• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3071-3075
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• 2012

Human ${\alpha}$-synuclein is the major component of the protein aggregates known as Lewy bodies or Lewy neurites, which define the intracellular lesions of Parkinson's disease. Despite extensive efforts, the physiological function of ${\alpha}$-synuclein has not yet been elucidated in detail. As an approach to defining its function, proteins that interacted with ${\alpha}$-synuclein were screened in phage display assays. The SNARE protein vesicle t-SNARE-interacting protein homologous 1B (VTI1B) was identified as an interacting partner. A selective interaction between ${\alpha}$-synuclein and VTI1B was confirmed by coimmunoprecipitation and GST pull-down assays. VTI1B and ${\alpha}$-synuclein were colocalized in N2a neuronal cells, and overexpression of ${\alpha}$-synuclein changed the subcellular localization of VTI1B to be more dispersed throughout the cytosol. Considering the role played by VTI1B, ${\alpha}$-synuclein is likely to modulate vesicle trafficking by interacting with a SNARE complex.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4655-4660
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• 2012

Opuntia humifusa, member of the Cactaceae family, was previously demonstrated to have radical scavenging, anti-inflammatory and anti-proliferative effects in in vitro models. It was suggested that O. humifusa could function in the prevention of carcinogenesis. To investigate the in vivo chemopreventive effect of O. humifusa, mice were fed a diet containing either 1% or 3% following 7, 12-dimethylbenz[a] anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) induction of skin carcinogenesis. Significant decrease in the numbers of papilloma and epidermal hyperplasia were observed in mice fed with O. humifusa, compared to the control group. O. humifusa also upregulated high total antioxidant capacity and level of phase II detoxifying enzyme such as superoxide dismutase and glutathione S-transferase activity in the skin. Lipid peroxidation activity level was measured in skin cytosol and significantly inhibited in 3% OH fed group compared to the control group. These results suggest that O. humifusa exerts chemopreventive effects on chemical carcinogenesis in mouse skin and that prevention effects are associated with reduction of oxidative stress via the modulation of cutaneous lipid peroxidation, enhancing of total antioxidant capacity especially in phase II detoxifying enzyme system and partial apoptotic influence.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.725-730
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• 1994

This study was conducted to investigate the effect of dietary zinc (Zn) and/or cadmium (Cd) on hepatic microsomal and cytosol enzyme activities. Male Spraque-Dawley rats (110$\pm$10g ) received zinc (0, 30 and 300 ppm/) and Cd-treated groups were administered oral intubation with Cd chloride (5.0mg/kg of body weight 0 at the same time once a week. The effect of Cd on the activity of hepatic cytochromep-450 , xanthine oxidase(X. O) and superoxide dismutase (SOd) was studied in rats. Cd oral intubation resulted in a decrease in cytochrome P-450 content and SOD activity whereas a significant increase in the X.O. activity was observed was observed . Intake of excessive Zn led to an increased activity of microsomal alcohol dehydrogenase (ADH) , whereas Zn deficiency group led to a decreased group. The mechanism by which Zn induces the decreasing of Cd toxicity in rats, seems to rely on the protection of the enzyme systems P-450, ADH, aldehyde dehydrogenase (ALDH) and X.O. in the liver, possibly by forming non-toxic Cd metallothionein. These results indicate that Zn and Cd regulation might occur via inhibitory protein component of the $H_2O$$_2$ -generator system.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.75.2-75
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• 2003

To develop an effective protection strategy against tomato bushy stunt virus (TBSV), tobacco plants expressing single-chain Fv antibodies (scFv), were established. A previous had shown that the replication activity of viral replicase was inhibited by the selected scFvs. Moreover, no systemic symptom was found after virus inoculation on leaves of wt N. benthamiana infiltrated with an Agrobacterium suspension resulting i3l expression of the scFvs. However, control plants showed systemic symptoms. In this study the localization of the scFvs within two transgenic plant lines, (CP28H3, CP-P55) was demonstrated using immunogold labelling. The gold particles, indicating the presence of scFv, were mostly found In the cytoplasm of the plant cells including chloroplasts and in the cell walls. However, they were hardly found in the vacuole, nucleoplasm and intercellular spaces. Gold particles often accumulated in either the cytosol or chloroplasts showing a specific labeling, There was no difference in type of gold labeling between both transgenic lines. The localization of the scFv in the cytoplasm further conforms the inhibition of the RNA-dependent RNA polymerase (RdRp) by the selected scFv because it is known that the RdRp is localized to membraneous cytosolic structures.

• IMMUNE NETWORK
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• v.12 no.5
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• pp.189-195
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• 2012

It has been reported that vitamin C plays an effective role in the treatment and prevention of cancer, but its specific mechanisms are still largely unknown. The incidence of colon cancer is now increasing in Korea. Therefore, we have examined here the effect of vitamin C on the induction of the apoptosis on colon cancer and its related mechanisms. We have found that remarkable increase of the apoptosis and the calcium influx in endoplasmic reticulum (ER) in human colon cancer cell line, HCT-8. However, vitamin C-induced apoptosis was effectively inhibited by the pre-treatment of BAPTA-AM (1,2-bis(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid), which is well-known as a calcium specific chelator. During the apoptosis, we found the increase of the translocation of Bad to mitochondria from cytosol, after releasing from 14-3-$3{\beta}$. In this process, the expression of Bax, a well-known pro-apoptotic protein, was also increased. Taken together, vitamin C induces apoptosis of colon cancer cell line, HCT-8 through the increase of 1) the calcium influx in endoplasmic reticulum (ER), 2) the translocation of Bad to mitochondria, and 3) the expression of Bax.

• The Korean Journal of Ecology
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• v.22 no.2
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• pp.95-100
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• 1999

The heavy metal concentrations in seawater and winkles (Littorina brevicula) collected from the Onsan bay area in southeast of Korea were analyzed. The heavy metal concentrations in the seawater obtained from the most polluted site showed approximately 189. 205. and 110 fold higher cadmium, copper. and zinc concentrations, respectively. than the uncontaminated control site. The contamination levels of these metals in winkles were 11.08 - 2.35, 334.5 - 212.5, and 426.0 - 499.2$\mu\textrm{g}$ per gram dry body weight. respectively. The concentrations of all three metals in both the seawater and winkles decreased gradually with increasing distance from Daejeong stream, suggesting the stream being the major source of heavy metal input into the bay. Among the four body parts of digestive gland and gonad. gill. kidney, and remaining tissue in contaminated winkles, kidney showed the highest accumulation level of cadmium: copper and zinc, however. were more or less distributed among the four body parts. Upon gel filtration chromatography of the cytosol from the kidney of cadmium induced winkles, one cadmium peak corresponded to the elution peak of horse kidney metallothionein.

• BMB Reports
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• v.30 no.3
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• pp.222-228
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• 1997

Protein phosphatase 2C (PP2C) is one of the four major serine/threonine phosphatases which is dependent on $Mg^{2+}$ for its activity. PP2C was purified from rat liver cytosol and its characteristics were investigated. The substrate employed for routine assay was $[^{32}P]casein$ phosphorylated by PKA. The purification process involved DEAE chromatography, ammonium sulfate fractionation, phenyl sepharose chromatography, sephacryl 5-200 gel filtration, and histone agarose chromatography. The SDS-PAGE of PP2C showed one major single protein band at a position corresponding to a molecular mass of 43 kd and the purification fold was 637. The enzyme showed a pH optimum of 8 and $K_M$ value was $1.9\;{\mu}M$. However, when the substrate was changed to $[^{32}P]histone$, the pH optimum was shifted to 7 and $K_M$ value was $2.3\;{\mu}M.\;Mg^{2+}$ was essential to the enzyme activity and okadaic acid did not exert any inhibitory effect on the enzyme. To examine residue in the active site of PP2C effects of some protein-modifying reagents were tested.

• BMB Reports
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• v.44 no.10
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• pp.674-679
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• 2011

Bacillus sphaericus produces mosquito-larvicidal binary toxin composed of BinA and BinB. While BinB is expected to bind to a specific receptor on the cell membrane, BinA interacts to BinB or BinB receptor complex and translocates into the cytosol to exert its activity via unknown mechanism. To investigate functional roles of aromatic cluster in BinA, amino acids at positions Y213, Y214, Y215, W222 and W226 were substituted by leucine. All mutant proteins were highly produced and their secondary structures were not affected by these substitutions. All mutants are able to insert into lipid monolayers as observed by Langmuir-Blodgett trough and could permeabilize the liposomes in a similar manner as the wild type. However, mosquito-larvicidal activity was abolished for W222L and W226L mutants suggesting that tryptophan residues at both positions play an important role in the toxicity of BinA, possibly involved in the cytopathological process after toxin entry into the cells.

• BMB Reports
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• v.40 no.2
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• pp.172-179
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• 2007

PCR-mediated recombination describes the process of in vitro chimera formation from related template sequences present in a single PCR amplification. The high levels of genetic redundancy in eukaryotic genomes should make recombination artifacts occur readily. However, few evolutionary biologists adequately consider this phenomenon when studying gene lineages. The cytosolic glyceraldehyde-3-phosphate dehydrogenase gene (GapC), which encodes a NADP-dependent nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase in the cytosol, is a classical lowcopy nuclear gene marker and is commonly used in molecular evolutionary studies. Here, we report on the occurrence of PCR-mediated recombination in the GapC gene family of Hibiscus tiliaceus. The study suggests that recombinant areas appear to be correlated with DNA template secondary structures. Our observations highlight that recombination artifacts should be considered when studying specific and allelic phylogenies. The authors suggest that nested PCR be used to suppress PCRmediated recombination.

• Molecules and Cells
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• v.23 no.1
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• pp.1-10
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• 2007

Invading pathogens are recognized by diverse germline-encoded pattern-recognition receptors (PRRs) which are distributed in three different cellular compartments: extracellular, membrane, and cytoplasmic. In mammals, the major extracellular PRRs such as complements may first encounter the invading pathogens and opsonize them for clearance by phagocytosis which is mediated by membrane-associated phagocytic receptors including complement receptors. The major membrane-associated PRRs, Toll-like receptors, recognize diverse pathogens and generate inflammatory signals to coordinate innate immune responses and shape adaptive immune responses. Furthemore, certain membrane-associated PRRs such as Dectin-1 can mediate phagocytosis and also induce inflammatory response. When these more forefront detection systems are avoided by the pathogens, cytoplasmic PRRs may play major roles. Cytoplasmic caspase-recruiting domain (CARD) helicases such as retinoic acid-inducible protein I (RIG-I)/melanoma differentiation-associated gene 5 (MDA5), mediate antiviral immunity by inducing the production of type I interferons. Certain members of nucleotide-binding oligomerization domain (NOD)-like receptors such as NALP3 present in the cytosol form inflammasomes to induce inflammatory responses upon ligand recognition. Thus, diverse families of PRRs coordinately mediate immune responses against diverse types of pathogens.