Figure 10. Sit4p orchestrates lipid metabolism in response to nutrients.

Snf1 kinase, a central regulator of energetic homeostasis, when phosphorylated and active, inhibits acetyl CoA carboxylase activity impairing fatty acids synthesis diminishing LD levels. It is dephosphorylated by Reg1/Glc7 phosphatase as glucose levels in the medium increase [50]. Our results suggest that the Sap190-Sit4 pair also participates in Snf1 dephosphorylation and links the TOR pathway to the AMP/ATP-sensitive pathway, mediated by Snf1.