• Molecules and Cells
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• 제25권1호
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• pp.7-19
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• 2008

Complexins play a critical role in the control of fast synchronous neurotransmitter release. They operate by binding to trimeric SNARE complexes consisting of the vesicle protein Synaptobrevin and the plasma membrane proteins Syntaxin and SNAP-25, which are key executors of membrane fusion reactions. SNARE complex binding by Complexins is thought to stabilize and clamp the SNARE complex in a highly fusogenic state, thereby providing a pool of readily releasable synaptic vesicles that can be released quickly and synchronously in response to an action potential and the concomitant increase in intra-synaptic $Ca^{2+}$ levels. Genetic elimination of Complexins from mammalian neurons causes a strong reduction in evoked neurotransmitter release, and altered Complexin expression levels with consequent deficits in synaptic transmission were suggested to contribute to the etiology or pathogenesis of schizophrenia, Huntington's disease, depression, bipolar disorder, Parkinson's disease, Alzheimer's disease, traumatic brain injury, Wernicke's encephalopathy, and fetal alcohol syndrome. In the present review I provide a summary of available data on the role of altered Complexin expression in brain diseases. On aggregate, the available information indicates that altered Complexin expression levels are unlikely to have a causal role in the etiology of the disorders that they have been implicated in, but that they may contribute to the corresponding symptoms.

• Journal of Breast Cancer
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• 제21권4호
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• pp.399-405
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• 2018

Purpose: Vesicle-associated membrane protein 8 (VAMP8) is a soluble N-ethylmaleimide-sensitive factor receptor protein that participates in autophagy by directly regulating autophagosome membrane fusion and has been reported to be involved in tumor progression. Nevertheless, the expression and prognostic value of VAMP8 in breast cancer (BC) remain unknown. This study aimed to evaluate the clinical significance and biological function of VAMP8 in BC. Methods: A total of 112 BC samples and 30 normal mammary gland samples were collected. The expression of VAMP8 was assessed in both BC tissues and normal mammary gland tissues via a two-step immunohistochemical detection method. Results: The expression of VAMP8 in BC tissues was significantly higher than that in normal breast tissues. Furthermore, increased VAMP8 expression was significantly correlated with tumor size (p=0.007), lymph node metastasis (p=0.024) and recurrence (p=0.001). Patients with high VAMP8 expression had significantly lower cumulative recurrence-free survival and overall survival (p<0.001 for both) than patients with low VAMP8 expression. In multivariate logistic regression and Cox regression analyses, lymph node metastasis and VAMP8 expression were independent prognostic factors for BC. Conclusion: VAMP8 is significantly upregulated in human BC tissues and can thus be a practical and potentially effective surrogate marker for survival in BC patients.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1271-1279
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• 2009

To develop low endotoxic and multi-immunogenic outer membrane vesicles (OMVs), a deletion mutant of the msbB gene in Salmonella enterica serovar Typhimurium (S. Typhimurium) was used as a source of low endotoxic OMV, and an expression vector of the canine parvovirus (CPV) VP2 epitope fused to the bacterial OmpA protein was constructed and transformed into the Salmonella ${\Delta}msbB$ mutant. In a lethality test, BALB/c mice injected intraperitoneally with the Salmonella ${\Delta}msbB$ mutant survived for 7 days, whereas mice injected intraperitoneally with the wild type survived for 3 days. Moreover, all mice inoculated orally with the ${\Delta}msbB$ mutant survived for 30 days, but 80% of mice inoculated orally with the wild type survived. The OmpA::CPV VP2 epitope fusion protein was expressed successfully and associated with the outer membrane and OMV fractions from the mutant S. Typhimurium transformed with the fusion protein-expressing vector. In immunogenicity tests, sera obtained from the mice immunized with either the Salmonella msbB mutant or its OMVs containing the OmpA::CPV VP2 epitope showed bactericidal activities against wild-type S. Typhimurium and contained specific antibodies to the CPV VP2 epitope. In the hemagglutination inhibition (HI) assay as a measurement of CPV-neutralizing activity in the immune sera, there was an 8-fold increase of HI titer in the OMV-immunized group compared with the control. These results suggested that the CPV-neutralizing antibody response was raised by immunization with OMV containing the OmpA::CPV VP2 epitope, as well as the protective immune response against S. Typhimurium in BALB/c mice.

• 대한의생명과학회지
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• 제6권1호
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• pp.11-17
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• 2000

SNAP-25는 presynaptic plasma membrane에 위치하는 단백질로서 synaptic vesicle의 docking과 fusion에 있어서 매우 중요한 역할을 한다. 생쥐 SNAP-25$^{2)}$ 유전자와 99%의 높은 homology를 갖고 있는 Z2 cDNA를 probe로 사용하여 쥐의 뇌 cDNA library에서 SNAP-25유전자를 screening하였다. 그 결과 6개 의 양성 클론을 분리 해 냈으며, 이들 각각을 S1, S2, S3, S4, S5, S6으로 명명하였다. 이 중에서 생쥐 SNAP-25와 가장 높은 homology를 보여 주고 있는 S5 클론을 선택하여 염기서열을 분석하였다. 2,100 bp의 염기서열로 구성된 쥐 SNAP-25 cDNA는 206개의 아미노산을 coding하는 618 bp의 open reading frame을 가지고 있으며, ORF는 209~211 bp에 위치하는 AUG codon에서 시작하여 827~829 bp에 위치하는 stop codon TAA에서 끝난다. 3' untranslated region에서 는 28과 19개 의 CA 반복 염기서열을 보여주고 있었으며, SNAP-25 peptide sequence에서 4개의 cystein residues는 84~91에 위치하고 있었으며, amino terminus 부분에서 amphipathic $\alpha$-helix를 형성하고 있는 것을 볼 수 있었다. 사람과 쥐의 SNAP-25 유전자는 88%, 생쥐와 쥐의 경우는 97%의 homology를 보여 주고 있었다. 그리고 사람과 쥐의 ORF에서 염기서열은 94%,생쥐와 쥐의 ORF에서 염기서열은 100%의 homology를 보여주고 있었으며 사람, 생쥐, 그리고 쥐의 ORF에서 아미노산 서열은 100%의 homology를 보여주고 있었다.

• 식물조직배양학회지
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• 제27권5호
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• pp.407-409
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• 2000

Outer envelope membrane proteins of chloroplasts encoded by the nuclear genome are transported without the N-terminal transit peptide. Here, we investigated the targeting mechanism of AtOEP7, an Arabidopsis homolog of small outer envelope membrane proteins in vivo. AtOEP7 was expressed transiently in protoplasts or stably in transgenic plants as fusion proteins with GFP. In both cases AtOEP7:GFP was targeted to the outer envelope membrane when assayed under a fluorescent microscope or by Western blot analysis. Except the transmembrane domain, deletions of the N- or C-terminal regions of AtOEP7 did not affect targeting although a region closed to the C-terminal side of the transmembrane domain affected the targeting efficiency. Targeting experiments with various hybrid transmembrane mutants revealed that the amino acid sequence of the transmembrane domain determines the targeting specificity The targeting mechanism was further studied using a fusion protein, AtOEP7：NLS：GFP, that had a nuclear localization signal. AtOEP7：NLS：GFP was efficiently targeted to the chloroplast envelope despite the presence of the nuclear localization signal. Taken together, these results suggest that the transmembrane domain of AtOEP7 functions as the sole determinant of targeting specificity and that AtOEP7 may be associated with a cytosolic component during translocation to the chloroplast envelope membrane.

• 대한바이러스학회지
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• 제27권1호
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• pp.9-17
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• 1997

Hepatitis C virus (HCV) E2 protein is known to be one of putative envelope proteins. To develop a sensitive detection method for HCV infected tissues and cells, monoclonal antibodys (MAbs) to the E2 protein of HCV were prepared from mice immunized with recombinant baculovirus-expressing E2 protein (Bac-E2). Several hybridoma clones secreting various levels of MAb were isolated and isotypes of these MAb were determined. One clone (L.2.3.3) was used for ascites production and the E2-MAb was purified and characterized. The L.2.3.3 reacted well with both Bac-E2 and E. coli expressed glutathione-S-transferase-E2 (GST-E2) fusion proteins. Using HCV patient sera, E2 envelope protein was found to be localized in the cell membrane boundary both in CHO cells and insect cells which express HCV E2 protein. Similar result was obtained when same cells were treated with the MAb L.2.3.3. These results demonstrated that Bac-E2 protein is capable of eliciting high titer antibody production in mice.

• Mycobiology
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• 제51권5호
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• pp.273-280
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• 2023

The nucleolus is the largest, membrane-less organelle within the nucleus of eukaryotic cell that plays a critical role in rRNA transcription and assembly of ribosomes. Recently, the nucleolus has been shown to be implicated in an array of processes including the formation of signal recognition particles and response to cellular stress. Such diverse functions of nucleolus are mediated by nucleolar proteins. In this study, we characterized a gene coding a putative protein containing a nucleolar localization sequence (NoLS) in the rice blast fungus, Magnaporthe oryzae. Phylogenetic and domain analysis suggested that the protein is orthologous to Rrp8 in Saccharomyces cerevisiae. MoRRP8-GFP (translational fusion of MoRRP8 with green fluorescence protein) co-localizes with a nucleolar marker protein, MoNOP1 fused to red fluorescence protein (RFP), indicating that MoRRP8 is a nucleolar protein. Deletion of the MoRRP8 gene caused a reduction in vegetative growth and impinged largely on asexual sporulation. Although the asexual spores of DMorrp8 were morphologically indistinguishable from those of wild-type, they showed delay in germination and reduction in appressorium formation. Our pathogenicity assay revealed that the MoRRP8 is required for full virulence and growth within host plants. Taken together, these results suggest that nucleolar processes mediated by MoRRP8 is pivotal for fungal development and pathogenesis.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.141-146
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• 2005

A new system for displaying proteins on the surface of Escherichia coli was developed using the Salmonella typhimurium outer membrane protein C (OmpC) as an anchoring motif. The C-terminal deletionfusion strategy was developed to fuse the polyhistidine peptides and green fluorescent protein (GFP) to the Cterminal of the truncated functional portion of OmpC. The polyhistidine peptides of up to 243 amino acids could besuccessfully displayed on the E. coli cell surface, which allowed recombinant E. coli to adsorb up to 34.2 μmol of Cd2+ per gram dry cell weight. The GFP could also be successfully displayed on the E. coli cell surface. These results suggest that the C-terminal deletion-fusion strategy employing the S. typhimurium OmpC as an anchoring motif provides a new efficient way for the display of large proteins on the surface of E. coli.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권1호
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• pp.1-7
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• 2013

In this paper, a biosensor based on a gated lateral bipolar junction transistor (BJT) is proposed. The gated lateral BJT can function as both a metal-oxide-semiconductor field-effect transistor (MOSFET) and a BJT. By using the self-assembled monolayer (SAM) method, the C-reactive protein antibodies were immobilized on the floating gate of the device as the sensing membrane. Through the experiments, the characteristics of the biosensor were analyzed in this study. According to the results, it is indicated that the gated lateral BJT device can be successfully applied as a biosensor. Additionally, we found that the sensitivity of the gated lateral BJT can be varied by adjusting the emitter (source) bias.

• BMB Reports
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• 제33권6호
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• pp.483-492
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• 2000

The Herpes simplex virus type 1 (HSV-1) strain F glycoprotein H (gH) gene in the pHLB-4 plasmid was recombinated into a baculovirus expression vector (lacZ-HcNPV) to construct a recombinant virus GH-HcNPV expressing gH. The sequences of gH and its expression were analyzed. The gH gene was located in the 6.41 kb BglII fragment. The open reading frame (ORF) of the gH gene was 2,517 bp and codes 838 amino acid residues. Insect cells infected with this recombinant virus synthesized a high level of the matured and gX-gH fusion protein with approximately 112 kDa. The fusion gH protein was localized on the membrane of the insect cells as seen by using immunofluorescence assay and accumulated in the cultured media by the SDS-PAGE and immunoprecipitation assays. The amino acid sequence presents additional characteristics compatible with the structure of a viral glycoprotein: signal peptide, putative glycosylation sites and a long C-terminal transmembrane sequence. Antibodies raised in mice to this recombinant protein recognized viral gH and neutralized the infectivity of HSV-1 in vitro. These results demonstrate that it is possible to produce a mature protein by gene transfer in eukaryotic cells, and indicate the utility of the HcNPV-insect cell system for producing and characterizing eukaryotic proteins. Furthermore, the neutralizing antibodies would appear to protect mice against HSV; accordingly, this particular recombinant protein may be useful in the development of a subunit vaccine.