• Archives of Pharmacal Research
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• v.28 no.6
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• pp.722-729
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• 2005

With the aim to improve the specificity and to reduce the cytotoxicity of polyethylenimine (PEI), we have synthesized the conjugates of the branched PEI (25 kDa) with transferrin. The trans-ferrin-PEI (TP) conjugates with five compositions were synthesized using periodate oxidation method and confirmed by FT-IR spectroscopy and gel permeation chromatography. The free amine contents of TP conjugates, which were able to condense and deliver DNA, increased as the amount of PEI increased. TP/DNA polyplexes were characterized by measuring gel elec-trophoresis, ethidium bromide fluorescence quenching, particle size and zeta potential of complexes. Complete complexation of the polyplexes was observed above the N/P ratio of 5 in TP/DNA, and above 3 in PEI/DNA, respectively. The zeta potential of the complexes decreased as the amount of transferrin in TP conjugates increased. Transfection efficiency of TP conjugates was evaluated in HeLa cell and Jurkat cell systems. Among the five compositions of TP conjugates, TP-2 system mediated a higher $\beta$-galactosidase gene expression than PEI system in Jurkat cell which was known to express elevated numbers of transferrin receptors. From the results of the cell viability based on MTT assay, TP conjugates showed lower cytotoxicity com-pared with the PEI system. We expect that the TP conjugate can be used efficiently as a non-viral gene delivery vector.

• Biomedical Science Letters
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• v.10 no.4
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• pp.385-389
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• 2004

A novel gene Jpk, originally isolated as a trans-acting factor associating with the position-specific regulatory element of murine Hox gene has been reported to be expressed differentially in the liver of diabetic animals. Therefore, in an attempt to develop a possible diagnostic marker and/or new therapeutic agent for the Diabetes Mellitus, we analysed the expression pattern of Jpk among organs of normal and diabetic Sprague-Dawley (SD) rats. Total RNAs were isolated from each organs (brain, lung, heart, liver, spleen, kidney, muscle, blood, and testis) of diabetic and normal rats in both normal feeding and after fasting condition. And then RT (reverse transcription) PCR has been performed using Jpk­specific primers. The Jpk gene turned out to be expressed in all organs tested, with some different expression profiles among normal and diabetes, though. Upon fasting, Jpk expressions were reduced in all organs tested except kidney, muscle and brain of normal rat. Whereas in diabetes, Jpk expressions were increased in all organs except heart, muscle and testis when fasted. Compared to the normal rat, the Jpk expression level in blood was remarkably upregulated (about 15-30times) in diabetic rat whether in normal feeding or fasting conditon, suggesting that the Jpk could be a candidate gene for the possible blood diagnostic marker for the Diabetes Mellitus.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.1031-1037
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• 2001

By a sequential action of ${\beta}$-ketothiolase and acetoacetyl-CoA reductase, two molecules of acetyl-CoA re converted into D-3-hydroxybutyryl-CoA, a substrate for PHB synthase to form poly-3-hydroxybutyryl-CoA, a substrate for PHB synthase to form poly-3-hydroxybutyrate (PHB) of rhodobacter sphaeroides. The ${\beta}$-ketothiolase gene, phbA, and acetoacetyl-CoA reductase gene, phbB, were cloned and analyzed for their expression. Enzyme activities of ${\beta}$-ketothiolase and acetoacetyl-CoA reductase showed constitutive levels during aerobic and photoheterotrophic growth of R. sphaeroides. In addition, no difference of each enzyme activity was observed between cells grown aerobically and photoheterotrophically. The constitutive level of the enzyme activities are regulated according to the growth phases along with growth conditions. Thus, phbAB expression is not determinative in regulating the PB content. On the other hand, phbA-deleted cell AZI accumulated only $10\%$ PHB of the wild-type, and an elevated dosage of phbAB in trans in R. sphaeroides resulted in a higher content of PHB, indicating that phbAB codes for the enzymes responsible for providing the main supply of subsyrate for PHB synthase. PHB formation by an alternative pathway that does not does not depend on the phbA-and phbB-coding enzymes is also proposed.

• Journal of Animal Science and Technology
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• v.58 no.5
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• pp.18.1-18.10
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• 2016

Muscle, studied mostly with respect to meat production, represents one of the largest protein reservoirs of the body. As gene expression profiling holds credibility to deal with the increasing demand of food from animal sources, excessive loss due to myopathies and other muscular dystrophies was found detrimental as it aggravates diseases that result in increased morbidity and mortality. Holding key point towards improving the developmental program of muscle in meat producing animals, elucidating the underlying mechanisms of the associated pathways in livestock animals is believed to open up new avenues towards enhancing the lean tissue deposition. To this end, identification of vital candidate genes having no known function in myogenesis, is believed to increase the current understanding of the physiological processes going on in the skeletal muscle tissue. Taking consequences of gene expression changes into account, knowledge of the pathways associated with their activation and as such up-regulation seems critical for the overall muscle homeostasis. Having important implications on livestock production, a thorough understanding of postnatal muscle development seems a timely step to fulfil the growing need of ever increasing populations of the world.

• BMB Reports
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• v.38 no.4
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• pp.440-446
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• 2005

A cDNA that was rapidly induced upon abscisic acid, cold, drought, mechanical wounding and to a lesser extent, by high salinity treatment, was isolated from Arabidopsis seedlings. It was classified as DREB subfamily member based on multiple sequence alignment and phylogenetic characterization. Since it encoded a protein with a typical ERF/AP2 DNA-binding domain and was closely related to the TINY gene, we named it TINY2. Gel retardation assay revealed that TINY2 was able to form a specific complex with the previously characterized DRE element while showed only residual affinity to the GCC box. When fused to the GAL4 DNA-binding domain, either full-length or its C-terminus functioned effectively as a trans-activator in the yeast one-hybrid assay while its N-terminus was completely inactive. Our data indicate that TINY2 could be a new member of the AP2/EREBP transcription factor family involved in activation of down-stream genes in response to environmental stress.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.14-14
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• 2003

Potato virus X (PVX), the type member of Potexvirus genus, is a flexuous rod-shaped virus containing a single-stranded (＋) RNA. Infection by PVX produces genomic plus- and minus-strand RNAs and two major subgenomic RNAs (sgRNAs). To understand the mechanism for PVX replication, we are studying the cis- and/or trans-acting elements required for RNA replication. Previous studies have shown that the conserved sequences located upstream of two major sgRNAs, as well as elements in the 5' non-translated region (NTR) affect accumulation of genomic and sg RNAs. Complementarity between sequences at the 5' NTR and those located upstream of two major sgRNAs and the binding of host protein(s) to the 5' NTR have shown to be important for PVX RNA replication. The 5 NTR of PVX contains single-stranded AC-rich sequence and stem-loop structure. The potential role(s) of these cis-elements on virus replication, assembly, and their interaction with viral and host protein(s) during virus infection will be discussed based on the data obtained by in vitro binding, in vitro assembly, gel shift mobility assay, host gene expression profiling using various mutants at these regions.

• BMB Reports
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• v.28 no.4
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• pp.368-373
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• 1995

The upstream regulatory region (URR) of bovine papillomavirus type 1 (BPV) contains promoters and a conditional transcriptional enhancer that is trans-activated by the viral E2 protein. After deleting the 5' and 3' ends of BPV URR, BamHI linkers were inserted into several positions of BPV URR without causing an addition or a deletion of URR sequences. Most linker scanning mutations did not show any effects on the transcription of P7940 and P89 promoters in BPV URR. However, several mutants showed reduced transcriptional activities. Based on our results we found that the AP-2 and Sp1 binding sites were important for basal level transcription of BPV URR in the absence of the E2 protein and that the CTF/NF-1 site is dispensable for E2 transactivation of BPV URR transcription.

• Journal of Photoscience
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• v.5 no.4
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• pp.149-152
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• 1998

Expression of light-harvesting chlorophyll a/b-binding protein gene(cab) is repressed in the dark and activited by light. However, the detail of its regulatory mechanism is not characterized so far. To identify the interactions of cis-acting elements and trans-acting factors involvedin this regulation, nuclear extracts from the light-grown and dark-adapted Arabidopsis thaliana leaves were anlayzed for mobility shift assay against 134bp fragments had two retarded bands and one retardation band, respectively, both in light-grown and dark-adapted bands in the dark-adapted tissues. A new retardation the cab 3 expression in the dark. Several light regulatory motifs are scattered in the 146 bp region of cab 3 promoter. One of the light-regulatory motifs could be the binding site for the negative regulatory factor.

• Fisheries and Aquatic Sciences
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• v.4 no.1
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• pp.25-31
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• 2001

4-Aminobutyrate aminotransferase plays an essential role in the 4-aminobutyric acid shunt, converting 4-aminobutyrate to succinic semi aldehyde. We isolated and sequenced' a fish cDNA fragment that encodes 4-aminobutyrate aminotransferase. A brain cDNA library from flounder (Paralichthys olivaceus) was constructed using the ZAP- III XR vector and screened for the fish 4-aminobutyrate aminotransferase gene using a probe derived from the conserved sequences of known mammalian 4-aminobutyrate aminotransferases. A partial cDNA for 4-aminobutyrate aminotransferase was cloned and found to be 700 bp in length corresponding to 66 amino acids. Nucleotide sequence of the clone was aligned with NCBI (National Center for Biotechnology Information) DNA sequence data base. The result showed high sequence identity with previously reported mammalian 4-aminobutyrate aminotransferases. The trans­criptional level of flounder 4-aminobutyrate aminotransferase was detected with the presence of mRNA at different flounder tissues by reverse transcription-polymerase chain reaction (RT-PCR). The expression of flounder 4-aminobutyrate aminotransferase was also tested and detected from the flounder tissues of the brain, liver, kidney and pancreas.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.111-111
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• 2001

Resveratrol (trans-3,4',5-trihydroxystilbene), which is a polyphenolic compound found in a variety of plants such as grapes and wine, has been reported to have a variety of anti-inflammatory, anti-platelet, and anti-carcinogenic effects. Recently resveratrol of was reported to serve as an estrogen agonist in MCF-7 cells Based on its structural similarity to diethylstilbestrol, a synthetic estrogen, we examined whether resveratrol and its derivatives might be estrogenic using stable MCF-7-ERE cells. Resveratrol functioned as a superagonist at high concentrations (i.e., produced a greater maximal transcriptional response than estradiol) Among the resveratrol derivatives, 10 compounds showed significant estrogenic activity.