• Applied Microscopy
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• 제48권2호
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• pp.33-42
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• 2018

Myosin X is one of myosin superfamily members having unique cellular functions on cytoskeletal reorganization. One of the most important cellular functions of myosin X is to facilitate the formation of membrane protrusions. Since membrane protrusions are important factors for diverse cellular motile processes including cell migration, cell invasion, path-finding of the cells, intercellular communications and so on, it has been thought that myosin X plays an important role in various processes that involve cytoskeletal reorganization including cancer progression and development of neuronal diseases. Recent studies have revealed that the unique cellular function of myosin X is closely correlated with its unique structural characteristics and motor properties. Moreover, it is found that the molecular and cellular activities of myosin X are controlled by its specific binding partner. Since recent studies have revealed the presence of various specific binding partners of myosin X, it is anticipated that the structural, biochemical and cell biological understanding of the binding partner dependent regulation of myosin X function can uncover the role of myosin X in diverse cell biological processes and diseases.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권1호
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• pp.13-17
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• 2002

Present communication deals with quantitative determination of total lipid, triglycerides, total free fatty acids, phospholipids and total cholesterol in the fat body tissue of the silkworm adapted to low and high temperatures. At the end of spinning process is characterized by a marked cellular reorganization of the different lipid fraction of the fat body irrespective of thermal acclimation. Accordingly, the per cent composition of triglycerides of the total lipid is increased accompanied by a corresponding decrease in free fatty acids, phospholipids and cholesterol.

• The Korean Journal of Physiology and Pharmacology
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• 제8권6호
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• pp.351-354
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• 2004

The cytotoxicological responses to insect growth regulator (IGR), using tebufenozide as ecdysteroid mimic, were investigated in Drosophila Kc cells. Treatment of Kc cells with tebufenozide showed significant growth inhibition and striking morphological changes including aggregation and elongation of the cells. In order to understand the cellular mechanism underlying the response of Drosophila cells to tebufenozide, immunofluorescence microscopy was performed. We found that treatment of Kc cells with tebufenozide enhanced the reorganization of f-actin and stimulated the expression of hsp27. These data suggest a possible association of filamentous actin (f-actin) and hsp27 in the cytotoxicological mechanisms of growth regulators in Drosophila cells.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.96-97
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• 2002

Lysophosphatidic acid (LPA) and sphingosine 1-phosphate (SIP) are bioactive lysophospholipids (LPs) that act as mediators in various cellular processes, such as cell growth, differentiation, survival, motility, and cytoskeletal reorganization (1,2). LPA and S1P are both abundant in serum and are produced by activated platelets and other cell types. (omitted)

• Molecules and Cells
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• 제28권5호
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• pp.417-422
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• 2009

Mitogen activated protein kinase (MAPK) are known to get activated during various stress signals and transduce the message from the cell membrane to the nucleus for appropriate cellular reorganization. Though, a certain basal activity of MAPK is often observed in the control plants. Prolonged exposure of rice plants to lowered or elevated temperature exhibited a rhythm in the activation of MAPKs. We analyzed existence of a possible endogenous rhythm in the activity of MAPKs in rice plants. The plants growing at constant temperature entrained in 16/8 h day-night cycle showed diurnal rhythm in activity. When the activation of MAPK was tested under continuous conditions by shifting plants to continuous darkness for a period of 72 h, the periodic rhythm persisted and followed a circadian pattern. Analysis of the transcripts of group A, B and C members of MAPKs under above conditions by quantitative real time PCR revealed that the members of group C exhibit periodic rhythm. Our data indicates that the MAP kinase activity in rice follows rhythmic expression in a circadian manner.

• BMB Reports
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• 제29권5호
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• pp.474-480
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• 1996

We present a study of evolutionary changes in expression of actin genes among closely related sea urchin species that exhibit different modes of early development. For this purpose, polyclonal antisera raised against peptides from the carboxyl terminus of the HeCyI cytoskeletal actin of Heliocidaris erythrogramma were used. H. erythrogramma is a direct developing sea urchin that proceeds from embryonic to adult stages without an intervening feeding larval stage. Expression patterns of the CyI actin isoform were compared with those of Heliocidaris tuberculata and to a related sea urchin Strongylocentrotus purpuratus, which both produce a feeding pluteus larval stage. The CyI actin of all three species is expressed in the same cell types. However, its expression patterns have been changed with reorganization of early cell lineage differentiation, which is apparent among the three species. Thus. evolutionary changes in CyI actin gene expression patterns are correlated with not only phylogenetic relationship, but developmental mode. The implication of this observation is that evolutionary changes in expression patterns of histospecific genes may underlie the emergence of novel developmental processes.

• Reproductive and Developmental Biology
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• 제39권2호
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• pp.37-41
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• 2015

The oocyte undergoes various events during maturation and requires many substances for the maturation process. Various intracellular organelles are also involved in maturation of the oocyte. During the process glucose is essential for nuclear and cytoplasmic maturation, and adenosine triphosphate is needed for reorganization of the organelles and cytoskeleton. If mitochondrial function is lost, several developmental defects in meiotic chromosome segregation and maturation cause fertilization failure. The endoplasmic reticulum, a store for $Ca^{2+}$, releases $Ca^{2+}$ into the cytoplasm in response to various cellular signaling molecules. This event stimulates secretion of hormones, growth factors and antioxidants in oocyte during maturation. Also, oocyte nuclear maturation is stimulated by growth factors such as epidermal growth factor. This review summarizes roles of organelles with focus on the Golgi apparatus during maturation in oocyte.

• BMB Reports
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• 제47권7호
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• pp.361-368
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• 2014

Lipid components in biological membranes are essential for maintaining cellular function. Phosphoinositides, the phosphorylated derivatives of phosphatidylinositol (PI), regulate many critical cell processes involving membrane signaling, trafficking, and reorganization. Multiple metabolic pathways including phosphoinositide kinases and phosphatases and phospholipases tightly control spatio-temporal concentration of membrane phosphoinositides. Metabolizing enzymes responsible for PI 4,5-bisphosphate (PI(4,5)P2) production or degradation play a regulatory role in Toll-like receptor (TLR) signaling and trafficking. These enzymes include PI 4-phosphate 5-kinase, phosphatase and tensin homolog, PI 3-kinase, and phospholipase C. PI(4,5)P2 mediates the interaction with target cytosolic proteins to induce their membrane translocation, regulate vesicular trafficking, and serve as a precursor for other signaling lipids. TLR activation is important for the innate immune response and is implicated in diverse pathophysiological disorders. TLR signaling is controlled by specific interactions with distinct signaling and sorting adaptors. Importantly, TLR signaling machinery is differentially formed depending on a specific membrane compartment during signaling cascades. Although detailed mechanisms remain to be fully clarified, phosphoinositide metabolism is promising for a better understanding of such spatio-temporal regulation of TLR signaling and trafficking.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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• pp.15-15
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• 2023

The chloroplast (cp) is an autonomous plant organelle with an individual genome that codes for essential cellular functions. The architecture and gene content of the cp genome is highly conserved in angiosperms. The plastome of Corydalis belongs to the Papaveraceae family, and the genome is comprised of unusual rearrangements and gene content. Thus far, no extensive comparative studies have been carried out to understand the evolution of Corydalis chloroplast genomes. Therefore, the Corydalis platycarpa cp genome was sequenced, and wide-scale comparative studies were conducted using publicly available twenty Corydalis plastomes. Comparative analyses showed that an extensive genome rearrangement and IR expansion occurred, and these events evolved independently in the Corydalis species. In addition, the protein-coding genes accD and the ndh gene loss events occurred in the common ancestor of the Corydalis and sub-clade of the Corydalis lineage, respectively. The gene ndh lost in the Corydalis-sub clade species is distributed predominantly in the Qinghai-Tibetan plateau (QTP) region. The molecular clock analysis suggests that the divergence time of all the ndh gene lost Corydalis sub-clade species occurred in the 44.31 - 15.71 mya. These results coincide very well with the uplift of the Qinghai-Tibet Plateau in the Oligocene and Miocene periods, and maybe during this period, it probably triggered the radiation of the Corydalis species. To the best of the authors' knowledge, this is the first large-scale comparative study of Corydalis plastomes and their evolution. The present study may provide insights into the plastome architecture and the molecular evolution of Corydalis species.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제11권1호
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• pp.130-152
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• 1989

The purpose of this study was to observe the effect of intermaxillary fixation on the chondrocytes of the mandibular condyle under the light and the electron microscope. For this study, twenty rabbits were placed in maxillomandibular fixation, and two were used as a control group. The experimental group was subdivided into 3, 7, 14, 21 and 28 day group. After the experimental period of 3, 7, 14, 21 and 28 days, the animals were sacrificed with a vascular perfusion of 2.5% glutaraldehyde. The condylar processes were exenterated, and decalcified in 0.1M EDTA with 2.5% glutaraldehyde solution for two weeks. The specimens were rinsed with phosphate buffer solution and the post-fixation was carried out with 2% osmium tetroxide at $4^{\circ}C$ for two hours. Thereafter the specimens were dehydrated in alcohol series, cleared with propylene oxide and embedded in Epon 812 resin. Thin sections and ultra-thin sections were made, and the cellular structures of the condylar cartilages were observed with light and electron microscope. The results were as follows: 1. In the intermaxillary fixation group, the cartilaginous tissues of mandibular condyles showed a marked decrease in the thickness compared to the control group. 2. A remarkable change was noticed in the proliferating and the hypertrophic zone of the condylar cartilages in the experimental group. 3. An atrophic change of the condylar cartilage was appeared in the 3 day experimental group and degenerative change was observed in the 7 day experimental group, and recovery was seen in thereafter 14 day experimental group. 4. Calcification, degeneration and resorption of condylar cartilage were recognizable, and the cellular zone of the condylar cartilage was appeared indistinctly in 3 day and 7 day experimental group. The chondroblasts, however, were differentiated into chondrocytes and resumed mitosis, and then the cellular zones of the condylar cartilage were reorganized from the 14 day experimental group under the findings of light microscope. 5. Under the findings of electron microscope, atrophic changes and decrease in number of intracellular organelles, degenerative changes of cytoplasm, and pyknosis of nuclei were observed in early stage, however, a gradual regeneration and reorganization of the intracellular organelles were observed from 14 day experimental group.