To further investigate this relationship, we mapped RNAPII occupancy along a group of genes with the lowest levels of RNAPII as well as a group with the highest levels of RNAPII and then mapped Rrd1 on the same groups. Indeed, when RNAPII levels were low, the Rrd1 levels were also low, and consistently, when RNAPII levels were high Rrd1 levels were also increased. This was also the case for INCB18424 rapamycin treated cells. To further confirm that Rrd1 changes in occupancy correlate with RNAPII in response to rapamycin, we plotted the difference in RNAPII occupancy between untreated and rapamycin-treated cells versus the difference in Rrd1 occupancy between these two conditions. This analysis revealed that both, Rrd1 and RNAPII are downregulated on a large group of genes and recruited to another group of genes in response to rapamycin. Taken together, this data suggest that Rrd1 and RNAPII co-localize on the coding region of most of the actively transcribed genes, even after massive transcriptional changes such as the ones caused by rapamycin treatment. The above data indicate that Rrd1 is required for an optimal transcriptional response following rapamycin exposure. Since rapamycin mimics nutrient starvation conditions, we next asked whether Rrd1 is required for optimal response to other Pazopanib environmental stresses. Previously work has shown that rrd1D mutants exhibit multiple phenotypes including resistance to caffeine, but sensitivity towards vanadate, 4-NQO and calcium. Both vanadate and 4-NQO are known to cause oxidative stress. To test whether Rrd1 is required for resistance to other oxidizing agents, we challenged cells with hydrogen peroxide and sodium arsenite and found that the rrd1D mutant was indeed sensitive to these agents. To determine whether the sensitivity was the result of a defect in gene regulation, we introduced a known arsenite-response reporter that bears the promoter of the ACR3 gene fused to lacZ. ACR3 encodes a plasma membrane efflux pump that is upregulated via the Yap8 transcriptional activator in response to arsenite. While there was a strong induction of the ACR3-lacZ reporter in the wild-type, it was hardly induced in the rrd1D mutant. This data suggests that the transcriptional response to oxidative stress is also affected in the rrd1D mutant. To explore this further, we monitored expression of 10 stress responsive genes using the GeXP multiplex PCR system in response to rapamycin, H2O2, NaAs and heat shock. We chose genes that are known to be upregulated or downregulated in response to environmental stresses as well as control genes which are not significantly altered under these conditions.