scholarly journals Methionine sulfoxide reductase 2 reversibly regulates Mge1, a cochaperone of mitochondrial Hsp70, during oxidative stress

2015 ◽  
Vol 26 (3) ◽  
pp. 406-419 ◽  
Author(s):  
Praveen Kumar Allu ◽  
Adinarayana Marada ◽  
Yerranna Boggula ◽  
Srinivasu Karri ◽  
Thanuja Krishnamoorthy ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Methionine Sulfoxide ◽  
Methionine Sulfoxide Reductase ◽  
Yeast Cells ◽  
Nucleotide Exchange ◽  
New Paradigm ◽  
Methionine Sulfoxide Reductases ◽  
Mitochondrial Hsp70

Peptide methionine sulfoxide reductases are conserved enzymes that reduce oxidized methionines in protein(s). Although these reductases have been implicated in several human diseases, there is a dearth of information on the identity of their physiological substrates. By using Saccharomyces cerevisiae as a model, we show that of the two methionine sulfoxide reductases (MXR1, MXR2), deletion of mitochondrial MXR2 renders yeast cells more sensitive to oxidative stress than the cytosolic MXR1. Our earlier studies showed that Mge1, an evolutionarily conserved nucleotide exchange factor of Hsp70, acts as an oxidative sensor to regulate mitochondrial Hsp70. In the present study, we show that Mxr2 regulates Mge1 by selectively reducing MetO at position 155 and restores the activity of Mge1 both in vitro and in vivo. Mge1 M155L mutant rescues the slow-growth phenotype and aggregation of proteins of mxr2Δ strain during oxidative stress. By identifying the first mitochondrial substrate for Mxrs, we add a new paradigm to the regulation of the oxidative stress response pathway.

scholarly journals Differential Responses of Methionine Sulfoxide Reductases A and B to Anoxia and Oxidative Stress in the Freshwater Turtle Trachemys scripta

Metabolites ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 458
Author(s):  
Melissa Reiterer ◽  
Lynsey Bruce ◽  
Sarah Milton
Keyword(s):  
Oxidative Stress ◽  
Epigallocatechin Gallate ◽  
Methionine Sulfoxide ◽  
Methionine Sulfoxide Reductase ◽  
Trachemys Scripta ◽  
Freshwater Turtle ◽  
Protein Levels ◽  
Methionine Sulfoxide Reductases ◽  
Vertebrate Model

Oxidative stress has been acknowledged as a major factor in aging, senescence and neurodegenerative conditions. Mammalian models are susceptible to these stresses following the restoration of oxygen after anoxia; however, some organisms including the freshwater turtle Trachemys scripta can withstand repeated anoxia and reoxygenation without apparent pathology. T. scripta thus provides us with an alternate vertebrate model to investigate physiological mechanisms of neuroprotection. The objective of this study was to investigate the antioxidant methionine sulfoxide reductase system (Msr) in turtle neuronal tissue. We examined brain transcript and protein levels of MsrA and MsrB and examined the potential for the transcription factor FOXO3a to regulate the oxygen-responsive changes in Msr in vitro. We found that Msr mRNA and protein levels are differentially upregulated during anoxia and reoxygenation, and when cells were exposed to chemical oxidative stress. However, while MsrA and MsrB3 levels increased when cell cultures were exposed to chemical oxidative stress, this induction was not enhanced by treatment with epigallocatechin gallate (EGCG), which has previously been shown to enhance FOXO3a levels in the turtle. These results suggest that FOXO3a and Msr protect the cells from oxidative stress through different molecular pathways, and that both the Msr pathway and EGCG may be therapeutic targets to treat diseases related to oxidative damage.

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

2008 ◽  
Vol 190 (17) ◽  
pp. 5806-5813 ◽  
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.

scholarly journals Inhibition of triosephosphate isomerase by phosphoenolpyruvate in the feedback-regulation of glycolysis

Open Biology ◽  
2014 ◽  
Vol 4 (3) ◽  
pp. 130232 ◽  
Author(s):  
Nana-Maria Grüning ◽  
Dijun Du ◽  
Markus A. Keller ◽  
Ben F. Luisi ◽  
Markus Ralser
Keyword(s):  
Oxidative Stress ◽  
Pyruvate Kinase ◽  
Feedback Loop ◽  
Triosephosphate Isomerase ◽  
Feedback Regulation ◽  
Pentose Phosphate ◽  
Yeast Cells ◽  
Dihydroxyacetone Phosphate

The inhibition of triosephosphate isomerase (TPI) in glycolysis by the pyruvate kinase (PK) substrate phosphoenolpyruvate (PEP) results in a newly discovered feedback loop that counters oxidative stress in cancer and actively respiring cells. The mechanism underlying this inhibition is illuminated by the co-crystal structure of TPI with bound PEP at 1.6 Å resolution, and by mutational studies guided by the crystallographic results. PEP is bound to the catalytic pocket of TPI and occludes substrate, which accounts for the observation that PEP competitively inhibits the interconversion of glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. Replacing an isoleucine residue located in the catalytic pocket of TPI with valine or threonine altered binding of substrates and PEP, reducing TPI activity in vitro and in vivo . Confirming a TPI-mediated activation of the pentose phosphate pathway (PPP), transgenic yeast cells expressing these TPI mutations accumulate greater levels of PPP intermediates and have altered stress resistance, mimicking the activation of the PK–TPI feedback loop. These results support a model in which glycolytic regulation requires direct catalytic inhibition of TPI by the pyruvate kinase substrate PEP, mediating a protective metabolic self-reconfiguration of central metabolism under conditions of oxidative stress.

scholarly journals Insight into the Influence of Cultivar Type, Cultivation Year, and Site on the Lignans and Related Phenolic Profiles, and the Health-Promoting Antioxidant Potential of Flax (Linum usitatissimum L.) Seeds

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2636 ◽  
Author(s):  
Laurine Garros ◽  
Samantha Drouet ◽  
Cyrielle Corbin ◽  
Cédric Decourtil ◽  
Thibaud Fidel ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Biological Activities ◽  
Yeast Cells ◽  
In Vivo Studies ◽  
Major Influence ◽  
Antioxidant Power ◽  
Accumulation Pattern ◽  
The Impact

Flaxseeds are a functional food representing, by far, the richest natural grain source of lignans, and accumulate substantial amounts of other health beneficial phenolic compounds (i.e., flavonols, hydroxycinnamic acids). This specific accumulation pattern is related to their numerous beneficial effects on human health. However, to date, little data is available concerning the relative impact of genetic and geographic parameters on the phytochemical yield and composition. Here, the major influence of the cultivar over geographic parameters on the flaxseed phytochemical accumulation yield and composition is evidenced. The importance of genetic parameters on the lignan accumulation was further confirmed by gene expression analysis monitored by RT-qPCR. The corresponding antioxidant activity of these flaxseed extracts was evaluated, both in vitro, using ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and iron chelating assays, as well as in vivo, by monitoring the impact of UV-induced oxidative stress on the lipid membrane peroxidation of yeast cells. Our results, both the in vitro and in vivo studies, confirm that flaxseed extracts are an effective protector against oxidative stress. The results point out that secoisolariciresinol diglucoside, caffeic acid glucoside, and p-coumaric acid glucoside are the main contributors to the antioxidant capacity. Considering the health benefits of these compounds, the present study demonstrates that the flaxseed cultivar type could greatly influence the phytochemical intakes and, therefore, the associated biological activities. We recommend that this crucial parameter be considered in epidemiological studies dealing with flaxseeds.

scholarly journals In Vivo Effects of Methionine Sulfoxide Reductase Deficiency in Drosophila melanogaster

Antioxidants ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 155 ◽  
Author(s):  
Lindsay Bruce ◽  
Diana Singkornrat ◽  
Kelsey Wilson ◽  
William Hausman ◽  
Kelli Robbins ◽  
...  
Keyword(s):  
Methionine Sulfoxide ◽  
Methionine Sulfoxide Reductase ◽  
Model Organisms ◽  
Methionine Sulfoxide Reductase A ◽  
Methionine Sulfoxide Reductases ◽  
Methionine Residues ◽  
Oxidation Of Methionine ◽  
And Function ◽  
In Vivo Effects

The deleterious alteration of protein structure and function due to the oxidation of methionine residues has been studied extensively in age-associated neurodegenerative disorders such as Alzheimer’s and Parkinson’s Disease. Methionine sulfoxide reductases (MSR) have three well-characterized biological functions. The most commonly studied function is the reduction of oxidized methionine residues back into functional methionine thus, often restoring biological function to proteins. Previous studies have successfully overexpressed and silenced MSR activity in numerous model organisms correlating its activity to longevity and oxidative stress. In the present study, we have characterized in vivo effects of MSR deficiency in Drosophila. Interestingly, we found no significant phenotype in animals lacking either methionine sulfoxide reductase A (MSRA) or methionine sulfoxide reductase B (MSRB). However, Drosophila lacking any known MSR activity exhibited a prolonged larval third instar development and a shortened lifespan. These data suggest an essential role of MSR in key biological processes.

scholarly journals Identification of Lactobacillus reuteri Genes Specifically Induced in the Mouse Gastrointestinal Tract

2003 ◽  
Vol 69 (4) ◽  
pp. 2044-2051 ◽  
Author(s):  
Jens Walter ◽  
Nicholas C. K. Heng ◽  
Walter P. Hammes ◽  
Diane M. Loach ◽  
Gerald W. Tannock ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Reporter Gene ◽  
Stress Responses ◽  
Lactobacillus Reuteri ◽  
Xylose Isomerase ◽  
Methionine Sulfoxide ◽  
Methionine Sulfoxide Reductase ◽  
Chromosomal Dna

ABSTRACT Lactobacilli are common inhabitants of the gastrointestinal tracts of mammals and have received considerable attention due to their putative health-promoting properties. Little is known about the traits that enhance the ability of these bacteria to inhabit the gastrointestinal tract. In this paper we describe the development and application of a strategy based on in vivo expression technology (IVET) that enables detection of Lactobacillus reuteri genes specifically induced in the murine gut. A plasmid-based system was constructed containing ′ermGT (which confers lincomycin resistance) as the primary reporter gene for selection of promoters active in the gastrointestinal tract of mice treated with lincomycin. A second reporter gene, ′bglM (β-glucanase), allowed differentiation between constitutive and in vivo inducible promoters. The system was successfully tested in vitro and in vivo by using a constitutive promoter. Application of the IVET system with chromosomal DNA of L. reuteri 100-23 and reconstituted lactobacillus-free mice revealed three genes induced specifically during colonization. Two of the sequences showed homology to genes encoding xylose isomerase (xylA) and peptide methionine sulfoxide reductase (msrB), which are involved in nutrient acquisition and stress responses, respectively. The third locus showed homology to the gene encoding a protein whose function is not known. Our IVET system has the potential to identify genes of lactobacilli that have not previously been functionally characterized but which may be essential for growth of these bacteria in the gastrointestinal ecosystem.

Methionine and methionine sulfoxide alter parameters of oxidative stress in the liver of young rats: in vitro and in vivo studies

2013 ◽  
Vol 384 (1-2) ◽  
pp. 21-28 ◽  
Author(s):  
Marcelo Zanusso Costa ◽  
Tatiane Morgana da Silva ◽  
Natália Porto Flores ◽  
Felipe Schmitz ◽  
Emilene Barros da Silva Scherer ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Methionine Sulfoxide ◽  
In Vivo Studies ◽  
Young Rats

scholarly journals Expression of magA in Legionella pneumophila Philadelphia-1 Is Developmentally Regulated and a Marker of Formation of Mature Intracellular Forms

2004 ◽  
Vol 186 (10) ◽  
pp. 3038-3045 ◽  
Author(s):  
Margot F. Hiltz ◽  
Gary R. Sisson ◽  
Ann Karen C. Brassinga ◽  
Elizabeth Garduno ◽  
Rafael A. Garduno ◽  
...  
Keyword(s):  
Hela Cells ◽  
Legionella Pneumophila ◽  
Protein Profile ◽  
Methionine Sulfoxide ◽  
Growth Cycle ◽  
Specific Protein ◽  
Methionine Sulfoxide Reductase ◽  
Developmental Cycle

ABSTRACT Legionella pneumophila displays a biphasic developmental cycle in which replicating forms (RFs) differentiate postexponentially into highly infectious, cyst-like mature intracellular forms (MIFs). Using comparative protein profile analyses (MIFs versus RFs), we identified a 20-kDa protein, previously annotated as “Mip-like” protein, that was enriched in MIFs. However, this 20-kDa protein shared no similarity with Mip, a well-characterized peptidyl-prolyl isomerase of L. pneumophila, and for clarity we renamed it MagA (for “MIF-associated gene”). We monitored MagA levels across the growth cycle (in vitro and in vivo) by immunoblotting and established that MagA levels increased postexponentially in vitro (∼3-fold) and nearly 10-fold during MIF morphogenesis in HeLa cells. DNA sequence analysis of the magA locus revealed an upstream divergently transcribed gene, msrA, encoding a peptide methionine sulfoxide reductase and a shared promoter region containing direct and indirect repeat sequences as well as −10 hexamers often associated with stationary-phase regulation. While MagA has no known function, it contains a conserved CXXC motif commonly found in members of the thioredoxin reductase family and in AhpD reductases that are associated with alkylhydroperoxide reductase (AhpC), suggesting a possible role in protection from oxidative stress. MIFs from L. pneumophila strain Lp02 containing a magA deletion exhibited differences in Giménez staining, as well as an apparent increase in cytopathology to HeLa cells, but otherwise were unaltered in virulence traits. As demonstrated by this study, MagA appears to be a MIF-specific protein expressed late in intracellular growth that may serve as a useful marker of development.

scholarly journals The Oxidized Protein Repair Enzymes Methionine Sulfoxide Reductases and Their Roles in Protecting against Oxidative Stress, in Ageing and in Regulating Protein Function

Antioxidants ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 191 ◽  
Author(s):  
Sofia Lourenço dos Santos ◽  
Isabelle Petropoulos ◽  
Bertrand Friguet
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Protein Function ◽  
Methionine Sulfoxide ◽  
Methionine Sulfoxide Reductase ◽  
Methionine Oxidation ◽  
Oxygen Species ◽  
Sulfenic Acid ◽  
Protein Repair ◽  
Methionine Sulfoxide Reductases

Cysteine and methionine residues are the amino acids most sensitive to oxidation by reactive oxygen species. However, in contrast to other amino acids, certain cysteine and methionine oxidation products can be reduced within proteins by dedicated enzymatic repair systems. Oxidation of cysteine first results in either the formation of a disulfide bridge or a sulfenic acid. Sulfenic acid can be converted to disulfide or sulfenamide or further oxidized to sulfinic acid. Disulfide can be easily reversed by different enzymatic systems such as the thioredoxin/thioredoxin reductase and the glutaredoxin/glutathione/glutathione reductase systems. Methionine side chains can also be oxidized by reactive oxygen species. Methionine oxidation, by the addition of an extra oxygen atom, leads to the generation of methionine sulfoxide. Enzymatically catalyzed reduction of methionine sulfoxide is achieved by either methionine sulfoxide reductase A or methionine sulfoxide reductase B, also referred as to the methionine sulfoxide reductases system. This oxidized protein repair system is further described in this review article in terms of its discovery and biologically relevant characteristics, and its important physiological roles in protecting against oxidative stress, in ageing and in regulating protein function.

scholarly journals In Vitro and In Vivo Oxidation of Methionine Residues in Small, Acid-Soluble Spore Proteins fromBacillus Species

1998 ◽  
Vol 180 (10) ◽  
pp. 2694-2700 ◽  
Author(s):  
Christopher S. Hayes ◽  
Berenice Illades-Aguiar ◽  
Lilliam Casillas-Martinez ◽  
Peter Setlow
Keyword(s):  
Dna Binding ◽  
Methionine Sulfoxide ◽  
Small Degree ◽  
Methionine Sulfoxide Reductase ◽  
Mutant Form ◽  
Wild Type ◽  
Spore Proteins ◽  
Methionine Residues

ABSTRACT Methionine residues in α/β-type small, acid-soluble spore proteins (SASP) of Bacillus species were readily oxidized to methionine sulfoxide in vitro by t-butyl hydroperoxide (tBHP) or hydrogen peroxide (H2O2). These oxidized α/β-type SASP no longer bound to DNA effectively, but DNA binding protected α/β-type SASP against methionine oxidation by peroxides in vitro. Incubation of an oxidized α/β-type SASP with peptidyl methionine sulfoxide reductase (MsrA), which can reduce methionine sulfoxide residues back to methionine, restored the α/β-type SASP’s ability to bind to DNA. Both tBHP and H2O2 caused some oxidation of the two methionine residues of an α/β-type SASP (SspC) in spores ofBacillus subtilis, although one methionine which is highly conserved in α/β-type SASP was only oxidized to a small degree. However, much more methionine sulfoxide was generated by peroxide treatment of spores carrying a mutant form of SspC which has a lower affinity for DNA. MsrA activity was present in wild-type B. subtilis spores. However, msrA mutant spores were no more sensitive to H2O2 than were wild-type spores. The major mechanism operating for dealing with oxidative damage to α/β-type SASP in spores is DNA binding, which protects the protein’s methionine residues from oxidation both in vitro and in vivo. This may be important in vivo since α/β-type SASP containing oxidized methionine residues no longer bind DNA well and α/β-type SASP-DNA binding is essential for long-term spore survival.

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