scholarly journals Enhancement of Iron Acquisition in Rice by the Mugineic Acid Synthase Gene With Ferric Iron Reductase Gene and OsIRO2 Confers Tolerance in Submerged and Nonsubmerged Calcareous Soils

2019 ◽  
Vol 10 ◽  
Author(s):  
Hiroshi Masuda ◽  
May Sann Aung ◽  
Takanori Kobayashi ◽  
Tatsuro Hamada ◽  
Naoko K. Nishizawa
Keyword(s):  
Ferric Iron ◽  
Iron Acquisition ◽  
Calcareous Soils ◽  
Mugineic Acid ◽  
Reductase Gene ◽  
Iron Reductase

scholarly journals Candida albicans Ferric Reductases Are Differentially Regulated in Response to Distinct Forms of Iron Limitation by the Rim101 and CBF Transcription Factors

2008 ◽  
Vol 7 (7) ◽  
pp. 1168-1179 ◽  
Author(s):  
Yong-Un Baek ◽  
Mingchun Li ◽  
Dana A. Davis
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Candida Albicans ◽  
Transcription Factors ◽  
Iron Acquisition ◽  
Mammalian Host ◽  
Regulatory Sequence ◽  
Ferric Reductase ◽  
Reductase Gene ◽  
Ferric Reductases

ABSTRACT Iron is an essential nutrient that is severely limited in the mammalian host. Candida albicans encodes a family of 15 putative ferric reductases, which are required for iron acquisition and utilization. Despite the central role of ferric reductases in iron acquisition and mobilization, relatively little is known about the regulatory networks that govern ferric reductase gene expression in C. albicans. Here we have demonstrated the differential regulation of two ferric reductases, FRE2 and FRP1, in response to distinct iron-limited environments. FRE2 and FRP1 are both induced in alkaline-pH environments directly by the Rim101 transcription factor. However, FRP1 but not FRE2 is also induced by iron chelation. We have identified a CCAAT motif as the critical regulatory sequence for chelator-mediated induction and have found that the CCAAT binding factor (CBF) is essential for FRP1 expression in iron-limited environments. We found that a hap5Δ/hap5Δ mutant, which disrupts the core DNA binding activity of CBF, is unable to grow under iron-limited conditions. C. albicans encodes three CBF-dependent transcription factors, and we identified the Hap43 protein as the CBF-dependent transcription factor required for iron-limited responses. These studies provide key insights into the regulation of ferric reductase gene expression in the fungal pathogen C. albicans.

Iron extraction efficacy of plant borne mugineic acid family phytosiderophores in indian calcareous soils

1992 ◽  
Vol 15 (10) ◽  
pp. 1625-1645 ◽  
Author(s):  
Kalyan Singh ◽  
M. Chino ◽  
N. K. Nisizawa ◽  
S. Goto ◽  
T. Nakanishi ◽  
...  
Keyword(s):  
Calcareous Soils ◽  
Iron Extraction ◽  
Mugineic Acid ◽  
Mugineic Acid Family Phytosiderophores

scholarly journals Genes Essential to Iron Transport in the Cyanobacterium Synechocystis sp. Strain PCC 6803

2001 ◽  
Vol 183 (9) ◽  
pp. 2779-2784 ◽  
Author(s):  
Hirokazu Katoh ◽  
Natsu Hagino ◽  
Arthur R. Grossman ◽  
Teruo Ogawa
Keyword(s):  
Iron Uptake ◽  
Iron Transport ◽  
Ferric Iron ◽  
Iron Acquisition ◽  
Complete Medium ◽  
Iron Starvation ◽  
Transporter Family ◽  
Genes Encoding ◽  
In Cells ◽  
Pcc 6803

ABSTRACT Genes encoding polypeptides of an ATP binding cassette (ABC)-type ferric iron transporter that plays a major role in iron acquisition inSynechocystis sp. strain PCC 6803 were identified. These genes are slr1295, slr0513, slr0327, and recently reportedsll1878 (Katoh et al., J. Bacteriol. 182:6523–6524, 2000) and were designated futA1, futA2, futB, andfutC, respectively, for their involvement in ferric iron uptake. Inactivation of these genes individually or futA1and futA2 together greatly reduced the activity of ferric iron uptake in cells grown in complete medium or iron-deprived medium. All the fut genes are expressed in cells grown in complete medium, and expression was enhanced by iron starvation. ThefutA1 and futA2 genes appear to encode periplasmic proteins that play a redundant role in iron binding. The deduced products of futB and futC genes contain nucleotide-binding motifs and belong to the ABC transporter family of inner-membrane-bound and membrane-associated proteins, respectively. These results and sequence similarities among the four genes suggest that the Fut system is related to the Sfu/Fbp family of iron transporters. Inactivation of slr1392, a homologue offeoB in Escherichia coli, greatly reduced the activity of ferrous iron transport. This system is induced by intracellular low iron concentrations that are achieved in cells exposed to iron-free medium or in the fut-less mutants grown in complete medium.

scholarly journals The fission yeast ferric reductase gene frp1+ is required for ferric iron uptake and encodes a protein that is homologous to the gp91-phox subunit of the human NADPH phagocyte oxidoreductase

1993 ◽  
Vol 13 (7) ◽  
pp. 4342-4350
Author(s):  
D G Roman ◽  
A Dancis ◽  
G J Anderson ◽  
R D Klausner
Keyword(s):  
Fission Yeast ◽  
Iron Uptake ◽  
Ferric Iron ◽  
Reductase Activity ◽  
Iron Acquisition ◽  
Protein A ◽  
Mutant Gene ◽  
Predicted Amino Acid Sequence ◽  
Mrna Levels ◽  
Ferric Reductase

We have identified a cell surface ferric reductase activity in the fission yeast Schizosaccharomyces pombe. A mutant strain deficient in this activity was also deficient in ferric iron uptake, while ferrous iron uptake was not impaired. Therefore, reduction is a required step in cellular ferric iron acquisition. We have cloned frp1+, the wild-type allele of the mutant gene. frp1+ mRNA levels were repressed by iron addition to the growth medium. Fusion of 138 nucleotides of frp1+ promoter sequences to a reporter gene, the bacterial chloramphenicol acetyltransferase gene, conferred iron-dependent regulation upon the latter when introduced into S. pombe. The predicted amino acid sequence of the frp1+ gene exhibits hydrophobic regions compatible with transmembrane domains. It shows similarity to the Saccharomyces cerevisiae FRE1 gene product and the gp91-phox protein, a component of the human NADPH phagocyte oxidoreductase that is deficient in X-linked chronic granulomatous disease.

An antioxidant role for catecholate siderophores in Salmonella

2013 ◽  
Vol 454 (3) ◽  
pp. 543-549 ◽  
Author(s):  
Maud E. S. Achard ◽  
Kaiwen W. Chen ◽  
Matthew J. Sweet ◽  
Rebecca E. Watts ◽  
Kate Schroder ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ferric Iron ◽  
Iron Acquisition ◽  
Oxygen Species ◽  
Functional Studies ◽  
Host Pathogen Interaction ◽  
Host Pathogen ◽  
Very High ◽  
Full Protection

Iron acquisition is an important aspect of the host–pathogen interaction. In the case of Salmonella it is established that catecholate siderophores are important for full virulence. In view of their very high affinity for ferric iron, functional studies of siderophores have been almost exclusively focused on their role in acquisition of iron from the host. In the present study, we investigated whether the siderophores (enterobactin and salmochelin) produced by Salmonella enterica sv. Typhimurium could act as antioxidants and protect from the oxidative stress encountered after macrophage invasion. Our results show that the ability to produce siderophores enhanced the survival of Salmonella in the macrophage mainly at the early stages of infection, coincident with the oxidative burst. Using siderophore biosynthetic and siderophore receptor mutants we demonstrated that salmochelin and enterobactin protect S. Typhimurium against ROS (reactive oxygen species) in vitro and that siderophores must be intracellular to confer full protection. We also investigated whether other chemically distinct siderophores (yersiniabactin and aerobactin) or the monomeric catechol 2,3-dihydroxy-benzoate could provide protection against oxidative stress and found that only catecholate siderophores have this property. Collectively, the results of the present study identify additional functions for siderophores during host–pathogen interactions.

scholarly journals Secreted Pyomelanin of Legionella pneumophila Promotes Bacterial Iron Uptake and Growth under Iron-Limiting Conditions

2013 ◽  
Vol 81 (11) ◽  
pp. 4182-4191 ◽  
Author(s):  
Huaixin Zheng ◽  
Christa H. Chatfield ◽  
Mark R. Liles ◽  
Nicholas P. Cianciotto
Keyword(s):  
Legionella Pneumophila ◽  
Ferrous Iron ◽  
Iron Uptake ◽  
Iron Transport ◽  
Ferric Iron ◽  
Iron Acquisition ◽  
Ferric Hydroxide ◽  
Supernatant Fraction ◽  
Content Type ◽  
Ferrous Iron Transport

ABSTRACTIron acquisition is critical to the growth and virulence ofLegionella pneumophila. Previously, we found thatL. pneumophilauses both a ferrisiderophore pathway and ferrous iron transport to obtain iron. We now report that two molecules secreted byL. pneumophila, homogentisic acid (HGA) and its polymerized variant (HGA-melanin, a pyomelanin), are able to directly mediate the reduction of various ferric iron salts. Furthermore, HGA, synthetic HGA-melanin, and HGA-melanin derived from bacterial supernatants enhanced the ability ofL. pneumophilaand other species ofLegionellato take up radiolabeled iron. Enhanced iron uptake was not observed with a ferrous iron transport mutant. Thus, HGA and HGA-melanin mediate ferric iron reduction, with the resulting ferrous iron being available to the bacterium for uptake. Upon further testing ofL. pneumophilaculture supernatants, we found that significant amounts of ferric and ferrous iron were associated with secreted HGA-melanin. Importantly, a pyomelanin-containing fraction obtained from a wild-type culture supernatant was able to stimulate the growth of iron-starved legionellae. That the corresponding supernatant fraction obtained from a nonpigmented mutant culture did not stimulate growth demonstrated that HGA-melanin is able to both promote iron uptake and enhance growth under iron-limiting conditions. Indicative of a complementary role in iron acquisition, HGA-melanin levels were inversely related to the levels of siderophore activity. Compatible with a role in the ecology and pathogenesis ofL. pneumophila, HGA and HGA-melanin were effective at reducing and releasing iron from both insoluble ferric hydroxide and the mammalian iron chelates ferritin and transferrin.

scholarly journals Ferric iron reductase activity of LuxG from Photobacterium leiognathi

2016 ◽  
Vol 52 (4) ◽  
pp. 495-499 ◽  
Author(s):  
Eui Ho Lee ◽  
Ki Seok Nam ◽  
Seon Kwang Lee ◽  
Eugeney Oh ◽  
Chan Yong Lee
Keyword(s):  
Ferric Iron ◽  
Reductase Activity ◽  
Photobacterium Leiognathi ◽  
Iron Reductase

scholarly journals Helicobacter pylori ribBA-Mediated Riboflavin Production Is Involved in Iron Acquisition

1998 ◽  
Vol 180 (6) ◽  
pp. 1473-1479 ◽  
Author(s):  
Dennis J. Worst ◽  
Monique M. Gerrits ◽  
Christina M. J. E. Vandenbroucke-Grauls ◽  
Johannes G. Kusters
Keyword(s):  
Helicobacter Pylori ◽  
Iron Reduction ◽  
Ferric Iron ◽  
Iron Acquisition ◽  
Cosmid Library ◽  
Dot Blot ◽  
E Coli ◽  
Reduction Activity ◽  
Dna Fragment ◽  
H Pylori

ABSTRACT In this study, we cloned and sequenced a DNA fragment from an ordered cosmid library of Helicobacter pylori NCTC 11638 which confers to a siderophore synthesis mutant of Escherichia coli (EB53 aroB hemA) the ability to grow on iron-restrictive media and to reduce ferric iron. Sequence analysis of the DNA fragment revealed the presence of an open reading frame with high homology to the ribA gene of Bacillus subtilis. This gene encodes a bifunctional enzyme with the activities of both 3,4-dihydroxy-2-butanone 4-phosphate (DHBP) synthase and GTP cyclohydrolase II, which catalyze two essential steps in riboflavin biosynthesis. Expression of the gene (designatedribBA) resulted in the formation of one translational product, which was able to complement both the ribA and theribB mutation in E. coli. Expression ofribBA was iron regulated, as was suggested by the presence of a putative FUR box in its promotor region and as shown by RNA dot blot analysis. Furthermore, we showed that production of riboflavin inH. pylori cells is iron regulated. E. coliEB53 containing the plasmid with H. pylori ribBAexcreted riboflavin in the culture medium, and this riboflavin excretion also appeared to be iron regulated. We postulate that the iron-regulated production of riboflavin and ferric-iron-reduction activity by E. coli EB53 transformed with the H. pylori ribBA gene is responsible for the survival of EB53 on iron-restrictive medium. Because disruption of ribBA inH. pylori eliminates its ferric-iron-reduction activity, we conclude that ribBA has an important role in ferric-iron reduction and iron acquisition by H. pylori.

scholarly journals The fission yeast ferric reductase gene frp1+ is required for ferric iron uptake and encodes a protein that is homologous to the gp91-phox subunit of the human NADPH phagocyte oxidoreductase.

1993 ◽  
Vol 13 (7) ◽  
pp. 4342-4350 ◽  
Author(s):  
D G Roman ◽  
A Dancis ◽  
G J Anderson ◽  
R D Klausner
Keyword(s):  
Fission Yeast ◽  
Iron Uptake ◽  
Ferric Iron ◽  
Reductase Activity ◽  
Iron Acquisition ◽  
Protein A ◽  
Mutant Gene ◽  
Predicted Amino Acid Sequence ◽  
Mrna Levels ◽  
Ferric Reductase

We have identified a cell surface ferric reductase activity in the fission yeast Schizosaccharomyces pombe. A mutant strain deficient in this activity was also deficient in ferric iron uptake, while ferrous iron uptake was not impaired. Therefore, reduction is a required step in cellular ferric iron acquisition. We have cloned frp1+, the wild-type allele of the mutant gene. frp1+ mRNA levels were repressed by iron addition to the growth medium. Fusion of 138 nucleotides of frp1+ promoter sequences to a reporter gene, the bacterial chloramphenicol acetyltransferase gene, conferred iron-dependent regulation upon the latter when introduced into S. pombe. The predicted amino acid sequence of the frp1+ gene exhibits hydrophobic regions compatible with transmembrane domains. It shows similarity to the Saccharomyces cerevisiae FRE1 gene product and the gp91-phox protein, a component of the human NADPH phagocyte oxidoreductase that is deficient in X-linked chronic granulomatous disease.

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