• Title/Summary/Keyword: Cell Polarity

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The Transcription Factor Mist1 Regulates the Cellular Polarity in Mouse Pancreatic Acinar Cells

  • Yang, Yu-Mi;Lee, Syng-Ill;Shin, Dong-Min
    • International Journal of Oral Biology
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    • v.37 no.1
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    • pp.37-41
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    • 2012
  • Pancreatic acinar cells exhibit a polarity that is characterized by the localization of secretory granules at the apical membrane. However, the factors that regulate cellular polarity in these cells are not well understood. In this study, we investigated the effect of Mist1, a basic helix-loop-helix transcription factor, on the cellular architecture of pancreatic acinar cells. Mist1-null mice displayed secretory granules that were diffuse throughout the pancreatic acinar cells, from the apical to basolateral membranes, whereas Mist1 heterozygote mice showed apical localization of secretory granules. Deletion of the Mist1 gene decreased the expression of type 3 inositol 1,4,5-triphosphate receptors ($IP_3R$) but did not affect apical localization and expression of $IP_3R2$. Mist1-null mice also displayed an increase in luminal areas and an increase in the expression of zymogen granules in pancreatic acinar cells. These results suggest that Mist1 plays a critical role in polar localization of cellular organelles and in maintaining cellular architecture in mouse pancreatic acinar cells.

Evo-Devo of Leaf Shape Control with a Special Emphasis on Unifacial Leaves in Monocots

  • Yamaguchi, Takahiro;Tsukaya, Hirokazu
    • Korean Journal of Plant Taxonomy
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    • v.37 no.4
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    • pp.351-361
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    • 2007
  • In angiosperms, leaves typically develop as three-dimensional structure with dorsoventral, longitudinal, and lateral axes. We have shown that the control of two axes of leaves, longitudinal and lateral axis, can be genetically separable, and four classes of genes are responsible for the polar cell expansion and polar cell proliferation in Arabidopsis. In monocots, unifacial leaf, in which leaf surface consists only of abaxial identity, has been evolved in a number of divergent species. The unifacial leaves provide very unique opportunities for the developmental studies of the leaf axes formation in monocots, because their leaf polarities are highly disorganized. In addition, the mechanism of the parallel evolution of such drastic changes in leaf polarities is of interest from an evolutionary viewpoint. In this article, we describe our recent approaches to reveal the mechanism of unifacial leaf development and evolution, including recent advances in the leaf polarity specification in angiosperms.

A New Production mettled of GRM coefficients using k-map (K-map상의 셀을 이용한 새로운 GRM 상수 생성 기법)

  • Lee Chol-U;Che Wenzhe;Kim Heung-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.9C
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    • pp.860-870
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    • 2005
  • In this paper we propose a new method to derive GRM(Generalized Reed-Muller) coefacients for each $2^{n}$ polarities using cell of karnaugh map(k-map). Generally, there are the serial and parallel method to derive GRM coefficients. As a serial method, Green method generates GRM coefncients using transform matrix. And as a parallel method, Besslich algorithm produces GRM coefficients of each polarity using the generated anteriorly. Green's method generates GRM coefficients for n-variable by calculating transform matrix for one-variable and n-times kronecker product this matrix. And Besslich's method generates GRM coefficients of each polarity in order of Grey-code. But those methods have disadvantages that the number of variable exceeding four makes transform matrix large and there are so many operation steps. In this paper, GRM coefficients is generated by producing cell [$f_{i}$] minimizing variable on k-map and operating this cell [$f_{i}$] and transform matrix for one-variable. So, we can generate GRM coefficients of all polarities easily by using the proposed method.

Overexpression of ginseng patatin-related phospholipase pPLAIIIβ alters the polarity of cell growth and decreases lignin content in Arabidopsis

  • Jang, Jin Hoon;Lee, Ok Ran
    • Journal of Ginseng Research
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    • v.44 no.2
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    • pp.321-331
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    • 2020
  • Background: The patatin-related phospholipase AIII family (pPLAIIIs) genes alter cell elongation and cell wall composition in Arabidopsis and rice plant, suggesting diverse commercial purposes of the economically important medicinal ginseng plant. Herein, we show the functional characterization of a ginseng pPLAIII gene for the first time and discuss its potential applications. Methods: pPLAIIIs were identified from ginseng expressed sequence tag clones and further confirmed by search against ginseng database and polymerase chain reaction. A clone showing the highest homology with pPLAIIIβ was shown to be overexpressed in Arabidopsis using Agrobacterium. Quantitative polymerase chain reaction was performed to analyze ginseng pPLAIIIβ expression. Phenotypes were observed using a low-vacuum scanning electron microscope. Lignin was stained using phloroglucinol and quantified using acetyl bromide. Results: The PgpPLAIIIβ transcripts were observed in all organs of 2-year-old ginseng. Overexpression of ginseng pPLAIIIβ (PgpPLAIIIβ-OE) in Arabidopsis resulted in small and stunted plants. It shortened the trichomes and decreased trichome number, indicating defects in cell polarity. Furthermore, OE lines exhibited enlarged seeds with less number per silique. The YUCCA9 gene was downregulated in the OE lines, which is reported to be associated with lignification. Accordingly, lignin was stained less in the OE lines, and the expression of two transcription factors related to lignin biosynthesis was also decreased significantly. Conclusion: Overexpression of pPLAIIIβ retarded cell elongation in all the tested organs except seeds, which were longer and thicker than those of the controls. Shorter root length is related to auxinresponsive genes, and its stunted phenotype showed decreased lignin content.

Wdpcp, a Protein that Regulates Planar Cell Polarity, Interacts with Multi‐PDZ Domain Protein 1 (MUPP1) through a PDZ Interaction (Planar cell polarity 조절단백질 Wdpcp와 multi-PDZ domain protein 1 (MUPP1)의 PDZ 결합)

  • Jang, Won Hee;Jeong, Young Joo;Choi, Sun Hee;Yea, Sung Su;Lee, Won Hee;Kim, Mooseong;Kim, Sang-Jin;Urm, Sang-Hwa;Moon, Il Soo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.26 no.3
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    • pp.282-288
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    • 2016
  • Protein-protein interactions regulate the subcellular localization and function of receptors, enzymes, and cytoskeletal proteins. Proteins containing the postsynaptic density-95/disks large/zonula occludens-1 (PDZ) domain have potential to act as scaffolding proteins and play a pivotal role in various processes, such as synaptic plasticity, neural guidance, and development, as well as in the pathophysiology of many diseases. Multi-PDZ domain protein 1 (MUPP1), which has 13 PDZ domains, has a scaffolding function in the clustering of surface receptors, organization of signaling complexes, and coordination of cytoskeletal dynamics. However, the cellular function of MUPP1 has not been fully elucidated. In the present study, a yeast two-hybrid system was used to identify proteins that interacted with the N-terminal PDZ domain of MUPP1. The results revealed an interaction between MUPP1 and Wdpcp (formerly known as Fritz). Wdpcp was identified as a planar cell polarity (PCP) effector, which is known to have a role in collective cell migration and cilia formation. Wdpcp bound to the PDZ1 domain but not to other PDZ domains of MUPP1. The C-terminal end of Wdpcp was essential for the interaction with MUPP1 in the yeast two-hybrid assay. This interaction was further confirmed in a glutathione S-transferase (GST) pull-down assay. When coexpressed in HEK-293T cells, Wdpcp was coimmunoprecipitated with MUPP1. In addition, MUPP1 colocalized with Wdpcp at the same subcellular region in cells. Collectively, these results suggest that the MUPP1-Wdpcp interaction could modulate actin cytoskeleton dynamics and polarized cell migration.

STUDIES ON ANTICANCER EFFECTS OF EXTRACTS CAESALPINIA SAPPAN ON ORAL CARCINOMA AND OSTEOSARCOMA CELLS (소목 추출물의 구강암 및 골육종 세포주에 대한 항암작용에 관한 연구)

  • Lee, Jong-Su;Kim, Yeo-Gab;Kim, Jeong-Hee
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.27 no.4
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    • pp.281-288
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    • 2001
  • Anticancer effect of methanol extract of Caesalpinia sappan L. on oral carcinoma (KB) and osteosarcoma (HOS) cells were investigated in this study. In order to elucidate the anticancer mechanism of Caesalpinia sappan L, we analyzed telomerase inhibitory effect of the methanol extract of Caesalpinia sappan L. In addition we prepared 5 fraction samples according to its polarity differences and analyzed anticancer effects on oral carcinoma and osteosarcoma cells. Following results are obtained in this study. 1. 50% cell proliferation inhibitory value ($IC_{50}$) of the methanol extract of Caesalpinia sappan L. against oral carcinoma (KB) cells and osteosarcoma (HOS) cells were $9.0{\mu}g/ml$ and $10.9{\mu}g/ml$, respectively. 2. The methanol extract of Caesalpinia sappan L. showed inhibitory effect of telomerase which is required for cancer cell immortality. Therefore, it seems that the anticancer effect of methanol extract of Caesalpinia sappan is at least partially due to telomerase inhibitory effect. 3. Five fraction samples were prepared according to its polarity and 88.7% of ingredient of total methanol extract was transferred to ethylacetate fraction. Thin layer chromatography analysis showed that dichloromethane fraction contained ingredient with relatively high polarity and ethylacetate fraction contained similar ingredient found in total methanol extract. 4. Anticancer effect was observed in n-hexane, dichloromethane, and ethylacetate fractions. The highest anticancer effect was found in dichloromethane fraction which had $IC_{50}$ value of 4.4 and $>4.0{\mu}g/ml$ against oral carcinoma (KB) cells and osteosarcoma (HOS) cells, respectively.

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ANTICANCER EFFECTS OF CAESALPINIA SAPPAN EXTRACTS ON ORAL CARCINOMA AND OSTEOSARCOMA CELLS (소목 추출물의 구강암 및 골육종 세포주에 대한 항암작용에 관한 연구)

  • Lee, Jong-Su;Kim, Jeong-Hee;Kim, Yeo-Gab
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.33 no.6
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    • pp.583-590
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    • 2007
  • Anticancer effect of methanol extract of Caesalpinia sappan L. on oral carcinoma(KB) and osteosarcoma(HOS) cells were investigated in this study. In order to elucidate the anticancer mechanism of Caesalpinia sappan L, we analyzed telomerase inhibitory effect of the methanol extract of Caesalpinia sappan L. In addition, we prepared 5 fraction samples according to its polarity differences and analyzed anticancer effects on oral carcinoma and osteosarcoma cells. Following results are obtained in this study. 1. 50% cell proliferation inhibitory value($IC_{50}$) of the methanol extract of Caesalpinia sappan L. against oral carcinoma(KB) cells and osteosarco ma(HOS) cells were $9.0{\mu}g/ml\;and\;10.9{\mu}g/ml$, respectively. 2. The methanol extract of Caesalpinia sappan L. showed inhibitory effect of telomerase which is required for cancer cell immortality. Therefore, it seems that the anticancer effect of methanol extract of Caesalpinia sappan is at least partially due to telomerase inhibitory effect. 3. Five fraction samples were prepared according to its polarity and 88.7% of ingredient of total methanol extract was transferred to ethylacetate fraction. Thin layer chromatography analysis showed that dichloromethane fraction contained ingredient with relatively high polarity and ethylacetate fraction contained similar ingredient found in total methanol extract. 4. Anticancer effect was observed in n-hexane, dichloromethane, and ethylacetate fractions. The highest anticancer effect was found in dichloromethane fraction which had $IC_{50}$ value of $4.4{\mu}g/ml$ and > $4.0{\mu}g/ml$ against oral carcinoma(KB) cells and osteosarcoma(HOS) cells, respectively.

A Study on the Efficient GRM Constant Generation (효율적인 GRM 상수 생성에 관한 연구)

  • Park, Chun-Myoung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.652-653
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    • 2014
  • This paper present a method of GRM constant generation using cell [fi] which is generated over karnaugh map. The proposed method is as following. First od all, we select the arbitrary cell over karnaugh map. Next we arithmetic operate the selected cell with single variable transformation matrix, and mapping into karnaugh map its result. Although we discuss the new GRM generation method applied to polarity circulation.

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Solving the commutation problem of single-phase PWM AC-AC converter using basic switching cell (스위칭 셀을 이용하여 커뮤테이션 문제를 해결한 단상 PWM AC-AC 컨버터)

  • Shin, Hyunhak;Cha, Honnyong;Kim, Heung-Geun
    • Proceedings of the KIPE Conference
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    • 2013.07a
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    • pp.194-195
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    • 2013
  • This paper presents novel single-phase PWM AC-AC converters that can solve commutation problem in single-phase direct AC-AC converter without sensing input voltage polarity. By using the basic switching cell concept and coupled inductor, the proposed converter can be short and open-circuit without damping switching devices. A 120 W prototype is built and tested to verify performance of the proposed converter.

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Isolation and Characterization of Bud6p, an Actin Interacting Protein, from Yarrowia lipolytica

  • Yunkyoung Song;Cheon, Seon-Ah;Hwang, Ji-Sook;Kim, Jeong-Yoon
    • Journal of Microbiology
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    • v.41 no.2
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    • pp.121-128
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    • 2003
  • The identification of genes involved in true hypha formation is important in the study of mechanisms underlying the morphogenetic switch in yeast. We isolated a gene responsible for the morphogenetic switch in Yarrowia lipolytica, which forms true hyphae in response to serum or N-acetylglucosamine. The isolated gene, encoding 847 amino acids, had sequence identities of 27% and 25% with the Bud6 (Aip3) proteins of Saccharomyces cerevisiae and Schizosaccharomyces pombe, respectively. Disruption of this gene, designated YIBUD6, in haploid and diploid strains significantly reduced the ability of Y. lipolytica to switch from the yeast form to the hyphal form in hypha-inducing media. It was also found that YIBud6$\Delta$ mutants were rounder than the wild type when grown in the yeast form. These results indicate that the YIBud6 protein is necessary for hyphal growth and cell polarity in both haploid and diploid Y. lipolytica cells.