• Title/Summary/Keyword: cilium

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The Fungal Metabolite Brefeldin A Inhibits Dvl2-Plk1-Dependent Primary Cilium Disassembly

  • Lee, Uijeong;Kim, Sun-Ok;Hwang, Jeong-Ah;Jang, Jae-Hyuk;Son, Sangkeun;Ryoo, In-Ja;Ahn, Jong Seog;Kim, Bo Yeon;Lee, Kyung Ho
    • Molecules and Cells
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    • v.40 no.6
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    • pp.401-409
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    • 2017
  • The primary cilium is a non-motile microtubule-based organelle that protrudes from the surface of most human cells and works as a cellular antenna to accept extracellular signals. Primary cilia assemble from the basal body during the resting stage ($G_0$ phase) and simultaneously disassemble with cell cycle re-entry. Defective control of assembly or disassembly causes diverse human diseases including ciliopathy and cancer. To identify the effective compounds for studying primary cilium disassembly, we have screened 297 natural compounds and identified 18 and 17 primary cilium assembly and disassembly inhibitors, respectively. Among them, the application of KY-0120, identified as Brefeldin A, disturbed Dvl2-Plk1-mediated cilium disassembly via repression of the interaction of $CK1{\varepsilon}-Dvl2$ and the expression of Plk1 mRNA. Therefore, our study may suggest useful compounds for studying the cellular mechanism of primary cilium disassembly to prevent ciliopathy and cancer.

Three-dimensional analysis of the arrangement of microtubules of the outer segment in the ciliary-type photoreceptor cell in the Onchidium dorsal eye

  • Katagiri, Nobuko;Shimatani, Yuichi;Katagiri, Yasuo
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.284-286
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    • 2002
  • The inverted retina of the Onchidium dorsal eye (DE) is composed only of ciliary-type photoreceptor cells (CC's). The outer segment (OS) of the CC is a concentric lamellar structure consisting of many modified ciliary membranes and stains positively with anti-$\beta$-tubulin antibody. Near the base of the OS there are about 30 basal bodies each connecting individually to a cilium. The cilia are rod-shaped at the base, progressing upwards to a flattened sheet-like shape with increasing surface area. Three-dimensional analysis on serial sections demonstrates the ladle-shape of a modified cilium. Many modified cilia wrap around each other like the leaves of a cabbage. Nine pairs of microtubules (MT's) are located regularly in a ring at the base of the cilium, gradually losing their regular arrangement towards the periphery, where they separate into two subgroups that are contained within two swollen portions of a modified cilium. Within the CC of the Onchidium DE, MT's in the modified cilium exist as two poles extending longitudinally in a thin expanded ciliary membrane. This arrangement may support the photoreceptive OS and serve to maintain its structural integrity.

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Analysis of Network Security Policy Enforcement in Container Environments (컨테이너 환경에서의 네트워크 보안 정책 집행 분석)

  • Bom Kim;Seungsoo Lee
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.6
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    • pp.961-973
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    • 2023
  • With the changes in the modern computing landscape, securing containerized workloads and addressing the complexities of container networking have become critical issues. In particular, the complexity of network policy settings and the lack of cloud security architecture cause various security issues. This paper focuses on the importance of network security and efficiency in containerized environments, and analyzes the security features and performance of various container network interface plugins. In particular, the features and functions of Cilium, Calico, Weave Net, and Kube-router were compared and evaluated, and the Layer 3/4 and Layer 7 network policies and performance features provided by each plugin were analyzed. We found that Cilium and Calico provide a wide range of security features, including Layer 7 protocols, while Weave Net and Kube-router focus on Layer 3/4. We also found a decrease in throughput when applying Layer 3/4 policies and an increase in latency due to complex processing when applying Layer 7 policies. Through this analysis, we expect to improve our understanding of network policy and security configuration and contribute to building a safer and more efficient container networking environment in the future.

Proposed Operating Parameters for Advanced Treatment Process using a Cilium Media BNR Process (섬모상담체를 이용한 고도처리공정의 운전인자 도출)

  • Ahn, Yoon Hee;Park, Chan Gyu;Ko, Kwang Baik;Lee, Kang Soo
    • Journal of Korean Society on Water Environment
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    • v.23 no.5
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    • pp.761-765
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    • 2007
  • The study were conducted in order to investigate the effect of operating parameters including the internal recycle (nitrification return) rates, hydraulic retention times (HRTs) and temperature when using a cilium media method. The first experiment was for evaluating the effect of HRT (12 hr, 10 hr, 8 hr, 6 hr, 4 hr). The second experiment was for analyzing effect of internal recycle rate (100%, 200%, 300%, 400%). As a result of the first experiment, BOD was removed to 97~98% for 6~8 hr HRT. Effluent water quality was not significantly influenced with HRT within that range. However the nitrogen removal was sensitive to HRT. T-P removal efficiency was invariable at various HRTs. The average BOD removal efficiency was about 97% in spite of change of internal recycle rate while T-N removal efficiency was increased at the internal recycle rate of 100~200%, but invariable at the internal recycle rate of 200~300%.

The Ciliary Transition Zone: Finding the Pieces and Assembling the Gate

  • Goncalves, Joao;Pelletier, Laurence
    • Molecules and Cells
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    • v.40 no.4
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    • pp.243-253
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    • 2017
  • Eukaryotic cilia are organelles that project from the surface of cells to fulfill motility and sensory functions. In vertebrates, the functions of both motile and immotile cilia are critical for embryonic development and adult tissue homeostasis. Importantly, a multitude of human diseases is caused by abnormal cilia biogenesis and functions which rely on the compartmentalization of the cilium and the maintenance of its protein composition. The transition zone (TZ) is a specialized ciliary domain present at the base of the cilium and is part of a gate that controls protein entry and exit from this organelle. The relevance of the TZ is highlighted by the fact that several of its components are coded by ciliopathy genes. Here we review recent developments in the study of TZ proteomes, the mapping of individual components to the TZ structure and the establishment of the TZ as a lipid gate.

The Nitrogen and Phosphorus Removal of Municipal Wastewater with CNR Process using Influent as a Carbon Source (유입수를 탄소원으로 이용한 CNR공법의 질소, 인의 제거특성)

  • 김영규;김인배;이영준
    • Journal of Environmental Health Sciences
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    • v.27 no.3
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    • pp.81-85
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    • 2001
  • The aim of this study was to evaluate on the removal effect of total nitrogen and posphorus in municipal wastewater by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process using influent as a Carbon Source. CNR(Cilium Nutrient Romoval) is the process combining $A^2$/O process with cilium media of H2L corporation. The removal efficiencies for BOD$_{5}$, T-N and T-P were 81.1%, 61.4%, 61.4%, respectively. The removal efficiency of nitrogen and posphorus were low by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process.s.

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The Nitrogen Removal of Municipal Wastewater with HRT using CNR Process (CNR공법의 체류시간에 따른 도시하수의 질소제거)

  • 김영규;양익배;김인배
    • Journal of Environmental Health Sciences
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    • v.26 no.3
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    • pp.98-102
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    • 2000
  • The aim of this study was to evaluate on the removal effect of total nitrogen in municipal wastewater by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process. CNR-A(Cilia Nutrient Removal) is the process combining A2/O process with cilium media of H2L corporation. The removal efficiencies for T-N were 63.1% in A-1 reactor, and 73.5% in A-2 reactor and 77.0% in A-3 reactor. The specific nitrification(g-NH3-N/g-MLVSS.d) of Oxic in CNR-A process was 0.07-0.32. The specific denitrification in Anoxic and the specific nitrification inOxic was higher in HRT 4 hour because of optimum F/M ratio.

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Cercaria caribbea LVIII Cable, 1963 (Digenea: Cyathocotylidae) in the Republic of Korea and Its Surface Ultrastructure

  • Han, Eun-Taek;Park, Jeong-Hyun;Chai, Jong-Yil
    • Parasites, Hosts and Diseases
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    • v.50 no.2
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    • pp.177-180
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    • 2012
  • Cercaria caribbea LVIII Cable, 1963 (Digenea: Cyathocotylidae) was detected from a brackish water gastropod species (Cerithideopsilla cingulata) in a coatal area of Shinan-gun, Jeollanam-do (Province), the Republic of Korea, and its surface ultrastructure was studied using a scanning electron microscope. The cercariae were found freely swimming or enveloped within daughter sporocysts when the snail host was mechanically broken. They were morphologically characterized by a linguiform and ventrally concave body, a long and bifurcated tail, and the presence of a holdfast (=tribocytic) organ posterior to the ventral sucker. On the whole ventral and dorsal surfaces, peg-like tegumental spines were densely distributed. Around the oral sucker, several sensory papillae, each with a short cilium, were distributed, and on the tail, sensory papillae, each with an extensively long cilium, were observed. This is the first record describing a cyathocotylid cercaria from a brackish water gastropod in the Republic of Korea.

Deficiency of calpain-6 inhibits primary ciliogenesis

  • Kim, Bo Hye;Kim, Do Yeon;Oh, Sumin;Ko, Je Yeong;Rah, Gyuyeong;Yoo, Kyung Hyun;Park, Jong Hoon
    • BMB Reports
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    • v.52 no.10
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    • pp.619-624
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    • 2019
  • The primary cilium is a microtubule-based structure projecting from a cell. Although the primary cilium shows no motility, it can recognize environmental stimuli. Thus, ciliary defects cause severe abnormalities called ciliopathies. Ciliogenesis is a very complex process and involves a myriad of components and regulators. In order to excavate the novel positive regulators of ciliogenesis, we performed mRNA microarray using starved NIH/3T3 cells. We selected 62 murine genes with corresponding human orthologs, with significantly upregulated expression at 24 h after serum withdrawal. Finally, calpain-6 was selected as a positive regulator of ciliogenesis. We found that calpain-6 deficiency reduced the percentage of ciliated cells and impaired sonic hedgehog signaling. It has been speculated that this defect might be associated with decreased levels of ${\alpha}-tubulin$ acetylation at lysine 40. This is the first study to report a novel role of calpain-6 in the formation of primary cilia.

ANKS1A-Deficiency Aberrantly Increases the Entry of the Protein Transport Machinery into the Ependymal Cilia

  • Haeryung Lee;Jiyeon Lee;Miram Shin;Soochul Park
    • Molecules and Cells
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    • v.46 no.12
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    • pp.757-763
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    • 2023
  • In this study, we examine whether a change in the protein levels for FOP in Ankyrin repeat and SAM domain-containing protein 1A (ANKS1A)-deficient ependymal cells affects the intraflagellar transport (IFT) protein transport system in the multicilia. Three distinct abnormalities are observed in the multicilia of ANKS1A-deficient ependymal cells. First, there were a greater number of IFT88-positive trains along the cilia from ANKS1A deficiency. The results are similar to each isolated cilium as well. Second, each isolated cilium contains a significant increase in the number of extracellular vesicles (ECVs) due to the lack of ANKS1A. Third, Van Gogh-like 2 (Vangl2), a ciliary membrane protein, is abundantly detected along the cilia and in the ECVs attached to them for ANKS1A-deficient cells. We also use primary ependymal culture systems to obtain the ECVs released from the multicilia. Consequently, we find that ECVs from ANKS1A-deficient cells contain more IFT machinery and Vangl2. These results indicate that ANKS1A deficiency increases the entry of the protein transport machinery into the multicilia and as a result of these abnormal protein transports, excessive ECVs form along the cilia. We conclude that ependymal cells make use of the ECV-based disposal system in order to eliminate excessively transported proteins from basal bodies.