Higher Ssd1 levels and calorie restriction may extend yeast lifespan by reducing harmful iron buildup with age

Overexpression of the mRNA binding protein Ssd1 extends the yeast replicative lifespan.

• Lifespan extension is associated with the formation of age-dependent cytoplasmic Ssd1 foci that appear during the cell cycle.
• Failure of these Ssd1 foci to resolve during mitosis correlates with the end of lifespan.
• Ssd1 overexpression and calorie restriction both promote resistance to lifespan shortening caused by iron supplementation.
• Aft1, a transcriptional regulator, translocates to the nucleus during aging in a way that predicts remaining lifespan, but this is inhibited by calorie restriction.
• Calorie restriction and Ssd1 overexpression reduce the age-dependent activation of iron transporters in yeast, which is linked to decreased intracellular iron accumulation during aging.

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