Mitochondrial-Derived Peptides: The MOTS-c Research Field
Mitochondrial-derived peptides are a relatively recent discovery in signalling biology, and MOTS-c is among the most studied. The concept itself is what makes the field interesting.
An unexpected coding source
Mitochondria retain their own small circular genome, long understood to encode a limited set of respiratory chain components along with mitochondrial transfer and ribosomal RNAs. Mitochondrial-derived peptides are short peptides encoded within short open reading frames inside those RNA regions. MOTS-c is a sixteen-residue peptide encoded within the 12S ribosomal RNA region of mitochondrial DNA, first described in 20151. Its identification supported a broader idea: that mitochondria communicate with the rest of the cell not only through metabolites and reactive oxygen species but through peptide signals.
Proposed mechanisms
Published work has reported that MOTS-c influences metabolic regulation with involvement of the AMP-activated protein kinase pathway, a central cellular energy sensor, and connections to folate-dependent one-carbon metabolism. A notable reported feature is that under metabolic stress the peptide translocates to the nucleus2, where it has been described as influencing expression of stress-responsive genes. If robust, this places a mitochondrially encoded peptide in a direct retrograde signalling role from organelle to nucleus.
Research context
Much of the work is in cell culture and rodent models examining metabolic and exercise physiology. Some human association studies have examined a mitochondrial DNA variant affecting the MOTS-c sequence in specific populations. The field is young, and detection and quantification of endogenous mitochondrial-derived peptides remain technically demanding, which is a recognised methodological caveat when comparing results across laboratories.
Why researchers care
Independent of any application, the discovery expanded the recognised coding capacity of the mitochondrial genome. That is a conceptual shift, and it is the primary reason the area attracts continued investigation.
References
- Lee C, Zeng J, Drew BG, et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metab. 2015;21(3):443–454. doi:10.1016/j.cmet.2015.02.009
- Kim KH, Son JM, Benayoun BA, Lee C. The mitochondrial-encoded peptide MOTS-c translocates to the nucleus to regulate nuclear gene expression in response to metabolic stress. Cell Metab. 2018;28(3):516–524. doi:10.1016/j.cmet.2018.06.008
Disclosure. This article is educational and summarises published scientific literature. It is not medical advice, and it does not describe outcomes you should expect. These statements have not been evaluated by the Food and Drug Administration, and the products discussed are not intended to diagnose, treat, cure, or prevent any disease. The products discussed are supplied for laboratory and research use only and are not for human or veterinary use, administration, or consumption. For adults 21 and over.
