• Proceedings of the Korean Society of Plant Pathology Conference
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• 1995.06b
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• pp.97-117
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• 1995

Copper resistance in Pseudomonas syringae pv. tomato is determined by copper-resistance operon (cop) on a highly conserved 35 kilobase plasmid. Copper-resistant strains of Pseudomonas syringae containing the cop operon accumulate copper and develop blue clonies on copper-containing media. The protein products of the copper-resistance operon were characterized to provide an understanding of the copper-resistance mechanism and its relationship to copper accumulation. The Cop proteins CopA (72 kDa), CopB (39 kDa), and CopC (12 kDa) were produced only under copper induction. CopA and CopC were periplasmic proteins and CopB was an outer membrane protein. Leader peptide sequences of CopA, CopB, and CopC were confirmed by amino-terminal peptide sequencing. CopA, CopB, and CopC were purified from strain PT23.2, and their copper contents were determined. One molecule of CopA bound 10.9${\pm}$1.2 atoms of copper and one molecule of CopC bound 0.6${\pm}$0.1 atom of copper. P. syringae cells containing copCD or copBCD cloned behind the lac promoter were hypersensitive to copper. The CopD (32 kDa), a probable inner membrane protein, function in copper uptake with CopC. The Cop proteins apparently mediate sequestration of copper outside of the cytoplasm as a copper-resistance mechanism.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.224-228
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• 2012

In order to screen interactor(s) of the Aspergillus nidulans ${\alpha}$-COP of COPI vesicle, we performed the yeast two hybrid screening by using the gene for A. nidulans ${\alpha}$-COP as a bait and identified ${\varepsilon}$-COP of the COPI vesicle as an interacting protein. The A. nidualns gene for the ${\varepsilon}$-COP was designated $aneA^+$ ($\underline{A.}$ $\underline{n}$idulans $\underline{e}$psi-lone-COP), which encoded 296 amino acid residues with high level of identity with orthologs from other fungi. Domain analyses with yeast two-hybrid system suggested that the interaction between ${\alpha}$-COP and ${\varepsilon}$-COP relied on the C-terminus of both proteins, and that the N-terminal WD domian of ${\alpha}$-COP and the TPR region of ${\varepsilon}$-COP were not essential but required for the enhancement of the interaction. These results indicate that the interaction mode between ${\alpha}$-COP and ${\varepsilon}$-COP of COPI vesicle is evolutionarily well conserved in eukaryotes.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.742-753
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• 2012

Copper-containing compounds are introduced into the environment through agricultural chemicals, mining, and metal industries and cause severe detrimental effects on ecosystems. Certain microorganisms exposed to these stressors exhibit molecular mechanisms to maintain intracellular copper homeostasis and avoid toxicity. We have previously reported that the soil bacterial isolate Achromobacter sp. AO22 is multi-heavy metal tolerant and exhibits a mer operon associated with a Tn21 type transposon. The present study reports that AO22 also hosts a unique cop locus encoding copper homeostasis determinants. The putative cop genes were amplified from the strain AO22 using degenerate primers based on reported cop and pco sequences, and a constructed 10,552 base pair contig (GenBank Accession No. GU929214). BLAST analyses of the sequence revealed a unique cop locus of 10 complete open reading frames, designated copSRABGOFCDK, with unusual separation of copCD from copAB. The promoter areas exhibit two putative cop boxes, and copRS appear to be transcribed divergently from other genes. The putative protein CopA may be a copper oxidase involved in export to the periplasm, CopB is likely extracytoplasmic, CopC may be periplasmic, CopD is cytoplasmic/inner membrane, CopF is a P-type ATPase, and CopG, CopO, and CopK are likely copper chaperones. CopA, B, C, and D exhibit several potential copper ligands and CopS and CopR exhibit features of two-component regulatory systems. Sequences flanking indicate the AO22 cop locus may be present within a genomic island. Achromobacter sp. strain AO22 is thus an ideal candidate for understanding copper homeostasis mechanisms and exploiting them for copper biosensor or biosorption systems.

• Journal of Life Science
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• v.32 no.1
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• pp.23-28
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• 2022

CopA3 (LLCIALRKK), an antimicrobial peptide isolated from the Korean dung beetle, has been shown to suppress apoptosis in various cell types. CopA3 inhibits not only bacterial toxin-induced colonocyte apoptosis but also 6-hydroxy dopamine-induced neural cell apoptosis. Our recent study revealed that CopA3 directly binds to caspases (key regulators of apoptosis) and inhibits the proteolytic cleavage required for their activation. But molecular mechanisms underlying CopA3-mediated inhibition of apoptosis in multiple cell types remain unknown. Here we assessed possible effects of CopA3 on expression of survivin, which is known to inhibit apoptosis. In HT29 human colonocytes, CopA3 exposure markedly upregulated survivin expression in a concentration- and time-dependent manner. RT-PCR revealed that CopA3-mediated upregulation of survivin was attributable to increased gene transcription, and further showed that CopA3 also increased expression of Sp1, one of many transcription factors known to be involved in transcription of the survivin gene. Notably, blocking Sp1 by treatment with the Sp1 inhibitor, tolfenamic acid, significantly reduced CopA3-mediated upregulation of survivin. These results collectively suggest that CopA3 induces Sp1 expression, which in turn is involved in upregulation of survivin in human colonocytes. These novel findings establish another pathway for explaining the anti-apoptotic effects of CopA3 against various cellular apoptosis systems.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.529-538
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• 2009

The purpose of this study was to investigate correlation between BBS(Berg balance scale), SPPB(short physical performance battery,) TUG(timed up and go) and COP(center of pressure) during quiet standing in elderly women. Ten elderly women aged 65 to 75 years participated in this study. Subjects were measured physical functional test and they were stood in quiet stance on force platform positioned in one of three different fixed positions(flat, downward, upward). The COP range and mean velocity data were calculated using an experimental setup with the ground reaction force system. COP range and mean velocity of AP direction showed significant more expanded than ML direction of all slope types. Physical performance scores were significant correlated between COP range and mean velocity according to surface slopes. After all elderly women get high score of physical performance that brought decreased on one's COP range and mean velocity. This study suggests that clinical therapist have application to COP parameters as well as BBS, SPPB, TUG of balance assessment in elderly women.

• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.227-233
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• 2007

We characterized a full-length cDNA of CaCOP1 from pepper. Phylogenetic analysis based on the deduced amino acid sequence of CaCOP1 cDNA revealed high sequence similarity to the COP1 gene in Oryza sativa (84% identity). CaCOP1 shares high sequence identity with regulatory protein in Arabidopsis (84%), constitutively photomorphogenic 1 protein in Pisum sativum (81%) and COP1 homolog in Lycopersicon esculentum (79%). CaCOP1 gene exists single copy in the chili pepper genome. Expression of CaCOP1 was reduced in response to inoculation of non-host pathogens. The expression of this gene under abiotic and oxidative stresses was investigated, including 200 mM NaCl, 200 mM mannitol, cold ($4^{\circ}C$), 100 ${\mu}M$ abscisic acid (ABA), and 10 mM hydrogen peroxide ($H_2O_2$). CaCOP1 was induced significantly 3 h after low temperature treatment but not by dehydration or high salinity. Moreover, CaCOP1 was not induced by plant hormone ABA. These observations suggest that CaCOP1 gene plays a role in abiotic stress and may be belong to ABA-independent regulation system.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2809-2812
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• 2014

The 43-residue defensin-like peptide coprisin, which is isolated from dung bettle, Copris tripartitus, is a potent antimicrobial peptide. In our previous work, we determined the tertiary structure of coprisin and found that alpha helical region of coprisin from residue 19 to residue 30 is important for its antimicrobial activities. Here, we designed cop12mer and cop9mer analogs of coprisin based on the tertiary structure of coprisin. To investigate the relationship between hydrophobicity and antimicrobial activities and develop the potent peptide antibiotics, we designed cop9mer-1 with substitution of $His^2$ with Trp in cop9mer. The results showed that cop9mer-1 has higher toxicities as well as improved antimicrobial activities compared to cop9mer. In order to reduce the toxicity of cop9mer-1, we designed cop9mer-2 and cop9mer-3 with substitution of $Cys^3$ with Lys or Ser. Substitution of $Cys^3$ with these hydrophilic amino acids results in lower cytotoxicities compared to cop9mer-1. Cop9mer-2 with substitution of $Cys^3$ with Lys in Cop9mer-1 showed high antibacterial activities against drug resistant bacteria without cytotoxicity. Antibiotic action of cop9mer-1 analog appears to involve permeabilization of the bacterial cell membrane while cop9mer-2 and cop9mer-3 may have different mechanism of action. These results imply that that optimum balance in hydrophobicity and hydrophilicity in these 9-meric peptides plays key roles in their antimicrobial activities as well as cytotoxicities.

• Journal of Photoscience
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• v.12 no.1
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• pp.1-9
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• 2005

The ubiquitin E3 ligase COP1 (Constitutive Photomorphogenesis 1) is a protein repressor of photomorphogenesis in Arabidopsisplants, and it found in various organisms, including animals. The COP1 protein regulates the stability of many of the light-signaling components that are involved in photomorphogenesis and in the developmental processes. To study the effect of COP1 on flowering in a short day plant, we have cloned a full-length of PnCOP1 (Pharbitis nil COP1) cDNA from Pharbitis nil Choisy cv. Violet, and we examined its transcript levels under various conditions. A full-length PnCOP1 cDNA consists of 2,280 bp nucleotidesthat contain 47 bp of 5'-UTR, 232 bp of 3'-UTR including the poly (A) tail, and 1,998 bp of the coding sequence. The deduced amino acid sequence contains 666 amino acids, giving it a theoretical molecular weight of 75 kD and a isolectric point of 6.2. The PnCOP1 contains three distinct domains, an N-terminal $Zn^2+$-binding RING-finger domain, a coiled-coil structure, and WD40 repeats at the C-terminal, implying that the protein plays a role in protein-protein interactions. The PnCOP1 transcript was detected in the cotyledon, hypocotyls and leaves, but not in root. The levels of the PnCOP1 transcript were reduced in leaves that were a farther distance away from the cotyledons. The expression level of the PnCOP1 gene was inhibited by light, while the expression was increased in the dark. During the floral inductive 16 hour-dark period for Pharbitis nil, the expression was increased and it reached its maximum at the 12th hour of the dark period. The levels of PnCOP1 mRNA were dramatically reduced upon light illumination. These results suggest that PnCOP1 may play an important function in the floral induction of Pharbitis nil.

• Journal of Life Science
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• v.34 no.2
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• pp.86-93
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• 2024

Since replication of plasmids must be strictly controlled, plasmids that generally perform rolling circle replication generally maintain a constant copy number by strictly controlling the replication initiator Rep at the transcriptional and translational levels. Plasmid pJB01 contains three orfs (copA, repB, repC or repABC) consisting of a single operon. From analysis of amino acid sequence, pJB01 CopA was homologous to the Cops, as a copy number control protein, of other plasmids. When compared with a CopG of pMV158, CopA seems to form the RHH (ribbon-helix-helix) known as a motif of generalized repressor of plasmids. The result of gel mobility shift assay (EMSA) revealed that the purified fusion CopA protein binds to the operator region of the repABC operon. To examine the functional role of CopA on transcriptional level, 3 point mutants were constructed in coding frame of copA such as CopA R16M, K26R and E50V. The repABC mRNA levels of CopA R16M, K26R and E50V mutants increased 1.84, 1.78 and 2.86 folds more than that of CopA wt, respectively. Furthermore, copy numbers owing to mutations in three copA genes also increased 1.86, 1.68 and 2.89 folds more than that of copA wt, respectively. These results suggest that CopA is the transcriptional repressor, and lowers the copy number of pJB01 by reducing repABC mRNA and then RepB, as a replication initiator.

• Journal of the Korean Magnetic Resonance Society
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• v.20 no.3
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• pp.76-81
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• 2016

Copper is an elemental ion in living organisms. CopP from Helicobacter Pylori (HpCopP) is a copper(I)-binding protein and was suggested as regulator of copper metabolism in vivo. Previously, the metal binding property of HpCopP for Ag(I), Cu(I), and Cu(II) as well as the tertiary structure of HpCopP was shown. In this study, the dynamic profiles of HpCopP depending on metal binding were studied using ${^1H}-^{15}N$ steady-state NOE analysis. The heteroNOE experiment was performed for apo-CopP or metal-bound CopP. The obtained NOE values were analyzed and compared to figure out the effect of metals on the structural flexibility of HpCopP. As a result, Ag(I) and Cu(I) ions improved the rigidity of the structure while Cu(II) ion increased the flexibility of the structure, suggesting the oxidation of the CXXC motif decreases the structural stability of HpCopP.