• Title/Summary/Keyword: Cellular transport

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Efficient scalable method of H.264 video coding for network transport (네트워크 전송을 위한 H.264 비디오의 효율적인 계층화 방법)

  • Hwang, Jeong-Taek;Park, Seung-Ho;Suh, Doug-Young
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.192-194
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    • 2005
  • Acceptance of the international standards for video compression, such as H.261, MPEG-1 and MPEG-2, along with the developments in video codec hardware, has created an explosion of application. Among these, the long time quest for long-distance digital video transmission causes an increasing interest in transporting compressed video over networks which are nontraditional for this purpose, including asynchronous transfer mode networks, the Internet, and cellular and wireless channels. Transmission of compression video over packet network is improved for error resilience. And layered video coding techniques improves error resilience. We present a efficient method of scalable video coding for low bandwidth.

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Interaction of a Kinesin Superfamily Protein 1A (KIF1A) with Calmodulin

  • Seog, Dae-Hyun
    • Journal of Life Science
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    • v.12 no.2
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    • pp.43-46
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    • 2002
  • Kinesin Superfamily Protein 1A (KIF1A) is an anterograde monomeric motor transporting a subset of synaptic vesicle precursors and plays an important role in neuronal function and survival. Here, f have used the yeast two-hybrid system to identify the proteins that interacts with the tail region of KIF1A. Calmodulin was found to interact specifically with the tail region of KIF1A. Calmodulin regulates many diverse cellular functions by modulating the activity of the proteins that interact with it. KIF1A interacts with calmodulin in the yeast two-hybrid assay, which is proved by immunoprecipitation with calmodulin in brain fraction. These results indicate that KIF1A is associated with calmodulin, suggesting that calmodulin may be a key role in the regulation of anterograde transport of synaptic 1 vesicle precursors.

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Imaging Single-mRNA Localization and Translation in Live Neurons

  • Lee, Byung Hun;Bae, Seong-Woo;Shim, Jaeyoun Jay;Park, Sung Young;Park, Hye Yoon
    • Molecules and Cells
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    • v.39 no.12
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    • pp.841-846
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    • 2016
  • Local protein synthesis mediates precise spatio-temporal regulation of gene expression for neuronal functions such as long-term plasticity, axon guidance and regeneration. To reveal the underlying mechanisms of local translation, it is crucial to understand mRNA transport, localization and translation in live neurons. Among various techniques for mRNA analysis, fluorescence microscopy has been widely used as the most direct method to study localization of mRNA. Live-cell imaging of single RNA molecules is particularly advantageous to dissect the highly heterogeneous and dynamic nature of messenger ribonucleoprotein (mRNP) complexes in neurons. Here, we review recent advances in the study of mRNA localization and translation in live neurons using novel techniques for single-RNA imaging.

Differential gene expression by chrysotile in human bronchial epithelial cells

  • Seo, Yoo-Na;Lee, Yong-Jin;Lee, Mi-Young
    • Animal cells and systems
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    • v.16 no.2
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    • pp.95-103
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    • 2012
  • Asbestos exposure has been known to contribute to several lung diseases named asbestosis, malignant mesothelioma and lung cancer, but the disease-related molecular and cellular mechanisms are still largely unknown. To examine the effects of asbestos exposure in human bronchial epithelial cells at gene level, the global gene expression profile was analyzed following chrysotile treatment. The microarray results revealed differential gene expression in response to chrysotile treatment. The genes up- and down-regulated by chrysotile were mainly involved in processes including metabolism, signal transduction, transport, development, transcription, immune response, and other functions. The differential gene expression profiles could provide clues that might be used to understand the pathological mechanisms and therapeutic targets involved in chrysotile-related diseases.

The AP-3 Clathrin-associated Complex Is Essential for Embryonic and Larval Development in Caenorhabditis elegans

  • Shim, Jaegal;Lee, Junho
    • Molecules and Cells
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    • v.19 no.3
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    • pp.452-457
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    • 2005
  • The adaptor protein (AP) complexes are involved in membrane transport of many proteins. There are 3 AP complexes in C. elegans unlike mammals that have four. To study the biological functions of the AP-3 complexes of C. elegans, we sought homologues of the mouse and human genes that encode subunits of the AP-3 complexes by screening C. elegans genomic and EST sequences. We identified single copies of homologues of the ${\mu}3$, ${\sigma}3$, ${\beta}3$ and ${\delta}$ genes. The medium chain of AP-3 is encoded by a single gene in C. elegans but two different genes in mammals. Since there are no known mutations in these genes in C. elegans, we performed RNAi to assess their functions in development. RNAi of each of the genes caused embryonic and larval lethal phenotypes. APM-3 is expressed in most cells, particularly strongly in spermatheca and vulva. We conclude that the products of the C. elegans ${\mu}3$, ${\sigma}3$, ${\beta}3$ and d genes are essential for embryogenesis and larval development.

Is Acetylation a Metabolic Rheostat that Regulates Skeletal Muscle Insulin Action?

  • LaBarge, Samuel;Migdal, Christopher;Schenk, Simon
    • Molecules and Cells
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    • v.38 no.4
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    • pp.297-303
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    • 2015
  • Skeletal muscle insulin resistance, which increases the risk for developing various metabolic diseases, including type 2 diabetes, is a common metabolic disorder in obesity and aging. If potential treatments are to be developed to treat insulin resistance, then it is important to fully understand insulin signaling and glucose metabolism. While recent large-scale "omics" studies have revealed the acetylome to be comparable in size to the phosphorylome, the acetylation of insulin signaling proteins and its functional relevance to insulin-stimulated glucose transport and glucose metabolism is not fully understood. In this Mini Review we discuss the acetylation status of proteins involved in the insulin signaling pathway and review their potential effect on, and relevance to, insulin action in skeletal muscle.

Flavonoids: An Emerging Lead in the P-glycoprotein Inhibition

  • Gadhe, Changdev G.;Cho, Seung Joo
    • Journal of Integrative Natural Science
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    • v.5 no.2
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    • pp.72-78
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    • 2012
  • Multidrug resistance is a major obstacle in cancer chemotherapy. Cancer cells efflux chemotherapeutic drug out of cell by means of transporter and reduce the active concentration of it inside cell. Such transporters are member of the ATP binding cassettes (ABC) protein. It includes P-gp, multiple resistant protein (MRP), and breast cancer resistant protein (BCRP). These proteins are widely distributed in the human cells such as kidney, lung, endothelial cells of blood brain barrier etc. However, there are number of drugs developed for it, but most of them are getting transported by it. So, still there is necessity of a good modulator, which could effectively combat the transport of chemotherapeutic agents. Natural products origin modulators were found to be effective against transporter such as flavonoids, which belongs to third generation modulators. They have advantage over synthetic inhibitor in the sense that they have simple structure and abundant in nature. This review focuses on the P-gp structure its architecture, efflux mechanism, herbal inhibitors and their mechanism of action.

ESCRT, autophagy, and frontotemporal dementia

  • Lee, Jin-A;Gao, Fen-Biao
    • BMB Reports
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    • v.41 no.12
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    • pp.827-832
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    • 2008
  • Many age-dependent neurodegenerative diseases are associated with the accumulation of abnormally folded proteins within neurons. One of the major proteolytic pathways in the cell is the autophagy pathway, which targets cytoplasmic contents and organelles to the lysosomes for bulk degradation under various physiological and stressful conditions. Although the importance of autophagy in cellular physiology is well appreciated, its precise roles in neurodegeneration remain largely unclear. Recent studies indicate that components of the endosomal sorting complex required for transport (ESCRT) are important in the autophagy pathway. Reduced activity of some ESCRT subunits leads to the accumulation of autophagosomes and failure to clear intracellular protein aggregates. Interestingly, rare mutations in CHMP2B, an ESCRT-III subunit, are associated with frontotemporal dementia linked to chromosome 3 (FTD3). Mutant CHMP2B proteins seem to disrupt the fusion of autophagosomes and lysosomes in cell culture models. These findings suggest a potential mechanism for the pathogenesis of FTD3 and possibly other neurodegenerative diseases as well.

Effects of Hydrocarbon Addition on Cellular Instabilities in Expanding Syngas-Air Spherical Premixed Flames (합성가스와 공기를 혼합한 예혼합화염의 셀 불안정성에 있어서 탄화수소 계 연료첨가에 대한 효과)

  • Vu, Tran Manh;Song, Won-Sik;Park, Jeong;Kwon, Oh-Boong;Bae, Dae-Seok;Yun, Jin-Han;Keel, Sang-In
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.2
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    • pp.179-188
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    • 2011
  • Experiments were conducted in a constant-pressure combustion chamber to investigate the effects of hydrocarbon addition on cellular instabilities of syngas-air flames. The measured laminar burning velocities were compared with the predicted results computed using reliable kinetic mechanisms with detailed transport and chemistry. The cellular instabilities that included hydrodynamic and diffusional-thermal instabilities of the hydrocarbon-added syngas-air flames were identified and evaluated. Further, experimentally measured critical Peclet numbers for fuel-lean flames were compared with the predicted results. Experimental results showed that the laminar burning velocities decreased significantly with an increase in the amount of hydrocarbon added in the reactant mixtures. With addition of propane and butane, the propensity for cell formation was significantly diminished whereas the cellular instabilities for methane-added syngas-air flames were not suppressed.