• Tuberculosis and Respiratory Diseases
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• 제48권6호
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• pp.879-886
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• 2000

연구배경: 폐특이 전사조절 유전자인 Thyroid Transcription Factor-1 (TTF-1)유전자는 폐에 선택적인 유전자의 표현의 조절에 중요한 전사인자로 작용하고 폐의 발생에서 morphogenic protein으로서 작용한다. 그러나 현재까지 이 TTF-1 유전자의 전사인자에 대한 연구는 거의 미미하다. DNase 1 hypersensitive(DH) regions은 활동적인 염색체에 대한 중요한 표식자이며 유전자를 조절하는 많은 DNA sequences와 밀접한 관계가 있다. 방법 : 추정적인 distal regulatory elements를 밝혀 내기 위해서 TTF-1을 표현하는 인간의 폐선암 세포주인 NCI-H441을 사용해 DNase 1 hypersensitive site assay를 이용하였다. 결과 : TTF-1 유전자에는 전사의 시작부위에서 +150, -450, -800, 그리고 -1500 base pair부위에 4곳의 DH sites가 있음을 할 수 있었다. 결론 : 이상의 결과로 전사 조절부위가 TTF-1 유전자 내에 그리고 5' prime부위에 위치함을 추정할 수 있었다.

• Molecules and Cells
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• 제40권8호
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• pp.577-586
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• 2017

Phytocystatins (PhyCYSs) are plant-specific proteinaceous inhibitors that are implicated in protein turnover and stress responses. Here, we characterized a PhyCYS from Arabidopsis thaliana, which was designated AtCYS5. RT-qPCR analysis showed that the expression of AtCYS5 in germinating seeds was induced by heat stress (HS) and exogenous abscisic acid (ABA) treatment. Analysis of the expression of the ${\beta}-glucuronidase$ reporter gene under the control of the AtCYS5 promoter showed that AtCYS5 expression during seed germination was induced by HS and ABA. Constitutive overexpression of AtCYS5 driven by the cauliflower mosaic virus 35S promoter led to enhanced HS tolerance in transgenic Arabidopsis, which was characterized by higher fresh weight and root length compared to wild-type (WT) and knockout (cys5) plants grown under HS conditions. The HS tolerance of AtCYS5-overexpressing transgenic plants was associated with increased insensitivity to exogenous ABA during both seed germination and post-germination compared to WT and cys5. Although no HS elements were identified in the 5'-flanking region of AtCYS5, canonical ABA-responsive elements (ABREs) were detected. AtCYS5 was upregulated in ABAtreated protoplasts transiently co-expressing this gene and genes encoding bZIP ABRE-binding factors (ABFs and AREB3). In the absence of ABA, ABF1 and ABF3 directly bound to the ABREs in the AtCYS5 promoter, which activated the transcription of this gene in the presence of ABA. These results suggest that an ABA-dependent pathway plays a positive role in the HS-responsive expression of AtCYS5 during seed germination and post-germination growth.

• Molecules and Cells
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• 제41권8호
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• pp.781-798
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• 2018

Plants have evolved strategies to cope with drought stress by maximizing physiological capacity and adjusting developmental processes such as flowering time. The WOX13 orthologous group is the most conserved among the clade of WOX homeodomain-containing proteins and is found to function in both drought stress and flower development. In this study, we isolated and characterized OsWOX13 from rice. OsWOX13 was regulated spatially in vegetative organs but temporally in flowers and seeds. Overexpression of OsWOX13 (OsWOX13-ov) in rice under the rab21 promoter resulted in drought resistance and early flowering by 7-10 days. Screening of gene expression profiles in mature leaf and panicles of OsWOX13-ov showed a broad spectrum of effects on biological processes, such as abiotic and biotic stresses, exerting a cross-talk between responses. Protein binding microarray and electrophoretic mobility shift assay analyses supported ATTGATTG as the putative cis-element binding of OsWOX13. OsDREB1A and OsDREB1F, drought stress response transcription factors, contain ATTGATTG motif(s) in their promoters and are preferentially expressed in OsWOX13-ov. In addition, Heading date 3a and OsMADS14, regulators in the flowering pathway and development, were enhanced in OsWOX13-ov. These results suggest that OsWOX13 mediates the stress response and early flowering and, thus, may be a regulator of genes involved in drought escape.

• 식물조직배양학회지
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• 제24권3호
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• pp.161-165
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• 1997

옥수수의 색소합성을 조절하는 pattern allele의 하나인 R-mb유전자의 구조와 유전적 분석을 수행하였다. R-mb 유전자의 유전분석을 수행한 결과를 검토하여 볼 때 후대로 진행됨에 따라 색소 발현빈도_의 감소경향을 보이고 있었다. 또한 R-mb 유전자가 몇 개의 R subcomplex로 존재하는가를 알기 위해서는 우선 R specific probe인 pR-nj:1를 이용하여 Southern blot hybridization을 실시한 결과 약 3.9kb 및 약 7.75kb영역에서 2개의 band가 관찰되었다. R-mb 유전자를 클로닝하기 위하여 λFIXIIvector를 이용하여 library를 만들고 이로부터 mb-II, III, V, Ⅵ, Ⅶ 등 5개의 clone을 3차의 screen을 거쳐 확보하고 이중 mb-II 및 mb-Ⅵ를 중심으로 제한효소지도를 작성하였으며, 이 유전자의 구조와 기타 R locus관련 유전자들과 비교하였으며, 이러한 두 개의 R 요소가 어떻게 색소발현에 영향을 미치는가에 대에 검토하였다.

• Molecules and Cells
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• 제42권2호
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• pp.123-134
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• 2019

Lysophosphatidic acid (LPA) is an endogenous lysophospholipid with signaling properties outside of the cell and it signals through specific G protein-coupled receptors, known as $LPA_{1-6}$. For one of its receptors, $LPA_1$ (gene name Lpar1), details on the cis-acting elements for transcriptional control have not been defined. Using 5'RACE analysis, we report the identification of an alternative transcription start site of mouse Lpar1 and characterize approximately 3,500 bp of non-coding flanking sequence 5' of mouse Lpar1 gene for promoter activity. Transient transfection of cells derived from mouse neocortical neuroblasts with constructs from the 5' regions of mouse Lpar1 gene revealed the region between -248 to +225 serving as the basal promoter for Lpar1. This region also lacks a TATA box. For the region between -761 to -248, a negative regulatory element affected the basal expression of Lpar1. This region has three E-box sequences and mutagenesis of these E-boxes, followed by transient expression, demonstrated that two of the E-boxes act as negative modulators of Lpar1. One of these E-box sequences bound the HeLa E-box binding protein (HEB), and modulation of HEB levels in the transfected cells regulated the transcription of the reporter gene. Based on our data, we propose that HEB may be required for a proper regulation of Lpar1 expression in the embryonic neocortical neuroblast cells and to affect its function in both normal brain development and disease settings.

• BMB Reports
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• 제52권6호
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• pp.403-408
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• 2019

Dorsoventral patterning of body axis in vertebrate embryo is tightly controlled by a complex regulatory network of transcription factors. Ventx1.1 is known as a transcriptional repressor to inhibit dorsal mesoderm formation and neural differentiation in Xenopus. In an attempt to identify, using chromatin immunoprecipitation (ChIP)-Seq, genome-wide binding pattern of Ventx1.1 in Xenopus gastrulae, we observed that Ventx1.1 associates with its own 5'-flanking sequence. In this study, we present evidence that Ventx1.1 binds a cis-acting Ventx1.1 response element (VRE) in its own promoter, leading to repression of its own transcription. Site-directed mutagenesis of the VRE in the Ventx1.1 promoter significantly abrogated this inhibitory autoregulation of Ventx1.1 transcription. Notably, Ventx1.1 and Xcad2, an activator of Ventx1.1 transcription, competitively co-occupied the VRE in the Ventx1.1 promoter. In support of this, mutation of the VRE down-regulated basal and Xcad2-induced levels of Ventx1.1 promoter activity. In addition, overexpression of Ventx1.1 prevented Xcad2 from binding to the Ventx1.1 promoter, and vice versa. Taken together, these results suggest that Ventx1.1 negatively regulates its own transcription in competition with Xcad2, thereby fine-tuning its own expression levels during dorsoventral patterning of Xenopus early embryo.

• Genomics & Informatics
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• 제20권2호
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• pp.19.1-19.15
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• 2022

Alfalfa (Medicago sativa) is an important food and feed crop which rich in mineral sources. The WUSCHEL-related homeobox (WOX) gene family plays important roles in plant development and identification of putative gene families, their structure, and potential functions is a primary step for not only understanding the genetic mechanisms behind various biological process but also for genetic improvement. A variety of computational tools, including MAFFT, HMMER, hidden Markov models, Pfam, SMART, MEGA, ProtTest, BLASTn, and BRAD, among others, were used. We identified 34 MsWOX genes based on a systematic analysis of the alfalfa plant genome spread in eight chromosomes. This is an expansion of the gene family which we attribute to observed chromosomal duplications. Sequence alignment analysis revealed 61 conserved proteins containing a homeodomain. Phylogenetic study sung reveal five evolutionary clades with 15 motif distributions. Gene structure analysis reveals various exon, intron, and untranslated structures which are consistent in genes from similar clades. Functional analysis prediction of promoter regions reveals various transcription binding sites containing key growth, development, and stress-responsive transcription factor families such as MYB, ERF, AP2, and NAC which are spread across the genes. Most of the genes are predicted to be in the nucleus. Also, there are duplication events in some genes which explain the expansion of the family. The present research provides a clue on the potential roles of MsWOX family genes that will be useful for further understanding their functional roles in alfalfa plants.

• Genomics & Informatics
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• 제20권4호
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• pp.45.1-45.7
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• 2022

Food security will be affected by climate change worldwide, particularly in the developing world, where the most important food products originate from plants. Plants are often exposed to environmental stresses that may affect their growth, development, yield, and food quality. Auxin is a hormone that plays a critical role in improving plants' tolerance of environmental conditions. Auxin controls the expression of many stress-responsive genes in plants by interacting with specific cis-regulatory elements called auxin-responsive elements (AuxREs). In this work, we performed an in silico prediction of AuxREs in promoters of five auxin-responsive genes in Zea mays. We applied a data fusion approach based on the combined use of Dempster-Shafer evidence theory and fuzzy sets. Auxin has a direct impact on cell membrane proteins. The short-term auxin response may be represented by the regulation of transmembrane gene expression. The detection of an AuxRE in the promoter of prolyl oligopeptidase (POP) in Z. mays and the 3-fold overexpression of this gene under auxin treatment for 30 min indicated the role of POP in maize auxin response. POP is regulated by auxin to perform stress adaptation. In addition, the detection of two AuxRE TGTCTC motifs in the upstream sequence of the bx1 gene suggests that bx1 can be regulated by auxin. Auxin may also be involved in the regulation of dehydration-responsive element-binding and some members of the protein kinase superfamily.

• Applied Biological Chemistry
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• 제38권1호
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• pp.55-62
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• 1995

한국 마늘 바이러스의 유전자 구조와 병 발생 메카니즘을 연구하기 위하여, 바이러스가 감염된 마늘잎으로부터 바이러스 입자를 분리하고 RNA를 추출하였다. 그 virus RNA를 이용하여 마늘 바이러스 cDNA 유전자 은행을 만들어 일부 clone의 염기 서열을 결정하였다. 여기에서 얻은 cDNA clones 중에서 poly(A) tail을 갖는 clone S81를 분리하고 873 bp의 전체 염기서열을 결정하였다. Clone S81의 염기서열을 다른 식물 바이러스와 비교한 결과 potexvirus의 껍질단백질 부분의 염기서열과 $30{\sim}40%$의 유사성을 보여주었다. Clone S81은 바이러스 RNA의 3' 말단 부위에 해당하고, 껍질단백질의 N-terminal 3개 아미노산이 빠진 open reading frame (ORF) 및 3'-noncoding region을 포함하고 있다. 3' 말단 부분에는 바이러스 복제과정에서 cis-acting element로 작용한다고 여겨지는 hexamer motif와 polyadenylation signal이 존재한다. 이 clone을 probe로 하여 Northern blot을 실시한 결과 genome의 크기는 7.5 knt라는 것을 알 수 있었고 clone S81은 potexvirus의 cDNA clone이라는 결론을 얻었다. 한국 마늘에서 이 바이러스의 분포 양상을 알아보기 위해 껍질단백질에 대한 항체를 만들었다. 먼저 발현벡터를 이용하여 대장균에서 대량으로 발현시키고 affinity chromatography로 껍질단백질을 정제하였다. 그 단백질을 토끼에 주사하여 껍질단백질에 대한 항체를 얻었다. 이 항체를 사용하여 다양한 지역에서 재배되는 마늘잎의 추출액에 대해 immunoblot을 실시하였다. 그 결과 분자량 29,000과 27,000 위치에서 signal을 보였다. 분자량 27,000 단백질이 29,000이 분해되어 생긴 산물인지 알아보기 위하여 그 추출액을 $37^{\circ}C$에서 시간을 달리하여 incubation한 후 immunoblotting하였다. 그 결과도 마찬가지로 같은 위치에서 signal을 보여줬다. 따라서 한국 마늘에는 재배되는 지역에 따라 다소 다르기는 하지만 대체로 두 종류의 potexvirus로 감염되어 있다고 추정된다.

• 생명과학회지
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• 제15권6호
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• pp.994-1004
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• 2005

Dihydrofolate reductase (dhfr) promoter에는 전사 인자 Spl과 E2F가 결합하는 cis-acting 배열을 가지고 있다. dhfr 유전자의 전사는 세포 주기 Gl/S기 동안 최대의 발현을 나타낸다. 또한 Spl 전사 인자는 dhfr 유전자 발현의 활성화 및 불활성화를 조절하는 다양한 역할에 대한 연구가보고 되고 있으며, 최근 Spl-Rb과 E2F4-pl30 복합체가 CHOC400 세포에서 dhfr 유전자 발현에 안정한 형태를 형성하여 dhfr 발현을 억제한다는 연구 결과가 보고되었다. 본 연구에서는 Rb-양성 골육종 세포인 U2OS 및 Rb음성인 자궁경부암 C33A 세포에서 histon deacetylase (HDAC)에 대한 특이적인 저해제인 trichostatn A (TSA)를 처리한 후 세포주기 조절에 중심적 인자들인 dhfr cyclin E 및 cyclin A의 전사활성에 대한 HDACl의 기능을 조사하였다. U2OS 및 C33A 세포에서 TSA를 처리한 후, dhfr, cyclin E, cyclin A에 대한 mRNA 및 단백질 발현을 조사한 결과 U2OS 세포 특이적으로 dhfr cyclin E의 mRNA 발현과 단백질 발현이 크게 증가하였지만, cyclin A의 발현은 감소하였다. U2OS 세포에서 dhfr promoter construct에 대한 전사활성을 검사한 결과, TSA 처리는 dhfr promoter 영역으로부터 E2F 결합부위를 제거시킨 DHFR-Spl-luc를 통하여 dhfr promoter활성이 약 14배 증가되었다, 그러나 dhfr promoter 영역으로부터 Spl 결합부위를 제거시킨 DHFR-E2F-luc 영역을 포함하고 있는 promoter 활성은 TSA 처리에 의해 크게 증가되지 않았다. 본 연구에서 이러한 결과는 HDACI이 Spl을 통하여 dhfr promoter활성을 제어한다는 사실을 입증하였다. 한편 TSA는 U2OS 세포에서 HDAC의 활성을 통해서 세포주기 관련 인자들 가운데서 Gl 후기부터 활성화되는 대표적인 인자들인 dhfr과 cyclin E의 발현을 증가시키지만 G2 기에서 활성화되는 대표적인 인자인 cyclin A의 발현을 억제하는 상반된 기능을 가지고 있다는 사실을 확인하였다.