• Proceedings of the Microbiological Society of Korea Conference
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• 2001.11a
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• pp.97-101
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• 2001

The fusion between viral envelope and target cell membrane is a central step of viral infection, and the fusion proteins located at viral envelope mediate such process. Gp41 of HIV is one of the fusion proteins whose structure and mechanism of membrane fusion had been extensively studied. Functionally important motives of gp41 are the N-terminus fusion peptide, the coiled-coil and the membrane proximal C-peptide regions. The role of these regions during the fusion process had been thoroughly examined. Specially, insertion of the fusion peptide into membrane and conformational change of the coiled-coil and C-peptide regions are assumed to be critical for the fusion mechanism. In addition, the coiled-coil region has been shown to interact with membrane, and the C-peptide region regulates the interaction in a dose dependent manner. Furthermore, fusion defective mutations of the coiled-coil region dramatically changed its binding affinity to membrane. These results suggested that the membrane binding property of the coiled-coil region is important for the fusion activity of gp41, and such property could be modulated by the interaction with the C-peptide region.

• Korean Journal of Microbiology
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• v.41 no.4
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• pp.239-245
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• 2005

Transformation-Associated Recombination (TAR) cloning technique allows selective isolation of chromosomal regions and genes from complex genomes. The procedure requires knowledge of relatively small genomic sequences that reside adjacent to the chromosomal region of interest. This technique involves homologous recombination during yeast spheroplast transformation between genomic DNA and a TAR vector that has 5' and 3' gene targeting sequences. In this study, we examined the effect of non-homologous spacing sequence in target hooks on homologous recombination using a plasmid model system. The efficiency of homologous recombination between the modified his3-TRP1-his3 fragments and HlS3 gene on plasmid were analyzed by the characterization of $Ura^+$ transformants. The numbers of $Ura^+$ transformant showed same level when seven different modified his3-TRP1-his3 fragments were used. But the percentage of positive recombinants. $Trp^+His^-$, dramatically decreased when used the modified his3-TRP1-his3 fragments contained incorrect spacing of nonhomologous region. As a result, we suggest that incorrect spacing inhibits the homologous recombination between target hook and substrate DNA. Therefore, we should consider the correct spacing in target hook when the target hook are used for cloning of orthologue gene.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.52-55
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• 1987

In tihis paper an improved matching method using subtemplate of moving region and 3-step search algorithm is proposed It reduces heavy computational load of the conventional method. The proposed method is applied to an automatic target tracker using high speed 16 bit microprocessor in order to track one moving target in real time. Expericmental results show that the proposed method has better performance over the conventional methodin spite of greately reducing the computational load, even in came complex background.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.77-80
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• 2001

A variety of different methods to generate diverse proteins, including random mutagenesis and recombination, are currently available, and most of them accumulate the mutations on the target gene of a protein, whose sequence space remains unchanged. On the other hand, a pool of diverse genes, which is generated by random insertions, deletions, and exchange of the homologous domains with different lengths in the target gene, would present the protein lineages resulting in new fitness landscapes. Here we report a method to generate a pool of protein variants with different sequence spaces by employing green fluorescent protein (GFP) as a model protein. This process, designated functional salvage screen (FSS), comprises the following procedures： a defective GFP template expressing no fluorescence is firstly constructed by genetically disrupting a predetermined region(s) of the protein, and a library of GFP variants is generated from the defective template by incorporating the randomly fragmented genomic DNA from E. coli into the defined region(s) of the target gene, followed by screening of the functionally salvaged, fluorescence-emitting GFPs. Two approaches, sequence-directed and PCR-coupled methods, were attempted to generate the library of GFP variants with new sequences derived from the genomic segments of E. coli. The functionally salvaged GFPs were selected and analyzed in terms of the sequence space and functional property. The results demonstrate that the functional salvage process not only can be a simple and effective method to create protein lineages with new sequence spaces, but also can be useful in elucidating the involvement of a specific region(s) or domain(s) in the structure and function of protein.

• Journal of Microbiology and Biotechnology
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• v.31 no.8
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• pp.1098-1108
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• 2021

The literature indicates that LINC00174 promotes the growth of colorectal cancer (CRC) cells, but its research needs to be enriched. We tried to explore the function and mechanism of LINC00174 in CRC cell proliferation and migration. Bioinformatics analysis predicted the binding relationship and expressions of lncRNA, miRNA and mRNA. Clinical study analyzes the relationship between LINC00174 and clinical data characteristics of CRC patients. The expressions of LINC00174, miR-3127-5p and E2F7 were verified by RT-qPCR, and the combination of the two was verified by dual luciferase analysis and RNA immunoprecipitation as needed. Western blot was used to detect the expression of EMT-related protein and E2F7 protein. Functional experiments were used to evaluate the function of the target gene on CRC cells. LINC00174 was up-regulated in CRC clinical samples and cells and was related to the clinical characteristics of CRC patients. High-expression of LINC00174, contrary to the effect of siLINC00174, promoted cell viability, proliferation, migration and invasion, up-regulated the expressions of N-Cadherin, Vimentin, E2F7, and inhibited the expression of E-Cadherin. MiR-3127-5p was one of the targeted miRNAs of LINC00174 and was down-regulated in CRC samples. In addition, miR-3127-5p mimic partially reversed the malignant phenotype of CRC cells induced by LINC00174. Besides, E2F7 was a target gene of miR-3127-5p, and LINC00174 repressed miR-3127-5p to regulate E2F7. Our research reveals that LINC00174 affected the biological characteristics of CRC cells through regulated miR-3127-5p/ E2F7 axis.

• BMB Reports
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• v.53 no.7
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• pp.373-378
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• 2020

Phosphorylation of the signaling component by protein kinase often leads to a kinase cascade or feedback loop. 3-Phosphoinositide-dependent kinase 1 (PDK1) signaling pathway diverges into various kinases including Akt and p70 S6 kinase (p70S6k). However, the PDK1 feedback mechanism remains elusive. Here, we demonstrated that UNC-51-like kinase (ULK1), an autophagy initiator kinase downstream of mechanistic target of rapamycin (mTOR), directly phosphorylated PDK1 on serine 389 at the linker region. Furthermore, our data showed that this phosphorylation affected the kinase activity of PDK1 toward downstream substrates. These results suggest a possible negative feedback loop between PDK1 and ULK1.

• Genomics & Informatics
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• v.3 no.3
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• pp.53-62
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• 2005

MicroRNAs play an important role in regulating gene expression, but their target identification is a difficult task due to their short length and imperfect complementarity. Burge and coworkers developed a program called TargetScan that allowed imperfect complementarity and established a procedure favoring targets with multiple binding sites conserved in multiple organisms. We improved their algorithm in two major aspects - (i) using well-defined UTR (untranslated region) database, (ii) examining the extent of conservation inside the 3' UTR specifically. Average length in our UTR database, based on the ECgene annotation, is more than twice longer than the Ensembl. Then, TargetScan was used to identify putative binding sites. The extent of conservation varies significantly inside the 3' UTR. We used the 'tight' tracks in the UCSC genome browser to select the conserved binding sites in multiple species. By combining the longer 3' UTR data, TargetScan, and tightly conserved blocks of genomic DNA, we identified 107 putative target genes with multiple binding sites conserved in multiple species, of which 85 putative targets are novel.

• Journal of the Optical Society of Korea
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• v.8 no.4
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• pp.174-181
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• 2004

Various kinds of systems, that can do target recognition and position detection simultaneously by using infrared sensing detectors, have been developed. In this paper, the detection system TRSS (Thermal target Recognition by Spiral Scanning) adopts linear array shaped uncooled IR detector and uses spiral type fast scanning method for relative position detection of target objects, which radiate an IR region wavelength spectrum. It can detect thermal energy radiating from a 9 m-size target object as far as 200 m distance. And the maximum field of a detector is fully filled with the same size of target object at the minimum approaching distance 50 m. We investigate two types of lens systems. One is a singlet lens and the other is a doublet lens system. Every system includes one aspheric surface and free positioned aperture stop. Many designs of F/1.5 system with ${\pm}5.2^{\circ}$ field at the Efl=20, 30 mm conditions for single element and double elements lens system respectively are compared in their resolution performance [MTF] according to the aspheric surface and stop position changing on their optimization process. Optimum design is established including mechanical boundary conditions and manufacturing considerations.

• Korean Journal of Remote Sensing
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• v.40 no.2
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• pp.167-177
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• 2024

With advancements in satellite technology, interest in target detection and identification is increasing quantitatively and qualitatively. Synthetic Aperture Radar(SAR) images, which can be acquired regardless of weather conditions, have been applied to various areas combined with machine learning based detection algorithms. However, conventional studies primarily focused on the detection of stationary targets. In this study, we proposed a method to identify moving targets using an algorithm that integrates sub-aperture SAR images and cosine similarity calculations. Utilizing a transformer-based deep learning target detection model, we extracted the bounding box of each target, designated the area as a region of interest (ROI), estimated the similarity between sub-aperture SAR images, and determined movement based on a predefined similarity threshold. Through the proposed algorithm, the quantitative evaluation of target identification capability enhanced its accuracy compared to when training with the targets with two different classes. It signified the effectiveness of our approach in maintaining accuracy while reliably discerning whether a target is in motion.

• ETRI Journal
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• v.29 no.5
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• pp.697-699
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• 2007

Spatiograms are histograms augmented with spatial means and covariances to capture a richer description of the target. We present a particle filtering framework for region-based tracking using spatiograms. Unlike mean shift, the framework allows for non-differentiable similarity measures to compare two spatiograms; we present one such similarity measure, a combination of a recent weighting scheme and histogram intersection. Experimental results show improved performance with the new measure as well as the importance of global spatial information for tracking. The performance of spatiograms is compared with color histograms and several texture histogram methods.