• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.579-585
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• 2007

Formation of inclusion bodies is usually observed when foreign proteins are overexpressed in E. coli. The formation of inclusion bodies might be prevented by lowering the rate of protein synthesis, and appropriate regulation of the protein expression rate may lead to the soluble expression. In this study, human growth hormone (rhGH) was expressed in a soluble form by slowing down the protein synthesis rate, which was controlled in the transcriptional and translational levels. The transcriptional level was controlled by the regulation of the amount of RNA polymerase specific to the promoter in front of the rhGH gene. For lowering the rate of translation, the T7 transcription terminator-deleted vector was used to synthesize the longer mRNA of the target gene because the longer mRNA is expected to reduce the availability of tree ribosomes. In both methods, the percentage of soluble expression increased when the expression rate slowed down, and more than 93% of rhGH expressed was a soluble form in the T7 transcription terminator-deleted expression system.

• Molecules and Cells
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• v.45 no.8
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• pp.537-549
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• 2022

Preproenkephalin (PPE) is a precursor molecule for multiple endogenous opioid peptides Leu-enkephalin (ENK) and Met-ENK, which are involved in a wide variety of modulatory functions in the nervous system. Despite the functional importance of ENK in the brain, the effect of brain-derived factor(s) on PPE expression is unknown. We report the dual effect of neural epidermal growth factor (EGF)-like-like 2 (NELL2) on PPE gene expression. In cultured NIH3T3 cells, transfection of NELL2 expression vectors induced an inhibition of PPE transcription intracellularly, in parallel with downregulation of protein kinase C signaling pathways and extracellular signal-regulated kinase. Interestingly, these phenomena were reversed when synthetic NELL2 was administered extracellularly. The in vivo disruption of NELL2 synthesis resulted in an increase in PPE mRNA level in the rat brain, suggesting that the inhibitory action of intracellular NELL2 predominates the activation effect of extracellular NELL2 on PPE gene expression in the brain. Biochemical and molecular studies with mutant NELL2 structures further demonstrated the critical role of EGF-like repeat domains in NELL2 for regulation of PPE transcription. These are the first results to reveal the spatio-specific role of NELL2 in the homeostatic regulation of PPE gene expression.

• Proceedings of the Korean Nutrition Society Conference
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• 1995.11b
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• pp.10-10
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• 1995

• Proceedings of the PSK Conference
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• 2004.10a
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• pp.86-86
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• 2004

• The Zoological Society Korea : Newsletter
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• v.12 no.2
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• pp.95.2-95
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• 1995

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.223.2-223
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• 1995

No Abstract, See Full Text

• The Korea Genome Conference
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• 2003.09a
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• pp.41.1-41.1
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• 2003

• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.879-886
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• 2000

Background : Thyroid Transcription Factor-1(TTF-1) acts as a tissue specific transcription factor in the regulation of lung specific gene expression and as morphogenic protein during lung organogenesis. Currently, there is very little information on the cis-acting sequences and transcription factors that direct the TTF-1 gene expression. DNAse 1 hypersensitive (DH) sites represent a marker for active or potentially active chromatin and are likely to be especially important in gene regulation, being associated with many DNA sequences that regulate gene expression. It is clear that DH regions correlate with genetic regulatory loci and binding for sequence-specific DNA-binding proteins. Methods : We have used DH site assays to identify putative distal regulatory elements in H441 lung adenocarcinoma cells, which express the TTF-1 gene and HeLa cells. Results : There are four DH sites 5' of the TTF-1 gene. These sites are located at base pair approximately +150, -450, -800, and -1500 from the start of transcription. Conclusion : These data suggest that there may be at least one intragenic site and regulatory region 5' prime to the promotor region.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6245-6248
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• 2013

Aims: To study effects of down-regulation of pituitary tumor-transforming gene (PTTG) on proliferation and metastasis ability of the SCL-1 cutaneous squamous cell carcinoma (CSCC) cell line and explore related mechanisms. Methods: SCL-1 cells were divided into 3 groups (untreated, siRNA control and PTTG siRNA). Cell proliferation assays were performed using a CCK-8 kit and proliferation and metastasis ability were analyzed using Boyden chambers. In addition, expression of MMP-2 and MMP-9 was detected by r-time qPCR and Western blotting. Results: Down-regulation of PTTG could markedly inhibit cell proliferation in SCL-1 cells, compared to untreated and control siRNA groups (P < 0.05). Real-time qPCR demonstrated that expression levels of PTTG, MMP-2 and MMP-9 in the PTTG siRNA group were 0.8%, 23.2% and 21.3% of untreated levels. Western blotting revealed that expression of PTTG, MMP-2 and MMP-9 proteins in the PTTG siRNA group was obviously down-regulated. The numbers of migrating cells ($51.38{\pm}4.71$) in the PTTG siRNA group was obviously lower than that in untreated group ($131.33{\pm}6.12$) and the control siRNA group ($127.72{\pm}5.20$) (P < 0.05), suggesting that decrease of proliferation and metastasis ability mediated by PTTG knock-down may be closely correlated with down-regulation of MMP-2 and MMP-9 expression. Conclusion: Inhibition of PTTG expression may be a new target for therapy of CSCC.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1684-1690
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• 2005

Using mRNA differential display technique, we investigated differential gene expression in hybrids relative to their parents in a diallel cross involving four chicken breeds in order to provide an insight into the molecular basis of heterosis in chicken. The results indicated that there was extensive differential gene expression between chicken F1 hybrids and their parents which was classified into four kinds of patterns as following: (1) bands only detected in hybrid F1; (2) bands only absent in hybrid F1; (3) bands only detected in parent P1 or P2; (4) bands absent in parent P1 or P2. Forty-two differentially expressed cDNAs were cloned and sequenced, and their expression patterns were confirmed by Reverse-Northern dot blot. Sequence analysis and database searches revealed that genes showed differential expression between hybrid and parents were regulatory and functional genes involved in metabolism, mRNA splicing, transcriptional regulation, cell cycles and protein modification. These results indicated that hybridization between two parents can cause changes in expression of a variety of genes. In conclusion, that the altered pattern of gene expression in hybrids may be responsible for heterosis in chickens.