J, Bar-Shai A, Basisty N, Schilling B, Cohen P · Journal of Clinical Investigation 2022;132(8):e158449 · review · n/a · Comprehensive review of 8 MDPs as metabolic signal transducers; aging-decline and disease associations · local PDF confirmed in a local paper archive (91 citations; fwci 22.4) ↩ ↩2

  3. doi:10.1152/ajpendo.00249.2020 · Merry TL, Chan A, Woodhead JST, Reynolds JC, Kumagai H, Kim SJ, Lee C · American Journal of Physiology–Endocrinology and Metabolism 2020;319(4):E541–E548 · review · n/a · Eight MDPs identified; circulating levels of humanin, MOTS-c, SHLP2 reduced in obesity/diabetes; treatment of rodents with MDPs enhances insulin sensitivity · download pending (green OA via PMC; 134 citations; fwci 15.5) ↩

  4. doi:10.3390/metabo13010125 · Gao Y, Li X, Zheng X, Ding Z, Zheng X, Liao Y · Metabolites 2023;13(1):125 · review · n/a · MOTS-c mechanisms via folate-methionine cycle → AICAR-AMPK; downstream gene targets GLUT4, STAT3, IL-10; metabolic disorder prevention · download pending (gold OA; 21 citations; fwci 8.6) ↩ ↩2

  5. doi:10.1016/j.intimp.2019.106174 · Yin X, Jing Y, Chen Y, et al. · International Immunopharmacology 2020;78:106174 · in-vivo · model: BALB/c mice, LPS-induced acute lung injury · MOTS-c targets methionine-folate cycle → AICAR → AMPK activation; MOTS-c treatment promoted p-AMPKα, SIRT1, suppressed inflammatory signalling; improved lung pathology · PMID 31931370 ↩ ↩2 ↩3

  6. doi:10.1038/s41467-020-20790-0 · Reynolds JC, Lai RW, Woodhead JST, Joly JH, Mitchell CJ, Cameron-Smith D, Lu R, Cohen P, Graham NA, Benayoun BA, Merry TL, Lee C · Nature Communications 2021;12(1):470 · in-vivo (mouse) + human observational (exercise) · n=10 (human exercise cohort; healthy young males 24.5 ± 3.7 yr); n=10–19 (aged C57BL/6N mouse groups) · Exercise increases muscle MOTS-c 11.9-fold in humans; MOTS-c translocates to nucleus under metabolic stress; late-life MOTS-c 15 mg/kg/day IP 3×/week in C57BL/6N mice (~24 mo) improved grip strength, gait, walking capacity, blood glucose; lifespan trended upward (P=0.05 until 31.8 mo, ns overall) · local PDF confirmed in a local paper archive ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  7. doi:10.1016/j.mito.2021.02.010 · Yu W, Kim Y, Cho M, Seok J, Kim G, Lee C, Ko J, Kim Y, Lee J · Mitochondrion 2021 · in-vitro · model: aged human placenta-derived mesenchymal stem cells · MOTS-c 0.5 μM activated AMPK, inhibited mTORC1, restored mitochondrial morphology and function, reduced ROS, reduced lipid accumulation in aged hPD-MSCs · PMID 33639272 ↩ ↩2 ↩3

  8. doi:10.1016/j.bbagen.2021.130011 · Woodhead JST, Merry TL · Biochimica et Biophysica Acta – General Subjects 2021 · review · Mitochondrial-derived peptides and exercise; MOTS-c and humanin increase with acute exercise · PMID 34520826 ↩

  9. doi:10.4093/dmj.2022.0092 · Yoon TK · Diabetes & Metabolism Journal 2022 · review · n/a · Exercise, mitohormesis, and MOTS-c; MOTS-c expression increases during exercise in skeletal muscle and circulation; systemic MOTS-c administration boosts muscle stress response and exercise performance · PMID 35656563 ↩

  10. doi:10.3389/fendo.2023.1120533 · Zheng Y, Wei Z, Wang T · Frontiers in Endocrinology 2023 · review · n/a · MOTS-c: a promising mitochondrial-derived peptide for therapeutic exploitation; plasma MOTS-c declines with aging; exercise-mimetic and metabolic protection roles; decline in diabetes and CVD · PMID 36761202 ↩ ↩2

  11. doi:10.18632/aging.202529 · Zempo H, Kim SJ, Fuku N, Nishida Y, Higaki Y, Wan J, Yen K, Miller B, Vicinanza R, Miyamoto-Mikami E, Kumagai H, Naito H, Xiao J, Mehta HH, Lee C, Hara M, Patel YM, Setiawan VW, Moore TM, Hevener AL, Sutoh Y, Shimizu A, Kojima K, Kinoshita K, Arai Y, Hirose N, Maeda S, Tanaka K, Cohen P · Aging 2021;13(4 — Vol 13, No 2):1692–1703 · observational (3 cohorts) + functional · n=27,527 (J-MICC n=11,852, MEC n=3,387, TMM n=12,288) · m.1382A>C mtDNA variant encodes K14Q MOTS-c with diminished insulin-sensitising efficacy in vitro and in vivo (CD-1 mice, HFD); C-allele males have elevated T2D prevalence (pooled OR 1.34, 95% CI 1.14–1.54) driven by sedentary condition; kinesio-genomic interaction confirmed; NO centenarian enrichment found (n=736 centenarians: C allele 7.7% vs 7.5% controls) · PMID 33468709 ↩ ↩2 ↩3

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