• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.110.1-110.1
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• 2007

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• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.810-820
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• 2016

This study is focused on the investigation of the genes which are induced by various stresses of the halophyte Salicornia herbacea. One of the factors influencing in the germination of Salicornia herbacea is salt stress. The highest germination rate was found in the condition without NaCl, and the upper limit of the NaCl concentration for the germination of Salicornia herbacea was 7%. The optimal temperature of $20^{\circ}C$showed a germination rate of 98%. Among genes induced by stress the 2CysPrx gene was cloned and analyzed for this study. The 2CysPrx gene has two cysteine conserved residues and is composed of 275 amino acids with molecular weight of 30.1kDa. The 2CysPrx gene appeared to be one copy in the genome and consists of 6 introns and 7 exons. Quantitative real-time PCR revealed that the highest transcription rate induced by NaCl and $H_2O_2$ appeared to be at the concentration of 3.5% NaCl and 40mM $H_2O_2$, respectively. The amount of transcript induced by high temperature($40^{\circ}C$) and $75{\mu}M$ of ABA was respectively highest. The gene at low temperature ($4^{\circ}C$) appeared not to be expressed. We are conducting to clone other peroxyredoxin genes induced by various environmental stresses.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.1-9
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• 2006

Peroxiredoxins (Prxs) are ubiquitously distributed and play important functions in diverse cellular signaling systems. The proteins are largely classified into three groups, such as typical 2-Cys Prx, atypical 2-Cys Prx, and 1-Cys Prx, that are distinguished by their catalytic mechanisms and number of Cys residues. From the three classes of Prxs, the typical 2-Cys Prx containing the two-conserved Cys residues at its N-terminus and C-terminus catalyzes $H_2O_2$ with the use of thioredoxin (Trx) as an electron donor. During the catalytic cycle, the N-terminal Cys residue undergoes a peroxide-dependent oxidation to sulfenic acid, which can be further oxidized to sulfinic acid at the presence of high concentrations of $H_2O_2$ and a Trx system containing Trx, Trx reductase, and NADPH. The sulfinic acid form of 2-Cys Prx is reduced by the action of sulfiredoxin which requires ATP as an energy source. Under the strong oxidative or heat shock stress conditions, 2-Cys Prx in eukaryotes rapidly switches its protein structure from low-molecular-weight species to high-molecular-weight protein structures. In accordance with its structural changes, the protein concomitantly triggers functional switching from a peroxidase to a molecular chaperone, which can protect its substrate denaturation from external stress. In addition to its N-terminal active site, the C-terminal domain including 'YF-motif' of 2-Cys Prx plays a critical role in the structural changes. Therefore, the C-terminal truncated 2-Cys Prxs are not able to regulate their protein structures and highly resistant to $H_2O_2$-dependent hyperoxidation, suggesting that the reaction is guided by the peroxidatic Cys residue. Based on the results, it may be concluded that the peroxidatic Cys of 2-Cys Prx acts as an '$H_2O_2$-sensor' in the cells. The oxidative stress-dependent regulation of 2-Cys Prx provides a means of defense systems in cells to adapt stress conditions by activating intracellular defense signaling pathways. Particularly, 2-Cys Prxs in plants are localized in chloroplasts with a dynamic protein structure. The protein undergoes conformational changes again oxidative stress. Depending on a redox-potential of the chloroplasts, the plant 2-Cys Prx forms super-molecular weight protein structures, which attach to the thylakoid membranes in a reversible manner.

• IMMUNE NETWORK
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• v.3 no.4
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• pp.276-280
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• 2003

Background: Peroxidases (Prx) of the peroxiredoxin family reduce hydrogen peroxide and alkyl hydroperoxides to water and alcohol respectively. Hydrogen peroxide is implicated as an intracellular messenger in various cellular responses such as proliferation and differentiation. And Prx I activity is regulated by Cdc-2 mediated phosphorylation. This work was undertaken to investigate the proliferation role of peroxiredoxin III as a member of Prx family in Prx III overexpressed HeLa cell line. Methods: To provide further evidence of proliferation, we selected Prx III stably expressed HeLa Tet-off cell lines. Cell proliferation was examined by using proliferation reagent WST-1 in the presence or absence of doxycycline. Prx III, 2-cys Prx enzymes exist as homodimer. The activation of Prx III heterodimer with induced and endogenous Prx III was examined by immunoprecipitation. Results: Immunoprecipitation analysis of the induced and endogenous Prx III with anti-myc showed that the induced wild type (WT) and dominant negative (DN) Prx III from HeLa Prx III Tet-off stable cell heterodimerized with endogenous Prx III each other. And the expression level of induced Prx III was examined after addition of doxycycline. By 72 hr, the expression level of induced Prx III was diminished gradually and the half-life of the induced wild type Prx III was approximately 17 hr. The proliferation experiment demonstrated that the relative proliferation value of induced and endogenous WT Prx III stable cell has no changes but the DN Prx III induced HeLa Tet-off stable cells were lower than endogenous Prx III. Conclusion: In conclusion, the HeLa dominant negative Prx III Tet-off stable cells were decreased the proliferation.

• Journal of Life Science
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• v.20 no.12
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• pp.1777-1783
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• 2010

Plants generate reactive oxygen species (ROS) as a by-product of normal aerobic metabolism or when exposed to a variety of stress conditions, which can cause widespread damage to biological macromolecules. To protect themselves from oxidative stress, plant cells are equipped with a wide range of antioxidant proteins. However, the detailed reaction mechanisms of these are still unknown. Peroxiredoxins (Prxs) are ubiquitous thiol-containing antioxidants that reduce hydrogen peroxide with an N-terminal cysteine. The active-site cysteine of peroxiredoxins is selectively oxidized to cysteine sulfinic acid during catalysis, which leads to inactivation of peroxidase activity. This oxidation was thought to be irreversible. Recently identified small protein sulphiredoxin (Srx1), which is conserved in higher eukaryotes, reduces cysteine.sulphinic acid in yeast peroxiredoxin. Srx1 is highly induced by $H_2O_2$-treatment and the deletion of its gene causes decreased yeast tolerance to $H_2O_2$, which suggest its involvement in the metabolism of oxidants. Moreover, Srx1 is required for heat shock and oxidative stress induced functional, as well as conformational switch of yeast cytosolic peroxiredoxins. This change enhances protein stability and peroxidase activity, indicating that Srx1 plays a crucial role in peroxiredoxin stability and its regulation mechanism. Thus, the understanding of the molecular basis of Srx1 and its regulation is critical for revealing the mechanism of peroxiredoxin action. We postulate here that Srx1 is involved in dealing with oxidative stress via controlling peroxiredoxin recycling in Arabidopsis. This review article thus will be describing the functions of Prxs and Srx in Arabidopsis thaliana. There will be a special focus on the possible role of Srx1 in interacting with and reducing hyperoxidized Cys-sulphenic acid of Prxs.

• Molecules and Cells
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• v.43 no.9
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• pp.813-820
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• 2020

NB4 cell, the human acute promyelocytic leukemia (APL) cell line, was treated with various concentrations of arsenic trioxide (ATO) to induce apoptosis, measured by staining with 7-amino-actinomycin D (7-AAD) by flow cytometry. 2', 7'-dichlorodihydro-fluorescein-diacetate (DCF-DA) and MitoSOX™ Red mitochondrial superoxide indicator were used to detect intracellular and mitochondrial reactive oxygen species (ROS). The steady-state level of SO₂ (Cysteine sulfinic acid, Cys-SO₂H) form for peroxiredoxin 3 (PRX3) was measured by a western blot. To evaluate the effect of sulfiredoxin 1 depletion, NB4 cells were transfected with small interfering RNA and analyzed for their influence on ROS, redox enzymes, and apoptosis. The mitochondrial ROS of NB4 cells significantly increased after ATO treatment. NB4 cell apoptosis after ATO treatment increased in a time-dependent manner. Increased SO₂ form and dimeric PRX3 were observed as a hyperoxidation reaction in NB4 cells post-ATO treatment, in concordance with mitochondrial ROS accumulation. Sulfiredoxin 1 expression is downregulated by small interfering RNA transfection, which potentiated mitochondrial ROS generation and cell growth arrest in ATO-treated NB4 cells. Our results indicate that ATO-induced ROS generation in APL cell mitochondria is attributable to PRX3 hyperoxidation as well as dimerized PRX3 accumulation, subsequently triggering apoptosis. The downregulation of sulfiredoxin 1 could amplify apoptosis in ATO-treated APL cells.

• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.55-64
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• 2012

Peroxiredoxin II (Prdx II; a typical 2-Cys Prdx) has been originally isolated from erythrocytes, and its structure and peroxidase activity have been adequately studied. Prdx II has been reported to protect a wide range of cellular environments as antioxidant enzyme, and its dysfunctions may be implicated in a variety of disease states associated with oxidative stress, including cancer and aging-associated pathologies. But, the precise mechanism is still obscure in various aspects of aging containing ovarian aging. Identification and relative quantification of the increased proteins affected by Prdx II deficiency may help identify novel signaling mechanisms that are important for oxidative stress-related diseases. To identify the increased proteins in Prdx $II^{-/-}$ mice, we performed RBC comparative proteome analysis in membrane fraction and cytosolic fractions by nano-UPLC-$MS^E$ shotgun proteomics. We found the increased 86 proteins in membrane (32 proteins) and cytosolic (54 proteins) fractions, and analyzed comparative expression pattern in healthy RBCs of Prdx $II^{+/+}$ mice, healthy RBCs of Prdx $II^{-/-}$ mice, and abnormal RBCs of Prdx $II^{-/-}$ mice. These proteins belonged to cellular functions related with RBC lifespan maintain, such as cellular morphology and assembly, cell-cell interaction, metabolism, and stress-induced signaling. Moreover, protein networks among the increased proteins were analyzed to associate with various diseases. Taken together, RBC proteome may provide clues to understand the clue about redox-imbalanced diseases.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.682-682
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• 2005

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.145-146
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• 2012

• Microbiology and Biotechnology Letters
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• v.45 no.1
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• pp.81-86
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• 2017

Alignment of 967 reference sequences of the typical 2-Cys peroxiredoxin family of proteins revealed that 10 amino acids were conserved, with over 99% identity. To investigate whether the conserved aspartic acid residues and serine residue affect the peroxidase and chaperone activity of the protein, we prepared yeast TSA1 mutant proteins in which aspartic acids at positions 75 and 103 were replaced by valine or asparagine, and serine at position 73 was replaced by alanine. By non-reducing SDS-PAGE, TSA1 and the S73A, D75V and D75N mutants were detected in dimeric form, whereas the D103V and D103N mutants were detected in various forms, ranging from high molecular-weight to monomeric. Compared with wild type TSA1, the D75N mutant exhibited 50% thioredoxin peroxidase activity, and the S73A and D75V mutants showed 25% activity. However, the D103V and D103N mutants showed no peroxidase activity. All proteins, except for the D103V and D103N mutants, exhibited chaperone activity at $43^{\circ}C$. Our results suggest that the two conserved aspartic acid residues and serine residue of TSA1 play important roles in its thioredoxin peroxidase activity, and D103 plays a critical role in its chaperone activity.