• BMB Reports
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• v.52 no.7
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• pp.445-450
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• 2019

TTYH2 is a calcium-activated, inwardly rectifying anion channel that has been shown to be related to renal cancer and colon cancer. Based on the topological prediction, TTYH2 protein has five transmembrane domains with the extracellular N-terminus and the cytoplasmic C-terminus. In the present study, we identified a vesicle transport protein, ${\beta}$-COP, as a novel specific binding partner of TTYH2 by yeast two-hybrid screening using a human brain cDNA library with the C-terminal region of TTYH2 (TTYH2-C) as a bait. Using in vitro and in vivo binding assays, we confirmed the protein-protein interactions between TTYH2 and ${\beta}$-COP. We also found that the surface expression and activity of TTYH2 were decreased by co-expression with ${\beta}$-COP in the heterologous expression system. In addition, ${\beta}$-COP associated with TTYH2 in a native condition at a human colon cancer cell line, LoVo cells. The over-expression of ${\beta}$-COP in the LoVo cells led to a dramatic decrease in the surface expression and activity of endogenous TTYH2. Collectively, these data suggested that ${\beta}$-COP plays a critical role in the trafficking of the TTYH2 channel to the plasma membrane.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.197-202
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• 1996

The effects of erythrosine on the oxidative stability of cholesterol in an aqueous model system were studied by depleted headspace oxygen and cholesterol oxidation products (COP). As the oncentration of erythrosine was increased, headspace oxygen depletion, 7-COP and total COP increased during storage at $25^{\circ}C$ for 50 hours under the fluorescent light. As the intensity of fluorescent light was increased, amounts of headspace oxygen depleted and COP formed in an aqueous cholesterol dispersion containing erythrosine also increased. Addition of ${\alpha}-,\;{\delta}-$, mixed-tocopherol and ${\beta}-carotene$ resulted in the enhanced oxidative stability of an aqueous cholesterol dispersion containing erythrosine during the fluorescent light storage.

• Journal of Life Science
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• v.23 no.1
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• pp.38-43
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• 2013

The objective of this study was to evaluate the effect of the synthetic CopA3 peptide of Copris tripartitus on skin inflammation. Regulatory mechanisms of cytokines and nitric oxide (NO) are involved in the immunological activity of RAW 264.7 cells. Tested cells were treated with different concentrations of CopA3 and further cultured for an appropriate time after lipopolyssacharide (LPS) addition. During the entire experimental period, 5, 25, 50, and 100 ${\mu}g/ml$ of CopA3 had no cytotoxicity. At these concentrations, CopA3 inhibited tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-$1{\beta}$ (IL-$1{\beta}$), and interleukin-6 (IL-6). CopA3 also inhibited the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). CopA3 inhibited the activity of iNOS and COX-2 by 41% and 59%, respectively, at 100 ${\mu}g/ml$. In addition, CopA3 reduced the release of inflammatory cytokines including TNF-${\alpha}$, IL-$1{\beta}$, and IL-6. These results suggest that CopA3 may have significant effects on inflammatory factors and that it may be a potential anti-inflammatory therapeutic agent.

• Journal of Pharmaceutical Investigation
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• v.33 no.2
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• pp.91-97
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• 2003

During the preparation of decoction from the mixture of Coptidis Rhizoma and Scutellariae Radix, insoluble copreciptate was formed. The coprecipitated product (COP) was composed of berberine and baicalin which was the active ingredient of Coptidis Rhizoma and Scutellariae Radix, respectively. COP was slightly soluble in water and could not be well absorbed after oral administration. This poor bioavailibility might be associated with its poor aqueous solubility. With the purpose of increasing the solubility and bioavailibility of COP, hydrolysis of COP by ${\beta}-glucuronidase$ was carried out. Hydrolyzed products (HOP) of COP were identified and assayed for active ingredients. The partition coefficient study, in situ absorption test, and pharmacokinetic study after oral administration were also performed. COP was found to be consisted of berberine and baicalin with molecular ratio of 1 to 1. This compound was hydrolyzed to berberine and baicalin by ${\beta}-glucuronidase$. The rate of hydrolysis was higher at higher temperature up to $50^{\circ}C$ and higher concentration of ${\beta}-glucuronidase$ up to 2500 unit under our experimental conditions. Baicalein, which is more liphophilic than baicalin, showed greater absorption in small intestine than baicalin did. The plasma concentrations of berberine and baicalein after oral administration of HOP were significantly higer than those of COP. The possible mechanism of increased bioavailibility of berberine and baicalein could be the hydrolysis of COP by ${\beta}-glucuronidase$. On the basis of the above results, it might be said that HOP should be a suitable preparation for increasing the bioavailibility of Coptidis Rhizoma and Scutellariae Radix.

• Molecules and Cells
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• v.38 no.10
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• pp.866-875
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• 2015

COPI vesicles are essential to the retrograde transport of proteins in the early secretory pathway. The COPI coatomer complex consists of seven subunits, termed ${\alpha}-$, ${\beta}-$, ${\beta}^{\prime}-$, ${\gamma}-$, ${\delta}-$, ${\varepsilon}-$, and ${\zeta}$-COP, in yeast and mammals. Plant genomes have homologs of these subunits, but the essentiality of their cellular functions has hampered the functional characterization of the subunit genes in plants. Here we have employed virus-induced gene silencing (VIGS) and dexamethasone (DEX)-inducible RNAi of the COPI subunit genes to study the in vivo functions of the COPI coatomer complex in plants. The ${\beta}^{\prime}-$, ${\gamma}-$, and ${\delta}$-COP subunits localized to the Golgi as GFP-fusion proteins and interacted with each other in the Golgi. Silencing of ${\beta}^{\prime}-$, ${\gamma}-$, and ${\delta}$-COP by VIGS resulted in growth arrest and acute plant death in Nicotiana benthamiana, with the affected leaf cells exhibiting morphological markers of programmed cell death. Depletion of the COPI subunits resulted in disruption of the Golgi structure and accumulation of autolysosome-like structures in earlier stages of gene silencing. In tobacco BY-2 cells, DEX-inducible RNAi of ${\beta}^{\prime}$-COP caused aberrant cell plate formation during cytokinesis. Collectively, these results suggest that COPI vesicles are essential to plant growth and survival by maintaining the Golgi apparatus and modulating cell plate formation.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.291-297
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• 1998

Cop protein has been overexpressed in Escherichia coli using a T7 RNA polymerase system. Purification to apparent homogeneity was achieved by the sequential chromatography on ion exchange, affinity chromatography, and reverse phase high performance liquid chromatography system. The molecular weight of the purified Cop was estimated as 6.1 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). But the molecular mass of the native state Cop was shown to be 19 kDa by an analytical high performance size exclusion chromatography, suggesting a trimer-like structure in 50 mM Tris-HCI buffer (pH 7.5) containing 100 mM NaCl. Cop protein Was calculated to contain $39.1% {\alpha}-helix, 16.8% {\beta}-sheet$, 17.4% turn, and 26.8% random structure. The DNA binding property of Cop protein expressed in E. coli Was preserved during the expression and purification process. The isoelectric point of Cop was determined to be 9.0. The results of amino acid composition analysis and N-terminal amino acid sequencing of Cop showed that it has the same amino acid composition and N-terminal amino acid sequence as those deduced from its DNA sequence analysis, except for the partial removal of N-terminal methionine residue by methionyl-aminopeptidase in E. coli.

• Journal of Microbiology and Biotechnology
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• v.22 no.2
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• pp.264-269
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• 2012

Recently, we reported that the synthetic Coprisin analog peptide 9-mer dimer CopA3 (consisted of all-L amino acid sequence) was designed based on a defensin-like peptide, Coprisin isolated from Copris tripartitus. The 9-mer dimer CopA3 (L-CopA3) had antibacterial activity and induced apoptosis in human leukemia cells via a caspase-independent pathway. In this study, all of amino acid sequences of L-CopA3 were modified to all D-form amino acids (DCopA3) to develop a more effective antimicrobial peptide. We investigated whether D-CopA3 had antimicrobial activities against pathogenic microorganisms and pro-apoptotic effects in human leukemia cells (U937, Jurkat, and AML-2). The synthetic peptide D-CopA3 had antimicrobial activities against various pathogenic bacteria and yeast fungus with MIC values in the 4~64 ${\mu}M$ range. Moreover, D-CopA3 caused cell growth inhibition, and increased the chromosomal DNA fragmentation and the expression of inflammatory cytokines, TNF-${\alpha}$ and IL1-${\beta}$, transcripts in human leukemia cells. The all-D amino acid peptide DCopA3 proved as effective as the L-CopA3 reported previously. These results provide the basis for developing D-CopA3 as a new antibiotic peptide.

• The Korean Journal of Mycology
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• v.35 no.1
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• pp.1-10
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• 2007

The cell wall is essential for the survival and osmotic integrity of fungal cells. It is the framework to which biologically active proteins such as cell adhesion molecules and hydrolytic enzymes are attached or within which they act. Recently it was shown that mutations in ${\alpha}-COP$, a subunit of COPI vesicle, is responsible for the thermo-sensitive osmo-fragile phenotype of fungi, such as Saccharomyces cerevisiae and Aspergillus nidulans, and suggested that ${\alpha}-COP$ may play a crucial role in translocation of protein(s) of the ${\beta}-1,3-gulcan$ synthase complex and cell wall proteins, thus may contribute to the maintenance of cell wall integrity. In this review, we summarized the relationship between the intra-cellular protein translocation machinery, especially the ${\alpha}-COP$ of COPI vesicle, and cell wall biogenesis in fungi. We also discussed potential use of secretory mutants in basic and applied research of the fungal cell walls.

• Journal of Microbiology
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• v.40 no.3
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• pp.219-223
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• 2002

In order to investigate the function of Soo1p/${\alpha}$-COP during post-translational modification and intra-cellular transport of cell wall proteins in Saccharomyces cerevisiae, cell wall proteins from the soo1-1/ret1-1 mutant cells were analyzed. SDS-PAGE analysis of biotin labeled cell wall proteins suggested that the soo1-1 mutation impairs post-translational modification of cell wall proteins, such as N- and/ or Ο-glycosylation. Analysis of cell wall proteins with antibodies against ${\beta}$-1,3-glucan and ${\beta}$-1,6-glucan revealed alteration of the linkage between cell wall proteins and ${\beta}$-glucans in the soo1-1 mutant cells. Compositional sugar analysis of the cell wall proteins also suggested that the soo1-1 mutation impairs glycosylation of cell wall protein in the ER, which is crucial for the maintenance of cell wall integrity.

• Korean Journal of Microbiology
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• v.37 no.1
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• pp.42-48
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• 2001

Allele rescue and sequence analysis of soo1-1 allele in Saccharomyces cerevisiae mutant LP0353 revealed that soo1-1 is identical to the previously reported ret1-1 allele, which has a base substitution of A for $G^{681}$ leading to an amino acid substitution of aspartic acid for $glycine^{227}$ in Soolp. However, it was revealed that the addition of osmotic stabilizer, such as 1.2M sorbitol can rescue the temperature sensitive phenotype of the ret1-1 mutant and that the soo1-1/ret1-1 mutation may confer defects in post-translational modification of proteins involved in the yeast cell wall biogenesis. Evidence for a putative role of 5th WD40 domain of the Soo1p/$\alpha$-COP in the construction and maintenance of cell walls was also presented by complementation test with deletion constructs of the SOOl.