• KSBB Journal
• /
• 제19권4호
• /
• pp.327-330
• /
• 2004

Inducible system을 이용하여 (R)-hydroxybutyric acid (R3HB)를 생산하는 재조합 대장균을 개발하였다. Ralstonia eutropha에서 유래한 PHB depolymerase 유전자를 inducible promoter에 의하여 발현되게 만들고, PHB 생합성 유전자가 있는 vector에 cloning하였다. PHB 생합성 유전자와 depolymerase 유전자를 가지고 있는 재조합 대장균을 배양하여 먼저 PHB를 축적시킨 후에 depolymerase를 발현시켜 배지 내로 분비된 R3HB를 확인하였다. 그 결과 축적된 PHB의 대부분은 발현된 depolymerase에 의하여 분해되었으며, depolymerase의 발현 이후에도 재조합 대장균은 PHB를 축적하고 분해하여 R3HB의 농도는 배양시간에 따라 증가하였다. 이러한 결과는 inducible depolymerase를 갖는 재조합 대장균을 이용하여 높은 농도의 R3IB를 얻을 수 있다는 것을 보여준다.

• Animal cells and systems
• /
• 제7권4호
• /
• pp.337-343
• /
• 2003

Methyl jasmonate (MeJA) is a signal molecule in the activation of defense responses in plants. In this study, we isolated 15 MeJA-inducible genes by subtractive hybridization. These genes encode two myrosinase-binding proteins, five lipase-like proteins, a polygalacturonase inhibitor, a putative chlorophyll-associated protein, a terpene synthase, a dehydroascorbate reductase, an ascorbate oxidase, a cysteine protease, an O-methyltransferase, and an epithiospecifier protein. Northern analysis showed that most of the Chinese cabbage genes are barely expressed in healthy leaves, but are strongly induced by MeJA treatment. We also examined whether these MeJA-inducible genes were activated by ethethon, BTH, and Pseudomonas syringae pv. tomato (Pst), a nonhost pathogen of Chinese cabbage. The results showed that none of the MeJA-inducible genes was strongly induced by ethephon or by BTH. The genes encoding lipase-like proteins and a myrosinase-binding protein were weakly induced by Pst. Other MeJA-inducible genes were not activated at all by the pathogen.

• 미생물학회지
• /
• 제29권6호
• /
• pp.392-396
• /
• 1991

Pseudomonas sp. DJ77의 chromosomal DNA로부터 6.9kb XhoI 절편 상에 존재하는 phenanthrene 분해에 관련된 유전자군을 vector pBLUESCRIPT SK(+)에 클로닝하였다. 이렇게 얻은 재조합 plasmid인 pHENX7을 가지고 있는 JM101 균주는 3-methylcarechol을 노란색의 meta-cleavage 화합물로 전환할 수 있었다. 그러나 삽입된 절편의 방향이 반대가 되도록 제조한 pHENX7은 extradiol dioxygenase 활성을 나타내지 않기 때문에 전사방향을 알 수 있었다. pHENX7과 이의 듀도체들을 지니는 JH101균주에서 PhnC(24kDa), PhnD(31KDa), PhnE(34kDa), PhnF(KDa)의 4 polypeptide를 확인 할 수 있었고 개개의 유전자의 위치와 범위를 알 수 있었다. 유전자 순서는 phnC-phnD-phnE-phnF-phnG이었으며, phnC, phnD, phnE, phnF, phnG는 각기 glutathione S-transferase, meta-cleavage compound hydrolase extradiol dioxygenase, meta-cleavage compound dehydrogenase의 유전자이었다.

• Nuclear Engineering and Technology
• /
• 제38권3호
• /
• pp.285-292
• /
• 2006

Thermoresistant (TR) clones of radiation-induced fibrosarcoma (RIF) cells have been reported to show an adaptive response to 1cGy of low dose radiation, and HSP25 and inducible HSP70 are involved in this process. In this study, to further elucidate the mechanism by which HSP25 and inducible HSP70 regulate the adaptive response, HSP25 or inducible HSP70 overexpressed RIF cells were irradiated with 1cGy and the cell cycle was analyzed. HSP25 or inducible HSP70 overexpressed cells together with TR cells showed increased G1 phase after 1cGy irradiation, while RIF cells did not. $[^3H]-Thymidine$ and BrdU incorporation also indicated that both HSP25 and inducible HSP70 are involved in G1 arrest after 1cGy irradiation. Molecular analysis revealed upregulation of p27Cip/Kip protein in HSP25 and inducible HSP70 overexpressed cells, and cotransfection of p27Cip/Kip antisense abolished the induction of the adaptive response and 1cGy-mediated G1 arrest. The above results indicate that induction of an adaptive response by HSP25 and inducible HSP70 is mediated by upregulation of p27Cip/Kip protein, resulting in low dose radiation-induced G1 arrest.

• Toxicological Research
• /
• 제19권1호
• /
• pp.33-37
• /
• 2003

Asiaticoside has been tested for the ability as an anti-inflammatory drug using lipopolysaccharide (LPS)-stimulated macrophage cell line (RAW 264.7 cell). LPS treatment induced dramatically inducible nitric oxide synthase (iNOS) in RAW cells. However, asiaticoside inhibited LPS-stimulated iNOS induction in a concentration-dependent manner. Especially, higher concentrations (＞50 $\mu\textrm{M}$) of asiaticoside completely blocked iNOS induction. In addition, LPS-stimulated expression of inducible cyclooxygenase (COX-2) and interleukin-1 $\alpha$ (IL-1 $\alpha$) was inhibited by asiaticoside treatment. Asiaticoside up to 50 $\mu\textrm{M}$ still required to inhibit COX-2 and IL-1 $\alpha$ induced by LPS. Consistent with these findings, treatment with asiaticoside suppressed do novo synthesis and cellular accumulation of prostaglandin $E_2$ to a lesser extent, suggesting that asiaticoside blocked the induction as well as the activity of COX-2 These results suggest the possibility that asiaticoside may be effective therapeutic agents for septic shock and other inflammatory diseases.

• 한국미생물·생명공학회지
• /
• 제49권3호
• /
• pp.449-457
• /
• 2021

The aim of the present study was to survey the frequency of inducible and constitutive phenotypes and inducible cross-resistant genes by regulating the methylation of 23S rRNA (ermA, ermB, and ermC) and macrolide efflux-related msrA gene in Staphylococcus aureus and S. epidermidis strains. A total of 172 bacterial isolates (identified based on standard tests), were examined in this study. Antibiotic susceptibility was determined by the disk diffusion method, and all isolates were evaluated with respect to inducible and constitutive phenotypes. The presence of ermA, ermB, ermC, and msrA genes was investigated by a PCR assay. The constitutive resistance phenotypes showed a higher distribution among the isolates. R phenotype was detected more among S. epidermidis isolates (46.25%). ermB, ermC, and msrA genes were detected more in methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. epidermidis (MRSE) isolates that had R and HD phenotypes (>77% strains). The ermA gene had the lowest frequency among MRSA, MRSE, MSSA, and MSSE strains (<14% isolates). Distribution of inducible resistance genes in MRSA and MRSE strains, and possibly other species, leads to increased constitutive resistance to erythromycin, clindamycin, and other similar antibiotics. Therefore, it can be challenging to treat infections caused by these resistant strains.

• Biomolecules & Therapeutics
• /
• 제1권2호
• /
• pp.177-182
• /
• 1993

From 84 clinical isolates of Staphylococcus species, ten strains showing inducible resistance to MLS antibiotics were selected by disk agar diffusion method. Colony hybridization was executed using two MLS inducible resistance genes, ermA and ermC, previously identified from S. aureus as probes. S. hemolyticus 401 and S. epidermidis 542 whose genes were not homologous to those probes were finally selected. It was determined that the resistance genes of S. hemolyticus 401 and S. epidermidis 542 were not homologous to ermA, ermC and ermAM by Southern hybridization. S. epidermidis 542 had a plasmid DNA. To know if the plasmid may have genes related to inducible resistance, it was attempted to transform B. subtilis BR151 and S. aureus RN4220 with the plasmid prepared from S. epidermidis 542. It was shown that the gene related to inducible resistance to MLS antibiotics did not exist in this plasmid. These results indicate that two clinical isolates of S. hemolyticus 401 and S. epidermidis 542 had novel genes which were not homologous to MLS resistance genes identified previously. It was assumed that these genes may exist in chromosomal DNA.

• 약학회지
• /
• 제38권3호
• /
• pp.293-299
• /
• 1994

Forty nine clinical isolates of S. aureus showing resistance to erythromycin(EM) were selected from 83 strains isolated recently in Korea. Fourteen strains of S. aureus showing inducible resistance to MLS antibiotics were selected by disc agar diffusion method. Colony hydridization was executed using two MLS inducible resistance genes, ermA and ermC, identified previously from S. aureus as probes. S. aureus 375 and S. aureus 507 whose genes were not homologous to those probes were finally selected. It was confirmed that the resistance genes of S. aureus 375 and S. aureus 507 had no homology with those probes in southern hybridization test using ermA, ermC and ermAM as probes. It was determined that S. aureus 375 had a plasmid whose size was about 35 kb. To know if the plasmid may have the genes related to inducible resistance to MLS antibiotics, it was attempted to transform Bacillus subtillis BR151 and S. aureus RN4220 with the plasmid isolated from S. aureus 375. It was shown that the gene related to inducible resistance to MLS antibiotics did not exist in this plasmid. These results indicate that two clinical isolates of S. aureus showing inducible resistance to MLS antibiotics have novel genes that have no homology with MLS resistance genes identified so far. It is assumed that these genes may exist in chromosomal DNA.

• Journal of Life Science
• /
• 제11권1호
• /
• pp.52-56
• /
• 2001

The present study intends to characterize the DNA damage-inducible responses in eukaryotic cells. The fission yeast, S. pombe, which displays efficient DNA repair systems, was used in this study as a model system for higher eukaryotes. To study UV-inducible responses in S. pombe, five UV-inducible cDNA clones were isolated from S. pombe by using subtration hybridization method. To investigate the expression of isolated genes, the cellular levels of the transcripts of these genes were determined by Northern blot analysis after UV-irradiation. The transcripts of isolated gene (UV130) increased rapidly and reached maximum accumulation after UV-irradiation. Compared to the message levels of control, the levels of maximal increase were approximately 5 fold to UV-irradiation. In order to investigation whether the increase of UV130 transcripts was a specific results of UV-irradiation, UV130 transcript levels were examined after treating the cells to Methylmethane sulfonate (MMS). The transcripts of UV130 were not induced by treatment of 0.25% MMS. These results implied that the effects of damaging agents are complex and different regulatory pathways exist for the induction of these genes. To characterize the structure of UV130 gene, nucleotide sequences were analyzed. The nucleotide sequence of 1,340 nucleotide excluding poly(A) tail contains one open reading frame, which encodes a protein of 270 amino acids. The predicted amino acid sequences of UV130 do not exhibit any significant similarity to ther known sequences in the database.

• 미생물학회지
• /
• 제30권5호
• /
• pp.347-354
• /
• 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.