Dps biomineralizing proteins: multifunctional architects of nature

2012 ◽  
Vol 445 (3) ◽  
pp. 297-311 ◽  
Author(s):  
Kornelius Zeth
Keyword(s):  
Iron Uptake ◽  
Iron Oxidation ◽  
Hollow Spheres ◽  
Cell Communication ◽  
Memory Storage ◽  
Oxygen Species ◽  
Inner Surface ◽  
Technical Production ◽  
Catalytic Functions ◽  
Ros Reactive Oxygen Species

Dps proteins are the structural relatives of bacterioferritins and ferritins ubiquitously present in the bacterial and archaeal kingdoms. The ball-shaped enzymes play important roles in the detoxification of ROS (reactive oxygen species), in iron scavenging to prevent Fenton reactions and in the mechanical protection of DNA. Detoxification of ROS and iron chaperoning represent the most archetypical functions of dodecameric Dps enzymes. Recent crystallographic studies of these dodecameric complexes have unravelled species-dependent mechanisms of iron uptake into the hollow spheres. Subsequent functions in iron oxidation at ferroxidase centres are highly conserved among bacteria. Final nucleation of iron as iron oxide nanoparticles has been demonstrated to originate at acidic residues located on the inner surface. Some Dps enzymes are also implicated in newly observed catalytic functions related to the formation of molecules playing roles in bacterium–host cell communication. Most recently, Dps complexes are attracting attention in semiconductor science as biomimetic tools for the technical production of the smallest metal-based quantum nanodots used in nanotechnological approaches, such as memory storage or solar cell development.

The preparation of TiO2/SiO2 composite hollow spheres with hydrophobic inner surface and their application in controlled release

2010 ◽  
Vol 45 (10) ◽  
pp. 1351-1356 ◽  
Author(s):  
Li-Feng Yao ◽  
Yan Shi ◽  
Su-Rong Jin ◽  
Mei-Juan Li ◽  
Lian-Meng Zhang
Keyword(s):  
Controlled Release ◽  
Hollow Spheres ◽  
Inner Surface

scholarly journals Mitochondrial Extracellular Vesicles – Origins and Roles

2021 ◽  
Vol 14 ◽  
Author(s):  
Lydia Amari ◽  
Marc Germain
Keyword(s):  
Reactive Oxygen Species ◽  
Extracellular Vesicles ◽  
Large Range ◽  
Inflammatory Responses ◽  
Cell Communication ◽  
Oxygen Species ◽  
Mitochondrial Content ◽  
Communication Devices ◽  
Metabolic Reactions ◽  
Cellular Compartments

Extracellular vesicles (EVs) have emerged in the last decade as critical cell-to-cell communication devices used to carry nucleic acids and proteins between cells. EV cargo includes plasma membrane and endosomal proteins, but EVs also contain material from other cellular compartments, including mitochondria. Within cells, mitochondria are responsible for a large range of metabolic reactions, but they can also produce damaging levels of reactive oxygen species and induce inflammation when damaged. Consistent with this, recent evidence suggests that EV-mediated transfer of mitochondrial content alters metabolic and inflammatory responses of recipient cells. As EV mitochondrial content is also altered in some pathologies, this could have important implications for their diagnosis and treatment. In this review, we will discuss the nature and roles of mitochondrial EVs, with a special emphasis on the nervous system.

scholarly journals Role of ROS/RNS in Preeclampsia: Are Connexins the Missing Piece?

2020 ◽  
Vol 21 (13) ◽  
pp. 4698 ◽  
Author(s):  
María F. Rozas-Villanueva ◽  
Paola Casanello ◽  
Mauricio A. Retamal
Keyword(s):  
Reactive Nitrogen Species ◽  
Molecular Mechanisms ◽  
Cell Communication ◽  
Transmembrane Proteins ◽  
Pregnancy Complication ◽  
Oxygen Species ◽  
Nitrogen Species ◽  
Gap Junction Channels ◽  
Contraction And Relaxation

Preeclampsia is a pregnancy complication that appears after 20 weeks of gestation and is characterized by hypertension and proteinuria, affecting both mother and offspring. The cellular and molecular mechanisms that cause the development of preeclampsia are poorly understood. An important feature of preeclampsia is an increase in oxygen and nitrogen derived free radicals (reactive oxygen species/reactive nitrogen species (ROS/RNS), which seem to be central players setting the development and progression of preeclampsia. Cell-to-cell communication may be disrupted as well. Connexins (Cxs), a family of transmembrane proteins that form hemichannels and gap junction channels (GJCs), are essential in paracrine and autocrine cell communication, allowing the movement of signaling molecules between cells as well as between the cytoplasm and the extracellular media. GJCs and hemichannels are fundamental for communication between endothelial and smooth muscle cells and, therefore, in the control of vascular contraction and relaxation. In systemic vasculature, the activity of GJCs and hemichannels is modulated by ROS and RNS. Cxs participate in the development of the placenta and are expressed in placental vasculature. However, it is unknown whether Cxs are modulated by ROS/RNS in the placenta, or whether this potential modulation contributes to the pathogenesis of preeclampsia. Our review addresses the possible role of Cxs in preeclampsia, and the plausible modulation of Cxs-formed channels by ROS and RNS. We suggest these factors may contribute to the development of preeclampsia.

Adenosine 5′-phosphosulfate reductase (APR2) mutation in Arabidopsis implicates glutathione deficiency in selenate toxicity

2011 ◽  
Vol 438 (2) ◽  
pp. 325-335 ◽  
Author(s):  
Kevron Grant ◽  
Nicole M. Carey ◽  
Miguel Mendoza ◽  
John Schulze ◽  
Marinus Pilon ◽  
...  
Keyword(s):  
Photosynthetic Efficiency ◽  
Sulfur Metabolism ◽  
Oxygen Species ◽  
Total Sulfur ◽  
Glutathione Biosynthesis ◽  
Model Plant Arabidopsis Thaliana ◽  
Glutathione Deficiency ◽  
Total Selenium ◽  
Ros Reactive Oxygen Species ◽  
Plant Arabidopsis Thaliana

APR2 is the dominant APR (adenosine 5′-phosphosulfate reductase) in the model plant Arabidopsis thaliana, and converts activated sulfate to sulfite, a key reaction in the sulfate reduction pathway. To determine whether APR2 has a role in selenium tolerance and metabolism, a mutant Arabidopsis line (apr2-1) was studied. apr2-1 plants had decreased selenate tolerance and photosynthetic efficiency. Sulfur metabolism was perturbed in apr2-1 plants grown on selenate, as observed by an increase in total sulfur and sulfate, and a 2-fold decrease in glutathione concentration. The altered sulfur metabolism in apr2-1 grown on selenate did not reflect typical sulfate starvation, as cysteine and methionine levels were increased. Knockout of APR2 also increased the accumulation of total selenium and selenate. However, the accumulation of selenite and selenium incorporation in protein was lower in apr2-1 mutants. Decreased incorporation of selenium in protein is typically associated with increased selenium tolerance in plants. However, because the apr2-1 mutant exhibited decreased tolerance to selenate, we propose that selenium toxicity can also be caused by selenate's disruption of glutathione biosynthesis leading to enhanced levels of damaging ROS (reactive oxygen species).

Molecular Response of the Acidophilic Iron Oxidizer “Ferrovum” sp. JA12 to the Exposure to Elevated Concentrations of Ferrous Iron

2017 ◽  
Vol 262 ◽  
pp. 482-486 ◽  
Author(s):  
Sophie R. Ullrich ◽  
Anja Poehlein ◽  
Gloria J. Levicán ◽  
Michael Schlömann ◽  
Martin Mühling
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Gene Cluster ◽  
Ferrous Iron ◽  
Iron Oxidation ◽  
Molecular Response ◽  
Oxygen Species ◽  
Transcriptome Data ◽  
Oxidation Model ◽  
Transcriptome Level

The response to elevated ferrous iron concentrations was investigated in the acidophilic iron oxidizer “Ferrovum” sp. JA12 at transcriptome level. Detoxification of reactive oxygen species appears to be the most important strategy to cope with oxidative stress. The proposed iron oxidation model in “Ferrovum” spp. was supported by the transcriptome data of “Ferrovum” sp. JA12. Several gene candidates of the iron oxidation model are organized in a gene cluster conserved in iron oxidizing betaproteobacteria and zetaproteobacteria possibly indicating a common origin of iron oxidation.

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