• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2002년도 춘계학술대회
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• pp.41-47
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these 'environmental or abiotic stresses', which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity. In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.

• Asian-Australasian Journal of Animal Sciences
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• 제25권6호
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• pp.758-763
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• 2012

As a member of a subclass of immunophilins, it is controversial that FKBP38 acts an upstream regulator of mTOR signaling pathway, which control the process of cell-growth, proliferation and differentiation. In order to explore the relationship between FKBP38 and mTOR in the Cashmere goat (Capra hircus) cells, a full-length cDNA was cloned (GenBank accession number JF714970) and expression pattern was analyzed. The cloned FKBP38 gene is 1,248 bp in length, containing an open reading frame (ORF) from nucleotide 13 to 1,248 which encodes 411 amino acids, and 12 nucleotides in front of the initiation codon. The full cDNA sequence shares 98% identity with cattle, 94% with horse and 90% with human. The putative amino acid sequence shows the higher homology which is 98%, 97% and 94%, correspondingly. The bioinformatics analysis showed that FKBP38 contained a FKBP_C domain, two TPR domains and a TM domain. Psite analysis suggested that the ORF encoding protein contained a leucine-zipper pattern and a Prenyl group binding site (CAAX box). Tissue-specific expression analysis was performed by semi-quantitative RT-PCR and showed that the FKBP38 expression was detected in all the tested tissues and the highest level of mRNA accumulation was detected in testis, suggesting that FKBP38 plays an important role in goat cells.

• BMB Reports
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• 제41권10호
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• pp.693-698
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• 2008

The full-length cDNA of LebZIP2 (Lycopersicon esculentum bZIP2) encodes a protein of 164 amino acids and contains a N-terminal basic-region leucine zipper domain. Analysis of the deduced tomato LebZIP2 amino acid sequence revealed that it shares 85% sequence identity with both tobacco bZIP and pepper CcbZIP. LebZIP2 mRNA is expressed at a high level exclusively in flowers. Presently, LebZIP2 was strongly increased also following NaCl and mannitol treatments. No significant LebZIP2 expression was evident following cold treatment. Transient LebZIP2 overexpression resulted in increased NbNOA1 and NbNR transcript levels in Nicotiana benthamiana leaves. Our results indicate that LebZIP2 might play roles as an abiotic stress-signaling pathway and as a transcriptional regulator of the NbNOA1 or NbNR genes.

• Molecules and Cells
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• 제38권5호
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• pp.416-425
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• 2015

NF-E2-related factor 2 (Nrf2), a basic leucine zipper transcription factor, has recently received a great deal of attention as an important molecule that enhances antioxidative defenses and induces resistance to chemotherapy or radiotherapy. In this study, we investigated the apoptosis-inducing and Nrf2- upregulating effects of quercetin on malignant mesothelioma (MM) MSTO-211H and H2452 cells. Quercetin treatment inhibited cell growth and led to upregulation of Nrf2 at both the mRNA and protein levels without altering the ubiquitination and extending the half-life of the Nrf2 protein. Following treatment with quercetin, analyses of the nuclear level of Nrf2, Nrf2 antioxidant response element-binding assay, Nrf2 promoter-luc assay, and RT-PCR toward the Nrf2-regulated gene, heme oxygenase-1, demonstrated that the induced Nrf2 is transcriptionally active. Knockdown of Nrf2 expression with siRNA enhanced cytotoxicity due to the induction of apoptosis, as evidenced by an increase in the level of proapoptotic Bax, a decrease in the level of antiapoptotic Bcl-2 with enhanced cleavage of caspase-3 and PARP proteins, the appearance of a sub-$G_0/G_1$ peak in the flow cytometric assay, and increased percentage of apoptotic propensities in the annexin V binding assay. Effective reversal of apoptosis was observed following pretreatment with the pan-caspase inhibitor Z-VAD. Moreover, Nrf2 knockdown exhibited increased sensitivity to the anticancer drug, cisplatin, presumably by potentiating the oxidative stress induced by cisplatin. Collectively, our data demonstrate the importance of Nrf2 in cytoprotection, survival, and drug resistance with implications for the potential significance of targeting Nrf2 as a promising strategy for overcoming resistance to chemotherapeutics in MM.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2016년도 춘계학술대회 및 임시총회
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• pp.27-27
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• 2016

The ascomycete fungus Fusarium graminearum is the most common pathogen of Fusarium head blight (FHB), a devastating disease for major cereal crops worldwide. FHB causes significant crop losses by reducing grain yield and quality as well as contaminating cereals with trichothecenes and zearalenone (ZEA) that pose a serious threat to animal health and food safety. ZEA is a causative agent of hyperestrogenic syndrome in mammals and can result in reproductive disorders in farm animals. In F. graminearum, the ZEA biosynthetic cluster is composed of four genes, PKS4, PKS13, ZEB1, and ZEB2, which encode a reducing polyketide synthase, a nonreducing polyketide synthase, an isoamyl alcohol oxidase, and a transcription factor, respectively. Although it is known that ZEB2 primarily acts as a regulator of ZEA biosynthetic cluster genes, the mechanism underlying this regulation remains undetermined. In this study, two isoforms (ZEB2L and ZEB2S) from the ZEB2 gene in F. graminearum were characterized. It was revealed that ZEB2L contains a basic leucine zipper (bZIP) DNA-binding domain at the N-terminus, whereas ZEB2S is an N-terminally truncated form of ZEB2L that lacks the bZIP domain. Interestingly, ZEA triggered the induction of both ZEB2L and ZEB2S transcription. In ZEA producing condition, the expression of ZEB2S transcripts via alternative promoter usage was directly or indirectly initiated by ZEA. Physical interaction between ZEB2L and ZEB2L as well as between ZEB2L and ZEB2S was observed in the nucleus. The ZEB2S-ZEB2S interaction was detected in both the cytosol and the nucleus. ZEB2L-ZEB2L oligomers activated ZEA biosynthetic cluster genes, including ZEB2L. ZEB2S inhibited ZEB2L transcription by forming ZEB2L-ZEB2S heterodimers, which reduced the DNA-binding activity of ZEB2L. This study provides insight into the autoregulation of ZEB2 expression by alternative promoter usage and a feedback loop during ZEA production.

• 생명과학회지
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• 제22권9호
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• pp.1201-1206
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• 2012

Crlz1 유전자는 B 세포 분화 과정 중 pre-B 세포 분화 단계에서 특이적으로 발현됨이 밝혀져 있다. Crlz1 유전자의 발현과 연관되는 3개의 DNase I hypersensitive site (HSS8, 9, 10)가 Crlz1 유전자의 전사 시작점으로부터 바로 위쪽의 chromatin 상에서 발견되었고, 그 중에서 HSS9/10은 Crlz1 promoter 지역에 해당하며 매우 높은 전사 활성을 가지는 것으로 이미 보고 되었다. 본 연구에서는 앞의 연구에서 더 나아가 HSS8이 Crlz1 promoter의 전사활성을 약 2 배 증가시키는 enhancer의 역할을 하고 있는 현상을 밝혔으며, 또한 HSS8의 위치가 Crlz1 유전자의 전사 시작점을 기준으로 하였을 때 -1055와 -1159 사이, 즉 104 bp 길이의 chromatin DNA 상에 존재하며, 이러한 HSS8의 위치는 luciferase reporter의 활성 측정으로 비교 분석되어진 deletion construct들의 전사 활성에 대한 결과와도 잘 부합되었다.

• 생명과학회지
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• 제15권6호
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• pp.928-934
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• 2005

ATF2는 c-Fos와 c-Jun과 같은 전사인자이며 이들은 루신지퍼 단백질이다. 루신지퍼 단백질은 동형이합체 혹은 이형이합체를 형성하며 promoter 영역에 결합하여 전사조절에 중요한 역할을 한다. 세포의 전사인자 ATF2는 ATF/CRE site에 결합하며 특히 선택적인 interfamily 이형이량체를 형성함으로써 전사 조절에 있어서 다양한 메카니즘을 제공할 수 있다. 본 연구에서는 ATF2 cDNA를 6xHis를 가진 expression vector에 subcloning하여 E.cnli BL2l에서 발현시켰다. 6xHis tag은 nickel-chelating chromatography를 가능하게 하였다 발현된 ATF2는 In vitro binding pull-down assay에서 동형이합체를 이를 뿐만 아니라 AP-1 그룹의 인자들과 선택적인 이형이합체를 형성함을 보여 주었다. BATF와는 강하게 결합하였으며 c-Jun과도 안정된 이합체를 형성하였다. 그러나 c-Fos와는 이합체를 형성하지 않으므로서 AP-1그룹 내에서도 이합체 형성이 선택적으로 이루어짐을 알 수 있다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.33-33
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• 2022

Rice (Oryza sativa L.) is a widely studied domesticated model plant. Seed awning is an unfavorable trait during rice harvesting and processing. Hence, awn was one of the target characters selected during domestication. However, the genetic mechanisms underlying awn development in rice are not well understood. In this study, we analyzed the genes for awn development using a mapping population derived from a cross between the Korean indica cultivar 'Milyang23' and NIL4/9 (derived from a cross between 'Hwaseong' and O. minuta). Two quantitative trait loci (QTLs), qAwn4 and qAwn9 were mapped on chromosome 4 and 9, respectively, increased awn length in an additive manner. Through comparative sequencing analyses parental lines, LABA1 was determined as the causal gene underlying qAwn4. qAwn9 was mapped to a 199-kb physical region between markers RM24663 and RM24679. Within this interval, 27 annotated genes were identified, and five genes, including a basic leucine zipper transcription factor 76 (OsbZIP76), were considered candidate genes for qAwn9 based on their functional annotations and sequence variations. Haplotype analysis using the candidate genes revealed tropical japonica specific sequence variants in the qAwn9 region, which partly explains the non-detection of qAwn9 in previous studies that used progenies from interspecific crosses. This provides further evidence that OsbZIP76 is possibly a causal gene for qAwn9. The O. minuta qAwn9 allele was identified as a major QTL associated with awn development in rice, providing an important molecular target for basic genetic research and domestication studies. Our results lay the foundation for further cloning of the awn gene underlying qAwn9.

• 생명과학회지
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• 제17권7호통권87호
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• pp.889-895
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• 2007

KIF5는 2분자의 kinesin heavy chain (KHC)과 2분자의 kinesin light cham (KLC)으로 구성되며 미세소관과 직접 결합한다. KIF5는 여러가지 세포 내 소기관을 이동시키나 KIF5가 이동시키는 운반체가 어떻게 특이적으로 결합하는지는 아직 밝혀지지 못하였다. 본 연구에서 효모 two-hybrid system을 사용하여 KLC1의 tetratricopeptide repeats (TRP) 부위와 결합하는 세포 내의 단백질을 분리하였다. 결과 KLC1와 특이적으로 결합하는JNK/stress-activated protein kinase-associated protein 1 (JSAP1/JIP3)을 분리하였다. 이러한 결합은 KLC1의 TRP1, 2 영역과 JSAP1의 leucine zipper 영역이 결합에 관여하며, 또한 효모 two-hybrid assay에서 JSAP1은 KLC2와 결합하지만 신경세포에서 발현하는 KIF5A, KIF5C 그리고 모든 세포에서 발현하는 KIF5B와는 결합하지 않았다. 단백질간의 결합을 pull-down assay로 확인한 결과 KLC1은 glutathione S-transferase (GST)와는 결합하지 않으나 GST결한 JSAP1과는 결합하였다. 또한 생쥐의 뇌 파쇄 액으로부터 JSAP1 항체로 면역침강을 행한 결과 KLC1은 JSAP1과 같이 침강하였다. 이러한 결과들은 KLC1은 JSAP1과 결합하며, JSAP1은 KLC1의 수용체로세포 내 KIF5의 수송의 매개 단백질로 작용함을 시사한다.

• 생명과학회지
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• 제26권9호
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• pp.991-998
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• 2016

NF-κB는 anti-apoptotic gene을 유도하는 전사인자로서 대부분의 세포의 생존에 필요하다. 그러나 NF-κB가 많은 종류의 암세포에서 지속적으로 과다 활성화됨이 알려지면서 NF-κB의 활성억제가 암의 예방과 치료에 유효하다는 점이 알려지게 되었다. 한편, Hsp70가 NF-κB의 활성을 조절한다는 사실이 알려지면서 Hsp70를 이용한 암예방과 치료가 주목받게 되었으나 아직 Hsp70에 의한 NF-κB의 활성조절기전은 명확하지 않다. 본 연구에서는 Hsp70에 의한 NF-κB의 활성조절과정에서 IKK complex의 구성성분인 IKKγ의 역할을 검토하였다. IKKγ의 wild type과 deletion mutants를 이용하여 Hsp70와 관련된 NF-κB의 활성조절을 연구한 결과 Hsp70는 NF-κB의 활성화를 억제하였으며, 이러한 억제효과는 IKKγ가 과발현되었을 때 더욱 증가하였다. 또한 IKKγ의 N-말단의 IKKβ 결합부위와 C-말단의 Leucine zipper 및 Zinc finger부위는 Hsp70와 연관된 NF-κB억제작용에 필요하지 않는 것으로 나타났으며, Hsp70와 IKKγ에 의한 NF-κB의 활성억제는 IκBα의 인산화와 분해를 저해함에 의해 일어나는 것으로 나타났다. 또한 RAW264.7 macrophage세포에서 LPS에 의한 COX-2의 발현유도는 Hsp70와 IKKγ가 동시에 발현 되었을 때 가장 효과적으로 억제되었다. 이상의 결과로부터 Hsp70에 의한 NF-κB의 활성억제작용은 IKKγ에 의해 상승됨을 알 수 있었으며, Hsp70와 IKKγ를 적절히 이용하면 NF-κB의 과다활성에 의해 발생하는 각종 질병의 예방과 치료에 도움을 줄 수 있을 것으로 기대된다.