Phosphoproteomic Responses of Distal TORC1 Target Kinases Reveal Discrete and Convergent Mechanisms that Orchestrate the Quiescence Program in Yeast

TORC1 inhibition following nutrient limitation unlocks various distally controlled kinases (e.g., Atg1, Gcn2, Slt2/Mpk1, Npr1, Rim15, and Yak1), which cooperate through poorly defined circuits to orchestrate the quiescence program. To better define the signaling landscape of the latter kinases, we used in vivo quantitative phosphoproteomics. While pinpointing known and numerous hitherto uncharted Slt2/Mpk1, Npr1, Rim15, and Yak1 effectors, our study reveals insight into the architecture of the distally controlled TORC1 kinase network.