Figure 8.

(a,b) Relative sensitivity of proteasomal mutants to mild inhibition of TORC1. (a) Deletion mutants of non-essential genes encoding UPS components and (b) DAmP mutants of essential proteasomal genes were grown in quadruplicates in YPD medium containing 50 ng ml⁻¹ of rapamycin or drug vehicle. Relative sensitivity was calculated by normalizing mutant cells' growth rate in the presence of rapamycin to that in the presence of the drug vehicle. (c) Relative growth rates of the three catalytically compromised DAmP mutants in response to increasing rapamycin concentrations. (d) The working model. STRE/PDS gene expression, mediated by Msn2/4, Gis1 and possibly Hsf1, is controlled by the proteasome and multiple TORC1-negatively regulated proteins, Rim15, Yak1 and others. The arrows and bars denote positive and negative controls, respectively. The question marks and dashed lines refer to unconfirmed or unidentified nodes and regulatory connections.