• The Korean Journal of Mycology
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• v.38 no.2
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• pp.89-94
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• 2010

Plant pathogenic fungi are the most diverse and drastic causal agents of crop diseases threatening stable food production all over the world. Plant have evolved efficient innate immune system to scout and counterattack fungal invasion and pathogenic fungi also developed virulence system to nullify plant resistance machinery or signaling pathways and to propagate and dominate within their niche. A growing body of evidences suggests that post translational modifications (PTMs) and selective/nonselective degradations of proteins involved in virulence expression of plant pathogenic fungi and plant defense machinery should play pivotal roles during the compatible and incompatible interactions. This review elucidates recent investigations about the effects of PTMs and protein degradations on host defense and fungal pathogens' invasions.

• Journal of Plant Biotechnology
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• v.41 no.1
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• pp.1-9
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• 2014

So far it has been generally considered that proteomic approaches are very useful for studying plant-microbes interaction. In this review, recent studies based on papers published from 2010 to 2013 have investigated proteomics analysis in various interaction during plant-fungal pathogen infection by means of gel-based proteomics coupled with mass spectrometry (MS)-based analysis. In rice, three papers focused on rice-Magnaporthe oryzae interaction were mainly reviewed in this study. Interestingly, another study showed proteomic changes in rice inoculated with Puccinia triticina, which is not only an fungal pathogen in wheat and but also results to the disease resistance with non-host defense manner in rice. Additionally, proteomics analysis has been widely subjected to understand defense mechanism during other crops (wheat, tomato, strawberry and mint) and their fungal pathogen interaction. Crops inoculated are analyzed to identify differentially regulated proteins at various tissues such as leaf and apoplast using 2-DE analysis coupled with various MS approaches such as MALDI-TOF MS, nESI-LC-MS/MS and MudPIT, respectively. Taken together, this review article shows that proteomics is applicable to various organisms to understand plant-fungal pathogen interaction and will contribute to provide important information for crop disease diagnosis and crop protection.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.79-86
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• 2013

Objectives : The purpose of this study is to investigate neuroprotective effects and molecular mechanisms of luteolin against ${\beta}$-amyloid ($A{\beta}_{25-35}$)-induced oxidative cell death in BV-2 cells. Methods : The protective effects of luteolin against $A{\beta}_{25-35}$-induced cytotoxicity and apoptotic cell death were determined by MTT dye reduction assay and TUNEL staining, respectively. The apoptotic cell death was further analyzed by measuring mitochondrial transmembrane potential and expression of pro- and/or anti-apoptotic proteins. To elucidate the molecular mechanisms underlying the protective effects of luteolin, intracellular accumulation of reactive oxygen species, oxidative damages, and expression of antioxidant enzymes were examined. Results : Luteolin pretreatment effectively attenuated $A{\beta}_{25-35}$-induced apoptotic cell death indices such as DNA fragmentation, dissipation of mitochondrial transmembrane potential, increased Bax/Bcl-2 ratio, and activation of c-Jun N-terminal kinase and caspase-3 in BV-2 cells. Furthermore, $A{\beta}_{25-35}$-induced intracellular formation of reactive oxygen species and subsequent oxidative damages such as lipid peroxidation and depletion of endogenous antioxidant glutathione were suppressed by luteolin treatment. The neuroprotective effects of luteolin might be mediated by up-regulation of cellular antioxidant defense system via up-regulation of ${\gamma}$-glutamylcysteine ligase, a rate-limiting enzyme in the glutathione biosynthesis and superoxide dismutase, an enzyme involved in dismutation of superoxide anion into oxygen and hydrogen peroxide. Conclusions : These findings suggest that luteolin has a potential to protect against $A{\beta}_{25-35}$-induced neuronal cell death and damages thereby exhibiting therapeutic utilization for the prevention and/or treatment of Alzheimer's disease.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.69-80
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• 2007

Among the photoactive semiconductors such as $TiO_2,\;ZnO,\;Fe_2O_3,\;WO_3,\;and\;CdSe,\;TiO_2$ is the most widely used as photocatalyst in different media, because of its lack of toxicity and stability. In this study, the effects of titanium dioxide were investigated to obtain the information of physiological change in rice plant. Light-adapted Chlorophyll flourescence index decreased and relative electron transport rate of rice leaves was activated by titanium dioxide under $2,400\;{\mu}mol\;m^{-2}\;s^{-1}$ PAR (Photosynthetic active radiation). Relative electron transport rate of rice leaf treated with titanium dioxide 10 ppm was high in order of $2,400\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR,\;2,200\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR,\;450\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR$ and titanium dioxide 10 ppm (45.1%), control (32.4%), diuron 10 ppm (15.3%) under $2,400\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR$. Titanium dioxide increased photosynthesis of the rice leaf under $13.6\;KJ\;m^{-2}\;day^{-1}$ UV-B only. With titanium dioxide 20 ppm, reduced UV-B ($0.15\;KJ\;m^{-2}\;day^{-1}$) intensity changed the induction of proteins and twenty-five proteins were identified. Among them, seventy proteins were up-regulated, four proteins were down-regulated and four proteins were newly synthesized. Function of these proteins was related to photosynthesis (52%), carbohydrate metabolism (4%), stress/defense (8%), secondary metabolism (4%), energy/electron transport (4%), and miscellaneous (28%).

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.770-780
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• 2002

The airway surface liquid (ASL), often referred to as mucus, is a thin layer of fluid covering the luminal surface of the airway. The major function of mucus is to protect the lung through mucociliary clearance against foreign particles and chemicals entering the lung. The mucus is comprised of water, ions, and various kinds of macromolecules some of which possess the protective functions such as anti-microbial, anti-protease, and anti-oxidant activity. Mucus glycoproteins or mucins are mainly responsible for the viscoelastic property of mucus, which is crucial for the effective mucociliary clearance. There are at least eight mucin genes identified in the human airways, which will potentially generate various kinds of mucin molecules. At present, neither the exact structures of mucin proteins nor their regulation are understood although it seems likely that different types of mucins are involved in different functions and might also be associated with certain airway diseases. The fact that mucins are tightly associated with various macromolecules present in ASL seems to suggest that the defensive role of ASL is determined not only by these individual components but rather by a combination of these components. Collectively, mucins in ASL may be compared to aircraft carriers carrying various types of weapons in defense of airborne enemies.

• BMB Reports
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• v.42 no.2
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• pp.113-118
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• 2009

Despite the growing body of evidence suggesting a role for MsrA in antioxidant defense, little is currently known regarding the function of MsrB in cellular protection against oxidative stress. In this study, we overexpressed the mammalian MsrB and MsrA genes in Saccharomyces cerevisiae and assessed their subcellular localization and antioxidant functions. We found that the mitochondrial MsrB3 protein (MsrB3B) was localized to the cytosol, but not to the mitochondria, of the yeast cells. The mitochondrial MsrB2 protein was detected in the mitochondria and, to a lesser extent, the cytosol of the yeast cells. In this study, we report the first evidence that MsrB3 overexpression in yeast cells protected them against $H_2O_2$-mediated cell death. Additionally, MsrB2 overexpression also provided yeast cells with resistance to oxidative stress, as did MsrA overexpression. Our results show that mammalian MsrB and MsrA proteins perform crucial functions in protection against oxidative stress in lower eukaryotic yeast cells.

• Journal of environmental and Sanitary engineering
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• v.21 no.1 s.59
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• pp.52-57
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• 2006

Metallothioneins(MTs) belong to the class of low molecular weight proteins. Recently, it has been suggested that MTs may playa direct role in cellular defense against oxidative stress by functioning as antioxidants. Oxidative damage to different cellular components makes a major contribution to many pathogenenesses. Several studies have demonstrated that MT is able to quench a wide range of reactive oxygen species at a higher efficiency than other well known antioxidants such as superoxide dismutate(SOD). The present study was designed to evaluate the effect of MT on the activities of the reactive oxygen species removal system. MT showed the scavenging of superoxide in the SOD assay system in the presence or absence of SOD. When MT was added to nicotinamide adenine dinucleotide phosphate(NADPH) oxidation system in presence of fixed amount of SOD increase the breakdown rate of superoxide. When MT was added to the system that form nitrite from hydroxylammonium chloride, the formation of nitrite was inhibit. We concluded that the function of MT as antioxidant might have an effect on the level of superoxide scavenging.

• BMB Reports
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• v.40 no.4
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• pp.532-538
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• 2007

Mouse ficolin A is a plasma protein with lectin activity, and plays a role in host defense by binding carbohydrates, especially GlcNAc, on microorganisms. The ficolin A subunit consists of an N-terminal signal peptide, a collagen-like domain, and a C-terminal fibrinogen-like domain. In this study, we show that ficolin A can be synthesized and oligomerized in a cell and secreted into culture medium. We also identify a functionally relevant signal peptide of ficolin A by using MS/MS analysis to determine the N-terminal sequence of secreted ficolin A. When the signal peptide of mouse ficolin A was fused with enhanced green fluorescent protein (EGFP), EGFP was released into HEK 293 cell medium, suggesting that the signal peptide can efficiently direct ficolin A secretion. Moreover, our results suggest that the signal peptide of ficolin A has potential application for the production of useful secretory proteins.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.1
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• pp.37-43
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• 2006

Enterococcus faecalis was isolated from the body fluid of dead Galleria mellonella larvae. Upon injection of E. faecalis into the hemocoel of G. mellonella, the bacteria destroyed parts of humoral defense systems in the hemolymph. In a test for the proteolytic activity of E. faecalis CS, it was confirmed that the enzyme degraded three well-known a-helical antimicrobial peptides, cecropin A, melittin and halocidin, and abolished their activities. We also determined putative cleavage sites on the primary sequences of three peptides through purification and mass analysis of peptide fragments digested by E. faecalis CS. Furthermore it was found that apolipophorin-III, recently known as a critical recognition protein for invading microbes in the hemolymph of G. mellonella, was also degraded by E. faecalis CS. Taken together, the present work shows that the protease in secretions from E. faecalis destroyed two critical humoral immune factors in the hemolymph of G. mellonella larvae. In addition, this paper demonstrates that the relationship between the host insect and the pathogenic bacteria might provide a valuable model system to study the enterococcal virulence mechanism, which may be relevant to mammalian pathogenesis.

• BMB Reports
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• v.45 no.2
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• pp.114-119
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• 2012

Salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline) is a compound derived from dopamine metabolism and is capable of causing dopaminergic neurodegeneration. Oxidative modification of neurofilament proteins has been implicated in the pathogenesis of neurodegenerative disorders. In this study, oxidative modification of neurofilament-L (NF-L) by salsolinol and the inhibitory effects of histidyl dipeptides on NF-L modification were investigated. When NF-L was incubated with 0.5 mM salsolinol, the aggregation of protein was increased in a time-dependent manner. We also found that the generation of hydroxyl radicals (${\bullet}OH$) was linear with respect to the concentrations of salsolinol as a function of incubation time. NF-L exposure to salsolinol produced losses of glutamate, lysine and proline residues. These results suggest that the aggregation of NF-L by salsolinol may be due to oxidative damage resulting from free radicals. Carnosine, histidyl dipeptide, is involved in many cellular defense processes, including free radical detoxification. Carnosine, and anserine were shown to significantly prevent salsolinol-mediated NF-L aggregation. Both compounds also inhibited the generation of ${\bullet}OH$ induced by salsolinol. The results indicated that carnosine and related compounds may prevent salsolinol-mediated NF-L modification via free radical scavenging.