Proteomic and Phosphoproteomic Analyses of Yeast Reveal the Global Cellular Response to Sphingolipid Depletion

ABSTRACT: Sphingolipids are essential components of eukaryotic cells with important functions in membrane biology and cellular signaling. Their levels are tightly controlled and coordinated with the abundance of other membrane lipids. How sphingolipid homeostasis is achieved is not yet well understood. Studies performed primarily in yeast showed that the phosphorylation states of several enzymes and regulators of sphingolipid synthesis are important, although a global understanding for such regulation is lacking. Here, we used high-resolution mass-spectrometry-based proteomics and phosphoproteomics, in combination with data from a chemical genetic screen, to analyze the cellular response to sphingolipid synthesis inhibition. Our dataset reveals that changes in protein phosphorylation, rather than protein abundance, dominate the response to blocking sphingolipid synthesis. We identified Ypk1 signaling as a major pathway that is activated under these conditions, and we confirmed and identified Ypk1 targets. We also revealed key aspects of the cellular response to sphingolipid deprivation, including nodes that intersect with sterol metabolism and modification of lipid transport. Our data provide a rich resource for on-going mechanistic studies of key elements of the cellular response to the depletion of sphingolipid levels and the maintenance of sphingolipid homeostasis.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)

SUBMITTER: romain christiano  

LAB HEAD: Tobias C Walther

PROVIDER: PXD003854 | Pride | 2016-12-23

REPOSITORIES: Pride