S6K1 Phosphorylation of H2B Mediates EZH2 Trimethylation of H3: A Determinant of Early Adipogenesis

Yi, S.,Um, S.,Lee, J.,Yoo, J.,Bang, S.,Park, E.,Lee, M.,Nam, K.,Jeon, Y.,Park, J.,You, J.,Lee, S.J.,Bae, G.U.,Rhie, J.,Kozma, Sara C.,Thomas, G.,Han, J.W. Cell Press 2016 Molecular Cell Vol.62 No.3

S6K1 has been implicated in a number of key metabolic responses, which contribute to obesity. Critical among these is the control of a transcriptional program required for the commitment of mesenchymal stem cells to the adipocytic lineage. However, in contrast to its role in the cytosol, the functions and targets of nuclear S6K1 are unknown. Here, we show that adipogenic stimuli trigger nuclear translocation of S6K1, leading to H2BS36 phosphorylation and recruitment of EZH2 to H3, which mediates H3K27 trimethylation. This blocks Wnt gene expression, inducing the upregulation of PPARγ and Cebpa and driving increased adipogenesis. Consistent with this finding, white adipose tissue from S6K1-deficient mice exhibits no detectable H2BS36 phosphorylation or H3K27 trimethylation, whereas both responses are highly elevated in obese humans or in mice fed a high-fat diet. These findings define an S6K1-dependent mechanism in early adipogenesis, contributing to the promotion of obesity.

Geochronological and geochemical implications of Early to Middle Jurassic continental adakitic arc magmatism in the Korean Peninsula

Kim, S.W.,Kwon, S.,Ko, K.,Yi, K.,Cho, D.L.,Kee, W.S.,Kim, B.C. Universitetsforlaget ; Elsevier Science Ltd 2015 Lithos Vol.227 No.-

Sensitive high-resolution ion microprobe (SHRIMP) zircon U-Pb ages and whole-rock chemical compositions of Early to Middle Jurassic plutons from the central to southern Korean Peninsula are reported to investigate the effect of paleo-Pacific plate subduction preserved along the continental margin. Twenty-one plutonic rocks from the Yeongnam massif (i.e., Sunchang and Namwon plutons), the Okcheon belt (Jeongup, Boeun, and Mungyeong plutons), the northeast (Gangreung pluton), and the Gyeonggi massif (Gonam, Anheung, and Ganghwa plutons) have age ranges from ca. 189-186Ma to 177Ma, 177-166Ma, and 177-173Ma, respectively. Most plutonic rocks have chemical compositions similar to adakites, showing high SiO<SUB>2</SUB> (45.62-74.96wt.%), low MgO (0.01-2.84wt.%), high Na<SUB>2</SUB>O (2.65-4.83wt.%), high Sr/Y and La/Yb, low Y and Yb, as well as low HFSEs (Nb and Ta), but initial Sr ratios (0.7048-0.7262), K<SUB>2</SUB>O (0.50-5.88wt.%), and K<SUB>2</SUB>O/Na<SUB>2</SUB>O (0.34-2.1) were unlikely to have been formed by melting of either a thickened and/or delaminated lower continental crust, or an altered oceanic crust. These suggest that the ''adakitic'' plutonic rocks in this region resulted from partial melting of an enriched mantle source metasomatized by dewatering from a delaminated flat-slab. The spatial distributions of this continental adakitic plutonic belt, based on the present study, together with previously reported geochronological results, indicate that magmatic pulses gradually migrated toward the continent across the Korean Peninsula as a result of slab shallowing caused by periodic slab buckling. The similar geochronological and geochemical characteristics, petrogenesis and tectonic setting of the plutonic belt spanning the Korean Peninsula, Japan, eastern China, and eastern Russia indicate a possible link to an active subduction system that existed during the Early to Middle Jurassic, although the products of the plate subduction might differ in different locations along the East Asian continental margin.

Effects of a bio-assay guided fraction from Polygonum cuspidatum root on the viability, acid production and glucosyltranferase of mutans streptococci

Ban, S.H.,Kwon, Y.R.,Pandit, S.,Lee, Y.S.,Yi, H.K.,Jeon, J.G. Inverni Della Beffa S.p.A ; Elsevier Science 2010 Fitoterapia Vol.81 No.1

Polygonum cuspidatum root has been traditionally used for the treatment of dental diseases in Korea. The purpose of this study was to evaluate effects of P. cuspidatum root on the development of dental caries, especially its effects against bacterial viability and caries-inducing factors of Strptococcus mutans and Strptococcus sobrinus. Among methanol extract of P. cuspidatum root and its fraction tested, ethyl acetate fraction, composed of polydatin, resveratrol, anthraglycoside B, and emodin, showed inhibitory effects on glycolytic acid production and glucosyltransferase activity of S. mutans and S. sobrinus in addition to antibacterial activities.

Tectonic and deformation history of the Gyeonggi Massif in and around the Hongcheon area, and its implications in the tectonic evolution of the North China Craton

Yengkhom, K.S.,Lee, B.C.,Oh, C.W.,Yi, K.,Kang, J.H. Elsevier Scientific Pub. Co., etc.] 2014 Precambrian research Vol.240 No.-

The Precambrian rocks of the Gyeonggi Massif (GM) in and around the Hongcheon area, South Korea, consist of the Yongduri Gneiss Complex (YGC), Euiam Group (EG) and Euiam Gneiss Complex (EGC). The YGC and EG are composed mainly of partially migmatised metasedimentary rocks and the EGC is Paleoproterozoic intrusive rock that intruded the EG. At least three major folding (F<SUB>1</SUB>, F<SUB>2</SUB> & F<SUB>3</SUB>) accompanied with the two-stages of ductile shearing and three-stages of metamorphic events (M1, M2 & M3) occurred in the study area. The F<SUB>1</SUB> folds are extremely drawn out, isoclinal, intrafolial folds and have Class 2 to Class 1C geometry. The F<SUB>1</SUB> folds and regional S<SUB>1</SUB> foliation in the YGC and EG are the results of E-W compression during the D<SUB>1</SUB> deformation. Ductile shearing in the southern part of the EG is marked by the Palbongsan Shear Zone that indicates top-to-the SW sheared movement during syn to post-F<SUB>1</SUB> folding. The F<SUB>2</SUB> folds are open to tight, SW plunging and inclined folds, and have Class 1A to 1C geometry. The F<SUB>2</SUB> folding and subsequent NNE thrusting along multiple ductile shear zone parallel to S<SUB>2</SUB> planar fabrics, represent the D<SUB>2</SUB> deformation due to N-S progressive shortening. The D<SUB>3</SUB> deformation was coaxial with the D<SUB>1</SUB> deformation, leading to the development of the F<SUB>3</SUB> kink bands in the mylonite zones. The SHRIMP zircon ages form the EG yield M1 metamorphism age of 1917-1925Ma. However ca. 1867-1883Ma, M2 metamorphism previously reported from the YGC is absent or weakly preserved in the EG representing that the M2 metamorphism was not strong enough to form new zircon in the EG. The igneous zircons from the augen gneiss in the EGC yield intrusion age of ca. 1867-1881Ma and the geochemistries of the EGC gneisses show post-collision tectonic origin. The D<SUB>1</SUB> deformation observed in the YGC and EG but not in the EGC. The D<SUB>1</SUB> deformation occurred during M1 metamorphism, and then the M2 metamorphism and 1867-1881Ma igneous activities could have occurred together during post-collision tectonic stage. The M1 metamorphism and ca. 1867-1881Ma post collision magmatism in the study area are well matched with the collision related metamorphism at ca. 1.90-1.93Ga and post collision igneous activities at ca. 1.80-1.86Ga along the Jiao-Liao-Ji belt in the North China Craton suggesting that M1 metamorphism could have caused by the collision along the Jiao-Liao-Ji belt. The M3 metamorphism occurred at ca. 230-260Ma and its peak metamorphic conditions were 720-730<SUP>o</SUP>C/13-14.5kbar. The D<SUB>2</SUB> deformation and the M3 intermediate-P/T metamorphism occurred during the Permo-Triassic collision event between the North China Craton and South China Craton. The study area was not a collision boundary but located in the peripheral areas of the collision belt during the Paleoproterozoic and the Permo-Triassic time. The D<SUB>3</SUB> deformation occurred at a time gap between the Permo-Triassic collision and the subduction related Jurassic intrusion in the Korean Peninsula.

Novel method for investigation of a K-Mg-based CO₂ sorbent for sorption-enhanced water-gas shift reaction

Byun, C.K.,Kwon, S.J.,Im, H.B.,Ahn, H.S.,Ryu, H.J.,Yi, K.B. Pergamon Press 2016 RENEWABLE ENERGY Vol.87 No.1

CO<SUB>2</SUB> sorption reactions at 20 bar and two different temperatures (i.e., 180 and 220 <SUP>o</SUP>C) using a K-Mg-based CO<SUB>2</SUB> sorbent were carried out in a custom-designed high-pressure thermogravimetric analyzer (pressurized bubbling fluidized bed reactor on a scale) coupled with a gas chromatograph. The experimental apparatus, including the thermogravimetric analyzer, was custom-designed to measure weight changes caused by either CO<SUB>2</SUB> sorption or water sorption or both. Analysis of the CO<SUB>2</SUB> sorption reaction revealed that water sorption takes place rapidly with a moderate CO<SUB>2</SUB> sorption rate at the early stage of the reaction. Then, the reaction migrates to CO<SUB>2</SUB> sorption with simultaneous water desorption. Therefore, the mechanism of the CO<SUB>2</SUB> sorption reaction is assumed to consist of fast hydration of K<SUB>2</SUB>CO<SUB>3</SUB> and MgO, formation and decomposition of KHCO<SUB>3</SUB>, and finally carbonation of Mg(OH)<SUB>2</SUB> resulting in MgCO<SUB>3</SUB> as the main product. K<SUB>2</SUB>CO<SUB>3</SUB> is assumed to provide an efficient pathway for CO<SUB>2</SUB> and water to travel into the core region of the sorbent via a reversible reaction between K<SUB>2</SUB>CO<SUB>3</SUB> and KHCO<SUB>3</SUB>.

Novel signaling axis for ROS generation during K-Ras-induced cellular transformation

Park, M-T,Kim, M-J,Suh, Y,Kim, R-K,Kim, H,Lim, E-J,Yoo, K-C,Lee, G-H,Kim, Y-H,Hwang, S-G,Yi, J-M,Lee, S-J Macmillan Publishers Limited 2014 CELL DEATH AND DIFFERENTIATION Vol.21 No.8

Reactive oxygen species (ROS) are well known to be involved in oncogene-mediated cellular transformation. However, the regulatory mechanisms underlying ROS generation in oncogene-transformed cells are unclear. In the present study, we found that oncogenic K-Ras induces ROS generation through activation of NADPH oxidase 1 (NOX1), which is a critical regulator for the K-Ras-induced cellular transformation. NOX1 was activated by K-Ras-dependent translocation of p47<SUP>phox</SUP>, a subunit of NOX1 to plasma membrane. Of note, PKCδ, when it was activated by PDPK1, directly bound to the SH3-N domain of p47<SUP>phox</SUP> and catalyzed the phosphorylation on Ser348 and Ser473 residues of p47<SUP>phox</SUP> C-terminal in a K-Ras-dependent manner, finally leading to its membrane translocation. Notably, oncogenic K-Ras activated all MAPKs (JNK, ERK and p38); however, only p38 was involved in p47<SUP>phox</SUP>-NOX1-dependent ROS generation and consequent transformation. Importantly, K-Ras-induced activation of p38 led to an activation of PDPK1, which then signals through PKCδ, p47<SUP>phox</SUP> and NOX1. In agreement with the mechanism, inhibition of p38, PDPK1, PKCδ, p47<SUP>phox</SUP> or NOX1 effectively blocked K-Ras-induced ROS generation, anchorage-independent colony formation and tumor formation. Taken together, our findings demonstrated that oncogenic K-Ras activates the signaling cascade p38/PDPK1/PKCδ/p47<SUP>phox</SUP>/NOX1 for ROS generation and consequent malignant cellular transformation.

Pressure-induced changes in local electronic structures of SiO₂ and MgSiO₃ polymorphs: Insights from ab initio calculations of O K-edge energy-loss near-edge structure spectroscopy

Yi, Y.S.,Lee, S.K. MINERALOGICAL SOCIETY OF AMERICA 2012 The American mineralogist Vol.97 No.5

Effect of inbreeding in Korean white pine, Pinus koraiensis S. & Z. Ⅰ. The Most Suitable Time for Pollen Collection

J. S. Yi(李在善),K. B. Yim(任慶彬) 한국육종학회 1981 한국육종학회지 Vol.13 No.3

This investigation of pollen formation and germination, and strobilus characteristics in Pinus koraiensis was carried out to determine the most adequate time for pollen collection. The pollen before the first mitotic cell division, not having a prothalial and a central cell, did not germinate; only the pollen containing 2 to4nuclei (after the first, second, or third mitotic division) germinated. The pollen procured from the male strobili (which ware dried in the shade for 3 days immediately after collection) showed 59% germination rate. At this stage, the pollen grains completed the third mitotic cell division. The staminate flowers were a light yellow-green or a bright yellow-green color. The tip part of staminate strobilus was tinted with dull red or deep red-purple spots. The bracts were bent back and individual sporangia separated each other. The pollen at the stage of dispersion showed germination rate of 99%.

Recurrent rare earth element mineralization in the northwestern Okcheon Metamorphic Belt, Korea: SHRIMP U-Th-Pb geochronology, Nd isotope geochemistry, and tectonic implications

Cheong, C.s.,Kim, N.,Yi, K.,Jo, H.J.,Jeong, Y.J.,Kim, Y.,Koh, S.M.,Iizuka, T. Elsevier 2015 Ore geology reviews Vol.71 No.-

Rare earth element (REE) mineralization is hosted within Neoproterozoic alkaline metaigneous rocks in the northwestern part of the Okcheon Metamorphic Belt (OMB), a polymetamorphosed fold-and-thrust belt transecting the Paleoproterozoic Gyeonggi and Yeongnam Massifs in the southern Korean Peninsula. The principal carrier phase of REEs is allanite. Allanite grains can be subdivided into several types based on the texture and mineral assemblage including quartz, K-feldspar, biotite, britholite, apatite, fergusonite, andradite, magnetite, zircon, titanite and fluorite. Electron microprobe analysis of allanite clearly distinguishes sample-to-sample variations in total REEs, Ca, Al, Fe and Y but the textural varieties from each rock sample do not show marked differences in those elements. Sensitive high-resolution ion microprobe dating of allanite and zircon reveals a complex history of multistage mineralization. Allanite grains from REE ores yielded Late Ordovician (444.6+/-8.0Ma), Permian to Triassic (ca. 300-220Ma) and Early Jurassic (199-183Ma) <SUP>208</SUP>Pb/<SUP>232</SUP>Th ages. These multiple age components often coexist in single grains showing slight differences in backscattered electron brightness. The Ordovician components have distinctly higher Th/U than the younger domains in the same rock sample. The cores and rims of zircon from a syenite hosting REE ore bodies yielded Neoproterozoic (858.2+/-6.3Ma) and Early Jurassic (ca. 190Ma) <SUP>206</SUP>Pb/<SUP>238</SUP>U ages, respectively. The Early Jurassic ages (194-187Ma) also obtained from zircon grains from granites taken from dykes occurring close to the ores and a drill core indicate the correspondence between granitic magmatism and REE mineralization. The Neoproterozoic zircon inheritance (weighted mean=853.9+/-3.8Ma) in these granites is in sharp contrast to the dominant Paleoproterozoic inherited zircon from the widespread earliest Middle Jurassic granites enclosing the mineralized zone. The geotectonic significance of the Late Ordovician event recorded in the allanite, as well as in detrital zircon from the OMB, is still unclear but its temporal coincidence with intraplate volcanism and arc-related igneous activity, respectively, reported from the southwestern edge of the adjacent Taebaeksan Basin and the southwestern Gyeonggi Massif is noteworthy. The following Permian-Triassic and Early Jurassic mineralization events are probably linked to the continental suturing between the North and South China blocks and subsequent post-orogenic magmatism, and arc magmatism resulting from the paleo-Pacific plate subduction, respectively. Sub-grain Sm-Nd isotopic analyses of allanite by laser ablation multiple collector ICPMS yielded initial ε<SUB>Nd</SUB> values plotting along the Nd isotopic evolution path of the Neoproterozoic metaigneous rocks, indicating that REEs originating from the host rock have been recycled during multistage mineralization events. The profound differences in inherited zircon ages and Nd isotopic compositions between the Early and Middle Jurassic granites may reflect the presence of a major thrust-bounded crustal structure beneath the OMB.

The SAURON project – XIII. SAURON–GALEX study of early-type galaxies: the ultraviolet colour–magnitude relations and Fundamental Planes

Jeong, Hyunjin,Yi, Sukyoung K.,Bureau, Martin,Davies, Roger L.,Falcó,n-Barroso, Jesú,s,van de Ven, Glenn,Peletier, Reynier F.,Bacon, Roland,Cappellari, Michele,de Zeeuw, Tim,Emsellem, Eric Blackwell Publishing Ltd 2009 Monthly notices of the Royal Astronomical Society Vol.398 No.4

<P>ABSTRACT</P><P>We present <I>Galaxy Evolution Explorer</I> far-ultraviolet (FUV) and near-ultraviolet (NUV) imaging of 34 nearby early-type galaxies from the SAURON representative sample of 48 E/S0 galaxies, all of which have ground-based optical imaging from the MDM Observatory. The surface brightness profiles of nine galaxies (≈26 per cent) show regions with blue UV−optical colours suggesting RSF. Five of these (≈15 per cent) show blue integrated UV–optical colours that set them aside in the NUV integrated colour–magnitude relation. These are objects with either exceptionally intense and localized NUV fluxes or blue UV−optical colours throughout. They also have other properties confirming they have had RSF, in particular Hβ absorption higher than expected for a quiescent population and a higher CO detection rate. This suggests that residual star formation is more common in early-type galaxies than we are used to believe. NUV blue galaxies are generally drawn from the lower stellar velocity dispersion (σ<SUB>e</SUB> < 200 km s<SUP>−1</SUP>) and thus lower dynamical mass part of the sample. We have also constructed the first UV Fundamental Planes and show that NUV blue galaxies bias the slopes and increase the scatters. If they are eliminated, the fits get closer to expectations from the virial theorem. Although our analysis is based on a limited sample, it seems that a dominant fraction of the tilt and scatter of the UV Fundamental Planes is due to the presence of young stars in preferentially low-mass early-type galaxies. Interestingly, the UV–optical radial colour profiles reveal a variety of behaviours, with many galaxies showing signs of RSF, a central UV-upturn phenomenon, smooth but large-scale age and metallicity gradients and in many cases a combination of these. In addition, FUV−NUV and FUV−<I>V</I> colours even bluer than those normally associated with UV-upturn galaxies are observed at the centre of some quiescent galaxies. Four out of the five UV-upturn galaxies are slow rotators. These objects should thus pose interesting challenges to stellar evolutionary models of the UV upturn.</P>