• Title/Summary/Keyword: 3′-End formation

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Sequential Polyadenylation to Enable Alternative mRNA 3' End Formation

  • Yajing Hao;Ting Cai;Chang Liu;Xuan Zhang;Xiang-Dong Fu
    • Molecules and Cells
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    • v.46 no.1
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    • pp.57-64
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    • 2023
  • In eukaryotic cells, a key RNA processing step to generate mature mRNA is the coupled reaction for cleavage and polyadenylation (CPA) at the 3' end of individual transcripts. Many transcripts are alternatively polyadenylated (APA) to produce mRNAs with different 3' ends that may either alter protein coding sequence (CDS-APA) or create different lengths of 3'UTR (tandem-APA). As the CPA reaction is intimately associated with transcriptional termination, it has been widely assumed that APA is regulated cotranscriptionally. Isoforms terminated at different regions may have distinct RNA stability under different conditions, thus altering the ratio of APA isoforms. Such differential impacts on different isoforms have been considered as post-transcriptional APA, but strictly speaking, this can only be considered "apparent" APA, as the choice is not made during the CPA reaction. Interestingly, a recent study reveals sequential APA as a new mechanism for post-transcriptional APA. This minireview will focus on this new mechanism to provide insights into various documented regulatory paradigms.

Screening of Herbal Medicines from China with Inhibitory Activity on Advanced Glycation End Products Formation (XIII) (중국 약용식물의 최종당화산물 생성저해활성 검색(XIII))

  • Choi, So Jin;Kim, Young Sook;Kim, Joo Hwan;Hang, Sun;Kim, Jin Sook
    • Korean Journal of Pharmacognosy
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    • v.46 no.3
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    • pp.260-267
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    • 2015
  • Advanced glycation end products (AGEs) have been postulated to play a central role in the development of diabetic complications. A variety of different agents that inhibit AGEs have been under investigation. In this study, 111 herbal medicines from China have been investigated with an in vitro evaluation system using AGEs formation inhibitory activity. Of these, 9 herbal medicines (IC50: <5 μg/ml) were found to have significant AGEs formation inhibitory activity. Particularly, herbal medicines Barleria cristata (leaves), Calotropis gigantea (stems), Ardisia virens (leaves), Dalbergia yunnanensis (leaves) Pittosporum runcatum (leaves), Ardisia japonica (leaves), Rhododendron racemosum (twigs), Oxyria sinensiss (aerial parts), Pyrrosia calvata (whole plants), showed more potent inhibitory activity (approximately 15-40 fold) than the positive control aminoguanidine (IC50: 76.47 μg/ml).

Screening of Herbal Medicines from Vietnam with Inhibitory Activity on Advanced Glycation End Products Formation (XIV) (베트남 약용식물의 최종당화산물 생성저해활성 검색(XIV))

  • Choi, So Jin;Kim, Young Sook;Kim, Joo Hwan;Bach, Tran The;Kim, Jin Sook
    • Korean Journal of Pharmacognosy
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    • v.46 no.3
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    • pp.268-278
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    • 2015
  • In this study, 80 herbal medicines from Vietnam have been investigated with an in vitro evaluation system using advanced glycation end products (AGEs) formation inhibitory activity. Of these, 10 herbal medicines (IC50: <5 μg/ml) were found to have significant AGEs formation inhibitory activity. Particularly, herbal medicines Strobilanthes pateriformis (aerial parts), Rhodamnia dumetorum (twigs), Glochidion rubrum (twigs), Dipterocarpus obtusifolius (twigs), Bombax ceiba (twigs), Amesiodendron chinense (twigs), Bauhinia coccinea (twigs), Lithocarpus laouanensis (twigs), Bauhinia bracteata (twigs) and Connarus paniculatus (twigs), showed more potent inhibitory activity (approximately 16-31 fold) than the positive control aminoguanidine (IC50: 76.47 μg/ml).

Screening of Herbal Medicines from China with Inhibitory Activity on Advanced Glycation End Products (AGEs) Formation (X) (중국 약용식물의 최종당화산물 생성저해활성 검색 (X))

  • Kim, Young Sook;Lee, Yun Mi;Kim, Joo Hwan;Kim, Jin Sook
    • Korean Journal of Pharmacognosy
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    • v.44 no.3
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    • pp.305-311
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    • 2013
  • Advanced glycation end products (AGEs) have been postulated to play a central role in the development of diabetic complications. A variety of different agents that inhibit AGEs have been under investigation. In this study, 54 herbal medicines from China have been investigated with an in vitro evaluation system using AGEs formation inhibitory activity. Of these, 6 herbal medicines ($IC_{50}&lt;5{\mu}g/ml$) were found to have significant AGEs formation inhibitory activity. Particularly, herbal medicines Punica granatum (peels), Terminalia chebula (fruits), Rheum palmatum (roots), Oxyria digyna (stems and leaves), Anisodus luridus (roots) and Quercus schottkyana(stems and leaves) showed more potent inhibitory activity (approximately 9-43 fold) than the positive control aminoguanidine ($IC_{50}=77.04{\mu}g/ml$).

Screening of Herbal Medicines from Korea with Inhibitory Activity on Advanced Glycation End Products Formation (XII) (한국 약용식물의 최종당화산물 생성저해활성 검색(XII))

  • Choi, So Jin;Kim, Young Sook;Kim, Joo Hwan;Kim, Jin Sook
    • Korean Journal of Pharmacognosy
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    • v.46 no.3
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    • pp.250-259
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    • 2015
  • Advanced glycation end products (AGEs) have been implicated in diabetic complications. In this study, the inhibitory effect on AGEs formation of 156 Korean herbal medicines has been evaluated. Among them, 15 Korean herbal medicines were showed to have significant effect (IC50: <10 μg/ml) compared to positive reference, aminoguandine (IC50: 76.47±4.81 μg/ml). Especially, four herbal medicines, Alnus firma (leaves, IC50: 3.25±0.10 μg/ml), Juncus decipiens (whole plants, IC50: 4.30±0.44 μg/ml), Smilax china (stems, IC50: 3.55±0.21 μg/ml), and Vicia amoena (Aerial parts, IC50: 4.25±0.06 μg/ml) showed more potent inhibitory activity approximately 8-24 fold) than the positive control aminoguanidine.

Pulp Bleaching Effect and Ionization Rate of Chlorine Dioxide by Additives and Various pH Conditions(I)-Ionization of ClO$_2$ and Formation of Chlorate in Pulp Bleaching- (pH와 첨가제에 의한 이산화염소의 분해율 및 펄프표백 효과(1)-표백 중에서 이산화염소의 분해와 Chlorate의 생성-)

  • ;Li Jun Wang
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.30 no.3
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    • pp.1-6
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    • 1998
  • Elementally Chlorine Free (ECF) bleaching will be superior than Totally Chlorine free (TCF) bleaching, not only because they have no significant difference in effluent toxicity, but also those pulps bleached by ECF have higher brightness, strength, yield, etc., over those by TCF. With this belief, this paper focused on the chemistry of chlorine dioxide decomposition and ionization, both in water solution and in pulp slurry. Special attention was paid to chlorate ion because there have been controversies as how it is formed and what its behavior to the end pH of pulp bleaching is. As a result, during ionization of chlorine dioxide with water, both chlorate and chlorite were found to increase with increasing pH, but during ionization with pulp, chlorite was found to increase with end pH while chlorate decreased with increasing end pH. In the case of ionization with water, the disproportion equation $2CIO_2 + OH^{-} \lightarrow H_2O + CIO_3^{-} + CIO_2^{-}$ was thought to become the main reaction with the increasing pH, while in the case of ionization with pulp, the reaction $HCIO + CIO_2^{-}\lightarow H^{+} + Cl^{-} + CIO_3^{-}$ was the main reaction contributing to the formation of chlorate. Based on this above opinion, the contrary results of chlorine dioxide ionization from different researchers were discussed and explained.

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Fluid Dynamics near end-to-end Anastomoses Part III in Vitro wall Shear Stress Measurement

  • Kim, Y.H.
    • Journal of Biomedical Engineering Research
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    • v.13 no.3
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    • pp.253-262
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    • 1992
  • The wall shear stress in the vicinity of end-to end anastomoses under steady flow condi- tions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experi- mental measurements were in good agreement lith numerical results except In flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compli- ance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia (ANFH) in end-to-end anastomoses.

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Screening of Korean Herbal Medicines with Inhibitory Activity on Advanced Glycation End Products (AGEs) Formation (II) (한국약용식물의 최종당화산물 생성저해활성 검색 (II))

  • Lee, Yun-Mi;Kim, Young-Sook;Kim, Jong-Min;Jang, Dae-Sik;Kim, Joo-Hwan;Yoo, Jeong-Lim;Kim, Jin-Sook
    • Korean Journal of Pharmacognosy
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    • v.39 no.3
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    • pp.223-227
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    • 2008
  • Advanced glycation end products (AGEs) contribute to the progression of micro and macrovsacular complication of diabetes and therefore present a promising target for therapeutic agents. In this study, 40 Korean herbal medicines have been investigated with an in vitro evaluation system using AGEs inhibitory activity. Of these, 21 herbal medicines $(IC_{50}<50{\mu}g/ml)$ exhibited an inhibitory activity against AGEs formation compared with anminoguanidine $(IC_{50}=72.12{\mu}g/ml)$. Particularly, 7 herbal medicines, Actinidia arguta (root and stem), Crataegus pinnatifida (twig), Camellia japonica (whole), Kalopanax pictus (bark), Lagerstroemia indica (leaf-stem), Reynoutria sachalinensis (root) showed more potent inhibitory activity (approximately 3-10 fold) than the positive control aminoguanidine.

Annual Ring Formation of Major Wood Species Growing in Chuncheon, Korea(I) - The Period of Cambium Activity - (춘천지역에서 생장하는 주요 수종의 연륜형성(I) - 형성층 활동기간에 관하여 -)

  • Kwon, Sung Min;Kim, Nam Hun
    • Journal of the Korean Wood Science and Technology
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    • v.33 no.4 s.132
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    • pp.1-8
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    • 2005
  • The initiation and cessation of cambial activities were investigated to find out the growth characteristics of the major species growing in Chuncheon, Korea. The division of cambial zone in Pinus densiflora and Pinus koraiensis began from the middle of March through the end of March. The activity of cambial zone in P. densiflora and P. koraiensis was vigorous from the end of May through the middle of July. During this period the number of cells increased rapidly in radial direction. However, the number of cells in P. densiflora was gradually increased. The division of cambial zone in ring-porous wood, such as Quercus mongolica and Robinia pseudoacacia began in the middle of March, before the formation of vessel. The division of cambial zone in diffuse-porous wood, such as Cornus controversa and Prunus sargentii, began in early April, and then the formation of vessels began after one to three weeks. It was considered that the cambial zone in softwood was ceased from the beginning of November, whereas cambial activities in hardwood ceased in the middle of October. Consequently, the formation of growth ring was different among the species, even though the trees were grown under the same conditions.

Constituents of the seeds of Cornus officinalis with Inhibitory Activity on the Formation of Advanced Glycation End Products (AGEs) (산수유 씨의 최종당화산물 생성저해활성 성분)

  • Lee, Ga-Young;Jang, Dae-Sik;Lee, Yun-Mi;Kim, Young-Sook;Kim, Jin-Sook
    • Applied Biological Chemistry
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    • v.51 no.4
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    • pp.316-320
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    • 2008
  • Ten compounds, (+)-pinoresinol (1), (-)-balanophonin (2), gallicin (3), vanillin (4), 4-hydroxybenzaldehyde (5), coniferaldehyde (6), betulinic acid (7), ursolic acid (8), 5-hydroxymethyl furfural (9), and malic acid (10), were isolated from a EtOAc-soluble fraction of the seeds of Cornus officinalis. The structures of these compounds were elucidated by spectroscopic methods as well as by comparison with reported values. Compounds 1, 2, and 4-7 were isolated from this species for the first time. All the isolates (1-10) were subjected to an in vitro bioassay to evaluate their inhibitory activity against advanced glycation end products (AGEs) formation. Among these, compounds 2 and 3 showed the significant inhibitory activity on AGEs formation with $IC_{50}$ values of 27.81 and 18.04${\mu}M$, respectively.