• Journal of Plant Biology
• /
• 제38권3호
• /
• pp.259-266
• /
• 1995

To investigate how the dyad symmetry region (DSR) and the distance between vir box and -35 sequence of the virE promoter plays a role in virE gene expression, two mutants were constructed by base substitution and insertional mutagenesis. The base substitutional mutation, a AAlongrightarrowCG substitution at positions -39 and -40 on the DSR, showed the level of $\beta$-galactosidase activity approximately 91% of the wild type virE promoter activity. Therefore, the native structure of the DSR seems to be not essential for virE expression. The insertional mutation, constructed by inserting 8 bp ClaI linker between -49 and -50, displayed the $\beta$-galactosidase activity at 12% of the native virE promoter activity. However, this striking reduction appears to be not caused by destruction of the native DSR structure, but by shifting the vir box far from putative -35 sequence.

• Journal of Microbiology and Biotechnology
• /
• 제1권4호
• /
• pp.240-245
• /
• 1991

We have constructed a promoter-probe vector pKU20 using pKT230, a derivative of broad-host-range plsmid RSF1010, as a base. The pKU20 contains structural gene for aminoglycoside phos-photransferase (aph), without promoter, and a multiple cloning site upstream the aph. Using this vector, a 412base pairs (bp) PstI fragment showing strong promoter activity both in Escherichia coli LE392 and Pseudomonas putida KCTC1644 has been cloned from Pseudomonas fluorescens chromosomal DNA on the basis of streptomycin resistance. The nucleotide sequence of the 412 bp fragment has been determined and the putative - 35 and -10 region was observed. Insecticidal protein gene of Bacillus thuringiensis subsp. kurstaki HD-73 inserted on downstream of the promoterlike DNA fragment was efficiently expressed in E. coli and P. putida. The toxin protein was efficiently synthesized in an insoluble form in both strains.

• Molecules and Cells
• /
• 제26권2호
• /
• pp.131-139
• /
• 2008

Expression of the seven open reading frames (ORFs) of single-stranded DNA Curtoviruses such as Beet curly top virus (BCTV) and Beet severe curly top virus (BSCTV) is driven by a bi-directional promoter. To investigate this bidirectional promoter activity with respect to viral late gene expression, transgenic Arabidopsis plants expressing a GUS reporter gene under the control of either the BCTV or BSCTV bi-directional promoter were constructed. Transgenic plants harboring constructs showed higher expression levels when the promoter of the less virulent BCTV was used than when the promoter of the more virulent BSCTV was used. In transgenic seedlings, the reporter gene constructs were expressed primarily in actively dividing tissues such as root tips and apical meristems. As the transgenic plants matured, reporter gene expression diminished but viral infection of mature transgenic plants restored reporter gene expression, particularly in transgenic plants containing BCTV virion-sense gene promoter constructs. A 30 base pair conserved late element (CLE) motif was identified that was present three times in tandem in the BCTV promoter and once in that of BSCTV. Progressive deletion of these repeats from the BCTV promoter resulted in decreased reporter gene expression, but BSCTV promoters in which one or two extra copies of this motif were inserted did not exhibit increased late gene promoter activity. These results demonstrate that Curtovirus late gene expression by virion-sense promoters depends on the developmental stage of the host plant as well as on the number of CLE motifs present in the promoter.

• 생명과학회지
• /
• 제9권1호
• /
• pp.50-57
• /
• 1999

STAT들은 다양한 cytokine이나 성장호르몬 등에 의해 활성화되어 핵으로 빠르게 이동되어 유전자 발현을 조절한다. 우리는 D-raf 유전자의 5' 발현조절영역에서 STAT결합부위 염기서열을 발견하였다. 본 연구는 D-raf 유전자발현조절에 있어서 STAT결합부위의 역할을 형질전환 초파리를 사용하여 조사하였다. STAT결합부위에 염기치환돌연변이를 도입시킨 D-raf promoter부분을 P인자 벡터의 IacZ유전자에 융합시킴으로써 리포터 플라스미드 pDraf-STATmut-lacZ를 제작하였다. 이 리포터 플라스미드를 이용하여 얻은 Draf-STATmut-lacZ형질전환 초파리의 lacZ발현을 발생단계별, 조직별로 조사한 결과, 거의 모든 발생단계에서 정상형 Draf-lacZ 형질전환 초파리의 lacZ발현에 비해 크게 감소하였다. 본 연구결과들은 STAT결합배열 부위가 D-raf유전자발현조절에 있어서 중요한 역할을 함을 개체수준에서 증명하고 있다.

• 농업과학연구
• /
• 제48권2호
• /
• pp.353-365
• /
• 2021

Previously, we reported that tissue factor (Tf) was included in the list of differentially expressed genes as an upregulated gene in a rejected porcine heart after xenotransplantation into monkey. In this study, we analyzed that expression of Tf in aortic endothelial cells (pAEC) isolated from alpha 1,3-galactosyltransferase knockout pig in response to allogeneic porcine serum and xenogeneic human serum. The consequence was significant upregulation of Tf expression by responding to human serum compared with porcine serum. To analyze the function of Tf gene as a promoter, we constructed reporter vectors for expression of luciferase linked to 1,246 and 787 base pairs of porcine Tf (pTF1246 and pTF787), and 535 base pairs of human TF (hTF535) sequences including putative promoter regions and AP-1 biding site at the 5' end. The reporter vectors were transfected into pAEC including cytomegalovirus enhancer/chicken β-actin (CAG)-luciferase vector as a control. Luciferase assay showed that all of the promoters were insufficient to express luciferase compared with CAG promoter in basic culture conditions. Notably, pTF1246, pTF787, and hTF535 led to a significant increase of luciferase expression in response to human serum compared with porcine serum while no change of CAG. pTF1246 and pTF787 showed higher expression than hTF535. Taken together, our findings suggest that pTF1246 and pTF787 promoters could mediate target gene expression specifically at xenogeneic stress condition.

• Animal cells and systems
• /
• 제2권1호
• /
• pp.117-122
• /
• 1998

D-raf, a Drosophila homolog of the human c-raf-1, is known as a signal transducer in cell proliferation and differentiation. A previous study found that the D-raf gene expression is regulated by the DNA replication-related element (DRE)/DRE-binding factor (DREF) system. In this study, we found the sequences homologous to transcription factor C/EBP, MyoD, STAT and Myc recognition sites in the D-raf promoter. We have generated various base substitutional mutations in these recognition sites and subsequently examined their effects on D-raf promoter activity through transient CAT assays in Kc cells with reporter plasmids p5'-878DrafCAT carrying the mutations in these binding sites. Through gel mobility shift assay using nuclear extracts of Kc cells, we detected factors binding to these recognition sites. Our results show that transcription factor C/EBP, STAT and Myc binding sites in D-raf promoter region play a positive role in transcriptional regulation of the D-raf gene and the Myo D binding site plays a negative role.

• Molecules and Cells
• /
• 제26권2호
• /
• pp.212-215
• /
• 2008

The GC-rich discriminator sequence between the -10 region and the transcription start site of the rnpB promoter is responsible for stringent control of M1 RNA synthesis. The rnpB promoter also contains a G nucleotide at the previously identified transcription start site. In this study, we examined by mutagenesis of G to A whether this +1G nucleotide is involved in the stringent response. We found that the change did not alter the stringent response. Since the +1 mutation might alter transcription initiation, we compared the transcription start sites of the wt and mutant promoters by primer extension analysis. Surprisingly, we found that wild type rnpB transcription starts at both the +1G position (70%) and the -1C position (30%), and that the +1A mutation led to transcription initiation exclusively at the -1C position. We also generated two transversion mutations at the -1 position, both of which led to transcription starting exclusively at that position. The -1G mutant promoter gave a stringent signal similar to the wild-type, whereas the -1A mutant generated a significantly less stringent signal. Base on these results, we propose that a short sequence, up to 7 bp downstream of the -10 region, is involved in the stringent response of the rnpB promoter.

• Bulletin of the Korean Chemical Society
• /
• 제7권1호
• /
• pp.12-15
• /
• 1986

Lead tolerance of $Pt/Al_2O_3$ catalysts was evaluated for CO oxidation depending on the properties of the alumina supports and base metals added as promoter. Among the four different alumina supports, the support with a large macropore volume (0.45 cc/g) and 5% Ce has shown the best resistence to lead poisoning. Most of the base metals added to the Pt-catalysts were found to be ineffective for improving lead resistence, but boron has shown an excellent lead tolerence, although it decreases the initial catalytic activity.

• 생명과학회지
• /
• 제12권2호
• /
• pp.208-212
• /
• 2002

온도 기울기 전기영동장치를 이용하여 d(CXG)와 d(GXC) 염기의 열 안정성을 결정하는데 사람의 $\varepsilon$-글로빈 DNA조각을 사용하였다. 염기 쌍의 안정성은 이웃하는 염기서열에 의한 수소결합과 base stocking 상호작용에 의존한다. 염기 쌍의 안정성은 d(CXG) d(CYG)의 경우에 T.AG.A = A.G>C.T>T.C>C.A>A.C이다.

• 한국자기공명학회논문지
• /
• 제1권1호
• /
• pp.31-44
• /
• 1997

The effect of the binding of CRP to the symmetrically synthetic 22, 28, and 30 bp lac promoter was investigated by 1H NMR. The binding of cAMP*CRP to the 22 bp DNA did not bring about any changes in the chemical shift values, but did cause selective line broadening of imino proton resonances of specific base pairs. However, The binding of cAMP*CRP to the 28 and 30 bp DNA brought about large changes on the imino proton resonances that seems to be induced by DNA bending. We studied also the role of cAMP as an activator of DNA/CRP complex formation by gel mobility shift assay. Gel mobility shift assay revealed that the cAMP*CRP complex was not able to bind to the 22 bp DNA fragment, but was able to bind to the 28 bp DNA fragment of lac promoter region.