Download TRANSCRIPTION FACTORS YAP1P AND PDR1P IN THE

TRANSCRIPTION FACTORS YAP1P AND PDR1P IN THE CONTROL OF
MULTIDRUG RESISTANCE IN KLUYVEROMYCES LACTIS
Svrbická A., Balážfyová Z., Tóth Hervay N., Gbelská Y.
Department of Microbiology and Virology, Faculty of Natural Sciences,
Comenius University in Bratislava, 842 15 Bratislava, Slovak Republic
Multidrug resistance (MDR), known as pleiotropic drug resistance (PDR) is
a ubiquitous cellular defence mechanism to deal with potential toxicity from
environmental small molecular toxins or bioactives. The rapid induction of MDR in the
model yeast Saccharomyces cerevisiae is controled by two networks of genes, YAP
and PDR. In these networks two types of transcription factors are involved: with the
structural motif of leucine zipper (bZIP) or zinc finger motifs Zn2Cys6, respectively. Many
duplicated or multiplicated genes encoding transcriptional regulators in S. cerevisiae
are present in fewer copies in Kluyveromyces lactis. Yap1p is a key determinant of
oxidative stress response. It regulates expression of genes encoding proteins that
maintain a favourable redox balance in the cell and proteins conferring metal and drug
resistance. The main determinants of MDR in S. cerevisiae include the transcription
factors Pdr1p and Pdr3p that control expression of ABC, MFS transporters and several
other genes. KlPdr1p is the only homologue of ScPdr1p and ScPdr3p in K. lactis. In
silico analysis of KlPDR1 gene promoter revealed the presence of one PDRE element
and two YRE elements. In vitro binding of KlYap1p to the KlPDR1 promoter showed
Hodúrová et al. (2011). In this work, we studied the mutual functional interaction
between KlPdr1p and KlYap1p in more detail. We compared the sensitivity of standard
strains and its isogenic deletion mutants (Klpdr1Δ, Klyap1Δ, Klpdr1Δyap1Δ) to
antifungal azoles. Our results showed differences in strain´s susceptibilities to the
cytotoxic drugs used. The influence of the transcription factors on the expression of the
main ABC transporter gene KlPDR5 in K. lactis was also analysed. The activity of the
reporter gene (promoter of KlPDR5 gene fused in frame with bacterial β-Dglucuronidase; PKlPDR5- gusA) was assessed together with the analysis of KlPDR5 gene
expression in the strains studied using qPCR. Our results indicate that KlPdr1p
influences the expression of KlPDR5 gene. Based on the results obtained, we propose
that the transcription factor KlYap1p binds to the YRE elements present in the KlPDR1
gene promoter and controls the KlPDR5 gene expression. Further clarification of the
relations between the main transcriptional regulators KlYap1p and KlPdr1p could help
to understand the origin and the control of the multidrug resistance phenomenon in K.
lactis yeast.
Acknowledgments
This work was supported by grants from the Slovak Grant Agency of Science (VEGA
1/0077/14 and 2/0111/15), the Slovak Research and Developmental Agency (APVV0282-10) and Comenius University (UK 246/2014). The contribution is also supported
by the Research and Development Operational Programme funded by the ERDF (ITMS
26240220086).
HODUROVA Z, TOTH HERVAY N, BALAZFYOVA Z, et al. 2011. Interplay among
regulators of multidrug resistance in Kluyveromyces lactis. Gen Physiol Biophys
30:S1–92.