Defining the DNA binding site recognized by the fission yeast Zn(2)Cys(6) transcription factor Pho7 and its role in phosphate homeostasis Journal Article


Authors: Schwer, B.; Sanchez, A. M.; Garg, A.; Chatterjee, D.; Shuman, S.
Article Title: Defining the DNA binding site recognized by the fission yeast Zn(2)Cys(6) transcription factor Pho7 and its role in phosphate homeostasis
Abstract: Fission yeast phosphate homeostasis entails transcriptional induction of genes encoding phosphate-mobilizing proteins under conditions of phosphate starvation. Transcription factor Pho7, a member of the Zn2Cys6 family of fungal transcription regulators, is the central player in the starvation response. The DNA binding sites in the promoters of phosphate-responsive genes have not been defined, nor have any structure-function relationships been established for the Pho7 protein. Here we narrow this knowledge gap by (i) delineating an autonomous DNA-binding domain (DBD) within Pho7 that includes the Zn2Cys6 module, (ii) deploying recombinant Pho7 DBD in DNase I footprinting and electrophoretic mobility shift assays (EMSAs) to map the Pho7 recognition sites in the promoters of the phosphateregulated pho1 and tgp1 genes to a 12-nucleotide sequence motif [5′-TCG(G/C)(A/T) xxTTxAA], (iii) independently identifying the same motif as a Pho7 recognition element via in silico analysis of available genome-wide ChIP-seq data, (iv) affirming that mutations in the two Pho7 recognition sites in the pho1 promoter efface pho1 expression in vivo, and (v) establishing that the zinc-binding cysteines and a pair of conserved arginines in the DBD are essential for Pho7 activity in vivo. IMPORTANCE Fungi respond to phosphate starvation by inducing the transcription of a set of phosphate acquisition genes that comprise a phosphate regulon. Pho7, a member of the Zn2Cys6 family of fungal transcription regulators, is the central player in the phosphate starvation response in fission yeast. The present study identifies a 12-nucleotide Pho7 DNA binding motif [5′-TCG(G/C)(A/T)xxTTxAA] in the promoters of phosphate-regulated genes, pinpoints DNA and protein features important for Pho7 binding to DNA, and correlates them with Pho7-dependent gene expression in vivo. The results highlight distinctive properties of Pho7 vis-a-vis other fungal zinc binuclear cluster transcription factors as well as the divergent cast of transcription factors deployed for phosphate homeostasis in fission yeast versus budding yeast. © 2017 Schwer et al.
Keywords: dna binding; transcriptional regulation; fission yeast; phosphate homeostasis
Journal Title: mBio
Volume: 8
Issue: 4
ISSN: 2150-7511
Publisher: American Society for Microbiology  
Date Published: 2017-07-01
Start Page: e01218-17
Language: English
DOI: 10.1128/mBio.01218-17
PROVIDER: scopus
PMCID: PMC5559640
PUBMED: 28811350
DOI/URL:
Notes: Article -- Export Date: 2 October 2017 -- Source: Scopus
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MSK Authors
  1. Stewart H Shuman
    532 Shuman
  2. Angad Garg
    19 Garg