Phosphoproteome dynamics of Saccharomyces cerevisiae under heat shock and cold stress

The ability of cells and organisms to survive and function through changes in temperature evolved from their specific adaptations to nonoptimal growth conditions. Responses to elevated temperatures have been studied in yeast and other model organisms using transcriptome profiling and provided valuable biological insights on molecular mechanisms involved in stress tolerance and adaptation to adverse environment. In contrast, little is known about rapid signaling events associated with changes in temperature. To gain a better understanding of global changes in protein phosphorylation in response to heat and cold, we developed a high temporal resolution phosphoproteomics protocol to study cell signaling in Saccharomyces cerevisiae. The method allowed for quantitative analysis of phosphodynamics on 2,777 phosphosites from 1,228 proteins. The correlation of kinetic profiles between kinases and their substrates provided a predictive tool to identify new putative substrates for kinases such as Cdc28 and PKA. Cell cycle analyses revealed that the increased phosphorylation of Cdc28 at its inhibitory site Y19 during heat shock is an adaptive response that delays cell cycle progression under stress conditions. The cellular responses to heat and cold were associated with extensive changes in phosphorylation on proteins implicated in transcription, protein folding and degradation, cell cycle regulation and morphogenesis. Synopsis High temporal resolution profiling of the yeast phosphoproteome upon heat shock and cold stress enabled the correlation of kinetic profiles between kinases and their substrates and identified cell signaling events associated with actin organization, septin assembly and cell cycle arrest. Changes in phosphoproteome of Saccharomyces cerevisiae were profiled for the first 30 min upon heat and cold stresses with a resolution of 2 min. Heat shock triggered more dramatic changes in phosphorylation compared to cold stress. The shape of the kinetic profiles was used to infer kinase-substrate relationships. Heat shock resulted in extensive changes in phosphorylation on proteins implicated in septin assembly, actin organization and cell cycle progression. High temporal resolution profiling of the yeast phosphoproteome upon heat shock and cold stress enabled the correlation of kinetic profiles between kinases and their substrates and identified cell signaling events associated with actin organization, septin assembly and cell cycle arrest. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.