— Research note —
MOTS-c
Mitochondrial-derived 16-amino-acid peptide investigated for AMPK activation, metabolic regulation, and age-related research applications.
MOTS-c (mitochondrial open reading frame of the twelve S rRNA-c) is a 16-amino-acid peptide encoded within the mitochondrial 12S rRNA gene rather than the nuclear genome. The molecule was identified in 2015 by the laboratory of Pinchas Cohen at the University of Southern California through bioinformatic analysis of small open reading frames in the mitochondrial DNA. Its discovery represented one of the first characterizations of a functionally active peptide encoded within a non-coding mitochondrial transcript, expanding the conceptual framework of the "mitochondrial-derived peptide" (MDP) family that also includes humanin and the SHLP series.
In research models, MOTS-c has been observed to translocate from mitochondria to the nucleus under conditions of metabolic stress, where it appears to regulate nuclear gene expression related to mitochondrial biogenesis, antioxidant defense, and metabolic homeostasis. Circulating MOTS-c levels decline with age in rodent and human cohorts, and exogenous administration in murine models has been reported to attenuate diet-induced insulin resistance, preserve exercise capacity in aged animals, and modulate inflammatory markers.
The compound has attracted considerable academic interest as a tool molecule for studies of retrograde mitochondrial signaling, the concept that organelles communicate with the nucleus through diffusible peptide messengers. Research programs at USC, NIH, and several international groups have used MOTS-c to probe AMPK signaling, folate metabolism, and the molecular biology of exercise adaptation. Clinical-stage development by CohBar and successor entities has explored related MDPs as candidates for metabolic disease research.
MOTS-c is supplied here for in vitro and in vivo research use only. The compound is not intended for human consumption, and the research context emphasized here reflects its primary utility as a probe of mitochondrial-nuclear communication.
Mechanism
MOTS-c has been proposed to act primarily through activation of AMP-activated protein kinase (AMPK), the central cellular energy sensor. In skeletal muscle and adipose tissue preparations, the peptide elevates phosphorylated AMPK and downstream phospho-ACC, mimicking aspects of caloric restriction and exercise signaling. The upstream mechanism is thought to involve modulation of folate-methionine metabolism: MOTS-c has been observed to inhibit the AICAR-to-IMP conversion catalyzed by AICAR transformylase, elevating intracellular AICAR and thereby activating AMPK.
Under metabolic stress, MOTS-c translocates to the nucleus where it co-occupies stress-responsive promoter regions with nuclear factor erythroid 2-related factor 2 (NRF2) and other transcription factors, modulating expression of antioxidant and metabolic genes. The peptide has also been reported to engage cell-surface signaling through unidentified receptors, with effects on insulin sensitivity in hepatocyte and adipocyte preparations.
Research history
Lee, Cohen, and colleagues at the University of Southern California reported the identification of MOTS-c in Cell Metabolism in 2015, characterizing the peptide's metabolic actions in murine models. The original paper established that MOTS-c expression and circulating levels decline with age and that exogenous administration improved insulin sensitivity in high-fat-diet rodents.
Subsequent publications from the Cohen group and independent laboratories extended the characterization to exercise physiology, with reports that MOTS-c administration enhanced running capacity in aged mice and that endogenous MOTS-c levels rose acutely with exercise in human research volunteers. The nuclear translocation phenomenon was reported in 2018, providing a mechanistic basis for the peptide's effects on nuclear gene expression.
Research from 2019 through 2024 has examined MOTS-c in osteoporosis models, cardiovascular research applications, and neurodegenerative contexts. A polymorphism in the MOTS-c coding region (K14Q) has been identified at elevated frequency in certain East Asian populations and associated with metabolic phenotypes in epidemiological studies. CohBar and successor entities advanced related mitochondrial-derived peptide analogs through early-phase clinical research, while academic interest in MOTS-c as a mitochondrial signaling probe has continued to grow.
References
- Lee C, et al. 2015. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metab. PMID: 25738459
- Reynolds JC, et al. 2021. MOTS-c is an exercise-induced mitochondrial-encoded regulator of age-dependent physical decline and muscle homeostasis. Nat Commun. PMID: 33623019
- Kim KH, et al. 2018. The mitochondrial-encoded peptide MOTS-c translocates to the nucleus to regulate nuclear gene expression in response to metabolic stress. Cell Metab. PMID: 29983246
- Yen K, et al. 2020. The mitochondrial derived peptide humanin is a regulator of lifespan and healthspan. Aging.
- Merry TL, et al. 2020. Mitochondrial-derived peptides in energy metabolism. Am J Physiol Endocrinol Metab. PMID: 32893671
- Kim SJ, et al. 2018. Mitochondrially derived peptides as novel regulators of metabolism. J Physiol. PMID: 30144099
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Information presented in third-person scientific context. Research use only. Not medical advice; not for human consumption.