MOTS-c

MOTS-c is unusual in this catalogue because the mitochondrial genome encodes it, not the nuclear one. The 16-amino-acid sequence sits in the MT-RNR1 region, the gene for 12S rRNA, inside an open reading frame that went unrecognised until the peptide was identified. Its name records that origin: Mitochondrial ORF of the 12S rRNA type-c.

The mechanism is indirect and worth following, because it is not a receptor story. MOTS-c interferes with the folate cycle, which throttles de novo purine biosynthesis downstream. AICAR accumulates as a consequence, and AICAR activates AMPK. So the metabolic signalling attributed to MOTS-c arrives through a metabolite, several steps from the peptide itself.

That places MOTS-c in the retrograde signalling literature: mitochondria sending instructions outward to the cell, rather than only receiving them. Published rodent and cell work has measured insulin sensitivity, glucose handling, exercise response, and age-related metabolic change.

SS-31 is the other mitochondrial compound here, and the two are not interchangeable. SS-31 binds cardiolipin in the inner membrane and stays structural. MOTS-c leaves the mitochondrion and acts through metabolic signalling.

Supplied as a lyophilised powder at ≥99% purity by HPLC, with batch LC-MS identity confirmation and a certificate of analysis. Reconstitute with bacteriostatic water. Store the sealed vial at -20°C and keep reconstituted solution at 2-8°C, protected from light.

For in-vitro laboratory research only. Not for human or veterinary use.