Evidence map›Paper›PMID 26994077›Full record

ArticleApplied and environmental microbiology2016

Silica-Induced Protein (Sip) in Thermophilic Bacterium Thermus thermophilus Responds to Low Iron Availability.

Yasuhiro Fujino, Yuko Nagayoshi, Makoto Iwase, Takushi Yokoyama, Toshihisa Ohshima, Katsumi Doi

Open access · bronzeAbstract read
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Article in Applied and environmental microbiology, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
0.5field-weighted citation impact, top 30% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed, 10 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 2 institutions in 1 country.

Yasuhiro FujinoFaculty of Arts and Science, Kyushu University, Fukuoka, Japan.
Yuko NagayoshiInstitute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Makoto IwaseInstitute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Takushi YokoyamaDepartment of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka, Japan.
Toshihisa OhshimaDepartment of Biomedical Engineering, Faculty of Engineering, Osaka Institute of Technology, Osaka, Japan.
Katsumi DoiInstitute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka, Japan doi@agr.kyushu-u.ac.jp.ORCID http://orcid.org/0000-0001-5989-9936
Kyushu University · JPOsaka Institute of Technology · JP

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

unlabelledThermus thermophilus HB8 expresses silica-induced protein (Sip) when cultured in medium containing supersaturated silicic acids. Using genomic information, Sip was identified as a Fe(3+)-binding ABC transporter. Detection of a 1-kb hybridized band in Northern analysis revealed that sip transcription is monocistronic and that sip has its own terminator and promoter. The sequence of the sip promoter showed homology with that of the σ(A)-dependent promoter, which is known as a housekeeping promoter in HB8. Considering that sip is transcribed when supersaturated silicic acids are added, the existence of a repressor is presumed. DNA microarray analysis suggested that supersaturated silicic acids and iron deficiency affect Thermus cells similarly, and enhanced sip transcription was detected under both conditions. This suggested that sip transcription was initiated by iron deficiency and that the ferric uptake regulator (Fur) controlled the transcription. Three Fur gene homologues (TTHA0255, TTHA0344, and TTHA1292) have been annotated in the HB8 genome, and electrophoretic mobility shift assays revealed that the TTHA0344 product interacts with the sip promoter region. In medium containing supersaturated silicic acids, free Fe(3+) levels were decreased due to Fe(3+) immobilization on colloidal silica. This suggests that, because Fe(3+) ions are captured by colloidal silica in geothermal water, Thermus cells are continuously exposed to the risk of iron deficiency. Considering that Sip is involved in iron acquisition, Sip production may be a strategy to survive under conditions of low iron availability in geothermal water. IMPORTANCE: The thermophilic bacterium Thermus thermophilus HB8 produces silica-induced protein (Sip) in the presence of supersaturated silicic acids. Sip has homology with iron-binding ABC transporter; however, the mechanism by which Sip expression is induced by silicic acids remains unexplained. We demonstrate that Sip captures iron and its transcription is regulated by the repressor ferric uptake regulator (Fur). This implies that Sip is expressed with iron deficiency. In addition, it is suggested that negatively charged colloidal silica in supersaturated solution absorbs Fe(3+) ions and decreases iron availability. Considering that geothermal water contains ample silicic acids, it is suggested that thermophilic bacteria are always facing iron starvation. Sip production may be a strategy for surviving under conditions of low iron availability in geothermal water.

Indexed as

Gene Expression Regulation, BacterialATP-Binding Cassette TransportersBacterial ProteinsCulture MediaDNA, BacterialElectrophoretic Mobility Shift AssayGene Expression ProfilingIronMicroarray AnalysisOligonucleotide Array Sequence AnalysisPromoter Regions, GeneticProtein BindingRepressor ProteinsSilicic AcidThermus thermophilusTranscription, GeneticATP-Binding Cassette TransportersBacterial ProteinsCulture MediaDNA, BacterialIronRepressor ProteinsSilicic Acid

Identifiers

PMID26994077
PMCPMC4959228
OpenAlexW2320530726

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.