MOTS-c

Origin and discovery

MOTS-c was identified by scanning the mitochondrial genome for short open reading frames capable of producing bioactive peptides. The resulting 16-residue product is translated from the 12S rRNA region and has been detected in plasma and multiple tissues, which is why it is often described in the literature as a mitochondrial signal acting on the nucleus — a form of retrograde communication.

Metabolic signaling

Most published work examines the peptide in the context of energy sensing:

• Reported activation of the AMPK pathway in cultured cells and rodent skeletal muscle
• Effects on glucose uptake and insulin sensitivity described in diet-induced obesity models
• Changes in fatty-acid oxidation markers reported in isolated muscle preparations

Aging and exercise models

Genetic variation

A mitochondrial single-nucleotide variant (m.1382A>C) changes one residue of the peptide and is enriched in certain Northeast Asian populations. Association studies of this variant with longevity and metabolic phenotypes are ongoing and remain an active question rather than a settled finding.

Analytical notes

The sequence contains two methionine residues and a tryptophan, so oxidation and light exposure are relevant stability considerations. Researchers commonly verify integrity by LC-MS after reconstitution when a preparation is stored for an extended period.

Allow the sealed vial to reach room temperature before opening so that condensation does not settle on the lyophilized cake. Reconstitute by directing the diluent slowly down the vial wall rather than onto the powder, then swirl gently until the solution is clear; do not shake or vortex aggressively, as mechanical stress can degrade the peptide. Keep working solutions cold and protected from light, aliquot to avoid repeated freeze–thaw cycles, and record the reconstitution date on the vial. Store unopened vials at −20 °C. All handling should follow standard laboratory practice for research chemicals.