Figure 3. Mitochondrial signaling may mediate the cross-talk between the insulin/IGF-1 signaling and TOR pathways to regulate longevity.
Mitochondria are known to signal to the nucleus by at least two mechanisms: one is the retrograde signaling pathway (RTG) that involves LST8 and possibly TOR; the other uses reactive oxygen species and signals through the JNK–FOXO pathway. AMPK also receives input from mitochondria and is yet another protein involved in the mitochondrial control of lifespan.