Mots C: Mechanism of Action

Mecanismo de Acao

Primary Pathway: Folate → AICAR → AMPK ("Master Metabolic Switch")

MOTS-c inibe the folate cycle at 5-methyltetrahydrofolate (5Me-THF), blocking de novo purine biosynthesis. This leads to accumulation of AICAR (5-aminoimidazole-4-carboxamide ribonucleotide), que mimics AMP and ativa diretamente AMPK.[1]

1. MOTS-c → inibe folate cycle (5Me-THF)
2. Blocked purine synthesis → AICAR accumulation
3. AICAR (AMP mimetic) → direto(a) AMPK ativacao
4. AMPK → ACC fosforilacao → fatty acid oxidation
5. AMPK → GLUT4 translocation → aprimorou glucose uptake

Direct Binding Partners

Target	Binding Domain	Functional Consequence
CK2α	Cationic tail (¹³RKLR¹⁶)	Skeletal muscle insulin sensibilizacao; K14Q polymorphism reduz this binding[7]
Raptor (mTORC1)	Hydrophobic core (⁸YIFY¹¹)	Allosteric mTORC1 inibicao → shifts T-cell diferenciacao from Th1 to FOXP3+ Tregs[8]
Nrf2 (nuclear)	Direct chromatin binding	Nuclear translocation under stress → ARE → antioxidante expressao genica (~1,000 genes)[3]

Nuclear Translocation

Under metabolic stress (glucose restriction, estresse oxidativo), MOTS-c translocates from mitochondria/cytoplasm para o(a) nucleus. It lacks a canonical nuclear localization signal (NLS) — instead relying on its hydrophobic core for entry. Once nuclear, it binds chromatin at ARE via Nrf2 transcricao factor para regular antioxidante expressao genica.[3]

SIRT1/PGC-1α Pathway

MOTS-c aumenta intracellular NAD+ → ativa SIRT1 → PGC-1α deacetilacao → biogenese mitocondrial and anti-inflamatorio(a) cytokine regulacao.[6]

MAPK/ERK (Tissue-Dependent)

• Adipose tissue: Activates ERK → UCP1/PGC-1α → thermogenesis/browning of white fat[9]
• Inflammation: Inhibits ERK/JNK/p38 → suprime NF-κB[10]

TGF-β/SMAD (Bone)

In osteoblastos: upregula TGF-β1/2 and SMAD7 → Type I sintese de colageno → osteogenic diferenciacao.[11]

vs. Related Compounds

Compound	Origin	Key Difference
MOTS-c	mtDNA 12S rRNA (MT-RNR1)	Targets folate cycle, nuclear translocation, exercise mimetic
Humanin	mtDNA 16S rRNA	Cytoprotective but nao target folate or nuclear expressao genica
CB4211 (analog)	Synthetic (CohBar)	Engineered for melhorou stability/longer meia-vida; Phase 1b completed