Transcription activator involved in multidrug resistance, oxidative stress response, and redox homeostasis. Regulates the transcription of genes encoding antioxidant enzymes like catalase ctt1 and components of the cellular thiol-reducing pathways, including the thioredoxin system (trx2, trr1), ABC tansporters involved in multidrug resistance like bfr1/hba2 and pmd1 as well as the gene obr1/apt1. Preferentially binds to promoters with the core binding site 5'-TTA[CG]TAA-3'. Activity of the transcription factor is controlled through oxidation of specific cysteine residues resulting in the alteration of its subcellular location. Oxidative stress induces nuclear accumulation and as a result pap1 transcriptional activity. Required for sty1/spc1-confered staurosporine resistance. Homodimer (PubMed:11017199). The reduced form of pap1 interacts in the nucleus with the nuclear export protein crm1, and in the cytoplasm with the peroxiredoxin tpx1 (PubMed:12100563, PubMed:24316080). Oxidized pap1 is found predominantly in the nucleus, while reduced pap1 is continuously exported to the cytoplasm by crm1/exportin 1. Contains two cysteine rich domains (CRD), referred to as the N- and C-terminal CRD's, n-CRD (Cys-259, Cys-278, Cys-285 and Cys-290) and c-CRD (Cys-501, Cys-523 and Cys-532), respectively. Cys-259 and Cys-290 are not conserved in orthologs in other yeast species. A nuclear export signal is embedded in the c-CRD, with which the nuclear export protein crm1/exportin 1 interacts only in the absence of disulfide bonds (or otherwise oxidized cysteines) within the c-CRD or between the c-CRD and the n-CRD. Depending on the oxidative stress inducing agent, pap1 can undergo two distinct conformational changes, both masking the nuclear export signal, thus abolishing nuclear export by crm1/exportin 1. The glutathione-depleting agent diethylmaleate (DEM) leads to the non-reversible modification of at least 2 cysteine residues in the c-CRD. Peroxide stress induces the formation of a tpx1-dependent interdomain disulfide bond between Cys-278 and Cys-501. Belongs to the bZIP family. YAP subfamily.