• 제목/요약/키워드: Regulatory Sequences

검색결과 125건 처리시간 0.037초

Regulatory Sequences in the 5' Flanking Region of Goat β-Casein Gene

  • Huang, Mu-Chiou;Chao, Jiunn-Shiuan
    • Asian-Australasian Journal of Animal Sciences
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    • 제14권11호
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    • pp.1628-1633
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    • 2001
  • A goat ${\beta}$-casein gene was cloned and sequenced. Our previous study had determined the nucleotide sequences of the 5' flanking region and the structural gene including all 9 exons. In the present study, investigations were done on the regulatory sequences in the 5' flanking region of the goat ${\beta}$-casein gene by aligning and comparing it with the same gene from other mammals. The results showed that -200/-1 bp of the 5' flanking sequences contained six conserved clusters, in which the sites of gene expression regulated by the transcription factor and hormone might exist. It showed that fourteen glucocorticoid receptor elements, two cAMP responsive elements, two SV40 virus enhancer core sequences, two OCT-1 binding elements and one CTF/NF-1 binding element were dispersed in the 5' flanking region of goat ${\beta}$-casein gene. Our findings are perhaps valuable for the elucidation of the molecular mechanisms that control the expression of the goat ${\beta}$-casein gene.

Selection of Putative Iron-responsive Elements by Iron Regulatory Protein-2

  • Kim, Hae-Yeong
    • Journal of Applied Biological Chemistry
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    • 제42권2호
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    • pp.62-65
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    • 1999
  • Iron regulatory proteins (IRPs) 1 and 2 bind with equally high affinity to specific RNA stem-loop sequences known as iron-responsive elements (IRE) which mediate the post-transcriptional regulation of many genes of iron metabolism. To study putative IRE-like sequences in RNA transcripts using the IRP-IRE interaction, Eight known genes from database were selected and the RNA binding activity of IRE-like sequences were compared to IRP-2. Among them, the IRE-like sequence in 3'-untranslational region (UTR) of divalent ration transporter-1 (DCT-1) shows a significant RNA binding affinity. This finding predicts that IRE consensus sequence present within 3'-UTR of DCT-1 might confer the regulation by IRP-2.

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Accelerated Evolution of the Regulatory Sequences of Brain Development in the Human Genome

  • Lee, Kang Seon;Bang, Hyoeun;Choi, Jung Kyoon;Kim, Kwoneel
    • Molecules and Cells
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    • 제43권4호
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    • pp.331-339
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    • 2020
  • Genetic modifications in noncoding regulatory regions are likely critical to human evolution. Human-accelerated noncoding elements are highly conserved noncoding regions among vertebrates but have large differences across humans, which implies human-specific regulatory potential. In this study, we found that human-accelerated noncoding elements were frequently coupled with DNase I hypersensitive sites (DHSs), together with monomethylated and trimethylated histone H3 lysine 4, which are active regulatory markers. This coupling was particularly pronounced in fetal brains relative to adult brains, non-brain fetal tissues, and embryonic stem cells. However, fetal brain DHSs were also specifically enriched in deeply conserved sequences, implying coexistence of universal maintenance and human-specific fitness in human brain development. We assessed whether this coexisting pattern was a general one by quantitatively measuring evolutionary rates of DHSs. As a result, fetal brain DHSs showed a mixed but distinct signature of regional conservation and outlier point acceleration as compared to other DHSs. This finding suggests that brain developmental sequences are selectively constrained in general, whereas specific nucleotides are under positive selection or constraint relaxation simultaneously. Hence, we hypothesize that human- or primate-specific changes to universally conserved regulatory codes of brain development may drive the accelerated, and most likely adaptive, evolution of the regulatory network of the human brain.

대두 원형질체와 형질전환된 담배에서의 대두 glycinin 유전자 Gy2 promoter의 발현조절 기작 (Analysis of the Glycinin Gy2 Promoter Activity in Soybean Protoplasts and Transgenic Tobacco Plants)

  • 김수정;이지영;김정호;최양도
    • Applied Biological Chemistry
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    • 제38권5호
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    • pp.387-392
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    • 1995
  • 대두 glycinin 유전자의 조직 특이적이고 분화 발달 특이적인 발현 조절 메카니즘을 연구하기 위하여 Gy2 유전자의 5' upstream 부위 염기서열을 조사한 결과, glycinin 유전자의 발현을 조절하는 인자로 여겨지는 여러 가지 조절 인자들을 발견하였다. 진핵세포 유전자에 공통적으로 존재하는 TATA box와 AGGA box가 존재하고, 종자 저장 단백질에서 공통적으로 발견되는 embryo factor binding sequence, RY repeat CACA sequence, ${\beta}$-conglycinin enhancer 와 유사한 sequence 등이 발견되었다. 이러한 조절 요소들이 Gy2 유전자의 발현 조절에 미치는 영향을 알아보기 위해 Gy2유전자의 5' upstream부위를 Exo III nuclease와 여러가지 제한효소를 이용하여 일련의 deletion mutants를 제조한 후 GUS 유전자와 결합시켰다. 이들 여러가지 chimeric constructs를 대두 원형질체에 전입하고 원형질체로부터 추출물을 분리하여 GUS 활성을 조사한 결과, $-28l{\sim}-223$ 혹은 $-l70{\sim}-122$ 부위를 포함하였을 경우 활성이 감소하였고, $-223{\sim}-170$ 혹은 $-l22{\sim}-16$ 부위를 포함하였을 경우 활성이 높게 나타났다. 이러한 Gy2 유전자의 이중적인 발현 양상은 glycinin 유전자의 발현조절에 음성 조절 요소와 양성 조절 요소가 관여하고있다는 사실을 제시해 주고 있다. 또한 이들 여러가지 chimeric constructs로 형질 전환된 담배의 종자와 잎에서 GUS활성을 조사한 결과, CaMV promoter를 포함하는 chimeric construct는 종자와 잎에서 모두 활성을 나타냈으나, Gy2 Promoter를 포함하는 chimeric constructs는 종자에서만 GUS 활성을 나타내고 잎에서는 활성이 나타나지 않는 조직 특이적인 발현 양상을 나타내었다.

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Regulatory Viral and Cellular Elements Required for Potato Virus X Replication

  • Kim, Kook-Hyung
    • The Plant Pathology Journal
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    • 제17권3호
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    • pp.115-122
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    • 2001
  • Potato virus X (PVX) is a flexuous rod-shaped virus containing a single plus-strand RNA. Viral RNA synthesis is precisely regulated by regulatory viral sequences and by viral and/or host proteins. RNA sequence element as well as stable RNA stem-loop structure in the 5' end of the genome affect accumulation of genomic RNA and subgenomic RNA (sgRNA). The putative sgRNA promoter regions upstream of the PVX triple gene block (TB) and coat protein (CP) gene were critical for both TB and CP sgRNA accumulation. Mutations that disrupted complementarity between a region at the 5' end of the genomic RNA and the sequences located upstream of each sgRNA initiation site is important for PVX RNA accumulation. Compensatory mutations that restore complementarity restored sgRNA accumulation levels. However, the extent of reductions in RNA levels did not directly correlate with the degree of complementarity, suggesting that the sequences of these elements are also important. Gel-retardation assays showed that the 5' end of the positive-strand RNA formed an RNA-protein complex with cellular proteins, suggesting possible involvement of cellular proteins for PVX replication. Future studies on cellular protein binding to the PVX RNA and their role in virus replication will bring a fresh understanding of PVX RNA replication.

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Production of Human Serum Albumin in Chloroplast-Transformed Tobacco Plants

  • Ko, Suk-Min;Kim, Hyun-Chul;Yoo, Byung-Ho;Woo, Je-Wook;Chung, Hwa-Jee;Choi, Dong-Woog;Liu, Jang-R.
    • Journal of Plant Biotechnology
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    • 제33권4호
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    • pp.233-236
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    • 2006
  • Human serum albumin (HSA) is the most abundant protein in plasma and is the most often used intravenous protein in many human therapies. However, HSA is currently extracted only from plasma because commercially feasible recombinant expression systems are not available. This study attempted to develop an efficient system for recombinant HSA production by chloroplast transformation of tobacco. A HSA cDNA was isolated from a cDNA library constructed with human liver tissue. Chloroplast transformation vectors were constructed by introducing various regulatory elements to HSA regulatory sequences. Vectors were delivered by particle bombardment into leaf explants and chloroplast-transformed plants were subsequently regenerated into whole plants. Southern blot analysis confirmed that the HSA cDNA was incorporated between rps12 and orf70B of the chloroplast genome as designed. Western blot analysis revealed that hyper-expression and increasing the stability of HSA were achieved by modification of the regulatory sequences using the psbA5'UTRs in combination with elements of the 14 N-terminal amino acids of the GFP and the FLAG tag. However, only plants transformed with the vector containing all of these elements were able to accumulate HSA.

TALENs Construction: Slowly but Surely

  • Hegazy, Wael Abdel Halim;Youns, Mahmoud
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권7호
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    • pp.3329-3334
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    • 2016
  • Cancer is thought to be a direct result of transcriptional misregulation. Broad analysis of transcriptional regulatory elements in healthy and cancer cells is needed to understand cancer development. Nucleases regulatory domains are recruited to bind and manipulate a specific genomic locus with high efficacy and specificity. TALENs (transcription activator-like effector nuclease) fused to endonuclease FokI have been used widely to target specific sequences to edit several genes in healthy and cancer cells. This approach is promising to target specific cancer genes and for this purpose it is needed to pack such TALENs into viral vectors. There are some considerations which control the success of this approach, targeting appropriate sequences with efficient construction of TALENs being crucial factors. We face some obstacles in construction of TALENs; in this study we made a modification to the method of Cermk et al 2011 and added one step to make it easier and increase the availability of constructs.

Calibrating Thresholds to Improve the Detection Accuracy of Putative Transcription Factor Binding Sites

  • Kim, Young-Jin;Ryu, Gil-Mi;Park, Chan;Kim, Kyu-Won;Oh, Berm-Seok;Kim, Young-Youl;Gu, Man-Bok
    • Genomics & Informatics
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    • 제5권4호
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    • pp.143-151
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    • 2007
  • To understand the mechanism of transcriptional regulation, it is essential to detect promoters and regulatory elements. Various kinds of methods have been introduced to improve the prediction accuracy of regulatory elements. Since there are few experimentally validated regulatory elements, previous studies have used criteria based solely on the level of scores over background sequences. However, selecting the detection criteria for different prediction methods is not feasible. Here, we studied the calibration of thresholds to improve regulatory element prediction. We predicted a regulatory element using MATCH, which is a powerful tool for transcription factor binding site (TFBS) detection. To increase the prediction accuracy, we used a regulatory potential (RP) score measuring the similarity of patterns in alignments to those in known regulatory regions. Next, we calibrated the thresholds to find relevant scores, increasing the true positives while decreasing possible false positives. By applying various thresholds, we compared predicted regulatory elements with validated regulatory elements from the Open Regulatory Annotation (ORegAnno) database. The predicted regulators by the selected threshold were validated through enrichment analysis of muscle-specific gene sets from the Tissue-Specific Transcripts and Genes (T-STAG) database. We found 14 known muscle-specific regulators with a less than a 5% false discovery rate (FDR) in a single TFBS analysis, as well as known transcription factor combinations in our combinatorial TFBS analysis.