• Mycobiology
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• 제42권1호
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• pp.52-58
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• 2014

A nucleoside diphosphate-linked moiety X (Nudix) hydrolase-like gene, YSA1, has been identified as one of the gromwell plant extract-responsive genes in Cryptococcus neoformans. Ysa1 is known to control intracellular concentrations of ADP-ribose or O-acetyl-ADP-ribose, and has diverse biological functions, including the response to oxidative stress in the ascomycete yeast, Saccharomyces cerevisiae. In this study, we characterized the role of YSA1 in the stress response and adaptation of the basidiomycete yeast, C. neoformans. We constructed three independent deletion mutants for YSA1, and analyzed their mutant phenotypes. We found that ysa1 mutants did not show increased sensitivity to reactive oxygen species-producing oxidative damage agents, such as hydrogen peroxide and menadione, but exhibited increased sensitivity to diamide, which is a thiol-specific oxidant. Ysa1 was dispensable for the response to most environmental stresses, such as genotoxic, osmotic, and endoplasmic reticulum stress. In conclusion, modulation of YSA1 may regulate the cellular response and adaptation of C. neoformans to certain oxidative stresses and contribute to the evolution of antifungal drug resistance.

• Molecular & Cellular Toxicology
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• 제1권3호
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• pp.164-171
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• 2005

Toxicological studies have an object of detecting adverse effects of a chemical on an organism based on observed toxicity marker (i.e., serum biochemical markers and chemical-specific gene expression) or phenotypic outcome. To date, most toxicogenomic studies concentrated on hepatic toxicity. cDNA microarray analysis enable discrimination of the responses in animals exposed to different classes of hepatotoxicants. In an effort to further characterize the mechanisms of 2, 3, 7, 8,-Tetrachlorodibenzo-p-dioxin (TCDD or dioxin)-mediated toxicity, comprehensive temporal-responsive microarray analyses were performed on hepatic tissue from Sprague-Dawley rats treated with TCDD. Hepatic gene expression profiles were monitored using custom DNA chip containing 490 cDNA clones related with toxicology. Gene expression analysis identified 26 features which exhibited a significant change. In this study, we observed that the genes related with oxidative stress in rats exposed to Dioxin, such as CYPIIA3 and glutathione S-transferase, were up-regulated at 24hr after exposure. In this study, we carried out to discover novel evidence for previously unknown gene expression patterns related to mechanism of hepatic toxicity in rats exposed to dioxin, and to elucidate the effects of dioxin on the gene expression after exposure to dioxin.

• Molecules and Cells
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• 제25권2호
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• pp.258-264
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• 2008

Deschampsia antarctica is the only monocot that thrives in the tough conditions of the Antarctic region. It is an invaluable resource for the identification of genes associated with tolerance to various environmental pressures. In order to identify genes that are differentially regulated between greenhouse-grown and Antarctic field-grown plants, we initiated a detailed gene expression analysis. Antarctic plants were collected and greenhouse plants served as controls. Two different cDNA libraries were constructed with these plants. A total of 2,112 cDNA clones was sequenced and grouped into 1,199 unigene clusters consisting of 243 consensus and 956 singleton sequences. Using similarity searches against several public databases, we constructed a functional classification of the ESTs into categories such as genes related to responses to stimuli, as well as photosynthesis and metabolism. Real-time PCR analysis of various stress responsive genes revealed different patterns of regulation in the different environments, suggesting that these genes are involved in responses to specific environmental factors.

• Journal of Plant Biotechnology
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• 제46권3호
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• pp.180-188
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• 2019

옥신은 식물의 생장과 발달 과정에서 중요한 조절자로서 기능한다. 옥신 신호전달 과정은 3개의 주요 옥신 반응 전사인자인 Auxin/indole-3-acetic acid (Aux/IAA), Gretchen Hagen 3 (GH3), 그리고 small auxin up RNA (SAUR) 유전자에 의해 조절된다. 특히, Aux/IAA는 옥신 신호에 반응하여 빠르게 축적되는 수명이 짧은 핵 단백질이다. 이 실험에서 우리는 현사시 나무(Populus alba ${\times}$ P. glandulosa)로 부터 PagAux/IAA1 유전자를 분리하고 발현 특성을 분석하였다. PagAux/IAA1 cDNA는 4개의 보존된 도메인과 2개의 nuclear localization sequence (NLS)을 포함한 200개의 아미노산을 암호화하고 있다. Southern blot 분석으로 현사시나무 genome에 PagAux/IAA1 유전자가 single copy로 존재하는 것을 확인하였다. PagAux/IAA1 유전자는 잎과 꽃에서 특이적으로 발현되었다. 그리고 PagAux/IAA1 유전자는 현탁배양세포의 생장 과정에서 초기 지수생장기에 발현되었다. PagAux/IAA1 유전자의 발현을 분석한 결과, 건조와 염 스트레스 및 식물호르몬인 ABA 처리에 의해 발현이 감소된 반면 저온 스트레스, 형성층의 세포 분열 과정 그리고 식물호르몬인 GA와 JA 처리에서 발현이 증가하였다. 따라서 PagAux/IAA1 유전자가 현사시나무에서 저온 스트레스 반응뿐 아니라 생장 과정에 관여할 것으로 판단된다.

• Molecules and Cells
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• 제37권1호
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• pp.43-50
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• 2014

Jumonji domain-containing proteins (JMJD) catalyze the oxidative demethylation of a methylated lysine residue of histones by using $O_2$, ${\alpha}$-ketoglutarate, vitamin C, and Fe(II). Several JMJDs are induced by hypoxic stress to compensate their presumed reduction in catalytic activity under hypoxia. In this study, we showed that an H3K27me3 specific histone demethylase, JMJD3 was induced by hypoxia-inducible factor (HIF)-$1{\alpha}/{\beta}$ under hypoxia and that treatment with Clioquinol, a HIF-$1{\alpha}$ activator, increased JMJD3 expression even under normoxia. Chromatin immunoprecipitation (ChIP) analyses showed that both HIF-$1{\alpha}$ and its dimerization partner HIF-$1{\beta}$/Arnt occupied the first intron region of the mouse JMJD3 gene, whereas the HIF-$1{\alpha}/{\beta}$ heterodimer bound to the upstream region of the human JMJD3, indicating that human and mouse JMJD3 have hypoxia-responsive regulatory regions in different locations. This study shows that both mouse and human JMJD3 are induced by HIF-1.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1995년도 Proceedings of special lectures on Molecular Biological Approaches to Plant Disease National Agricultural Science and Technology Institute Suwon, Korea
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• pp.55-75
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• 1995

Induction of HMG-Co A reductase (HMGR) is essential for the biosynthesis of sesquiterpenoid phytoalexins and steroid derivatives in Solanaceous plants following wounding and pathogen infection. To better understand this complex step in stress-responsive isoprenoid synthesis, three classes of cDNAs for HMGR (hmg1, hmg2, and hmg3) were isolated from a potato tuber library. The potato cDNAs had extensive homology in open reading frames but had low homology in the 3'-untranslated regions. RNA gel blot analysis using gene-specific probes revealed that hmg1 is induced by wounding but wound induction is strongly suppressed by arachidonic acid or by inoculation with Phytophthora infestants. In contrast, hmg2 and hmg3 are slightly induced by wounding and strongly enhanced by arachidonic acid or inoculation. The induction and suppression of HMGR genes parallel the suppression of steroid and stimulation of sesquiterpenoid accumulations observed in earlier investigations. Treatment of the tuber disks with a low concentration of methyl-jasmonate doubled the wound induced accumulation of hmg1 transcripts and steroid-glycoalkaloid accumulation, but did not affect the abundance of transcripts for hmg2 or hmg3 nor induce phytoalexins. High concentration of methyl-jasmonate suppressed hmg1 mRNA and steroid-glycoalkaloid accumulation, induced hmg3 mRNA, and did not elicit phytoalexins. Lipoxygenase inhibitors suppressed the accumulation of of hmg1 transcripts and steroid-glycoalkaloids, which were restored by exogeneous methyl-jasmonate. Methyl-jasmonate applied together with arachidonic acid enhanced the elicitor induced accumulation of sesquiterpenes and sustained steroid-glycoalkaloid levels with transcript levels for the various HMGR mRNAs equal to or greater than wound-only treatment. These results domonstrate that the consequences of wound- and pathogen-responses of plants are different at the levels of gene expression and associated secondary metabolism.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1998년도 한국생물과학협회 학술발표대회
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• pp.113-113
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• 1998

In Saccharomyces cerevisiae UV irradiation and a variety of chemical DNA -damaging agents induce the transcription of specific genes, including several involved in DNA repair. One of the best characterized of DNA -damage inducible genes is PHRI, which encodes the apoenzyme for DNA photolyase. Basal-level and damage-induced expression of PHRI require an upstream activation sequence, UASPHRI. Here we report the identification of the UlvIE6 gene of S. cerevisiae as a regulator of UASPHRl activity. Surprisingly, the effect of deletion of UME6 is growth phase dependent. In wild-type cells PHRI is induced in late exponential phase, concomitant with the initiation of glycogen accumulation that precedes the diauxic shift. Deletion of UNIE6 abolishes this induction, decreases the steady-state concentration of photolyase molecules and PHRI mRNA, and increases the UV sensitivity of a rad2 mutant. The results suggest that UM E6 contributes to the regulated expression of a subset of damage-responsive genes in yeast. Furthermore, the upstream repression sequence, URSPHRI, is required for repression and damage-induced expression of PHRl. Here we show identification of YER169W and YDR096W as putative regulators acting through $URS_{PHRI}$. These open reading frames were designated as RPHI (YERl69W) and RPH2 (YDR096W) indicating regulator of PHRI. Simultaneous disruption of both genes showed a synergistic effect, producing a four-fold increase in basal level expression and a similar decrease m the induction ratio following treatment of methyl methanesulfonate(MMS). Mutation of the sequence ($AG_4$) bound by Rphlp rendered the promoter of PHRI insensitive to changes in RPHI or RPH2 status. The data suggest that RPHI and RPH2 act as damage-responsive negative regulators of PHRI. Surprisingly, the sequence bound by Rphlp in vitro is found to be $AG_4$ which is identical to the consensus binding site for the regulators Msn2p and Msn4p involved in stress-induced expression. Deletion of MSN2 and MSN4 has little effect on the induction$.$ ratio following DNA damage. However, all deletions led to a significant decrease in basal-level and induced expression of PHRI. These results imply that MSN2 and MSN4 are positive regulators of P HRI but are not required for DNA damage repression. [Supported by grant from NIH]om NIH]

• 생명과학회지
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• 제26권2호
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• pp.265-274
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• 2016

Toxin-antitoxin (TA) system은 박테리아와 고세균에서 진화적으로 보존되어 흔히 발견되는 유전적 모듈이다. 기본적으로 이 시스템은 세포 내 toxin과 그들의 억제자로 작용하는 antitoxin으로 구성되어있으며, 현재 총 다섯가지 유형으로 구분된다. 공통적으로 toxin은 스트레스 조건에서 활성화됨으로써 세포 내 다양한 과정을 억제하는 활성을 가지는데 이는 결과적으로 세포 사멸 혹은 가역적인 생장 저해를 일으킨다. Toxin의 이러한 효과들은 유전자 발현의 조절, 성장 조절, programmed cell arrest, programmed cell death, persister cell의 형성, 박테리오파지 방어기작, 가동성 유전인자의 안정화, 플라스미드 유지 기작 등 다양한 생리학적 역할을 나타낸다. 그러므로 TA system은 일반적인 스트레스 반응모듈로서 여겨진다. 하지만 이를 역이용한다면 TA system으로부터 toxin을 활성화 시키는 인자를 개발하여 새로운 항균 물질로 이용할 수 있다. 그뿐만 아니라 TA system은 toxin의 세포 사멸 효과를 이용하여 원하는 타겟 유전자가 존재하는 세포만 선택적으로 살아남도록 하는 효율적인 클로닝 전략에 이용될 수 있다. 또한, toxin의 서열 특이적 리보핵산 가수분해효소 활성을 이용하여 타겟 단백질 이외의 단백질 합성을 막아 효과적인 단일 단백질 대량 생산을 위해서도 이용할 수 있다. 더 나아가 일부 TA system의 toxin은 진핵 세포에서도 세포 독성을 나타내기 때문에 암세포, 바이러스 감염 세포에서 toxin의 발현을 유도하여 세포사멸을 일으킴으로써 인간의 질병 치료로 이어질 수 있다.

• 대한소아치과학회지
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• 제30권2호
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• pp.308-319
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• 2003

기능력은 뼈의 형성, 유지 및 개조 이외에도 치아이동, 교정치료, 기능성 악교정장치의 사용 등과 관련한 치주인대세포의 특성 변화 등에 중요한 영향을 미친다. 또한, 하악과두에서도 기능력의 변화에 따라서 다양한 특성의 변화가 나타난다. 본 연구에서는 ICR 생쥐를 8주 동안 soft-diet와 hard-diet의 식이 조절을 통해 기능력의 변화를 유도하여, 기능력의 변화와 관련한 특이 유전자를 검출하기 위하여 subtractive hybridization, northern 분석 및 mRNA in-situ hybidization 등의 실험을 시행하여 다음과 같은 결과를 얻었다. 1. Soft-diet군과 hard-diet군의 subtractive hybridization을 통하여 총 39개의 clone을 얻었고 이중에서 11개의 서로 다른 hard-diet군 특이 후보 유전자들을 분리하였다. 2. 11개의 후보 유전자들 중에서 homology 검색과 northern 분석을 통하여 기능력과 관련이 있을 것으로 생각되거나 hard-diet군에서 mRNA가 선택적으로 발현되는 FS-s2, FS-s5, FS-s18 및 Fs-s22 유전자를 선택하였다. 3. Soft-diet군과 hard-diet군의 형태학적 분석에서 soft-diet군은 hard-diet군에 비하여 골모세포의 활성과 골개조의 특성은 저하된 것으로 관찰되었으나, 하악과두의 연골성골화 과정은 오랜 시간동안 지속되는 것으로 나타났다. 4. FS-s2, FS-s5, FS-s18 및 Fs-s22 유전자의 cRNA 탐침자를 이용한 in-situ hybridization에서 4개의 유전자의 mRNA들은 hard-diet군의 세포들에서는 강하게 발현되었으나 soft-diet군의 세포들에서는 그 발현이 미약하거나 나타나지 않았다. 이상의 결과를 종합하여 FS-s2, FS-s5, FS-s18 및 Fs-s22 유전자들은 대부분이 기능이 거의 알려져 있지 않는 것들로 기능력의 변화 과정에서 중요한 역할을 할 것으로 생각되나 앞으로 보완 연구를 통하여 각 각의 유전자들의 보다 정확한 기능을 이해하는 것이 필요 할 것으로 사료된다.