• BMB Reports
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• 제52권7호
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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.

• 한국식품과학회지
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• 제28권1호
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• pp.197-202
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• 1996

콜레스테롤을 함유하는 수용성 모형계에서 erythrosine의 첨가농도, 광도, tocopherol과 ${\beta}-carotene$의 첨가에 따른 headspace내의 산소량의 변화와 콜레스테롤 산화물의 생성량의 변화를 연구하였다. Erythrosine의 첨가량이 증가할수록 headspace내 산소량의 감소가 컸고, 각종 COP 생성량은 증가하였다. 형광등의 조도가 증가할수록 headspace내 산소량의 감소가 컸고, 이에 비례하여 콜레스테롤은 감소하였고 총 COP의 생성량은 증가하였다. 일중항 산소 소거제로 tocopherol과 ${\beta}-carotene$을 첨가하였을 때 headspace내의 산소량은 완만하게 감소하였으며, 이에 비례하여 콜레스테롤의 감소가 완만하였고 총 COP의 생성량 또한 감소하였다.

• 생명과학회지
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• 제23권1호
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• pp.38-43
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• 2013

CopA3를 이용하여 피부 염증에 대하여 연구를 하였다. 산화질소와 cytokine의 생산은 면역세포의 대표적인 염증인자이다. 세포는 LPS 처리 후 한 시간 뒤에 CopA3를 처리하였다. 세포 독성이 나타나지 않는 농도인 5, 25, 50, 100 ${\mu}g/ml$를 사용하였다. CopA3는 NO, TNF-${\alpha}$, IL-$1{\beta}$, IL-6, iNOS, COX-2의 생성을 저해 시켰다. iNOS와 COX-2 역시 100 ${\mu}g/ml$의 농도에서 각각 54%, 65%가 저해가 되었다. 게다가 CopA3는 염증성 사이토 카인인 TNF-${\alpha}$, IL-$1{\beta}$, IL-6의 생성을 감소 시켰다. 이러한 결과로 CopA3는 염증 예방과 치료에 효과적임을 확인 할 수 있었다.

• Journal of Pharmaceutical Investigation
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• 제33권2호
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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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• 제38권10호
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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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• 제21권3호
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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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• 제22권2호
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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.

• 한국균학회지
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• 제35권1호
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• pp.1-10
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• 2007

세포벽은 진균류의 생존과 삼투안전성 유지에 필수적인 구조체로, 세포부착성 단백질이나 가수분해효소 등과 같은 생물학적 활성을 갖는 다양한 단백질이 결합하거나 그 속에 자리잡고 작용할 수 있게 한다. 최근 효모류인 Saccharomyces cerevisiae와 사상균인 Aspergillus nidulans에서 세포 내 단백질 분비 소낭의 하나인 COPI 소낭을 구성하는 ${\alpha}-COP$ 단백질에 돌연변이가 일어날 경우, 온도의존적 삼투감수성이 나타나는 것으로 밝혀졌다. 이러한 사실은 ${\alpha}-COP$이 베타-1,3-글루칸 합성효소 복합체를 구성하는 단백질과 세포벽 단백질의 이송과정에 중요한 역할을 함으로써 세포벽 안정성 유지에 기여함을 시사하는 것이다. 본 총설에서는 세포 내 단백질 이송기구 중에서도 COPI 소낭을 구성하는 ${\alpha}-COP$과 균류의 세포벽 형성과정과의 관계에 대하여 기술하는 한편, 단백질 분비기구에 결손이 생긴 돌연변 이주를 이용한 세포벽 합성기작에 대한 기초 및 응용연구의 가능성에 대하여 검토하여 보았다.

• Journal of Microbiology
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• 제40권3호
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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.

• 미생물학회지
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• 제37권1호
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• pp.42-48
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• 2001

출아 효모인 Saccharomyces cerevisiae의 베타-1,3-글루칸 생합성의 결함을 초래하는 돌연변이 유전자(sool-1)를 분리하여 돌연변이 부위의 염기서열을 결정하고 그 특성을 분석하였다. cool-1 유전자의 염기서열 분석 결과, 681번의 염기인 G가 A로 치환되어 Soolp의 $Gly^{227}$이 Asp로 치환되는 결과를 나타내는 것으로 판명되었고, cool-1 유전자는 기존에 보고된 retl-1 유전자와 동일한 돌연변이 유전자로 판명되었다. 그러나, ret1-1이 나타내는 온도감수성 형질은 배지에 1.2 M sorbitol 등의 삼투안정제를 첨가하면 극복될 수 있으며, cool-l/retl-1의 돌연변이 부위가 세포벽합성 관련 단백질의 번역 후 수식과정에 영향을 미친 것임을 확인하였다. 한편, Soolp/$\alpha$-COP의 N-말단에 존재하는 6개의 WD40 domain중 5번째 WD40 domain이 효모의 세포벽 합성이나 구조유지에 중요한 역할을 담당할 것임을 시사하는 결과를 얻었다.