Involvement of S6K1 in mitochondria function and structure in HeLa cells

Park, J.,Tran, Q.,Mun, K.,Masuda, K.,Kwon, S.H.,Kim, S.H.,Kim, D.H.,Thomas, G.,Park, J. Pergamon Press ; Elsevier Science Ltd 2016 Cellular signalling Vol.28 No.12

The major biological function of mitochondria is to generate cellular energy through oxidative phosphorylation. Apart from cellular respiration, mitochondria also play a key role in signaling processes, including aging and cancer metabolism. It has been shown that S6K1-knockout mice are resistant to obesity due to enhanced beta-oxidation, with an increased number of large mitochondria. Therefore, in this report, the possible involvement of S6K1 in regulating mitochondria dynamics and function has been investigated in stable lenti-shS6K1-HeLa cells. Interestingly, S6K1-stably depleted HeLa cells showed phenotypical changes in mitochondria morphology. This observation was further confirmed by detailed image analysis of mitochondria shape. Corresponding molecular changes were also observed in these cells, such as the induction of mitochondrial fission proteins (Drp1 and Fis1). Oxygen consumption is elevated in S6K1-depeleted HeLa cells and FL5.12 cells. In addition, S6K1 depletion leads to enhancement of ATP production in cytoplasm and mitochondria. However, the relative ratio of mitochondrial ATP to cytoplasmic ATP is actually decreased in lenti-shS6K1-HeLa cells compared to control cells. Lastly, induction of mitophagy was found in lenti-shS6K1-HeLa cells with corresponding changes of mitochondria shape on electron microscope analysis. Taken together, our results indicate that S6K1 is involved in the regulation of mitochondria morphology and function in HeLa cells. This study will provide novel insights into S6K1 function in mitochondria-mediated cellular signaling.

Study of B^+/-→K^+/-(K_SKπ)⁰ decay and determination of η_c and η_c(2S) parameters

Belle Collaboration,Vinokurova, A.,Kuzmin, A.,Eidelman, S.,Arinstein, K.,Aulchenko, V.,Aushev, T.,Bakich, A.M.,Balagura, V.,Barberio, E.,Belous, K.,Bhardwaj, V.,Bondar, A.,Bozek, A.,Bracko, M.,Brodzic North-Holland Pub. Co 2011 Physics letters: B Vol.706 No.2

We report the results of a study of B<SUP>+/-</SUP>→K<SUP>+/-</SUP>η<SUB>c</SUB> and B<SUP>+/-</SUP>→K<SUP>+/-</SUP>η<SUB>c</SUB>(2S) decays followed by η<SUB>c</SUB> and η<SUB>c</SUB>(2S) decays to (K<SUB>S</SUB>Kπ)<SUP>0</SUP>. The results are obtained from a data sample containing 535 million BB@?-meson pairs collected by the Belle experiment at the KEKB e<SUP>+</SUP>e<SUP>-</SUP> collider. We measure the products of the branching fractions B(B<SUP>+/-</SUP>→K<SUP>+/-</SUP>η<SUB>c</SUB>)B(η<SUB>c</SUB>→K<SUB>S</SUB>K<SUP>+/-</SUP>π<SUP>@?</SUP>)=(26.7+/-1.4(stat)<SUB>-2.6</SUB><SUP>+2.9</SUP>(syst)+/-4.9(model))x10<SUP>-6</SUP> and B(B<SUP>+/-</SUP>→K<SUP>+/-</SUP>η<SUB>c</SUB>(2S))B(η<SUB>c</SUB>(2S)→K<SUB>S</SUB>K<SUP>+/-</SUP>π<SUP>@?</SUP>)=(3.4<SUB>-1.5</SUB><SUP>+2.2</SUP>(stat+model)<SUB>-0.4</SUB><SUP>+0.5</SUP>(syst))x10<SUP>-6</SUP>. Interference with the non-resonant component leads to significant model uncertainty in the measurement of these product branching fractions. Our analysis accounts for this interference and allows the model uncertainty to be reduced. We also obtain the following charmonia masses and widths: M(η<SUB>c</SUB>)=(2985.4+/-1.5(stat)<SUB>-2.0</SUB><SUP>+0.5</SUP>(syst)) MeV/c<SUP>2</SUP>, Γ(η<SUB>c</SUB>)=(35.1+/-3.1(stat)<SUB>-1.6</SUB><SUP>+1.0</SUP>(syst)) MeV/c<SUP>2</SUP>, M(η<SUB>c</SUB>(2S))=(3636.1<SUB>-4.2</SUB><SUP>+3.9</SUP>(stat+model)<SUB>-2.0</SUB><SUP>+0.7</SUP>(syst)) MeV/c<SUP>2</SUP>, Γ(η<SUB>c</SUB>(2S))=(6.6<SUB>-5.1</SUB><SUP>+8.4</SUP>(stat+model)<SUB>-0.9</SUB><SUP>+2.6</SUP>(syst)) MeV/c<SUP>2</SUP>.

Fatigue performance of deepwater SCR under short-term VIV considering various S-N curves

Kim, D.K.,Choi, H.S.,Shin, C.S.,Liew, M.S.,Yu, S.Y.,Park, K.S. Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.5

In this study, a method for fatigue performance estimation of deepwater steel catenary riser (SCR) under short-term vortex-induced vibration was investigated for selected S-N curves. General tendency between S-N curve capacity and fatigue performance was analysed. SCRs are generally used to transport produced oil and gas or to export separated oil and gas, and are exposed to various environmental loads in terms of current, wave, wind and others. Current is closely related with VIV and it affects fatigue life of riser structures significantly. In this regards, the process of appropriate S-N curve selection was performed in the initial design stage based on the scale of fabrication-related initial imperfections such as welding, hot spot, crack, stress concentration factor, and others. To draw the general tendency, the effects of stress concentration factor (SCF), S-N curve type, current profile, and three different sizes of SCRs were considered, and the relationship between S-N curve capacity and short-term VIV fatigue performance of SCR was derived. In case of S-N curve selection, DNV (2012) guideline was adopted and four different current profiles of the Gulf of Mexico (normal condition and Hurricane condition) and Brazil (Amazon basin and Campos basin) were considered. The obtained results will be useful to select the S-N curve for deepwater SCRs and also to understand the relationship between S-N curve capacity and short-term VIV fatigue performance of deepwater SCRs.

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.

1H NMR Measurements of the Phase Transition of (NH₄)₃H(SO₄)₂ Single Crystals

S. H. Choi,Moohee Lee,Ae Ran Lim,K. S. Han,S. K. Kwon,S. K. Nam 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.2

$^1$H nuclear magnetic resonance (NMR) experiments have been performed in the temperature range of 30 -- 300 K at 7 T to investigate the phase-dependent nature of the dynamic network of hydrogen bonds in a ((NH₄)₃H(SO₄)₂ single crystal. The crystal has six phases, which are ferroelectric, antiferroelectric, incommensurate, antiferroelectric, ferroelastic, and superionic with the respective transition temperatures of 63, 133, 139, 256 and 413 K. The spin-lattice relaxation time, T₁, of ¹H NMR is similar for the ammonium protons and the hydrogen-bond protons over the entire range of experimental temperatures. The T₁, of ¹H NMR gradually decreases down to 120 K and starts to steeply increase below 100 K. Then, the T₁ shows an abrupt decrease below 68 K with a sharp minimum at 63 K, where the ferroelectric transition occurs. The ¹H NMR spectrum shifts to the high-frequency side at temperatures below 63 K due to the ferroelectric phase transition. This behavior of the T₁ and the spectrum confirms a dramatic change in the dynamics of hydrogen bonds associated with the ferroelectric phase transition at 63 K. $^1$H nuclear magnetic resonance (NMR) experiments have been performed in the temperature range of 30 -- 300 K at 7 T to investigate the phase-dependent nature of the dynamic network of hydrogen bonds in a ((NH₄)₃H(SO₄)₂ single crystal. The crystal has six phases, which are ferroelectric, antiferroelectric, incommensurate, antiferroelectric, ferroelastic, and superionic with the respective transition temperatures of 63, 133, 139, 256 and 413 K. The spin-lattice relaxation time, T₁, of ¹H NMR is similar for the ammonium protons and the hydrogen-bond protons over the entire range of experimental temperatures. The T₁, of ¹H NMR gradually decreases down to 120 K and starts to steeply increase below 100 K. Then, the T₁ shows an abrupt decrease below 68 K with a sharp minimum at 63 K, where the ferroelectric transition occurs. The ¹H NMR spectrum shifts to the high-frequency side at temperatures below 63 K due to the ferroelectric phase transition. This behavior of the T₁ and the spectrum confirms a dramatic change in the dynamics of hydrogen bonds associated with the ferroelectric phase transition at 63 K.

S–N Fatigue and Fatigue Crack Propagation Behaviors of X80 Steel at Room and Low Temperatures

Jung, D. H.,Kwon, J. K.,Woo, N. S.,Kim, Y. J.,Goto, M.,Kim, S. Springer Science + Business Media 2014 Metallurgical and Materials Transactions A - Physi Vol.45 No.2

<P>In the present study, the S-N fatigue and the fatigue crack propagation (FCP) behaviors of American Petroleum Institute X80 steel were examined in the different locations of the base metal (BM), weld metal (WM), and heat-affected zone (HAZ) at 298 K, 223 K, and 193 K (25 degrees C, 50 degrees C, and 80 degrees C). The resistance to S-N fatigue of X80 BM specimen increased greatly with decreasing temperature from 298 K to 193 K (25 degrees C to -80 degrees C) and showed a strong dependency on the flow strength (1/2(yield strength + tensile strength)). The FCP rates of X80 BM specimen were substantially reduced with decreasing temperature from 298 K to 223 K (25 degrees C to 50 degrees C) over the entire Delta K regime, while further reduction in FCP rates was not significant with temperature from 223 K to 193 K (-50 degrees C to -80 degrees C). The FCP rates of the X80 BM and the WM specimens were comparable with each other, while the HAZ specimen showed slightly better FCP resistance than the BM and the WM specimens over the entire Delta K regime at 298 K (25 degrees C). Despite the varying microstructural characteristics of each weld location, the residual stress appeared to be a controlling factor to determine the FCP behavior. The FCP behaviors of high strength X80 steel were discussed based on the microstructural and the fractographic observations. (C) The Minerals, Metals & Materials Society and ASM International 2013</P>

Diagnostic usefulness of a T cell-based assay for latent tuberculosis infection in kidney transplant candidates before transplantation

Kim, S.-H.,Lee, S.-O.,Park, I.-A.,Park, S.J.,Choi, S.-H.,Kim, Y.S.,Woo, J.H.,Park, S.-K.,Park, J.S.,Kim, S.C.,Han, D.J. Blackwell Publishing Inc 2010 Transplant infectious disease Vol.12 No.2

<P>S.-H. Kim, S.-O. Lee, I.-A. Park, S.J. Park, S.-H. Choi, Y.S. Kim, J.H. Woo, S.-K. Park, J.S. Park, S.C. Kim, D.J. Han. Diagnostic usefulness of a T cell-based assay for latent tuberculosis infection in kidney transplant candidates before transplantation.Transpl Infect Dis 2010: <B>12:</B> 113–119. All rights reserved</P><P>Background</P><P>The presence of latent tuberculosis (TB) infection (LTBI) should be evaluated before kidney transplantation. Although a new T cell-based assay for diagnosing LTBI gave promising results, this assay has not yet been compared with the tuberculin skin test (TST) for diagnosing LTBI in renal transplant candidates before transplantation.</P><P>Patients and methods</P><P>All adult patients admitted to a single institute for renal transplantation over a 1-year period were prospectively enrolled. A clinically predictive risk of LTBI was defined as: (i) recent close contact with a person with pulmonary TB; (ii) abnormal chest radiography; (iii) a history of untreated or inadequately treated TB; or (iv) a new infection (i.e., a recent conversion of TST).</P><P>Results</P><P>Of 209 renal recipients, 47 (22%) had a positive TST≥5 mm, 21 (10%) had a positive TST≥10 mm, 65 (30%) had a positive T-SPOT.<I>TB</I> test, and 25 (12%) had an indeterminate T-SPOT.<I>TB</I> test. The induration size of TST was significantly associated with a high positivity rate on T-SPOT.<I>TB</I> (<I>P</I><0.001). Agreement between T-SPOT.<I>TB</I> test and TST≥10 mm was fair (<I>k</I>=0.24, 95% confidence interval 0.11–0.36). However, neither univariate nor multivariate analysis showed any association between the clinical risk for LTBI and positivity on T-SPOT.<I>TB</I> or TST.</P><P>Conclusion</P><P>T-SPOT.<I>TB</I> test was more frequently positive than TST in renal transplant candidates. However, further longitudinal studies are awaited to determine whether the ability of T-SPOT.<I>TB</I> assay to detect LTBI in renal transplant recipients can better predict the development of TB than can TST after transplantation.</P>

A study of γγ->K_S⁰K_S⁰ production at energies from 2.4 to 4.0 GeV at Belle

Belle Collaboration,Chen, W.T.,Abe, K.,Abe, K.,Adachi, I.,Aihara, H.,Anipko, D.,Aulchenko, V.,Bakich, A.M.,Barberio, E.,Bay, A.,Bedny, I.,Bitenc, U.,Bizjak, I.,Blyth, S.,Bondar, A.,Bozek, A.,Bracko, M North-Holland Pub. Co 2007 Physics letters: B Vol.651 No.1

K<SUB>S</SUB><SUP>0</SUP>K<SUB>S</SUB><SUP>0</SUP> production in two-photon collisions has been studied using a 397.6 fb<SUP>-1</SUP> data sample collected with the Belle detector at the KEKB e<SUP>+</SUP>e<SUP>-</SUP> collider. For the first time the cross sections are measured in the two-photon center-of-mass energy range between 2.4 GeV and 4.0 GeV and angular range |cosθ<SUP>*</SUP>|<0.6. Combining the results with measurements of γγ->K<SUP>+</SUP>K<SUP>-</SUP> from Belle, we observe that the cross section ratio σ(K<SUB>S</SUB><SUP>0</SUP>K<SUB>S</SUB><SUP>0</SUP>)/σ(K<SUP>+</SUP>K<SUP>-</SUP>) decreases from ∼0.13 to ∼0.01 with increasing energy. Signals for the χ<SUB>c0</SUB> and χ<SUB>c2</SUB> charmonium states are also observed.

ZNF509S1 downregulates PUMA by inhibiting p53K382 acetylation and p53-DNA binding

Jeon, B.N.,Yoon, J.H.,Han, D.,Kim, M.K.,Kim, Y.,Choi, S.H.,Song, J.,Kim, K.S.,Kim, K.,Hur, M.W. Elsevier Science 2017 Biochimica et biophysica acta. Gene regulatory mec Vol.1860 No.9

Expression of the POK family protein ZNF509L, and -its S1 isoform, is induced by p53 upon exposure to genotoxic stress. Due to alternative splicing of the ZNF509 primary transcript, ZNF509S1 lacks the 6 zinc-fingers and C-terminus of ZNF509L, resulting in only one zinc-finger. ZNF509L and -S1 inhibit cell proliferation by activating p21/CDKN1A and RB transcription, respectively. When cells are exposed to severe DNA damage, p53 activates PUMA (p53-upregulated modulator of apoptosis) transcription. Interestingly, apoptosis due to transcriptional activation of PUMA by p53 is attenuated by ZNF509S1. Thus we investigated the molecular mechanism(s) underlying the transcriptional attenuation and anti-apoptotic effects of ZNF509S1. We show that ZNF509S1 modulation of p53 activity is important in PUMA gene transcription by modulating post-translational modification of p53 by p300. ZNF509S1 directly interacts with p53 and inhibits p300-mediated acetylation of p53 lysine K382, with deacetylation of p53 K382 leading to decreased DNA binding at the p53 response element 1 of the PUMA promoter. ZNF509S1 may play a role not only in cell cycle arrest, by activating RB expression, but also in rescuing cells from apoptotic death by repressing PUMA expression in cells exposed to severe DNA damage.

벼 육묘트레이를 이용한 어린 잎 채소 생육에 미치는 광 조절 영향

최기영 ( K. Y. Choi ),김시홍 ( S. H. Kim ),김재경 ( J. K. Kim ),유형주 ( H. J. Yoo ),김일섭 ( I. S. Kim ) 강원대학교 농업생명과학연구원(구 농업과학연구소) 2016 강원 농업생명환경연구 Vol.28 No.2

벼 육묘 트레이를 활용한 어린잎 채소 재배 가능성을 탐색하고자 재배 기간 중 차광 처리하여 다채, 청경채, 알파인배추, 청치마 상추 등 4종을 17일간 재배하였다. 차광 처리는 무차광 17일(NS), 차광 8일+무차광 9일 (S8NS9), 무차광 8일+차광 9일(NS8S9), 차광 17일(S17) 하였다. 처리에 따른 누적 광량은 NS>S8NS9>NS8S9>S17처리구 순으로 높았으나, 누적 온도는 처리에 따른 차이가 크지 않았다 차광 8일 째 어린잎채소 4종의 생육과 엽록소함량은 감소하였다. 광 조절 17일 째 어린잎채소 4종의 초장, 엽장, 엽폭, 경경, 생체중, 엽록소 함량 등의 생육은 무차광 NS 처리구에서 가장 높았다. 생육 초기 광조절에 따른 생육 후기 초장과 생체중 증가율이 어린잎채소 4종 모두 NS 또는 S8NS9 처리구에서 높았다. 따라서 벼 육묘장 다층 시스템에서의 공간 활용을 고려한 어린잎채소 재배시 차광이 많은 하부 공간은 생육초기에 활용하고, 수확기에는 광 확보가 이루어지는 상부에서 재배가 이루어짐이 적합하리라 본다. This study was conducted to investigate the effect of light control on growth of baby leaf vegetables (tatsoi, pak-choi, chinese cabbage ‘alpine’ and leaf lettuce ‘cheongchima’) in rice seedling tray. Light treatment controlled in non-shading (NS), shading for 8 days+non-shading for 9 days (S8NS9), non-shading for 8 days+shading for 9 days (NS8S9), and shading for 17 days (S17). Integrated solar radiation in NS was highest, and in S8NS9>NS8S9>S17 order. Integrated temperature did not shown difference among the treatments for growing periods. Growth and chlorophyll content of baby leaf vegetables were lowest in shading treatment for 8days. The highest growth characteristics (plant height, leaf length, leaf width, stem diameters, and fresh weight) and chlorophyll content of baby leaf vegetables was shown in NS. Increment rate of plant height and fresh weight of baby leaf vegetables were high in NS or S8NS9 as affected by light control for 8 days in early growth periods. These results suggest that we can utilize in low layer for early period and in high layer for harvest periods for baby vegetable production in rice seedling factory.