Figure 5.

Sumoylation of Rap1 mediates recruitment of the basal transcription machinery. (A) The level of RNAPII at RPL35A depends on the combined activity of TORC1 and Ubc9. Log-phase cells were treated with 100 nM rapamycin for 30 min, after which the level of RNAPII at RPL35A and SCR1 was analyzed by ChIP. The location of primer pairs is indicated. Error bars, SEM. (B) TFIID recruitment depends on TORC1 and Ubc9. Log-phase cells were treated as in A, and the level of TBP at RPL35A and ACT1 was determined by ChIP. Error bars, SEM. (C) Rap1 sumoylation promotes the interaction with TFIID. WT cells transformed with plasmids expressing HA-tagged wild-type RAP1, rap1-K2R, or rap1-K9R were subjected to immunoprecipitation with anti-HA beads followed by Western blotting with anti-Taf4 antibodies. (D) TORC1 activity does not modulate the interaction between Rap1 and TFIID. Cells treated with 100 nM rapamycin (30 min) were processed as in C. (E,F) Sumoylation of Rap1 promotes recruitment of TFIID and RNAPII to RPL35A. ChIPs were performed as in Figure 4E using antibodies against TBP (E) and RNAPII (F). Error bars, SEM. (G) Model of our findings. Sumoylation of Rap1 by Ubc9 promotes RPG transcription in parallel to TORC1.