Quantitative PCR reveals a role for oleate-enriched phosphorylation of Pip2p and Cst6p. A, yeast cells carrying a S783A-mutagenized version of Pip2p were tested for expression of oleate-responsive loci POT1, CTA1, FOX2, and POX1. Shown are the levels of induction after 30 min in oleate-inducing medium. By 90 min, the differences between wild type and the Pip2p S783A strain were not significant (data not shown). B, at 90 min of oleate induction, increased expression of oleate-responsive loci (POT1, CTA1, FOX2, and POX1) is detected in the two Cst6p mutagenized strains. Cst6-1 is multiply mutated (S396A,S399A,T401A), whereas Cst6-2 is singly mutated (T401A). Error bars show the standard deviation.