• Title/Summary/Keyword: Coiled-coil

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Experimental Study on In-Tube Condensation Heat Transfer Characteristics of Helically Coiled Spiral Tubes (코일형 나선 전열관의 내부 응축열전달 특성에 관한 실험 적 연구)

  • Park, Jong-Un;Gwon, Yeong-Cheol;Han, Gyu-Il
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.12
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    • pp.1676-1683
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    • 2001
  • An experimental study on condensation heat transfer characteristics of helically coiled spiral tubes was performed. The refrigerant is R-113. A refrigerant loop was established to measure the condensation heat transfer coefficients. Experiments were carried out uniform heat flux of 15 kw/m$^2$, refrigerant quality of 0.1∼0.9, curvature ratio of 0.016, 0.025 and 0.045. The curvature of a coil was defined as the ratio of the inside diameter of the tube to the diameter of the bending circle. To compare the condensation heat transfer coefficients of coiled spiral tubes, the previous results on coiled plain tubes and straight plain tubes were used. The results shows that the condensation heat transfer coefficients of coiled spiral tubes largely increase, as increasing Re and quality, compared to those of coiled plain tubes and straight plain tubes. As increasing degree of subcooling, however, the condensation heat transfer coefficients on coiled spiral tubes decrease. It is found that the heat transfer enhancement is more better than coiled plain tubes and straight plain tubes, as increasing curvature ratio.

Ectopic Overexpression of Coiled-Coil Domain Containing 110 Delays G2/M Entry in U2-OS Cells

  • Lee, Sue Nyoung;Hong, Kyeong-Man;Seong, Yeon Sun;Kwak, Sahng-June
    • Development and Reproduction
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    • v.24 no.2
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    • pp.101-111
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    • 2020
  • Coiled-coil domain containing 110 (CCDC110, KM-HN-1) is a protein containing C-terminal coiled-coil domain (CCD) which was previously discovered as a member of the human cancer/testis antigen (CTA). In addition, CCDC110 has both nuclear localization signal sequence and the leucine zipper motif. Although the functional role of CCDC110 has yet to be fully identified, the mRNA expression levels of CCDC110 are known to be highly elevated in various cancer types including testis, implying its relevance to cancer pathogenesis. In this study, we first developed several monoclonal antibody (mAb) hybridoma clones targeting CCDC110 and further isolated clone by characterizing for its specificity using immunoblotting and immunoprecipitation approaches with basal parenchymal sperm cells in testis tissue. Next, using these mAbs, we showed that the Tet-inducible overexpression of CCDC110 protein delayed the entry of G2/M phase in U2-OS osteosarcoma cells. Based on these results, we propose that CCDC110 plays a crucial role in cell cycle progression.

A Study on Performance Analysis of the Helically Coiled Evaporator with Circular Minichannels

  • Kim Ju-Won;Im Yong-Bin;Kim Jong-Soo
    • Journal of Mechanical Science and Technology
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    • v.20 no.7
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    • pp.1059-1067
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    • 2006
  • In order to develop a compact evaporator, experiments that show characteristics of evaporating heat transfer and pressure drop in the helically coiled minichannel were performed in our previous research. This study was focused on the performance analysis of helically coiled heat exchangers with circular minichannels with an inner diameter=1.0 mm. The working fluid was R-22, and the properties of R-22 were estimated using the REFPROP program. Numerical simulation was performed to compare results with the experimental results of the helically coiled heat exchanger. As the heat transfer rate and pressure drop were calculated at the micro segment of the branch channels, the performance of the evaporator was evaluated. The following conclusions were obtained through the numerical simulations of the helically coiled heat exchanger. It showed good performance when the flow rate of each branch channels was suitable to heat load of air-side. The numerical simulation value agreed with experimental results within ${\pm}15%$. In this study, a numerical simulation program was developed to estimate the performance of a helically coiled evaporator. And, an optimum helically coiled minichannels evaporator was designed.

Membrane interaction of the coiled-coil motif of HIV gp41 and its implication in the membrane fusion process

  • Jin, Bong-Suk;Yu, Yeon-Gyu
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.58-58
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    • 2003
  • The envelope glycoprotein of HIV, gp41, mediates the membrane fusion with human cells. The extracellular domain of gp41 has two helical regions. The N-terminus helical region (N-helix) forms trimeric coiled coil, interacts with the C-terminus helical region (C-helix) of gp41 to form a stable helical bundle structure. In this study, we have shown that the N-helix of gp41 has membrane interacting and disrupting abilities. It was localized into the interface of the lipidic phase and head group of the membrane. In contrast, the N-helix region with membrane fusion defective mutations could not bind to membrane. In addition, the N-helix bound on the membrane was released from the membrane by the C-helix, and the complex of the N- and C-helix did not interact with membrane. These results suggested that the membrane binding ability of the N-helix is necessary for the fusion activity of gp41, and such property is possibly controlled by the C-helm.

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Coiled-Coil Domain-Containing Protein 98 (CCDC98) Regulates Cyclin B1 Expression by Affecting WTAP Protein Stability (WTAP 단백질의 안정성을 통한 CCDC98 단백질의 cyclin B1 발현 조절)

  • Oh, Yun-Jung;Lee, Eun-Hee;Lee, Il-Kyu;Kim, Kyung-Soo;Kim, Hong-Tae
    • Journal of Life Science
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    • v.21 no.8
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    • pp.1067-1075
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    • 2011
  • Coiled-coil domain-containing protein 98 (CCDC98) plays a role in G2/M DNA damage checkpoint pathways by recruiting breast cancer 1 (BRCA1)-A complex to the DNA-damaged sites. However, the molecular mechanism of CCDC98 on the DNA damage-induced G2/M checkpoint pathways is unclear. In this study, we identifed Wilms tumor 1-associating protein (WTAP) as a novel CCDC98-binding protein, using tandem affinity purification. We confirmed the association between CCDC98 and WTAP using in vivo and in vitro binding assays. We demonstrated that CCDC98 regulates cyclin B1 expression by affecting WTAP protein stability. Based on these results, we suggest that CCDC98 may act as a novel cell cycle regulator by regulating the expression level of cyclin B1.

A Role of YlBud8 in the Regulation of Cell Separation in the Yeast Yarrowia lipolytica

  • Li, Yun-Qing;Xue, Qing-Jie;Yang, Yuan-Yuan;Wang, Hui;Li, Xiu-Zhen
    • Journal of Microbiology and Biotechnology
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    • v.29 no.1
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    • pp.141-150
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    • 2019
  • The spatial landmark protein Bud8 plays a crucial role in bipolar budding in the budding yeast Saccharomyces cerevisiae. The unconventional yeast Yarrowia lipolytica can also bud in a bipolar pattern, but is evolutionarily distant from S. cerevisiae. It encodes the protein YALI0F12738p, which shares the highest amino acid sequence homology with S. cerevisiae Bud8, sharing a conserved transmembrane domain at the C-terminus. Therefore, we named it YlBud8. Deletion of YlBud8 in Y. lipolytica causes cellular separation defects, resulting in budded cells remaining linked with one another as cell chains or multiple buds from a single cell, which suggests that YlBud8 may play an important role in cell separation, which is distinct from the function of Bud8 in S. cerevisiae. We also show that the YlBud8-GFP fusion protein is located at the cell membrane and enriched in the bud cortex, which would be consistent with a role in the regulation of cell separation. The coiled-coil domain at the N-terminus of YlBud8 is important to the correct localization and function of YlBud8, as truncated proteins that do not contain the coiled-coil domain cannot rescue the defects observed in $Ylbud8{\Delta}$. This finding suggests that a new signaling pathway controlled by YlBud8 via regulation of cell separation may exist in Y. lipolytica.

Characteristics of Heat Transfer and Pressure Drop of R-22 Inside an Evaporating Tube with Small Diameter Helical Coil (극세관 헬리컬 코일 증발관내 R-22의 열전달 및 압력손실 특성)

  • Kim, Ju-Won;Kim, Jeong-Hun;Seo, Seok-Ki;Kim, Jeung-Hoon;Kim, Jong-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.5
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    • pp.699-708
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    • 2000
  • To make compact evaporator, experiments that show characteristics of evaporating heat transfer and pressure drop in the helically coiled small diameter tube were taken in this research. The experiments were performed with HCFC-22 in the helically coiled small diameter tube; inner diameter=1.0(mm), tube length=2.0(m), and curvature diameter=31, 34, 46.2(mm). The experiments were also carried out with the following test conditions; saturation pressure=0.588(MPa), mass velocity=$150{\sim}500(kg/m^2s)$, and heat flux=$1{\sim}5(kW/m^2)$. The experiment results are that the empirical correlation to predict heat transfer coefficient for single phase flow in helically coiled small diameter tube was obtained. It was found that dry-out is occurred at low-quality region for evaporation heat transfer because of breaking of annular liquid film. The friction factor of single phase flow of helically coiled tube was agreed with Prandtl's correlation. Finally, It was proposed for correlation that can precisely predict the friction factor of two phase flow of helically coiled tube.

Expression and characterization of transmembrane and coiled-coil domain family 3

  • Sohn, Wern-Joo;Kim, Jae-Young;Kim, Dongbum;Park, Jeong-A;Lee, Younghee;Kwon, Hyung-Joo
    • BMB Reports
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    • v.49 no.11
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    • pp.629-634
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    • 2016
  • Transmembrane and coiled-coil domain family 3 (TMCC3) has been reported to be expressed in the human brain; however, its function is still unknown. Here, we found that expression of TMCC3 is higher in human whole brain, testis and spinal cord compared to other human tissues. TMCC3 was expressed in mouse developing hind brain, lung, kidney and somites, with strongest expression in the mesenchyme of developing tongue. By expression of recombinant TMCC3 and its deletion mutants, we found that TMCC3 proteins self-assemble to oligomerize. Immunostaining and confocal microscopy data revealed that TMCC3 proteins are localized in endoplasmic reticulum through transmembrane domains. Based on immunoprecipitation and mass spectroscopy data, TMCC3 proteins associate with TMCC3 and 14-3-3 proteins. This supports the idea that TMCC3 proteins form oligomers and that 14-3-3 may be involved in the function of TMCC3. Taken together, these results may be useful for better understanding of uncharacterized function of TMCC3.

Fouling Characteristics of Washable Shell and Coil Heat Exchanger (세척이 가능한 원통 코일형 열교환기의 파울링 특성에 관한 연구)

  • Hwang, Jun Hyeon;Na, Byung Chul;Oh, Sai Kee;Koo, Kyoung Min;Lee, Jae Keun;Ahn, Young Chull
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.2
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    • pp.69-74
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    • 2015
  • In this work, we studied the shell and helically coiled tube heat exchangers. Shell and coil heat exchangers with different rate of water flow and plate heat exchanger with same capacity were tested for condensing conditions. We proposed design guide using modified Wilson plot method. We compared fouling characteristics between shell and coil heat exchanger and plate heat exchanger, when they were washed and were not washed. The shell and coil heat exchanger showed 120% of higher saturated fouling resistance value and 4% of better heat transfer ratio than the plate heat exchanger.

Rab Effector EHBP1L1 Associates with the Tetratricopeptide Repeat Domain of Kinesin Light Chain 1 (Kinesin Light Chain 1 (KLC1)의 Tetratricopeptide Repeat (TPR) 도메인과 Rab effector, EHBP1L1의 결합)

  • Jeong, Young Joo;Park, Sung Woo;Kim, Sang-Jin;Kim, Mooseong;Urm, Sang-Hwa;Lee, Jung Goo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.30 no.1
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    • pp.10-17
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    • 2020
  • Kinesin-1 is microtubule-dependent plus-end direct molecular motor protein essential for intracellular transport. It is a member of the kinesin superfamily proteins (KIFs) which transport cargo, including organelles, vesicles, neurotransmitter receptors, cell-signaling molecules, and protein complexes through interaction between its light chain subunit and the cargo. Kinesin light chain 1 (KLC1) is a non-motor subunit that associates with the kinesin heavy chain (KHC). Although KLC1 interacts with many different adaptor proteins and scaffolding proteins, its binding proteins have not yet been fully identified. We used the yeast two-hybrid assay to identify proteins that interact with the tetratricopeptide repeat (TPR) domain of KLC1, and found an interaction between KLC1 and EH domain-binding protein 1 like 1 (EHBP1L1). EHBP1L1 bound to the region containing all six TPR repeats of KLC1 and did not interact with KIF5B (a motor protein of kinesin 1) or KIF3A (a motor protein of kinesin 2) in the yeast two-hybrid assay. The carboxyl-terminus of the coiled-coil domain of EHBP1L1 is essential for interaction with KLC1. However, another EHBP1L1 isoform, EHBP1, did not interact with KLC1 in the yeast two-hybrid assay. KLC1 interacted with GST-EHBP1L1 and its coiled-coil domain but not with GST only. When co-expressed in HEK-293T cells, EHBP1L1 co-localized with KLC1 and co-immunoprecipitated with KLC1 and KIF5B but not KIF3A. These results suggest that kinesin 1 motor protein may transport EHBP1L1-associated cargo in cells.