S6K1 (Ribosomal protein S6 kinase 1)

S6K1 is a key worker downstream of mTORC1, your cells' growth switch. Its full name is ribosomal protein S6 kinase 1 (gene RPS6KB1). It is an enzyme that drives protein-making. It does this by tagging two targets (ribosomal protein S6 and eIF4B), which boosts the cell's ribosome supply and translation capacity. It also sits in a feedback loop that dampens insulin signaling. So revved-up growth can promote insulin resistance. Across species from yeast to mice, turning S6K1 down extends lifespan. (In mice, the Selman 2009 study found this only in females, with no real benefit in males.) It also brings metabolic perks, like better insulin sensitivity and less age-related fat gain. In humans, an overactive S6K1 is tied to obesity, type 2 diabetes, and faster cellular aging, though direct human longevity evidence is still thin.

Last reviewed: June 22, 2026

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