Search results: Found 4

Listing 1 - 4 of 4
Sort by
Thiol-based redox homeostasis and signalling

Authors: --- --- --- --- et al.
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889192847 Year: Pages: 235 DOI: 10.3389/978-2-88919-284-7 Language: English
Publisher: Frontiers Media SA
Subject: Botany --- Physiology --- Science (General)
Added to DOAB on : 2015-12-10 11:59:07
License:

Loading...
Export citation

Choose an application

Abstract

In contrast to the situation in heterotrophic organisms, plant genomes code for a significantly larger number of oxidoreductases such as thioredoxins (TRXs) and glutaredoxins (GRXs). These proteins provide a biochemical mechanism that allows the rapid and reversible activation or deactivation of protein functions in response to changing environmental conditions, as oxidative conditions caused by excessive photosynthesis. Indeed, owing to the fact that cysteines are sensitive to oxidation, TRXs and GRXs play an essential role in controlling the redox state of protein thiol groups. These redox-dependent post-translational modifications have proven to be critical for many cellular functions constituting regulatory, signalling or protective mechanisms. The articles contained in this Research Topic provide timely overviews and new insights into thiol-dependent redox regulation mechanisms with a focus on TRX- and GRX-based reduction systems in plants. The different contexts discussed take into account physiological, developmental and environmental conditions.

Hemichannels; from the molecule to the function

Authors: ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889194674 Year: Pages: 122 DOI: 10.3389/978-2-88919-467-4 Language: English
Publisher: Frontiers Media SA
Subject: Physiology --- Science (General)
Added to DOAB on : 2016-03-10 08:14:32
License:

Loading...
Export citation

Choose an application

Abstract

Coordinated cell interactions are required to accomplish several complex and dynamic tasks observed in several tissues. Cell function may be coordinated by cell-to-cell communication through gap junctions channels (GJCs). These channels are formed by the serial docking of two hemichannels, which in turn are formed by six protein subunits called connexins (Cxs). It is well known that GJCs are involved in several functions, such as intercellular propagation of calcium waves, spread of electrotonic potentialsand spatial buffering of ions and metabolites. On the other hand, undocked hemichannels, which are not forming GJCs, can also serve other functions as “free hemichannels”. Currently, it is recognized that undocked hemichannels may have functional relevance in cell physiology allowing diffusional exchange of ions and small molecules between intra- and extra-cellular compartments. Additionally, another family of proteins calls pannexins (Panx) also forms functional hemichannels at the plasma membrane. Recently, Panxhemichannels have been involved in both pathological and physiological processes. Controlled hemichannel opening allows the release of small signaling molecules including ATP, glutamate, NAD+, adenosine, cyclic nucleotides, PGE2. They also allow uptake of relevant signaling molecules (e.g., cADPR) and metabolites (e.g., glucose). Additionally, a growing body of evidence shows that hemichannels are involved in important processes, such glucose detection in tanicytes, activation of the inflammasome, memory consolidation in the basolateral amygdala, potentiation of muscle contraction and release of nitric oxide from endothelial cells, among others. However, hemichannels can also play an important role in the homeostatic imbalance observed in diverse chronic diseases. In fact, massive and/or uncontrolled hemichannel opening induces or accelerates cell death in several pathological conditions including Charcot-Marie-Tooth disease, ischemia, oculodentodigital dysplasia, hydrotic ectodermic dysplasia, inflammatory responses, and deafness. Hemichannel-mediated cell death is due mainly to an entry of Ca+2. The latter activates proteases, nucleases and lipases, causing irreversible cell damage. An increasing amount of evidence demonstrates that blockade of uncontrolled hemichannel opening greatly reduces the cellular damage observed in several chronic diseases models. Therefore, Cx and Panx-hemichannels appear as promising drug targets for clinical treatment of human chronic diseases. Therefore, pharmacological tools are urgently needed to further elucidate hemichannels functions and to validate them as drug targets for the development of novel therapies for connexin-based diseases. Thus, understanding the role of Cx and Panx-hemichannels under physiological conditions and recognizing the molecular mechanisms controlling them, may provide us with a better picture of the hemichannels participation in some diseases and of the signals underlying their malfunctioning.

The changing faces of glutathione, a cellular protagonist

Authors: ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195954 Year: Pages: 142 DOI: 10.3389/978-2-88919-595-4 Language: English
Publisher: Frontiers Media SA
Subject: Therapeutics --- Science (General)
Added to DOAB on : 2016-03-10 08:14:32
License:

Loading...
Export citation

Choose an application

Abstract

Glutathione (GSH) has been described for a long time just as a defensive reagent against the action of toxic xenobiotics (drugs, pollutants, carcinogens), both directly and as a cofactor for GSH transferases. As a prototype antioxidant, it has been involved in cell protection from the noxious effect of excess oxidant stress, both directly and as a cofactor of glutathione peroxidases. In addition, it has long been known that GSH is capable of forming disulfide bonds with cysteine residues of proteins, and the relevance of this mechanism ("S-glutathionylation") in regulation of protein function has been well documented in a number of research fields. Rather paradoxically, it has also been highlighted that GSH—and notably its catabolites, as originated by metabolism by gamma-glutamyltransferase—can promote oxidative processes, by participating in metal ion-mediated reactions eventually leading to formation of reactive oxygen species and free radicals. Also, a fundamental role of GSH has been recognized in the storage and transport of nitric oxide (NO), in the form of S-nitrosoglutathione (GSNO). The significance of GSH as a major factor in regulation of cell life, proliferation, and death, can be regarded as the integrated result of all these roles, as well as of more which are emerging in diverse fields of biology and pathophysiology. Against this background, modulation of GSH levels and GSH-related enzyme activities represents a fertile field for experimental pharmacology in numerous and diverse perspectives of animal, plant and microbiologic research. This research topic includes 14 articles, i.e. 4 Opinion Articles, 6 Reviews, and 4 Original Research Articles. The contributions by several distinguished research groups, each from his own standpoint of competence and expertise, provide a comprehensive and updated view over the diverse roles, the changing faces of GSH and GSH-related enzymes in cell’s health, disease and death.

Thioredoxin and Glutaredoxin Systems

Authors: ---
ISBN: 9783038978367 / 9783038978374 Year: Pages: 280 DOI: 10.3390/books978-3-03897-837-4 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Biology
Added to DOAB on : 2019-06-26 08:44:06
License:

Loading...
Export citation

Choose an application

Abstract

This Special Issue features recent data concerning thioredoxins and glutaredoxins from various biological systems, including bacteria, mammals, and plants. Four of the sixteen articles are review papers that deal with the regulation of development of the effect of hydrogen peroxide and the interactions between oxidants and reductants, the description of methionine sulfoxide reductases, detoxification enzymes that require thioredoxin or glutaredoxin, and the response of plants to cold stress, respectively. This is followed by eleven research articles that focus on a reductant of thioredoxin in bacteria, a thioredoxin reductase, and a variety of plant and bacterial thioredoxins, including the m, f, o, and h isoforms and their targets. Various parameters are studied, including genetic, structural, and physiological properties of these systems. The redox regulation of monodehydroascorbate reductase, aminolevulinic acid dehydratase, and cytosolic isocitrate dehydrogenase could have very important consequences in plant metabolism. Also, the properties of the mitochondrial o-type thioredoxins and their unexpected capacity to bind iron–sulfur center (ISC) structures open new developments concerning the redox mitochondrial function and possibly ISC assembly in mitochondria. The final paper discusses interesting biotechnological applications of thioredoxin for breadmaking.

Keywords

methionine --- methionine sulfoxide --- methionine sulfoxide reductase --- physiological function --- protein --- plant --- repair --- redox homeostasis --- signaling --- stress --- mitochondria --- thioredoxin --- iron–sulfur cluster --- redox regulation --- ALAD --- tetrapyrrole biosynthesis --- redox control --- thioredoxins --- posttranslational modification --- chlorophyll --- redox regulation --- thioredoxin --- ferredoxin-thioredoxin reductase --- chloroplast --- H2O2 --- redox signalling --- development --- regeneration --- adult stem cells --- metazoan --- cyanobacteria --- thioredoxin --- photosynthesis --- redox active site --- thioredoxin --- disulfide --- flavin --- NADPH --- X-ray crystallography --- SAXS --- methanoarchaea --- chilling stress --- cold temperature --- posttranslational modification --- regulation --- ROS --- thiol redox network --- thioredoxin --- thioredoxin --- Calvin-Benson cycle --- photosynthesis --- carbon fixation --- chloroplast --- macromolecular crystallography --- protein-protein recognition --- electrostatic surface --- Chlamydomonas reinhardtii --- thioredoxin --- glutaredoxin --- legume plant --- symbiosis --- redox homeostasis --- stress --- thioredoxin --- monodehydroascorbate reductase --- water stress --- protein oxidation --- antioxidants --- ascorbate --- glutathione --- wheat --- thioredoxin --- thioredoxin reductase --- baking --- redox --- dough rheology --- protein oxidation --- methionine oxidation --- methionine sulfoxide reductases --- oxidized protein repair --- ageing --- Chlamydomonas reinhardtii --- cysteine alkylation --- cysteine reactivity --- MALDI-TOF mass spectrometry --- thioredoxin --- X-ray crystallography --- Isocitrate dehydrogenase --- glutathionylation --- nitrosylation --- glutaredoxin --- Arabidopsis thaliana --- thioredoxins --- plastidial --- specificity --- function --- proteomic --- photosynthesis --- Calvin cycle --- n/a

Listing 1 - 4 of 4
Sort by
Narrow your search