yAP-1- and yAP-2-mediated, heat shock-induced transcriptional activation of the multidrug resistance ABC transporter genes in Saccharomyces cerevisiae.

We have examined whether the stress-induced transcriptional activation of YDR1/PDR5/STS1 is mediated by yAP-1 and yAP-2. Of the stresses examined, heat shock-induced, rapid and transient PDR5 expression became very low in a yap1 yap2 double-gene disruptant, indicating that the yAP proteins mediate the response. Similar results were obtained with SNQ2, a close homologue of PDR5. A set of 5'-truncation derivatives of the PDR5 gene identified the region from -484 to -434 as being sufficient for the response. A sequence similar to the yAP-1 recognition element recently identified in the stress-responsive yeast genes was found in this region and in the 5'-flanking sequences of SNQ2.