Enhanced Grain Iron Levels in Rice Expressing an IRON-REGULATED METAL TRANSPORTER, NICOTIANAMINE SYNTHASE, and FERRITIN Gene Cassette

Populus alba ‘Villafranca’ clone is well-known for its tolerance to cadmium (Cd). To determine the mechanisms of Cd tolerance of this species, wild-type (wt) plants were compared with transgenic plants over-expressing an aquaporin (aqua1, GenBank GQ918138). Plants were maintained in hydroponic conditions with Hoagland’s solution and treated with 10 µM of Cd, renewed every 5 d. The transcription levels of heavy metal transporter genes (PaHMA2, PaNRAMP1.3, PaNRAMP2, PaNRAMP3.1, PaNRAMP3.2, PaABCC9, and PaABCC13) were analyzed at 1, 7, and 60 d of treatment. Cd application did not induce visible toxicity symptoms in wt and aqua1 plants even after 2 months of treatment confirming the high tolerance of this poplar species to Cd. Most of the analyzed genes showed in wt plants a quick response in transcription at 1 d of treatment and an adaptation at 60 d. On the contrary, a lower transcriptional response was observed in aqua1 plants in concomitance with a higher Cd concentration in medial leaves. Moreover, PaHMA2 showed at 1 d an opposite trend within organs since it was up-regulated in root and stem of wt plants and in leaves of aqua1 plants. In summary, aqua1 overexpression in poplar improved Cd translocation suggesting a lower Cd sensitivity of aqua1 plants. This different response might be due to a different transcription of PaNRAMP3 genes that were more transcribed in wt line because of the importance of this gene in Cd compartmentalization.

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Effect of iron deficiency on placental transfer of iron and expression of iron transport proteins in vivo and in vitro

Biochemical Journal ◽

10.1042/bj3560883 ◽

2001 ◽

Vol 356 (3) ◽

pp. 883-889 ◽

Cited By ~ 68

Author(s):

Lorraine GAMBLING ◽

Ruth DANZEISEN ◽

Susan GAIR ◽

Richard G. LEA ◽

Zehane CHARANIA ◽

...

Keyword(s):

Iron Deficiency ◽

Transferrin Receptor ◽

Iron Transport ◽

Receptor Expression ◽

Mrna Levels ◽

Iron Transfer ◽

Metal Transporter ◽

Protein Levels ◽

Copper Oxidase ◽

Maternal Iron

Maternal iron deficiency during pregnancy induces anaemia in the developing fetus; however, the severity tends to be less than in the mother. The mechanism underlying this resistance has not been determined. We have measured placental expression of proteins involved in iron transfer in pregnant rats given diets with decreasing levels of iron and examined the effect of iron deficiency on iron transfer across BeWo cell layers, a model for placental iron transfer. Transferrin receptor expression was increased at both mRNA and protein levels. Similarly, expression of the iron-responsive element (IRE)-regulated form of the divalent metal transporter 1 (DMT1) was also increased. In contrast, the non-IRE regulated isoform showed no change in mRNA levels. Protein levels of DMT1 increased significantly. Iron efflux is thought to be mediated by the metal transporter protein, IREG1/ferroportin1/MTP1, and oxidation of Fe(II) to Fe(III) prior to incorporation into fetal transferrin is carried out by the placental copper oxidase. Expression of IREG1 was not altered by iron deficiency, whereas copper oxidase activity was increased. In BeWo cells made iron deficient by treatment with desferrioxamine (‘deferioxamine’), iron accumulation from iron-transferrin increased, in parallel with increased expression of the transferrin receptor. At the same time, iron efflux also increased, showing a higher flux of iron from the apical to the basolateral side. The data show that expression of placental proteins of iron transport are up-regulated in maternal iron deficiency, resulting in an increased efficiency of iron flux and a consequent minimization of the severity of fetal anaemia.

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Divalent Metal Transporter 1 Knock-Down Modulates IL-1β Mediated Pancreatic Beta-Cell Pro-Apoptotic Signaling Pathways through the Autophagic Machinery

International Journal of Molecular Sciences ◽

10.3390/ijms22158013 ◽

2021 ◽

Vol 22 (15) ◽

pp. 8013

Author(s):

Taewook Kang ◽

Honggang Huang ◽

Thomas Mandrup-Poulsen ◽

Martin R. Larsen

Keyword(s):

Cell Death ◽

Divalent Metal ◽

Β Cells ◽

Β Cell ◽

Divalent Metal Transporter 1 ◽

Divalent Metal Transporter ◽

Knock Down ◽

Metal Transporter ◽

Cell Functions ◽

Protective Proteins

Pro-inflammatory cytokines promote cellular iron-import through enhanced divalent metal transporter-1 (DMT1) expression in pancreatic β-cells, consequently cell death. Inhibition of β-cell iron-import by DMT1 silencing protects against apoptosis in animal models of diabetes. However, how alterations of signaling networks contribute to the protective action of DMT1 knock-down is unknown. Here, we performed phosphoproteomics using our sequential enrichment strategy of mRNA, protein, and phosphopeptides, which enabled us to explore the concurrent molecular events in the same set of wildtype and DMT1-silenced β-cells during IL-1β exposure. Our findings reveal new phosphosites in the IL-1β-induced proteins that are clearly reverted by DMT1 silencing towards their steady-state levels. We validated the levels of five novel phosphosites of the potential protective proteins using parallel reaction monitoring. We also confirmed the inactivation of autophagic flux that may be relevant for cell survival induced by DMT1 silencing during IL-1β exposure. Additionally, the potential protective proteins induced by DMT1 silencing were related to insulin secretion that may lead to improving β-cell functions upon exposure to IL-1β. This global profiling has shed light on the signal transduction pathways driving the protection against inflammation-induced cell death in β-cells after DMT1 silencing.

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VTC4 Polyphosphate Polymerase Knockout Increases Stress Resistance of Saccharomyces cerevisiae Cells

Biology ◽

10.3390/biology10060487 ◽

2021 ◽

Vol 10 (6) ◽

pp. 487

Author(s):

Alexander Tomashevsky ◽

Ekaterina Kulakovskaya ◽

Ludmila Trilisenko ◽

Ivan V. Kulakovskiy ◽

Tatiana Kulakovskaya ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Heavy Metal ◽

Stress Response ◽

Stress Resistance ◽

Alkaline Stress ◽

Inorganic Polyphosphate ◽

Divalent Metal Transporter ◽

Metal Transporter ◽

Elevated Expression ◽

Chaperone Complex

Inorganic polyphosphate (polyP) is an important factor of alkaline, heavy metal, and oxidative stress resistance in microbial cells. In yeast, polyP is synthesized by Vtc4, a subunit of the vacuole transporter chaperone complex. Here, we report reduced but reliably detectable amounts of acid-soluble and acid-insoluble polyPs in the Δvtc4 strain of Saccharomyces cerevisiae, reaching 10% and 20% of the respective levels of the wild-type strain. The Δvtc4 strain has decreased resistance to alkaline stress but, unexpectedly, increased resistance to oxidation and heavy metal excess. We suggest that increased resistance is achieved through elevated expression of DDR2, which is implicated in stress response, and reduced expression of PHO84 encoding a phosphate and divalent metal transporter. The decreased Mg2+-dependent phosphate accumulation in Δvtc4 cells is consistent with reduced expression of PHO84. We discuss a possible role that polyP level plays in cellular signaling of stress response mobilization in yeast.

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Calcium-Promoted Interaction between the C2-Domain Protein EHB1 and Metal Transporter IRT1 Inhibits Arabidopsis Iron Acquisition

PLANT PHYSIOLOGY ◽

10.1104/pp.19.00163 ◽

2019 ◽

Vol 180 (3) ◽

pp. 1564-1581 ◽

Cited By ~ 4

Author(s):

Imran Khan ◽

Regina Gratz ◽

Polina Denezhkin ◽

Stephan N. Schott-Verdugo ◽

Kalina Angrand ◽

...

Keyword(s):

Iron Acquisition ◽

C2 Domain ◽

Metal Transporter ◽

Domain Protein

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The Role of Prophage for Genome Diversification within a Clonal Lineage of Lactobacillus johnsonii: Characterization of the Defective Prophage LJ771

Journal of Bacteriology ◽

10.1128/jb.01802-07 ◽

2008 ◽

Vol 190 (17) ◽

pp. 5806-5813 ◽

Cited By ~ 16

Author(s):

Emmanuel Denou ◽

Raymond David Pridmore ◽

Marco Ventura ◽

Anne-Cécile Pittet ◽

Marie-Camille Zwahlen ◽

...

Keyword(s):

Methionine Sulfoxide ◽

Gene Cassette ◽

Methionine Sulfoxide Reductase ◽

Toxin Gene ◽

Clonal Lineage ◽

Lactobacillus Johnsonii ◽

Reductase Gene ◽

Phage Dna

ABSTRACT Two independent isolates of the gut commensal Lactobacillus johnsonii were sequenced. These isolates belonged to the same clonal lineage and differed mainly by a 40.8-kb prophage, LJ771, belonging to the Sfi11 phage lineage. LJ771 shares close DNA sequence identity with Lactobacillus gasseri prophages. LJ771 coexists as an integrated prophage and excised circular phage DNA, but phage DNA packaged into extracellular phage particles was not detected. Between the phage lysin gene and attR a likely mazE (“antitoxin”)/pemK (“toxin”) gene cassette was detected in LJ771 but not in the L. gasseri prophages. Expressed pemK could be cloned in Escherichia coli only together with the mazE gene. LJ771 was shown to be highly stable and could be cured only by coexpression of mazE from a plasmid. The prophage was integrated into the methionine sulfoxide reductase gene (msrA) and complemented the 5′ end of this gene, creating a protein with a slightly altered N-terminal sequence. The two L. johnsonii strains had identical in vitro growth and in vivo gut persistence phenotypes. Also, in an isogenic background, the presence of the prophage resulted in no growth disadvantage.

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