Current Search: Proteins--Chemical modification (x)
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- Title
- Characterization of Methionine Sulfoxide Reductases A and Bs from Tobacco Plant.
- Creator
- Ding, Di, Zhang, Xing-Hai, Florida Atlantic University
- Abstract/Description
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One methionine sulfoxide reductase A (TMSRA) and two methionine sulfoxide reductase Bs (TMSRB 1 and TMSRB2) were isolated from tobacco plants. TMSRA showed specificity for the reduction of Met-(S)-SO and both TMSRBs were specific for the reduction of Met-(R)-SO. TMSRA was the cytosolic form and both TMSRBs were plastid forms based on sequence comparison and expression tests. TMSRA and TMSRB2 could use either thioredoxin (TRX) or dithiothreitol (DTT) as reducing system, while TMSRB 1 showed...
Show moreOne methionine sulfoxide reductase A (TMSRA) and two methionine sulfoxide reductase Bs (TMSRB 1 and TMSRB2) were isolated from tobacco plants. TMSRA showed specificity for the reduction of Met-(S)-SO and both TMSRBs were specific for the reduction of Met-(R)-SO. TMSRA was the cytosolic form and both TMSRBs were plastid forms based on sequence comparison and expression tests. TMSRA and TMSRB2 could use either thioredoxin (TRX) or dithiothreitol (DTT) as reducing system, while TMSRB 1 showed little activity with TRX but much more activity with DTT, which was similar to the mitochondrial MSRB2 from mammals. Ferredoxin (FD) is not the reducing system for Msrs, but might reflect the redox status in the cell and control the activity of Msrs indirectly.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fau/fd/FA00000746
- Subject Headings
- Proteins--Chemical modification, Genetic regulation, Plant genetic engineering, Antioxidants
- Format
- Document (PDF)
- Title
- Peroxiredoxin 3 and Methionine sulfoxide reductase A are Essential for Lens Cell Viability by Preserving Lens Cell Mitochondrial Function through Repair of Cytochrome c.
- Creator
- Lee, Wanda, Florida Atlantic University, Kantorow, Marc, Charles E. Schmidt College of Science, Department of Biomedical Science
- Abstract/Description
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The central premise of this dissertation is that mitochondrial antioxidant enzymes are essential to lens cell viability by preserving lens cell mitochondria and protecting and/or repairing lens cell proteins, and two mitochondrial-specific antioxidant enzymes, Peroxiredoxin 3 (PRDX3) and Methionine sulfoxide reductase A (MsrA), are explored. In this dissertation, we will examine the expression ofPRDX3 in the human lens, its colocalization to the lens cell mitochondria, its ability to be...
Show moreThe central premise of this dissertation is that mitochondrial antioxidant enzymes are essential to lens cell viability by preserving lens cell mitochondria and protecting and/or repairing lens cell proteins, and two mitochondrial-specific antioxidant enzymes, Peroxiredoxin 3 (PRDX3) and Methionine sulfoxide reductase A (MsrA), are explored. In this dissertation, we will examine the expression ofPRDX3 in the human lens, its colocalization to the lens cell mitochondria, its ability to be induced by H20 2-oxidative stress, and speculate how PRDX3 function/sf could affect the lens. We will also examine the reduced levels of MsrA by targeted gene silencing and its effect on reactive oxygen species production and mitochondrial membrane potential in human lens cells to determine its role in mitochondrial function in the lens. Lastly, we will examine the ability of MsrA to repair and restore function to a critical mitochondrial protein, Cytochrome c. The collective evidence strongly indicates that the loss of mitochondrial-specific enzymes, such as PRDX3 and MsrA, are responsible for increased reactive oxygen species levels, decreased mitochondrial membrane potential, protein aggregation and lens cell death, and further indicates that mitochondrial repair, protective, and reducing systems play key roles in the progression of age-related cataract and other agerelated diseases.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00000868
- Subject Headings
- Genetic regulation, Proteins--Chemical modification, Cellular signal transduction, Eye--Physiology, Mitochondrial pathology
- Format
- Document (PDF)
- Title
- Role of Methionine Sulfoxide Reductase (MsrA) on Aging and Oxidative Stress in Drosophila.
- Creator
- Foss, Katie, Binninger, David, Florida Atlantic University
- Abstract/Description
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Oxidative damage is an inevitable consequence of aerobic respiration. Methionine sulfoxide reductases (Msr) are a group of enzymes that function to repair oxidized methionine residues in both free methionine and methionine in proteins. MsrA was the first of these enzymes to be discovered and is the most thoroughly studied. It is thought to play a role in both the aging process and probably several neurodegenerative diseases. I recently obtained a strain of Drosophila that was reported to have...
Show moreOxidative damage is an inevitable consequence of aerobic respiration. Methionine sulfoxide reductases (Msr) are a group of enzymes that function to repair oxidized methionine residues in both free methionine and methionine in proteins. MsrA was the first of these enzymes to be discovered and is the most thoroughly studied. It is thought to play a role in both the aging process and probably several neurodegenerative diseases. I recently obtained a strain of Drosophila that was reported to have a P-element transposon located within Exon 2 (part of the open reading frame) of the eip71cd gene, which is the Drosophila homolog of MsrA. Thus, the transposon insertion should disrupt expression of the msrA gene. I did a series of experiments to "jump out" the P-element in an effort to recover two types of isogenic strains. The first would be a null mutation of the MsrA gene created by deletion of flanking genomic DNA when the P-element excised from the chromosome. The second would be a precise excision of the P-element, which would restore the genetic locus to its original structure. This study looks at the effect of a null mutant of the MsrA gene on aging and resistance to oxidative stress.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fau/fd/FA00000772
- Subject Headings
- Genetic regulation, Oxidation-reduction reaction, Antioxidants, Oxygen--Physiological effect, Proteins--Chemical modification
- Format
- Document (PDF)
- Title
- Methionine sulfoxide reductase (Msr) deficiency leads to a reduction of dopamine levels in Drosophila.
- Creator
- Hernandez, Caesar, Binninger, David, Weissbach, Herbert, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Biological homeostasis relies on protective mechanisms that respond to cellular oxidation caused primarily by free radical reactions. Methionine sulfoxide reductases (Msr) are a class of enzymes that reverse oxidative damage to methionine in proteins. The focus of this study is on the relationship between Msr and dopamine levels in Drosophila. Dopaminergic neurons in Drosophila have comparable roles to those found in humans. A deficit in dopamine leads to the onset of many neurological...
Show moreBiological homeostasis relies on protective mechanisms that respond to cellular oxidation caused primarily by free radical reactions. Methionine sulfoxide reductases (Msr) are a class of enzymes that reverse oxidative damage to methionine in proteins. The focus of this study is on the relationship between Msr and dopamine levels in Drosophila. Dopaminergic neurons in Drosophila have comparable roles to those found in humans. A deficit in dopamine leads to the onset of many neurological disorders including the loss of fine motor control—a neurodegenerative condition characteristic of Parkinson’s disease (PD). We found that dopamine levels in the heads of MsrAΔ/ΔBΔ/Δ mutants are significantly reduced in comparison to MsrA ⁺/⁺ B⁺/⁺ heads. In addition, wefound protein and expression levels are markedly reduced in an Msr-deficient system. Our findings suggest an important role for the Msr system in the CNS.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004202, http://purl.flvc.org/fau/fd/FA00004202
- Subject Headings
- Cellular signal transduction, Dopamine -- Receptors, Drosophila melanogaster -- Genetics, Mitochondrial pathology, Proteins -- Chemical modification
- Format
- Document (PDF)
- Title
- Neuroprotection During Acute Oxidative Stress: Role of the PKG Pathway and Identification of Novel Neuromodulatory Agents Using Drosophila Melanogaster.
- Creator
- Caplan, Stacee Lee, Dawson-Scully, Ken, Milton, Sarah L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Oxidant stress and injury is inherent in many human diseases such as ischemic vascular and respiratory diseases, heart failure, myocardial infarction, stroke, perinatal and placental insufficiencies, diabetes, cancer, and numerous psychiatric and neurodegenerative disorders. Finding novel therapeutics to combat the deleterious effects of oxidative stress is critical to create better therapeutic strategies for many conditions that have few treatment options. This study used the anoxia-tolerant...
Show moreOxidant stress and injury is inherent in many human diseases such as ischemic vascular and respiratory diseases, heart failure, myocardial infarction, stroke, perinatal and placental insufficiencies, diabetes, cancer, and numerous psychiatric and neurodegenerative disorders. Finding novel therapeutics to combat the deleterious effects of oxidative stress is critical to create better therapeutic strategies for many conditions that have few treatment options. This study used the anoxia-tolerant fruit fly, Drosophila melanogaster, to investigate endogenous cellular protection mechanisms and potential interactions to determine their ability to regulate synaptic functional tolerance and cell survival during acute oxidative stress. The Drosophila larval neuromuscular junction (NMJ) was used to analyze synaptic transmission and specific motor axon contributions. Drosophila Schneider 2 (S2) cells were used to assess viability. Acute oxidative stress was induced using p harmacological paradigms that generate physiologically relevant oxidant species: mitochondrial superoxide production induced by sodium azide (NaN3) and hydroxyl radical formation via hydrogen peroxide (H2O2). A combination of genetic and pharmacological approaches were used to explore the hypothesis that endogenous protection mechanisms control cellular responses to stress by manipulating ion channel conductance and neurotransmission. Furthermore, this study analyzed a group of marine natural products, pseudopterosins, to identify compounds capable of modulating synaptic transmission during acute oxidative stress and potential novel neuromodulatory agents.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004487, http://purl.flvc.org/fau/fd/FA00004487
- Subject Headings
- Drosophila melanogaster -- Life cycles, Oxidative stress -- Ecophysiology, Oxidative stress -- Prevention, Protein kinases, Proteins -- Chemical modification
- Format
- Document (PDF)
- Title
- Methionine sulfoxide reductase (MSR) modulates lifespan andLocomotion in drosophila melanogaster.
- Creator
- Bruce, Lindsay, Binninger, David, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Oxidative stress is considered a major factor in the etiology of age related diseases and the aging process itself. Organisms have developed mechanisms to protect against oxidative damage resulting from increased production of reactive oxygen species during aging. One of the major antioxidant systems is the methionine sulfoxide reductase (Msr) enzyme family. The two major Msr enzymes, MsrA and MsrB, can stereospecifically reduce the S and R epimers, respectively, of methionine sulfoxide in...
Show moreOxidative stress is considered a major factor in the etiology of age related diseases and the aging process itself. Organisms have developed mechanisms to protect against oxidative damage resulting from increased production of reactive oxygen species during aging. One of the major antioxidant systems is the methionine sulfoxide reductase (Msr) enzyme family. The two major Msr enzymes, MsrA and MsrB, can stereospecifically reduce the S and R epimers, respectively, of methionine sulfoxide in proteins back to methionine. This study, using Drosophila melanogaster, decribes the first animal system lacking both MsrA and MsrB. The loss of either MsrA or MsrB had no effect on lifespan in Drosophila, but loss of MsrB results in a slight decrease in locomotor activity from middle age onward. Double mutants lacking both forms of Msr have a significantly decreased lifespan and decreased locomotor activity at all ages examined. The double Msr mutants had no detectable increase in protein oxidation or decrease in mitochondrial function and were not more sensitive to oxidative stress. These results suggested that other cellular antioxidant systems were protecting the flies against oxidative damage and the decreased life span observed in the double knockouts was not due to widespread oxidative damage. However, one cannot exclude limited oxidative damage to a specific locus or cell type. In this regard, it was observed that older animals, lacking both MsrA and MsrB, have significantly reduced levels of dopamine, suggesting there might be oxidative damage to the dopaminergic neurons. Preliminary results also suggest that the ratio of F to G actin is skewed towards G actin in all mutants. The present results could have relevance to the loss of dopaminergic neurons in Parkinson’s disease.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004431, http://purl.flvc.org/fau/fd/FA00004431
- Subject Headings
- Aging -- Molecular aspects, Cellular signal transduction, Drosophila melanogaster -- Genetics, Mitochondrial pathology, Mutation (Biology), Oxidative stress, Proteins -- Chemical modification
- Format
- Document (PDF)
- Title
- Reduced Reproductivity and Larval Locomotion in the Absence of Methionine Sulfoxide Reductase in Drosophila.
- Creator
- Singkornrat, Diana, Binninger, David, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The inevitable aging process can be partially attributed to the accumulation of oxidative damage that results from the action of free radicals. Methionine sulfoxide reductases (Msr) are a class of enzymes that repair oxidized methionine residues. The two known forms of Msr are MsrA and MsrB which reduce the R- and S- enantiomers of methionine sulfoxide, respectively. Our lab has created the first genetic animal model that is fully deficient for any Msr activity. Previously our lab showed that...
Show moreThe inevitable aging process can be partially attributed to the accumulation of oxidative damage that results from the action of free radicals. Methionine sulfoxide reductases (Msr) are a class of enzymes that repair oxidized methionine residues. The two known forms of Msr are MsrA and MsrB which reduce the R- and S- enantiomers of methionine sulfoxide, respectively. Our lab has created the first genetic animal model that is fully deficient for any Msr activity. Previously our lab showed that these animals exhibit a 20 hour delay in development of the third instar larvae (unpublished data). My studies have further shown that the prolonged third-instar stage is due to a reduced growth rate associated with slower food intake and a markedly slower motility. These Msr-deficient animals also exhibit decreased egg-laying that can be attributed to a lack of female receptivity to mating.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004777, http://purl.flvc.org/fau/fd/FA00004777
- Subject Headings
- Proteins--Chemical modification., Oxidative stress., Oxidation-reduction reaction., Drosophila melanogaster--Genetics., Mitochondrial pathology., Cellular signal transduction., Mutation (Biology), Aging--Molecular aspects.
- Format
- Document (PDF)