• Title/Summary/Keyword: Molecular-level understanding

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Depolarizing Effectors of Bradykinin Signaling in Nociceptor Excitation in Pain Perception

  • Choi, Seung-In;Hwang, Sun Wook
    • Biomolecules & Therapeutics
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    • v.26 no.3
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    • pp.255-267
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    • 2018
  • Inflammation is one of the main causes of pathologic pain. Knowledge of the molecular links between inflammatory signals and pain-mediating neuronal signals is essential for understanding the mechanisms behind pain exacerbation. Some inflammatory mediators directly modulate the excitability of pain-mediating neurons by contacting the receptor molecules expressed in those neurons. For decades, many discoveries have accumulated regarding intraneuronal signals from receptor activation through electrical depolarization for bradykinin, a major inflammatory mediator that is able to both excite and sensitize pain-mediating nociceptor neurons. Here, we focus on the final effectors of depolarization, the neuronal ion channels, whose functionalities are specifically affected by bradykinin stimulation. Particular G-protein coupled signaling cascades specialized for each specific depolarizer ion channels are summarized. Some of these ion channels not only serve as downstream effectors but also play critical roles in relaying specific pain modalities such as thermal or mechanical pain. Accordingly, specific pain phenotypes altered by bradykinin stimulation are also discussed. Some members of the effector ion channels are both activated and sensitized by bradykinin-induced neuronal signaling, while others only sensitized or inhibited, which are also introduced. The present overview of the effect of bradykinin on nociceptor neuronal excitability at the molecular level may contribute to better understanding of an important aspect of inflammatory pain and help future design of further research on the components involved and pain modulating strategies.

A Crossed Beam Study of Atom-Radical Reaction Dynamics (원자-라디칼 반응 동력학의 교차 빔 연구)

  • Ju Seon-Gyu;Gwon Lee-Gyeong;Lee Ho-Jae;Choe Jong-Ho
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.05b
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    • pp.163-164
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    • 2003
  • Reaction dynamics plays an essential role in understanding the microscopic mechanism of elementary chemical processes at the molecular level. Detailed studies of the reactions of atomic species such as hydrogen and second-row atoms with small closed-shell molecules have provided important insights into hydrocarbon synthesis, combustion, interstellar space and atmospheric chemistry. Despite its mechanistic significance, however, the investigations of atom-radical reaction dynamics are quite scarce in comparison to the extensive studies of atom-molecule reactions. (omitted)

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Two-dimensional Surface Structures of Arenthiols Studied by STM

  • Gwon, Gi-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.89-89
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    • 2012
  • Arrangement of individual atoms and molecules with atomic precision and understanding the resulting properties at the molecular level are ultimate goals of chemistry, biology, and materials science. For the past three decades, scanning probe microscopy has made strides towards these goals through the direct observation of individual atoms and molecules, enabling the discovery of new and unexpected phenomena. This talk will discuss the origin of forces governing motion of small organic molecules and their extended self-assembly into two-dimensional surface structures by direct observation of individual molecules using scanning tunneling microscopy (STM).

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MicroRNA biogenesis and function in higher plants

  • Jung, Jae-Hoon;Seo, Pil Joon;Park, Chung-Mo
    • Plant Biotechnology Reports
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    • v.3 no.2
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    • pp.111-126
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    • 2009
  • MicroRNAs (miRNAs) are endogenous, non-coding, small RNA molecules consisting of 21-24 nucleotides (nts) that regulate target genes at the posttranscriptional level in plants and animals. In plants, miRNAs negatively regulate target mRNAs containing a highly complementary sequence by either mRNA cleavage or translational repression. MiRNAs are processed from single-stranded precursors containing stem-loop structures by a Dicer-like enzyme and are loaded into silencing complexes, where they act on target mRNAs. Although plant miRNAs were first reported in Arabidopsis 10 years later than animal miRNAs, numerous miRNAs have since been identified from various land plants ranging from mosses to flowering plants, and their roles in diverse aspects of plant developmental processes have been characterized. Furthermore, most of the annotated plant miRNAs are evolutionarily conserved in various plants. In particular, recent functional studies using Arabidopsis mutants have contributed a great deal of information towards establishing a framework for understanding miRNA biogenesis and functional roles. Extensive appraisal of miRNA-directed regulation during a wide array of plant development and plant responses to environmental conditions has confirmed the versatile roles of miRNAs as a key component of plant molecular biology.

Molecular genetic decoding of malformations of cortical development

  • Lim, Jae Seok;Lee, Jeong Ho
    • Journal of Genetic Medicine
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    • v.12 no.1
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    • pp.12-18
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    • 2015
  • Malformations of cortical development (MCD) cover a broad spectrum of developmental disorders which cause the various clinical manifestations including epilepsy, developmental delay, and intellectual disability. MCD have been clinically classified based on the disruption of developmental processes such as proliferation, migration, and organization. Molecular genetic studies of MCD have improved our understanding of these disorders at a molecular level beyond the clinical classification. These recent advances are resulted from the development of massive parallel sequencing technology, also known as next-generation sequencing (NGS), which has allowed researchers to uncover novel molecular genetic pathways associated with inherited or de novo mutations. Although an increasing number of disease-related genes or genetic variations have been identified, genotype-phenotype correlation is hampered when the biological or pathological functions of identified genetic variations are not fully understood. To elucidate the causality of genetic variations, in vivo disease models that reflect these variations are required. In the current review, we review the use of NGS technology to identify genes involved in MCD, and discuss how the functions of these identified genes can be validated through in vivo disease modeling.

Systems biology of virus-host signaling network interactions

  • Xue, Qiong;Miller-Jensen, Kathryn
    • BMB Reports
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    • v.45 no.4
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    • pp.213-220
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    • 2012
  • Viruses have evolved to manipulate the host cell machinery for virus propagation, in part by interfering with the host cellular signaling network. Molecular studies of individual pathways have uncovered many viral host-protein targets; however, it is difficult to predict how viral perturbations will affect the signaling network as a whole. Systems biology approaches rely on multivariate, context-dependent measurements and computational analysis to elucidate how viral infection alters host cell signaling at a network level. Here we describe recent advances in systems analyses of signaling networks in both viral and non-viral biological contexts. These approaches have the potential to uncover virus- mediated changes to host signaling networks, suggest new therapeutic strategies, and assess how cell-to-cell variability affects host responses to infection. We argue that systems approaches will both improve understanding of how individual virus-host protein interactions fit into the progression of viral pathogenesis and help to identify novel therapeutic targets.

Human intronless disease associated genes are slowly evolving

  • Agarwal, Subhash Mohan;Srivastava, Prashant K.
    • BMB Reports
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    • v.42 no.6
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    • pp.356-360
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    • 2009
  • In the present study we have examined human-mouse homologous intronless disease and non-disease genes alongside their extent of sequence conservation, tissue expression, domain and gene ontology composition to get an idea regarding evolutionary and functional attributes. We show that selection has significantly discriminated between the two groups and the disease associated genes in particular exhibit lower $K_{a}$ and $K_{a}/K_{s}$ while $K_{s}$ although smaller is not significantly different. Our analyses suggest that majority of disease related intronless human genes have homology limited to eukaryotic genomes and their expression is localized. Also we observed that different classes of intronless disease related genes have experienced diverse selective pressures and are enriched for higher level functionality that is essentially needed for developmental processes in complex organisms. It is expected that these insights will enhance our understanding of the nature of these genes and also improve our ability to identify disease related intronless genes.

Structural and dynamic views of the CRISPR-Cas system at the single-molecule level

  • Lee, Seung Hwan;Bae, Sangsu
    • BMB Reports
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    • v.49 no.4
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    • pp.201-207
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    • 2016
  • The CRISPR-Cas system has emerged as a fascinating and important genome editing tool. It is now widely used in biology, biotechnology, and biomedical research in both academic and industrial settings. To improve the specificity and efficiency of Cas nucleases and to extend the applications of these systems for other areas of research, an understanding of their precise working mechanisms is crucial. In this review, we summarize current studies on the molecular structures and dynamic functions of type I and type II Cas nucleases, with a focus on target DNA searching and cleavage processes as revealed by single-molecule observations.

Molecular Characterization of Plant Genes (식물 유전자의 구조와 특성)

  • 이종섭
    • Proceedings of the Botanical Society of Korea Conference
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    • 1987.07a
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    • pp.19-49
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    • 1987
  • Recent development of recombinant DNA techniques such as gene cloning and DNA sequencing has led to understanding of genetic information coded on plant genes and their application to crop improvements. Nuclear genes so far isolated and characterized at the molecular level from various plants are those involved mainly in photosynthesis, nitrogen fixation, seed development and defensive responses to environmental stresses. Most of plant genes contain intervening sequences (introns) flanked with GT and AG, as it typical of animal genes. The 5' flanking regions of plant gene revealed the presence of promoter elements such as TATAAA and CCAAT, which have been identified at animal genes to be involved in transcrip- tion initiation. The 3' untranslated regions include a sequence similar to AATAAA whcih functions as a polyadenylation signal in other eukaryotic genes. Furthermore, enhancer-type sequences were found at the 5' flanking regions of various plant genes. This indicates that the structure of plant genes is very similar to animal genes and mechanisms governing the synthesis and processing of mRNAs may be identical in higher eukaryotes. However, genes expression studies involving transformation revealed their differ ences within plants and between plant and animal systems.

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AKARI near-infrared spectral observations on the shocked H2 gas of a supernova remnant IC 443

  • Shinn, Jong-Ho;Koo, Bon-Chul;Seon, Kwang-Il;Lee, Ho-Gyu
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.69.1-69.1
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    • 2010
  • IC 443 is famous for its interaction with nearby molecular clouds and intense H2 emission lines in infrared. Therefore, it has been studied extensively for the understanding of molecular shocks. We observed H2 mission lines toward the shock-cloud interaction regions of IC 443, known as clumps B, C, and G. The observations were performed with the InfraRed Camera (IRC) onboard a satellite AKARI over 2.5-5.0 um, where previous space observations, e.g. Infrared Space Observatory (ISO) and Spitzer, do not cover. Our AKARI observations provide spectra of sequential pure-rotational and ro-vibrational H2 emission lines. For the clumps C and G, combining with previous mid-infrared observational results, we found that the H2 level populations show a significant separation between v=0 and v=1 levels; v=1 levels are under-populated than v=0 levels, therefore, the population cannot be described by two temperature LTE model, as many people have analyzed for the shocked H2 gas. We also applied the thermal admixture model, dN(H2; T)~T^(-b) dT, with varying ortho-to-para ratios according to the temperature, to describe the level population, and obtained plausible ranges of the H2 gas density and power-law index b.

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