A Novel Sit4 Phosphatase Complex Is Involved in the Response to Ceramide Stress in Yeast

Figure 4

Mass spectrometric analysis of sphingolipid species. Yeast cultures were diluted to an OD₆₀₀ of 0.2 in YPD and grown for 8 hours at 24°C. A total of 10 OD₆₀₀ units of cells were removed and lipids extracted for mass spectrometry analysis. (a) Ceramides, (b) long chain bases phytosphingosine (PHS) and dihydrosphingosine (DHS), and (c) Inositol phosphoceramide-C (IPC-C) were quantified using relevant internal standards. Average values for a minimum of three biological replicates are shown and error bars represent the standard error above and below the mean. A Student’s t-test was used to determine if the mutants showed a significant difference from the wild type CY4029. (^∗𝑃<0.05, ^∗∗𝑃<0.01, and ^∗∗∗𝑃<0.005).

(a)

(b)

(c)