uORF-mediated translational control of CAK and Cdk activation in response to low nutrients in yeast.

A uORF in CAK1 represses Cak1 synthesis in yeast, reducing Cdk activation and viability of quiescent cells under low-nutrient conditions.

• Why it matters: Understanding how nutrient availability influences cell cycle regulation is crucial, as it impacts cell proliferation and survival during nutrient scarcity, yet the mechanisms remain unclear.
• What they did: The study measured Cak1 levels and Cdc28 T169 phosphorylation in yeast under different nutrient conditions, and manipulated the CAK1 uORF to assess effects on Cak1 synthesis and cell cycle progression.
• The result: Eliminating the uORF increased Cak1 levels and accelerated cell division in phosphatase-deficient cells but decreased viability of quiescent cells, revealing a novel translational control layer linking protein synthesis to cell cycle activity.