scholarly journals Potential Implications of Interactions between Fe and S on Cereal Fe Biofortification

2020 ◽  
Vol 21 (8) ◽  
pp. 2827 ◽  
Author(s):  
Yuta Kawakami ◽  
Navreet K. Bhullar
Keyword(s):  
Amino Acid ◽  
Essential Elements ◽  
Metal Chelators ◽  
Physiological Processes ◽  
Cereal Species ◽  
Fe Uptake ◽  
Amino Acid Methionine ◽  
Fe Homeostasis

Iron (Fe) and sulfur (S) are two essential elements for plants, whose interrelation is indispensable for numerous physiological processes. In particular, Fe homeostasis in cereal species is profoundly connected to S nutrition because phytosiderophores, which are the metal chelators required for Fe uptake and translocation in cereals, are derived from a S-containing amino acid, methionine. To date, various biotechnological cereal Fe biofortification strategies involving modulation of genes underlying Fe homeostasis have been reported. Meanwhile, the resultant Fe-biofortified crops have been minimally characterized from the perspective of interaction between Fe and S, in spite of the significance of the crosstalk between the two elements in cereals. Here, we intend to highlight the relevance of Fe and S interrelation in cereal Fe homeostasis and illustrate the potential implications it has to offer for future cereal Fe biofortification studies.

Biogenic amino acid methionine-based corrosion inhibitors of mild steel in acidic media

2019 ◽  
Vol 26 (4) ◽  
pp. 467-482 ◽  
Author(s):  
L. K. M. O. Goni ◽  
M. A. Jafar Mazumder ◽  
S. A. Ali ◽  
M. K. Nazal ◽  
H. A. Al-Muallem
Keyword(s):  
Amino Acid ◽  
Mild Steel ◽  
Corrosion Inhibitors ◽  
Acidic Media ◽  
Amino Acid Methionine

Mineral Cycling and Lichens: The Physiological Basis

1991 ◽  
Vol 23 (3) ◽  
pp. 293-307 ◽  
Author(s):  
Dennis H. Brown ◽  
Rosalie M. Brown
Keyword(s):  
Toxic Metal ◽  
Distribution Patterns ◽  
Essential Elements ◽  
Mineral Matter ◽  
Physiological Basis ◽  
Wet And Dry Deposition ◽  
Mineral Cycling ◽  
Physiological Processes ◽  
Field And Laboratory Conditions

AbstractA number of physiological processes relevant to the role of lichens in mineral cycling are discussed. Consideration is given to the cellular location of positively-charged cations, showing (a) the benefits of quantifying intracellular elements for the interpretation of toxic metal stress, and (b) how distribution patterns of physiologically essential elements may be altered by desiccation and rehydration under field and laboratory conditions. The quantitative significance of these dynamic processes associated with metal uptake and loss requires verification under field conditions. A modified sequential elution procedure is proposed that enables quantification of insoluble paniculate mineral matter (acquired by wet and dry deposition) in addition to soluble elements in intercellular, extracellular-exchangeable and intracellular sites.

scholarly journals Cloning and characterization of a second member of the mouse mdr gene family.

1988 ◽  
Vol 8 (7) ◽  
pp. 2770-2778 ◽  
Author(s):  
P Gros ◽  
M Raymond ◽  
J Bell ◽  
D Housman
Keyword(s):  
Multidrug Resistance ◽  
Amino Acid ◽  
Nucleotide Sequence ◽  
Amino Acid Sequence ◽  
Gene Family ◽  
Predicted Amino Acid Sequence ◽  
Coding Region ◽  
Physiological Processes ◽  
Strong Homology ◽  
Energy Dependent

The mammalian mdr gene family comprises a small number of closely related genes. Previously, we have shown that one member, mdr1, has the capacity to convey multidrug resistance to drug-sensitive recipient cells in a gene transfer protocol. However, the functional characteristics of other members of this gene family have not been examined. In this report, we characterize a second member of the mdr gene family which we designated mdr2. We determined the nucleotide sequence corresponding to the complete coding region of this mdr2 transcript. The predicted amino acid sequence of this protein (1,276 amino acids) showed that it is a membrane glycoprotein highly homologous to mdr1 (85%), strongly suggesting that both genes originate from a common ancestor. Regions of divergence between mdr1 and mdr2 proteins are concentrated in two discrete segments of the predicted polypeptides, each approximately 100 residues in length. The mdr2 protein appears to be formed by the duplication of a structural unit which encodes three putative transmembrane loops and a predicted nucleotide-binding fold and is highly homologous to bacterial transport proteins such as hlyB. This strong homology suggests that mdr2 also participates in an energy-dependent membrane transport process. However, the direct relationship, if any, of this new member of the mdr family to multidrug resistance remains to be established. Knowledge of the complete nucleotide sequence and predicted amino acid sequence of the mdr2 gene product will enable the preparation of gene-specific probes and antibodies necessary to study the functional role of this gene in multidrug resistance and normal physiological processes.

scholarly journals Methionine in a protein hydrophobic core drives tight interactions required for assembly of spider silk

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Julia C. Heiby ◽  
Benedikt Goretzki ◽  
Christopher M. Johnson ◽  
Ute A. Hellmich ◽  
Hannes Neuweiler
Keyword(s):  
Amino Acid ◽  
Spider Silk ◽  
Tight Binding ◽  
Pivotal Role ◽  
Speed Limit ◽  
Hydrophobic Core ◽  
Complex Mechanism ◽  
Silk Proteins ◽  
Dragline Silk ◽  
Amino Acid Methionine

Abstract Web spiders connect silk proteins, so-called spidroins, into fibers of extraordinary toughness. The spidroin N-terminal domain (NTD) plays a pivotal role in this process: it polymerizes spidroins through a complex mechanism of dimerization. Here we analyze sequences of spidroin NTDs and find an unusually high content of the amino acid methionine. We simultaneously mutate all methionines present in the hydrophobic core of a spidroin NTD from a nursery web spider’s dragline silk to leucine. The mutated NTD is strongly stabilized and folds at the theoretical speed limit. The structure of the mutant is preserved, yet its ability to dimerize is substantially impaired. We find that side chains of core methionines serve to mobilize the fold, which can thereby access various conformations and adapt the association interface for tight binding. Methionine in a hydrophobic core equips a protein with the capacity to dynamically change shape and thus to optimize its function.

scholarly journals The amino-acid methionine; constitution and synthesis

1928 ◽  
Vol 22 (6) ◽  
pp. 1417-1425 ◽  
Author(s):  
George Barger ◽  
Frederick Philip Coyne
Keyword(s):  
Amino Acid ◽  
Amino Acid Methionine

scholarly journals Calcium and cell death signaling in neurodegeneration and aging

2009 ◽  
Vol 81 (3) ◽  
pp. 467-475 ◽  
Author(s):  
Soraya Smaili ◽  
Hanako Hirata ◽  
Rodrigo Ureshino ◽  
Priscila T. Monteforte ◽  
Ana P. Morales ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Apoptotic Cell ◽  
Essential Elements ◽  
Apoptotic Cell Death ◽  
Nuclear Fragmentation ◽  
Physiological Processes ◽  
Cell Death Signaling ◽  
Lines Of Evidence

Transient increase in cytosolic (Cac2+) and mitochondrial Ca2+ (Ca m2+) are essential elements in the control of many physiological processes. However, sustained increases in Ca c2+ and Ca m2+ may contribute to oxidative stress and cell death. Several events are related to the increase in Ca m2+, including regulation and activation of a number of Ca2+ dependent enzymes, such as phospholipases, proteases and nucleases. Mitochondria and endoplasmic reticulum (ER) play pivotal roles in the maintenance of intracellular Ca2+ homeostasis and regulation of cell death. Several lines of evidence have shown that, in the presence of some apoptotic stimuli, the activation of mitochondrial processes maylead to the release of cytochrome c followed by the activation of caspases, nuclear fragmentation and apoptotic cell death. The aim of this review was to show how changes in calcium signaling can be related to the apoptotic cell death induction. Calcium homeostasis was also shown to be an important mechanism involved in neurodegenerative and aging processes.

Fragmentation of the α-Amino Acid Methionine in Field Desorption Mass Spectrometry

1978 ◽  
Vol 33 (7) ◽  
pp. 770-781 ◽  
Author(s):  
J. van der Greef ◽  
N. M. M. Nibbering ◽  
H.-R. Schulten ◽  
W. D. Lehmann
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Desorption Kinetics ◽  
Fragmentation Pattern ◽  
Field Desorption ◽  
Stable Isotope Labelling ◽  
Desorption Mass Spectrometry ◽  
Combined Use ◽  
Field Desorption Mass Spectrometry ◽  
Amino Acid Methionine

AbstractField Desorption Mass Spectrometry, a-Amino Acid Methionine The fragmentation of methionine in field desorption mass spectrometry has been studied. Decomposition mechanisms are described which are based on stable isotope labelling, low and high resolution field desorption, and the application of field desorption kinetics. The combined use of these techniques for the study of some fundamental fragmentations in field desorption is demonstrated successfully. Further, a comparison with the fragmentation pattern of methionine under electron impact, chemical ionization and Curie point pyrolysis is given.

Regulation of Fe absorption by cultured intestinal epithelia (Caco-2) cell monolayers with varied Fe status

1996 ◽  
Vol 271 (3) ◽  
pp. G443-G447 ◽  
Author(s):  
V. Tapia ◽  
M. Arredondo ◽  
M. T. Nunez
Keyword(s):  
Intracellular Concentration ◽  
Apical Surface ◽  
Cell Monolayers ◽  
Intestinal Epithelia ◽  
Second Stage ◽  
Ferritin Synthesis ◽  
Fe Content ◽  
Fe Uptake ◽  
Fe Homeostasis

Body Fe homeostasis is maintained through the regulation of Fe absorption by the intestinal epithelia. Working under the hypothesis that the intracellular concentration of Fe is instrumental in the control of its transepithelial flux, we investigated in vitro which steps in Fe absorption are regulated by cellular Fe content. For that study, Caco-2 cells containing different concentrations of intracellular 55Fe were grown in porous filters, and the apical-to-cell-to- basolateral flux of 59Fe was then determined. We found that 1) at low (up to 0.1 mM) intracellular Fe content the apical-to-basal Fe transport was primarily regulated by a decrease in apical Fe uptake (first stage of regulation), 2) at higher levels of intracellular Fe (0.1-1 mM) the transepithelial Fe flux was regulated by intracellular factors that sequester most of the Fe taken up at the apical surface (second stage of regulation), and 3) a fraction of the apical-to-basolateral Fe flux was not regulated by the intracellular concentration of Fe. Ferritin synthesis preceded the onset of the second stage of regulation, suggesting a causal relationship between intracellular Fe levels, ferritin levels, and regulation of Fe absorption.

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