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Two transcription factors are necessary for iron homeostasis in a salt-dwelling archaeon.
Two transcription factors are necessary for iron homeostasis in a salt-dwelling archaeon.
- Source :
-
Nucleic acids research [Nucleic Acids Res] 2011 Apr; Vol. 39 (7), pp. 2519-33. Date of Electronic Publication: 2010 Nov 24. - Publication Year :
- 2011
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Abstract
- Because iron toxicity and deficiency are equally life threatening, maintaining intracellular iron levels within a narrow optimal range is critical for nearly all known organisms. However, regulatory mechanisms that establish homeostasis are not well understood in organisms that dwell in environments at the extremes of pH, temperature, and salinity. Under conditions of limited iron, the extremophile Halobacterium salinarum, a salt-loving archaeon, mounts a specific response to scavenge iron for growth. We have identified and characterized the role of two transcription factors (TFs), Idr1 and Idr2, in regulating this important response. An integrated systems analysis of TF knockout gene expression profiles and genome-wide binding locations in the presence and absence of iron has revealed that these TFs operate collaboratively to maintain iron homeostasis. In the presence of iron, Idr1 and Idr2 bind near each other at 24 loci in the genome, where they are both required to repress some genes. By contrast, Idr1 and Idr2 are both necessary to activate other genes in a putative a feed forward loop. Even at loci bound independently, the two TFs target different genes with similar functions in iron homeostasis. We discuss conserved and unique features of the Idr1-Idr2 system in the context of similar systems in organisms from other domains of life.
- Subjects :
- Amino Acid Sequence
Archaeal Proteins chemistry
Archaeal Proteins genetics
Binding Sites
Gene Deletion
Gene Expression Regulation, Archaeal
Halobacterium salinarum growth & development
Halobacterium salinarum metabolism
Homeostasis
Molecular Sequence Data
Promoter Regions, Genetic
Regulon
Sequence Homology, Amino Acid
Transcription Factors chemistry
Transcription Factors genetics
Archaeal Proteins physiology
Halobacterium salinarum genetics
Iron metabolism
Transcription Factors physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1362-4962
- Volume :
- 39
- Issue :
- 7
- Database :
- MEDLINE
- Journal :
- Nucleic acids research
- Publication Type :
- Academic Journal
- Accession number :
- 21109526
- Full Text :
- https://doi.org/10.1093/nar/gkq1211