• Animal cells and systems
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• 제8권1호
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• pp.49-55
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• 2004

In vertebrates, multisubunit cofactors regulate gene expression through interacting with cell-type- and gene-specific DNA-binding proteins in a chromatin-selective manner. ADD1/SREBP1c regulates fatty acid metabolism and insulin-dependent gene expression through binding to SRE and E-box motif with dual DNA binding specificity. Although its transcriptional and post-translational regulation has been extensively studied, its regulation by interacting proteins is not well understood. To identify cellular proteins that associate with nuclear form of ADD1/SEBP1c, we employed the GST pull-down system with Hela cell nuclei extract. In this study, we demonstrated that Ku proteins interact specifically with ADD1/SREP1c protein. GST pull-down combined with peptide sequencing analysis revealed that Ku80 binds to ADD1/SREBP1c in vitro. Additionally, western blot analysis showed that Ku70, a heterodimerizing partner of Ku80, also associates with ADD1/SREBP1c. Furthermore, co-transfection of Ku70/Ku80 with ADD1/SREBP1c enhanced the transcriptional activity of ADD1/SREBP1c. Taken together, these results suggest that the Ku proteins might be involved in the lipogenic and/or adipogenic gene expression through interacting with ADD1/SREBP1c.

• 미생물학회지
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• 제30권5호
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• pp.347-354
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• 1992

New regulatory, loci which participate in the regulation of anaerobic inducible gene expression in Salmonella typhimurium were identified. We observed the regulatory network of new regulator mutations to various anaerobic inducible gene (1). Some anaerobic inducible lac fusions were also induced at low pH condition which was severe environment to withstand for its virulence at the place like phagolysosome. Sic oxygen-regulated regulatory mutants (oxr) isolated by Tn10 mutagenesis were divided into two groups. Five of them were found to show negative effect on the regulation of anaerobic gene expression, while on e showed positive effect on the regulation. Genetic loci of four oxr were identified with 54 Mud-P22 lysogens covering the whole chromosome of S. typhimurium, in the nearby region of map unit 87 min (oxr101), 63 min (oxr104), 97 min (oxr 105), and 57 min (oxr 106), respectively. Two oxr mutants were subjected to two-dimensional polyacrylamide electrophoretic analysis of anaerobic inducible proteins for searching the control circuitry of our oxr mutants.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2001년도 한국생물과학협회 학술발표대회
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• pp.75-75
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• 2001

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
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• 한국동물학회 2001년도 한국생물과학협회 학술발표대회
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• pp.259.3-260
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• 2001

No Abstract, See Full Text

• BMB Reports
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• 제32권2호
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• pp.112-118
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• 1999

The presence of hypoxic cells in solid tumors has long been considered a problem in cancer treatment such as in radiation therapy or treatment with some anticancer drugs. It has been suggested that hypoxic cells are involved in the development of a more aggressive phenotype and contribute to metastasis. In this study, as an attempt to understand how tumor cells adapt to hypoxic stress, we investigated the regulation of the hypoxia-induced expression of proteins that control essential processes of tumor cell survival and angiogenesis. We first examined whether hypoxia induces stress protein gene expression of murine solid tumor RIF cells. We also examined hypoxia-induced changes in angiogenic gene expression in these cells. Finally, we investigated the association of the elevated levels of stress proteins with the regulation of hypoxia-induced angiogenic gene expression. Results demonstrated that hypoxia induced the expression of the erythropoietin (EPO) gene and at least two major members of stress proteins, heat shock protein 70 (HSP70) and 25 (HSP25) in RIF tumor cells. Evidence that the expression of EPO gene was greatly potentiated in TR cells suggested that the elevated levels of HSPs may play an important role in the regulation of the hypoxia-induced EPO gene expression. One of the RIF variant cell lines, TR, displays elevated levels of HSPs constitutively. Taken together, our results suggest that a hypoxic tumor microenvironment may promote the survival and malignant progression of the tumor cells by temporarily increasing the level of stress proteins and expressing angiogenic genes. We suspect that stress proteins may be associated with the increase of the angiogenic potential of tumor cells under hypoxia.

• Journal of Microbiology
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• 제44권1호
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• pp.35-41
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• 2006

The unique gene encoding thioredoxin reductase (TrxR) was previously cloned and characterized from the fission yeast Schizosaccharomyces pombe, and its expression was induced by oxidative stress. To elucidate tbe regulatory mechanism of the S. pombe TrxR gene, three fusion plasmids were generated using polymerase chain reaction: pYUTR20, pYUTR30, and pYUTR40. Plasmid pYUTR20 has an upstream region of 891 base pairs, pYUTR30 has 499 in this region, and pYUTR40 has an 186 bp upstream region. Negatively acting sequence is located between $-1,526\;\~\;-891bp$ upstream of the gene. The upstream sequence, responsible for the induction of TrxR by menadione (MD), is situated on the $-499\;\~\;-186bp$ region, which is also required for TrxR induction by mercuric chloride. The same region also appeared to be required for Pap1-mediated transcriptional regulation of the TrxR gene, which contains the two plausible Papl binding sites, TTACGAAT and TTACGCGA. Consistently, basal and inducible expression of the TrxR gene was markedly lower in the Pap1-negative TP108-3C cells than in wild-type yeast cells. In summary, up-regulation of the S. pombe TrxR gene is mediated by Pap1 via the transcriptional motif(s) located on the $-499\;\~\;-186bp$ region.

• Journal of Plant Biotechnology
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• 제46권3호
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• pp.137-142
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• 2019

유전자교정작물은 공여 DNA의 사용 여부와 돌연변이의 크기에 따라 SDN-1, SDN-2, SDN-3 작물로 분류한다. 특히 SDN-1과 SDN-2 작물들은 이들을 창출하기 위하여 사용한 운반체 DNA 단편 또는 guide RNA가 잔존 하지 않는 100% transgene-free 작물의 개발이 가능하다. 따라서 이들은 기존의 전통교배육종기술을 이용하거나 자연 상태에서도 창출이 가능한 작물들이다. 그러므로 기존의 GMO 법령에 따라 이들 유전자교정작물을 판별하거나 표시제에 근거한 관리 감독을 수행하기가 어렵다. 이러한 과학적 사실에 근거하여 호주는 SDN-1 작물은 GMO 규제에서 제외하도록 하였다. 또한, 아르헨티나, 브라질, 일본 등은 외래유전자가 최종산물에 잔존 하지 않는 유전자교정작물은 GMO 규제에서 제외하도록 하여 SDN-1은 물론 SDN-2 작물도 GMO에 포함되지 않을 수도 있도록 하였다. 이러한 추세에 따라 우리나라도 외래유전자가 잔존 하지 않는 유전자교정작물은 GMO 규제에서 제외하도록 하여 유전자교정기술을 이용한 다양한 작물 육종 계통 육성이 널리 이용되어 우수 품종 육성에 기여되길 기대한다.

• Toxicological Research
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• 제16권2호
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• pp.95-100
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• 2000

In previous study, both constitutive expression and 3-methylcholanthrene (3MC)-mediated elevation of CYP1A2 mRNA were demonstrated in human hepatoma HepG2 cells by reverse transcription-polymerase chain reaction (RT-PCR), suggesting that HepG2 cells would be appropriate for the study of human CYP1A2 regulation(Chung and Bresnick, 1994). Further studies were conducted to determine the basis of this induction phenomenon that is observed in HepG2 cells. Since CYP1A1 gene, another polycyclic hydrocarbon(PH)-inducible gene, is regulated by PHs through their interactions via receptors with cis-elements, the 5'-flanking region of human CYP 1A2 gene was analyzed to search such responsive elements. The promoter activity of various lengths of CYP1A2 gene sequence (-3203/+58bp) was measured in transiently-transfected HepG2 cells by fusion constructs containing the CAT, hGH or luciferase genes as a reporter. This region of the CYP1A2 gene, although containing a XRE, was only weakly responsive (less than 2 fold induction) to 10 nM of TCDD or 1 $\mu$M 3 MC treatment. This small enhancement of promoter activity is inconsistent with the previous observation, i.e., 12 to 14 fold-enhanced CYP1A2 mRNA from 1 $\mu$M 3 MC treated HepG2 cells, suggesting that additional mechanisms would exist for PH-mediated induction of CYP1A2 in these cells.

• BMB Reports
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• 제46권2호
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• pp.92-96
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• 2013

The breast cancer susceptibility gene BRCA1 encodes a nuclear protein, which functions as a tumor suppressor and is involved in gene transcription and DNA repair processes. Many families with inherited breast and ovarian cancers have mutations in the BRCA1 gene. However, only a few studies have reported on the mechanism underlying the regulation of BRCA1 expression in humans. In this study, we investigated the transcriptional regulation of BRCA1 in HeLa cells treated with etoposide. We found that three Egr-1-binding sequences (EBSs) were located at -1031, -1005, and -385 within the enhancer region of the BRCA1 gene. Forced expression of Egr-1 stimulated the BRCA1 promoter activity. EMSA data showed that Egr-1 bound directly to the EBS within the BRCA1 gene. Knockdown of Egr-1 through the expression of a small hairpin RNA (shRNA) attenuated etoposide-induced BRCA1 promoter activity. We conclude that Egr-1 targets the BRCA1 gene in HeLa cells exposed to etoposide.

• Animal cells and systems
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• 제7권1호
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• pp.63-68
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• 2003

Until recently, interest in human complement receptor type I (CR1) has focused on immune complex processing, which contributed to our understanding of regulatory mechanism of complement activation. However, the promoter structure and transcriptional regulation of human CR1 gene has not been clear. To study the unique regulation of human CR1 gene expression, we assessed promoter activity of the $5^1$-flanking region of human CR1 gene using transient transfection and gel mobility shift assays. In this study we demonstrated that NF-Y binds to the inverted CCAAT element and that the functional interaction with protein(s) which bind to the GC-rich motif may be necessary for optimal transcription of human CR1 gene. We also show that sequence elements which located at-95/58 and +45/+50 are important for optimal transcription of CR1 gene.