MOTS-c

MOTS-c (Mitochondrial Open Reading Frame of the 12S rRNA-c) is a 16-amino-acid mitochondrial-derived peptide — one of a growing class of bioactive peptides encoded within mitochondrial DNA rather than nuclear DNA. This is significant because it represents a direct line of communication from mitochondria to the nucleus: MOTS-c translocates to the nucleus under metabolic stress conditions and regulates nuclear gene expression, particularly genes involved in glucose and fatty acid metabolism.

Mechanistically, MOTS-c acts through at least three pathways: (1) AMPK activation via direct binding to the folate cycle enzyme MTHFD2, increasing AICAR levels and triggering AMPK phosphorylation — this enhances glucose uptake and fatty acid oxidation independent of insulin signaling; (2) SIRT1 activation via NAD+-dependent deacetylation, promoting PGC-1α-mediated mitochondrial biogenesis; (3) nuclear gene regulation via direct chromatin interaction, upregulating antioxidant response elements (AREs) and suppressing NF-κB-driven inflammation.

What makes MOTS-c unique among research peptides is its mitochondrial origin: it is one of the few peptides that signals "mitochondrial health status" to the rest of the cell, making it a key research tool in mitohormesis and metabolic flexibility studies.

MOTS-c was discovered in 2015 by Dr. Pinchas Cohen's lab at the University of Southern California, as part of a systematic search for open reading frames within mitochondrial DNA that could encode functional peptides. The discovery challenged the long-held assumption that mtDNA encodes only 13 proteins (all OXPHOS subunits), revealing a hidden peptide layer of mitochondrial gene expression.

Mouse studies demonstrated that MOTS-c administration prevents age-dependent and high-fat-diet-induced insulin resistance, increases skeletal muscle glucose uptake, and enhances physical endurance. Human studies (observational) have correlated lower MOTS-c levels with obesity and type-2 diabetes. The peptide has generated significant interest in the longevity research community as a potential mediator of the metabolic benefits of exercise, and as a tool for studying mitochondrial-nuclear communication pathways.

Store lyophilized MOTS-c at -20°C, protected from light. Stability data is more limited than for older peptides; conservative protocols recommend use within 12 months. The peptide's secondary structure includes a β-turn motif stabilized by hydrophobic interactions — avoid excessive agitation during reconstitution.

Reconstituted MOTS-c should be stored at 2–8°C and used within 14 days. Due to the 2–3× weekly research protocol, a single 10mg vial typically covers 1–2 weeks of research. The solution is clear and colorless; any turbidity indicates aggregation and the vial should be discarded.