Figure 5. Recruitment of prefoldin to transcribed genes depends on the integrity of the complex and is favored by Ser2-phosphorylation of the Rpb1 CTD.

A. Pfd1 binding to GAL1 partially depends on Gim5. Pfd1-Myc occupancy of GAL1 was analyzed in wild-type or gim5Δ cells exponentially growing in galactose-containing medium. The anti-Myc ChIP procedure is described in the Materials and methods section. Western blot experiments were performed in order to rule out any significant influence of the gim5Δ mutation on the Pfd1-Myc level. B. Gim5-Myc binding to GAL1 does not depend on Pfd1. Gim5-Myc occupancy of GAL1 was analyzed in wild-type or pfd1Δ cells exponentially growing in galactose-containing medium. Western blot experiments were performed in order to rule out any increase of Gim5-Myc level in the pfd1Δ mutant. C. The profile of Pfd1 binding to the transcribed region parallels Ser2-phosphorylation of the Rpb1 CTD. Occupancy of total (Rpb3), Ser5-phosphorylated (Se5-P) and Ser2-phosphorylated RNA polymerase II (Ser5-P) was analyzed across GAL1 under activating conditions. ChIP experiments were performed using the conditions and antibodies described in the Materials and methods section. D. Prefoldin recruitment to the transcribed region is diminished in a ctk1Δ mutant. Pfd1-Myc occupancy of GAL1 was analyzed by ChIP in wild-type or ctk1Δ cells exponentially growing in galactose-containing medium. In all panels, the results shown represent the mean and the standard deviation of three biological replicates.