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c-Cbl-Mediated Neddylation Antagonizes Ubiquitination and Degradation of the TGF-β Type II Receptor
Zuo, W.,Huang, F.,Chiang, Y.,Li, M.,Du, J.,Ding, Y.,Zhang, T.,Lee, H.,Jeong, L.,Chen, Y.,Deng, H.,Feng, X.H.,Luo, S.,Gao, C.,Chen, Y.G. Cell Press 2013 Molecular cell Vol.49 No.3
Transforming growth factor β (TGF-β) is a potent antiproliferative factor in multiple types of cells. Deregulation of TGF-β signaling is associated with the development of many cancers, including leukemia, though the molecular mechanisms are largely unclear. Here, we show that Casitas B-lineage lymphoma (c-Cbl), a known proto-oncogene encoding an ubiquitin E3 ligase, promotes TGF-β signaling by neddylating and stabilizing the type II receptor (TβRII). Knockout of c-Cbl decreases the TβRII protein level and desensitizes hematopoietic stem or progenitor cells to TGF-β stimulation, while c-Cbl overexpression stabilizes TβRII and sensitizes leukemia cells to TGF-β. c-Cbl conjugates neural precursor cell-expressed, developmentally downregulated 8 (NEDD8), a ubiquitin-like protein, to TβRII at Lys556 and Lys567. Neddylation of TβRII promotes its endocytosis to EEA1-positive early endosomes while preventing its endocytosis to caveolin-positive compartments, therefore inhibiting TβRII ubiquitination and degradation. We have also identified a neddylation-activity-defective c-Cbl mutation from leukemia patients, implying a link between aberrant TβRII neddylation and leukemia development.
Pyle, Bryan W.,Tran, Hue T.,Pickel, Benjamin,Haslam, Tegan M.,Gao, Zhizeng,MacNevin, Gillian,Vederas, John C.,Kim, Soox2010,Un,Ro, Daex2010,Kyun Blackwell Publishing Ltd 2012 The FEBS journal Vol.279 No.17
<P>Valerian (<I>Valeriana</I> <I>officinalis</I>) is a popular medicinal plant in North America and Europe. Its root extract is commonly used as a mild sedative and anxiolytic. Among dozens of chemical constituents (e.g. alkaloids, iridoids, flavonoids, and terpenoids) found in valerian root, valerena‐4,7(11)‐diene and valerenic acid (C15 sesquiterpenoid) have been suggested as the active ingredients responsible for the sedative effect. However, the biosynthesis of the valerena‐4,7(11)‐diene hydrocarbon skeleton in valerian remains unknown to date. To identify the responsible terpene synthase, next‐generation sequencing (Roche 454 pyrosequencing) was used to generate ∼ 1 million transcript reads from valerian root. From the assembled transcripts, two sesquiterpene synthases were identified (<I>VoTPS1</I> and <I>VoTPS2</I>), both of which showed predominant expression patterns in root. Transgenic yeast expressing <I>VoTPS1</I> and <I>VoTPS2</I> produced germacrene C/germacrene D and valerena‐4,7(11)‐diene, respectively, as major terpene products. Purified VoTPS1 and VoTPS2 recombinant enzymes confirmed these activities <I>in vitro</I>, with competent kinetic properties (<I>K</I><SUB>m</SUB> of ∼ 10 μ<SMALL>m</SMALL> and <I>k</I><SUB>cat</SUB> of 0.01 s<SUP>−1</SUP> for both enzymes). The structure of the valerena‐4,7(11)‐diene produced from the yeast expressing <I>VoTPS2</I> was further substantiated by <SUP>13</SUP>C‐NMR and GC‐MS in comparison with the synthetic standard. This study demonstrates an integrative approach involving next‐generation sequencing and metabolically engineered microbes to expand our knowledge of terpenoid diversity in medicinal plants.</P><P><B>Database</B> The sequences of cDNAs described in this work are available in the GenBank database under the following accession numbers: VoTPS1, JQ437839; VoTPS2, JQ437840</P>
Micropropagation of Cymbidium sinense using continuous and temporary airlift bioreactor systems
Gao, R.,Wu, S. Q.,Piao, X. C.,Park, S. Y.,Lian, M. L. POLISH ACADEMY SCIENCES WARSAW 2014 Acta physiologiae plantarum Vol.36 No.1
Airlift bioreactors were programmed for continuous and temporary immersion culture to investigate factors that affect the rhizome proliferation, shoot formation, and plantlet regeneration of Cymbidium sinense. During rhizome proliferation, the continuous immersion bioreactor system was used to explore the effects of activated charcoal (AC) in the culture medium, inoculation density, and air volume on rhizome differentiation and growth. The optimum conditions for obtaining massive health rhizomes were 0.3 g l(-1) AC in the culture medium, 7.5 g l(-1) inoculation density, and 150 ml min(-1) air. In addition, the temporary immersion bioreactor system was used for both shoot formation and plantlet regeneration. Supplementing 4 mg l(-1) 6-benzylaminopurine and 0.2 mg l(-1) naphthalene acetic acid (NAA) to the culture medium promoted shoot induction from the rhizome. Cutting the rhizome explants into 1 cm segments was better for massive shoot formation than cutting into 0.25 and 0.5 cm explant segments. NAA promoted plantlet regeneration and the rooting rate (94.7 %), with whole plantlets growing well in culture medium containing 1.0 mg l(-1) NAA. Therefore, applying bioreactors in C. sinense micropropagation is an efficient way for scaling up the production of propagules and whole plantlets for the industrial production of high-quality seedlings.
Discovery and Characterization of the Tuberculosis Drug Lead Ecumicin
Gao, Wei,Kim, Jin-Yong,Chen, Shao-Nong,Cho, Sang-Hyun,Choi, Jongkeun,Jaki, Birgit U.,Jin, Ying-Yu,Lankin, David C.,Lee, Ji-Ean,Lee, Sun-Young,McAlpine, James B.,Napolitano, Josex301,G.,Franzblau, Sc American Chemical Society 2014 ORGANIC LETTERS Vol.16 No.23
<P>The new tuberculosis (TB) lead ecumicin (<B>1</B>), a cyclic tridecapeptide, was isolated from <I>Nonomuraea sp.</I> MJM5123, following a high-throughput campaign for anti-TB activity. The large molecular weight of 1599 amu detected by LC-HR-MS precluded the initial inference of its molecular formula. The individual building blocks were identified by extensive NMR experiments. The resulting two possible planar structures were distinguished by LC-MS<SUP>2</SUP>. Determination of absolute configuration and unambiguous structural confirmation were carried out by X-ray crystallography and Marfey’s analysis.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2014/orlef7.2014.16.issue-23/ol5026603/production/images/medium/ol-2014-026603_0003.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol5026603'>ACS Electronic Supporting Info</A></P>
Comparison of Axi-symmetric Single-Hole Nozzle with Multi-Hole Sac Nozzles
( M. C. Lai ),( Y. Zheng ),( X. Xie ),( K. Im ),( S. Moon ),( Z. Liu ),( J. Gao ),( J. Wang ),( J. M. Shi ),( R. E. Winsor ) 한국액체미립화학회 2010 한국액체미립화학회 학술강연회 논문집 Vol.2010 No.-
It is well know that the internal flow field and nozzle geometry affect the spray behavior, but without high-speed microscopic visualization, it is difficult to characterize the spray structure in details. Single-hole Diesel injectors have been used in fundamental spray research, while most direct-injection engines use multi-hole nozzle to tailor the fuel spray to the combustion chamber geometry. Recent engine trends also use smaller orifice and higher injection pressure. This paper discussed the quasi-steady near-nozzle Diesel spray structures of an axisymmetric single-hole nozzle and a symmetric two-hole nozzle configuration, with a nominal nozzle size of 130 ㎛. Both nozzle holes originate from a sac of identical geometry, but different flow structure inside the nozzle cause significant difference in the observed flow structure near the nozzle exit. The ultrafast fast Phase-contrast X-ray images revealed unique surface and internal morphology of the fuel sprays that can be identified. The two-hole nozzle produces much more unstable jet structure under same injection conditions. The early wavelength developed in the jet is measured to be 30~80 ㎛, depending on the injection conditions. The differences between the nozzle configurations are investigated using CFD simulation. The results show that the three-dimensional fluid flow entering the two-hole nozzle generates stronger streamline curvature and stream-wise vortices which are by default absent in the axisymmetric single-hole nozzle. It also produces thicker shear layer and higher turbulence. The interactions of downwash entrance flow with turbulence potentially enhance the instability and produce wider spray cone angles. The number of holes also has interesting effects on the strength of the vortices and the downwash.
Atomically Thin Ohmic Edge Contacts Between Two-Dimensional Materials
Guimarax303,es, Marcos H. D.,Gao, Hui,Han, Yimo,Kang, Kibum,Xie, Saien,Kim, Cheol-Joo,Muller, David A.,Ralph, Daniel C.,Park, Jiwoong American Chemical Society 2016 ACS NANO Vol.10 No.6
<P>With the decrease of the dimensions of electronic devices, the role played by electrical contacts is ever increasing, eventually coming to dominate the overall device volume and total resistance. This is especially problematic for monolayers of semiconducting transition-metal dichalcogenides (TMDs), which are promising candidates for atomically thin electronics. Ideal electrical contacts to them would require the use of similarly thin electrode materials while maintaining low contact resistances. Here we report a scalable method to fabricate ohmic graphene edge contacts to two representative monolayer TMDs, MoS<SUB>2</SUB> and WS<SUB>2</SUB>. The graphene and TMD layer are laterally connected with wafer-scale homogeneity, no observable overlap or gap, and a low average contact resistance of 30 kΩ·μm. The resulting graphene edge contacts show linear current–voltage (<I>I</I>–<I>V</I>) characteristics at room temperature, with ohmic behavior maintained down to liquid helium temperatures.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2016/ancac3.2016.10.issue-6/acsnano.6b02879/production/images/medium/nn-2016-02879m_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn6b02879'>ACS Electronic Supporting Info</A></P>
( D. Q. Zhang ),( C. Shi ),( J. Li ),( L. X. Gao ),( K. Y. Lee ) 한국부식방식학회 2017 Corrosion Science and Technology Vol.16 No.1
The corrosion behavior of a ferritic/martensitic steel T91 exposed to an aqueous solution containing chloride and sulfate ions is investigated depending on the stimulated all-volatile treatment (AVT) and under oxygenated treatment (OT) conditions. The corrosion of T91 steel under OT condition is severe, while the corrosion under AVT condition is not. The co-existence of chloride and sulfate ions has antagonistic effect on the corrosion of T91 steel in both AVT and OT conditions. Unlike to corrosion resistance in the aqueous solution, OT pretreatment provides T91 steel lower oxidation-resistance than VAT pretreatment. From scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis, the lower corrosion resistance in the aqueous solution by VAT conditions possibly is due to the formation of pits. In addition, the lower oxidation resistance of T91 steel pretreated by OT conditions is explained as follows: the cracks formed during the immersion under OT conditions accelerated peeling-off rate of the oxide film.
Nanowire Perovskite Solar Cell
Im, Jeong-Hyeok,Luo, Jingshan,Franckevicx30c,ius, Marius,Pellet, Norman,Gao, Peng,Moehl, Thomas,Zakeeruddin, Shaik Mohammed,Nazeeruddin, Mohammad Khaja,Grax308,tzel, Michael,Park, Nam-Gyu American Chemical Society 2015 NANO LETTERS Vol.15 No.3
<P>Organolead iodide perovskite, CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3</SUB>, was prepared in the form of nanowire by means of a small quantity of aprotic solvent in two-step spin-coating procedure. One-dimensional nanowire perovskite with the mean diameter of 100 nm showed faster carrier separation in the presence of hole transporting layer and higher lateral conductivity than the three-dimensional nanocuboid crystal. Reduction in dimensionality resulted in the hypsochromic shift of both absorption and fluorescence spectra, indicative of more localized exciton states in nanowires. The best performing device employing nanowire CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3</SUB> delivered photocurrent density of 19.12 mA/cm<SUP>2</SUP>, voltage of 1.052 V, and fill factor of 0.721, leading to a power conversion efficiency (PCE) of 14.71% at standard AM 1.5G solar illumination. A small <I>I</I>–<I>V</I> hysteresis was observed, where a PCE at forward scan was measured to be 85% of the PCE at reverse scan.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2015/nalefd.2015.15.issue-3/acs.nanolett.5b00046/production/images/medium/nl-2015-00046q_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl5b00046'>ACS Electronic Supporting Info</A></P>
Y.C. Li,M.H. Li,M. Wang,L. Liu,X.J. Zhang,C.M. Qin,Y.F. Wang,C.B. Wu,L.N. Liu,J.C. Xu,B. J. Ding,X. D. Lin,B. J. Ding,X. D. Lin,J. F. Shan,F. K. Liu,Y. P. Zhao,T. Zhang,X. Gao 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.1
The suppression of high-intensity blob structures in the scrape-off layer (SOL) by ion-cyclotron range offrequencies (ICRF) power, leading to a decrease in the turbulent fluctuation level, is observed first in theExperimental Advanced Superconducting Tokamak (EAST) experiment. This suppression effect from ICRFpower injection is global in the whole SOL at EAST, i.e. blob structures both in the regions that aremagnetically connected to the active ICRF launcher and in the regions that are not connected to theactive ICRF launcher could be suppressed by ICRF power. However, more ICRF power is required to reachthe full blob structure suppression effect in the regions that are magnetically unconnected to the activelauncher than in the regions that are magnetically connected to the active launcher. Studies show that apossible reason for the blob suppression could be the enhanced Er B shear flow in the SOL, which issupported by the shaper radial gradient in the floating potential profiles sensed by the divertor probearrays with increasing ICRF power. The local RF wave power unabsorbed by the core plasma isresponsible for the modification of potential profiles in the SOL regions.