المؤلفون: Jennifer C. Klein, Andrew J. Gregory, Daniel G. Walgenbach

المصدر: Biochemical and biophysical research communications. 505(1)

مصطلحات موضوعية: 0301 basic medicine, Calmodulin, Glutamine, Biophysics, Mutation, Missense, Redox sensor, Molecular Dynamics Simulation, Biochemistry, Protein Structure, Secondary, Article, 03 medical and health sciences, chemistry.chemical_compound, Molecular dynamics, Amino Acids, Aromatic, Methionine, Molecular Biology, 030102 biochemistry & molecular biology, biology, Chemistry, EF hand, Functional protein, Cell Biology, Redox sensitive, 030104 developmental biology, biology.protein, Calcium, Oxidation-Reduction

الوصف: Calmodulin contains multiple redox sensitive methionines whose oxidation alters the regulation of numerous targets. Molecular dynamics simulations were used to define the molecular principles that govern how calmodulin is structurally poised to detect and respond to methionine oxidation. We found that calmodulin's open and closed states were preferentially stabilized by unique, redox sensitive, methionine-aromatic interactions. Key methionine-aromatic interactions were coupled to reorientation of EF hand helices. Methionine to glutamine substitutions designed to mimic methionine oxidation strongly altered conformational transitions by modulating the strength of methionine-aromatic interactions. Together, these results suggest a broadly applicable redox sensing mechanism though which methionine oxidation by cellular oxidants alters the strength of methionine-aromatic interactions critical for functional protein dynamics.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e7a8b959ee2589d9c0b45ba0c5aa3f80Test
https://pubmed.ncbi.nlm.nih.gov/30243720Test

المؤلفون: Karolina Jankowska, Stuart T. Fraser, Amandeep Kaur, Chelsea Pilgrim, Elizabeth J. New

المصدر: Antioxidants & Redox Signaling. 24:667-679

مصطلحات موضوعية: Lipopolysaccharides, 0301 basic medicine, Dinitrocresols, Physiology, Cellular differentiation, Clinical Biochemistry, Biosensing Techniques, Biology, Redox sensor, 010402 general chemistry, 01 natural sciences, Biochemistry, Redox, Mice, 03 medical and health sciences, chemistry.chemical_compound, Erythroid Cells, Animals, Molecular Biology, Reactive nitrogen species, General Environmental Science, chemistry.chemical_classification, Reactive oxygen species, Molecular Structure, Hematopoietic cell, Rhodamines, Macrophages, Cell Differentiation, Cell Biology, Fluorescence, Forum Original Research CommunicationRedox Imaging (T.P. Dick and A.J. Meyer, Eds.), Mitochondria, 0104 chemical sciences, RAW 264.7 Cells, 030104 developmental biology, chemistry, Biophysics, General Earth and Planetary Sciences, Signal transduction, Reactive Oxygen Species

الوصف: Aims: Chronic elevations in cellular redox state are known to result in the onset of various pathological conditions, but transient increases in reactive oxygen species (ROS)/reactive nitrogen species (RNS) are necessary for signal transduction and various physiological functions. There is a distinct lack of reversible fluorescent tools that can aid in studying and unraveling the roles of ROS/RNS in physiology and pathology by monitoring the variations in cellular ROS levels over time. In this work, we report the development of ratiometric fluorescent sensors that reversibly respond to changes in mitochondrial redox state. Results: Photophysical studies of the developed flavin–rhodamine redox sensors, flavin–rhodamine redox sensor 1 (FRR1) and flavin–rhodamine redox sensor 2 (FRR2), confirmed the reversible response of the probes upon reduction and re-oxidation over more than five cycles. The ratiometric output of FRR1 and FRR2 remained unaltered in the presence of other possible cellular interferants (metals and pH). Microscopy studies indicated clear mitochondrial localization of both probes, and FRR2 was shown to report the time-dependent increase of mitochondrial ROS levels after lipopolysaccharide stimulation in macrophages. Moreover, it was used to study the variations in mitochondrial redox state in mouse hematopoietic cells at different stages of embryonic development and maturation. Innovation: This study provides the first ratiometric and reversible probes for ROS, targeted to the mitochondria, which reveal variations in mitochondrial ROS levels at different stages of embryonic and adult blood cell production. Conclusions: Our results suggest that with their ratiometric and reversible outputs, FRR1 and FRR2 are valuable tools for the future study of oxidative stress and its implications in physiology and pathology. Antioxid. Redox Signal. 24, 667–679.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7dd0faec6860be9e477be54eb1a36715Test
https://doi.org/10.1089/ars.2015.6495Test

المؤلفون: Robert J. Fletterick, Paulomi Bhattacharya, Svetlana A. Kholodar, Harrison Liu, Pamela M. England, James M. Holton, Matthew P. Jacobson, Francesca Oltrabella, Yan Wang, Su Guo, Boxue Tian, John M. Bruning

المصدر: Cell Chem Biol
Cell chemical biology, vol 26, iss 5

مصطلحات موضوعية: nuclear receptor related 1 protein, Indoles, Parkinson's disease, Transcription, Genetic, Dopamine, Metabolite, Clinical Biochemistry, Neurodegenerative, Crystallography, X-Ray, 01 natural sciences, Biochemistry, chemistry.chemical_compound, 0302 clinical medicine, Transcription (biology), Nuclear Receptor Subfamily 4, Group A, Member 2, Drug Discovery, 2.1 Biological and endogenous factors, nuclear receptor, Aetiology, Zebrafish, Group A, 0303 health sciences, Tumor, Crystallography, Dopaminergic, Recombinant Proteins, 3. Good health, Cell biology, 6-dihydroxyindolequinone, redox sensor, Nurr1, 6-dihydroxyindole, DHICA, Larva, Neurological, DHI, Thermodynamics, Molecular Medicine, Transcription, dopamine metabolite, dopamine oxidation, medicine.drug, Nuclear Receptor Subfamily 4, Member 2, ligand-binding domain, 1.1 Normal biological development and functioning, Nuclear receptor related-1 protein, Molecular Dynamics Simulation, Biology, Article, Cell Line, 03 medical and health sciences, Genetic, Protein Domains, Underpinning research, Nr4A2, Cell Line, Tumor, Genetics, medicine, Animals, Humans, 6-indolequinone, Gene, Molecular Biology, 030304 developmental biology, Pharmacology, Binding Sites, ligand-binding pocket, 010405 organic chemistry, cysteine adduct, Neurosciences, dopamine homeostasis, medicine.disease, biology.organism_classification, Brain Disorders, 0104 chemical sciences, Oxidative Stress, Good Health and Well Being, chemistry, Nuclear receptor, IQ, X-Ray, biology.protein, 030217 neurology & neurosurgery, Homeostasis

الوصف: SUMMARYNurr1, a nuclear receptor essential for the development, maintenance, and survival of midbrain dopaminergic neurons, is a potential therapeutic target for Parkinson’s disease, a neurological disorder characterized by the degeneration of these same neurons. Efforts to identify Nurr1 agonists have been hampered by the recognition that it lacks several classic regulatory elements of nuclear receptor function, including the canonical ligand-binding pocket. Here we report that the dopamine metabolite 5,6-dihydroxyindole (DHI) binds directly to and modulates the activity of Nurr1. Using biophysical assays and x-ray crystallography we show that DHI binds to the ligand binding domain within a non-canonical pocket, forming a covalent adduct with Cys566. In cultured cells and zebrafish, DHI stimulates Nurr1 activity, including the transcription of target genes underlying dopamine homeostasis. These findings suggest avenues for developing synthetic Nurr1 ligands to ameliorate the symptoms and progression of Parkinson’s disease.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ca5bd236832a5ef0e35903b62f4f0616Test
https://doi.org/10.1016/j.chembiol.2019.02.002Test

المؤلفون: Adrie J. C. Steyn, Jack R. Lancaster, Ashwani Kumar, José Carlos de Toledo, Rakesh P. Patel

المصدر: Proceedings of the National Academy of Sciences. 104:11568-11573

مصطلحات موضوعية: Hemeproteins, Heme iron, Protamine Kinase, Redox sensor, Ligands, Nitric Oxide, Cofactor, Mycobacterium tuberculosis, chemistry.chemical_compound, Bacterial Proteins, medicine, Humans, Anaerobiosis, Heme, Carbon Monoxide, Multidisciplinary, biology, Biological Sciences, Hypoxia (medical), biology.organism_classification, Cell biology, Oxygen, Response regulator, Regulon, chemistry, Biochemistry, biology.protein, medicine.symptom, Oxidation-Reduction

الوصف: A fundamental challenge to the study of oxidative stress responses of Mycobacterium tuberculosis ( Mtb ) is to understand how the protective host molecules are sensed and relayed to control bacilli gene expression. The genetic response of Mtb to hypoxia and NO is controlled by the sensor kinases DosS and DosT and the response regulator DosR through activation of the dormancy/NO (Dos) regulon. However, the regulatory ligands of DosS and DosT and the mechanism of signal sensing were unknown. Here, we show that both DosS and DosT bind heme as a prosthetic group and that DosS is rapidly autooxidized to attain the met (Fe 3+ ) form, whereas DosT exists in the O 2 -bound (oxy) form. EPR and UV-visible spectroscopy analysis showed that O 2 , NO, and CO are ligands of DosS and DosT. Importantly, we demonstrate that the oxidation or ligation state of the heme iron modulates DosS and DosT autokinase activity and that ferrous DosS, and deoxy DosT, show significantly increased autokinase activity compared with met DosS and oxy DosT. Our data provide direct proof that DosS functions as a redox sensor, whereas DosT functions as a hypoxia sensor, and that O 2 , NO, and CO are modulatory ligands of DosS and DosT. Finally, we identified a third potential dormancy signal, CO, that induces the Mtb Dos regulon. We conclude that Mtb has evolved finely tuned redox and hypoxia-mediated sensing strategies for detecting O 2 , NO, and CO. Data presented here establish a paradigm for understanding the mechanism of bacilli persistence.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::75f179e59c4cdf66d0d66614894ba362Test
https://doi.org/10.1073/pnas.0705054104Test

المؤلفون: Elizabeth C. Theil, F. Wayne Outten

المصدر: Antioxidantsredox signaling. 11(5)

مصطلحات موضوعية: biology, Physiology, Chemistry, Iron, Clinical Biochemistry, Cell Biology, Metabolism, Redox sensor, Electrochemistry, Photosynthesis, Forum Review Articles, Biochemistry, Redox, Cofactor, chemistry.chemical_compound, Iron based, biology.protein, General Earth and Planetary Sciences, Molecular Biology, Heme, Oxidation-Reduction, General Environmental Science

الوصف: By virtue of its unique electrochemical properties, iron makes an ideal redox active cofactor for many biologic processes. In addition to its important role in respiration, central metabolism, nitrogen fixation, and photosynthesis, iron also is used as a sensor of cellular redox status. Iron-based sensors incorporate Fe-S clusters, heme, and mononuclear iron sites to act as switches to control protein activity in response to changes in cellular redox balance. Here we provide an overview of iron-based redox sensor proteins, in both prokaryotes and eukaryotes, that have been characterized at the biochemical level. Although this review emphasizes redox sensors containing Fe-S clusters, proteins that use heme or novel iron sites also are discussed. Antioxid. Redox Signal. 11, 1029–1046.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b2bc26e6841e0e4a819706c12e99063fTest
https://pubmed.ncbi.nlm.nih.gov/19021503Test

المؤلفون: Ha Yeon Cho, Beom Sik Kang, Myung Hee Kim, Hyo Je Cho

المصدر: FEBS Letters. (12):1873-1878

مصطلحات موضوعية: Hemeprotein, Mutant, DosS, GAF domain, Biophysics, chemistry.chemical_element, Plasma protein binding, Heme, Biochemistry, Oxygen, Mycobacterium tuberculosis, chemistry.chemical_compound, Oxygen sensor, Structural Biology, Genetics, Side chain, Transferase, Hypoxia, Molecular Biology, biology, Heme protein, Phosphoric Diester Hydrolases, Cell Biology, biology.organism_classification, Redox sensor, Protein Structure, Tertiary, chemistry, Oxidation-Reduction, Protein Binding

الوصف: Two sensor kinases, DosS and DosT, are responsible for recognition of hypoxia in Mycobacterium tuberculosis. Both proteins are structurally similar to each other, but DosS is a redox sensor while DosT binds oxygen. The primary difference between the two proteins is the channel to the heme present in their GAF domains. DosS has a channel that is blocked by E87 while DosT has an open channel. Absorption spectra of DosS mutants with an open channel show that they bind oxygen as DosT does when they are exposed to air, while DosT G85E mutant is oxidized similarly to DosS without formation of an oxy-ferrous form. This suggests that oxygen accessibility to heme is the primary factor governing the oxygen-binding properties of these proteins.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9b2090b50545f65f6862179cdae26179Test

المؤلفون: Albrecht M. Clement, Stefan Tenzer, Christian Behl, Martina P. Liebl, Bernd Moosmann, Romy Mittenzwei, Ali M. Kaya, Ingrid Koziollek-Drechsler, Hansjörg Schild

المصدر: Free Radical Biology and Medicine. :41-54

مصطلحات موضوعية: Thioredoxin reductase, Amino Acid Motifs, Blotting, Western, chemistry.chemical_element, Mice, Transgenic, Free radicals, Oxidative phosphorylation, Calcium, Protein aggregation, medicine.disease_cause, Biochemistry, Mass Spectrometry, Mice, chemistry.chemical_compound, Superoxide Dismutase-1, BAPTA, Physiology (medical), VILIP-1, medicine, Animals, Humans, Cysteine, Myristoylation, Superoxide Dismutase, Chemistry, HEK 293 cells, Amyotrophic lateral sclerosis, Redox sensor, Immunohistochemistry, Cell biology, Disease Models, Animal, Oxidative Stress, HEK293 Cells, Neurocalcin, Mutagenesis, Site-Directed, Protein Multimerization, Oxidation-Reduction, Oxidative stress

الوصف: Redox control of proteins that form disulfide bonds upon oxidative challenge is an emerging topic in the physiological and pathophysiological regulation of protein function. We have investigated the role of the neuronal calcium sensor protein visinin-like protein 1 (VILIP-1) as a novel redox sensor in a cellular system. We have found oxidative stress to trigger dimerization of VILIP-1 within a cellular environment and identified thioredoxin reductase as responsible for facilitating the remonomerization of the dimeric protein. Dimerization is modulated by calcium and not dependent on the myristoylation of VILIP-1. Furthermore, we show by site-directed mutagenesis that dimerization is exclusively mediated by Cys187. As a functional consequence, VILIP-1 dimerization modulates the sensitivity of cells to an oxidative challenge. We have investigated whether dimerization of VILIP-1 occurs in two different animal models of amyotrophic lateral sclerosis (ALS) and detected soluble VILIP-1 dimers to be significantly enriched in the spinal cord from phenotypic disease onset onwards. Moreover, VILIP-1 is part of the ALS-specific protein aggregates. We show for the first time that the C-terminus of VILIP-1, containing Cys187, might represent a novel redox-sensitive motif and that VILIP-1 dimerization and aggregation are hallmarks of ALS. This suggests that VILIP-1 dimers play a functional role in integrating the cytosolic calcium concentration and the oxidative status of the cell. Furthermore, a loss of VILIP-1 function owing to protein aggregation in ALS could be relevant in the pathophysiology of the disease.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::03b072a6b3f909a350b2a895bf8ca00dTest