Characterization of the DNA-binding motif of the arsenic-responsive transcription factor Yap8p.
Saccharomyces cerevisiae uses several mechanisms for arsenic detoxification including the arsenate reductase Acr2p and the arsenite efflux protein Acr3p. ACR2 and ACR3 are transcribed in opposite directions from the same promoter and expression of these genes is regulated by the AP-1 (activator protein 1)-like transcription factor Yap8p. Yap8p has been shown to permanently associate with this promoter and to stimulate ACR2/ACR3 expression in response to arsenic. In the present study we characterized the DNA sequence that is targeted by Yap8p. We show that Yap8p binds to a pseudo-palindromic TGATTAATAATCA sequence that is related to, but distinct from, the sequence recognized by other fungal AP-1 proteins. Probing the promoter by mutational analysis, we confirm the importance of the TTAATAA core element and pin-point nucleotides that flank this element as crucial for Yap8p binding and in vivo activation of ACR3 expression. A genome-wide search for this element combined with global gene expression analysis indicates that the principal function of Yap8p is to control expression of ACR2 and ACR3. We conclude that Yap8p and other yeast AP-1 proteins require distinct DNA-binding motifs to induce gene expression and propose that this fact contributed towards a separation of function between AP-1 proteins during evolution.
Ilina
Yulia
Y
Department of Cell and Molecular Biology/Microbiology, University of Gothenburg, S-405 30 Gothenburg, Sweden.
Sloma
Ewa
E
Maciaszczyk-Dziubinska
Ewa
E
Novotny
Marian
M
Thorsen
Michael
M
Wysocki
Robert
R
Tamás
Markus J
MJ
D001151:Arsenic / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016681:Genome, Fungal; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
C109281:ACR3 protein, S cerevisiae; C494591:ARR1 protein, S cerevisiae; D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D026901:Membrane Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; D004247:DNA; D001151:Arsenic