Stand-alone ClpG disaggregase confers superior heat tolerance to bacteria

Lee, Changhan,Franke, Kamila B.,Kamal, Shady Mansour,Kim, Hyunhee,Lunsdorf, Heinrich,Jager, Jasmin,Nimtz, Manfred,Trc0c,ek, Janja,Jansch, Lothar,Bukau, Bernd,Mogk, Axel,Romling, Ute National Academy of Sciences 2018 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.115 No.2

<P><B>Significance</B></P><P>Severe heat stress causes massive protein loss by aggregation ultimately causing cell death. Cellular survival relies on protein disaggregation mediated by the Hsp70-ClpB (Hsp100) bichaperone system in most bacteria. <I>Pseudomonas aeruginosa</I> additionally codes for two stand-alone ClpG disaggregases, which had been acquired by horizontal gene transfer by the species and most abundant clone C strains, respectively. These ClpG disaggregases largely contribute to the resolution of protein aggregates to confer superior heat tolerance partially replacing the DnaK-ClpB system.</P><P>AAA+ disaggregases solubilize aggregated proteins and confer heat tolerance to cells. Their disaggregation activities crucially depend on partner proteins, which target the AAA+ disaggregases to protein aggregates while concurrently stimulating their ATPase activities. Here, we report on two potent ClpG disaggregase homologs acquired through horizontal gene transfer by the species <I>Pseudomonas aeruginosa</I> and subsequently abundant <I>P. aeruginosa</I> clone C. ClpG exhibits high, stand-alone disaggregation potential without involving any partner cooperation. Specific molecular features, including high basal ATPase activity, a unique aggregate binding domain, and almost exclusive expression in stationary phase distinguish ClpG from other AAA+ disaggregases. Consequently, ClpG largely contributes to heat tolerance of <I>P. aeruginosa</I> primarily in stationary phase and boosts heat resistance 100-fold when expressed in <I>Escherichia coli</I>. This qualifies ClpG as a potential persistence and virulence factor in <I>P. aeruginosa</I>.</P>

Direct Reprogramming of Fibroblasts into Neural Stem Cells by Defined Factors

Han, D.,Tapia, N.,Hermann, A.,Hemmer, K.,Hoing, S.,Arauzo-Bravo, Marcos J.,Zaehres, H.,Wu, G.,Frank, S.,Moritz, S.,Greber, B.,Yang, J.,Lee, H.,Schwamborn, Jens C.,Storch, A.,Scholer, Hans R. Cell Press 2012 Cell stem cell Vol.10 No.4

Recent studies have shown that defined sets of transcription factors can directly reprogram differentiated somatic cells to a different differentiated cell type without passing through a pluripotent state, but the restricted proliferative and lineage potential of the resulting cells limits the scope of their potential applications. Here we show that a combination of transcription factors (Brn4/Pou3f4, Sox2, Klf4, c-Myc, plus E47/Tcf3) induces mouse fibroblasts to directly acquire a neural stem cell identity-which we term as induced neural stem cells (iNSCs). Direct reprogramming of fibroblasts into iNSCs is a gradual process in which the donor transcriptional program is silenced over time. iNSCs exhibit cell morphology, gene expression, epigenetic features, differentiation potential, and self-renewing capacity, as well as in vitro and in vivo functionality similar to those of wild-type NSCs. We conclude that differentiated cells can be reprogrammed directly into specific somatic stem cell types by defined sets of specific transcription factors.

ECONOMIC GROWTH OF OECD COUNTRIES : FOCUSING ON CANADA

LEE, FRANK C. 한국국제경제학회 1996 International Economic Journal Vol.10 No.2

Conditional Labor Productivity Convergence in Canada

Frank C. Lee 서울대학교 경제연구소 1997 Seoul journal of economics Vol.10 No.1

The purpose of this paper is to investigate the determinants of labor productivity growth at the provincial level in Canada over the 1966-92 period. The model considers differences in the initial level of labor productivity, human capital characteristics, private and public investments, and industry mix as explanatory variables in determining productivity growth. The main results are the following. The rate of human capital accumulation (its effect becomes more significant once the effects of inter-provincial migration are accounted for) and public investment (excluding government investment on non-residential construction) are positively correlated with productivity growth while the initial level of productivity and government consumption are negatively correlated with productivity growth. On the other hand, private investment is not significantly correlated with provincial productivity growth reflecting the high degree of private capital mobility between regions in Canada. Relatively slow convergence we observe in Canada appears, in part, to be due to differences in the industry mix across provinces.

Impolications of Technology and Imports foe Employment and Wages in Canada

Lee, Frank C. 세종대학교 국제경제연구소 1999 Journal of Economic Integration Vol.14 No.2

This paper analyzes the net effects of technology and import competition on employment, wages and inequality in the Canadian manufacturing sector over the 1970-1990 period by estimating reduced form employment and wage equations. The analysis uses non-production and production workers to distinguish between two types of workers. For each group, person-hours worked, the level of employment and the hourly labor compensation by industry are examined. The major findings for the study are as follows: (1) the growth of employment and real hourly labor compensation in the Canadian manufacturing sector is positively related to technical progress and to the price of imports; (2) the relative employment of non-production to production workers is negatively related to technical progress, while the relative real hourly labor compensation of non-production to production workers is positively associated with technical progress; (3) the relative employment of non-production to production workers is negatively related to the price of imports, and the relative real hourly labor compensation is positively associated with the price of imports.(JEL Classification: F14, J23, J31.)

Implications of Technology and Imports for Employment and Wages in Canada

( Frank C. Lee ) 세종대학교 경제통합연구소(구 세종대학교 국제경제연구소) 1999 Journal of Economic Integration Vol.14 No.2

This paper analyzes the net effects of technology and import competition on employment, wages and wage inequality in the Canadian manufacturing sector over the 1970-1990 period by estimating reduced form employment and wage equations. The analysis uses non-production and production workers to distinguish between two types of workers. For each group, person-hours worked, the level of employment and the hourly labor compensation by industry are examined. The major findings for the study are as follows: (1) the growth of employment and real hourly labor compensation in the Canadian manufacturing sector is positively related to technical progress and to the price of imports; (2) the relative employment of non-production to production workers is negatively related to technical progress, while the relative real hourly labor compensation of non-production to production workers is positively associated with technical progress; (3) the relative employment of non-production to production workers is negatively related to the price of imports, and the relative real hourly labor compensation is positively associated with the price of imports. (JEL Classification: F14, J23, J31.)

Excimer Emission from Pulsed Tandem Microhollow Cathode Discharges in Xenon

Lee, B.-J.,Rahaman, H.,Nam, S.H.,Iberler, M.,Teske, C.,Jacoby, J.,Frank, K. JAPAN SOCIETY OF APPLIED PHYSICS 2012 Applied physics express Vol.5 No.5

Absolute binding free energy calculations of CBClip host-guest systems in the SAMPL5 blind challenge

Lee, Juyong,Tofoleanu, Florentina,Pickard IV, Frank C.,Kö,nig, Gerhard,Huang, Jing,Damjanović,, Ana,Baek, Minkyung,Seok, Chaok,Brooks, Bernard R. Springer-Verlag 2017 Journal of computer-aided molecular design Vol.31 No.1

<P>Herein, we report the absolute binding free energy calculations of CBClip complexes in the SAMPL5 blind challenge. Initial conformations of CBClip complexes were obtained using docking and molecular dynamics simulations. Free energy calculations were performed using thermodynamic integration (TI) with soft-core potentials and Bennett's acceptance ratio (BAR) method based on a serial insertion scheme. We compared the results obtained with TI simulations with soft-core potentials and Hamiltonian replica exchange simulations with the serial insertion method combined with the BAR method. The results show that the difference between the two methods can be mainly attributed to the van der Waals free energies, suggesting that either the simulations used for TI or the simulations used for BAR, or both are not fully converged and the two sets of simulations may have sampled difference phase space regions. The penalty scores of force field parameters of the 10 guest molecules provided by CHARMM Generalized Force Field can be an indicator of the accuracy of binding free energy calculations. Among our submissions, the combination of docking and TI performed best, which yielded the root mean square deviation of 2.94 kcal/mol and an average unsigned error of 3.41 kcal/mol for the ten guest molecules. These values were best overall among all participants. However, our submissions had little correlation with experiments.</P>

Minimizing Energy Consumption of Parallel Mechanisms via Redundant Actuation

Giuk Lee,Sumin Park,Donghun Lee,Park, Frank C.,Jeong, Jay I.,Jongwon Kim IEEE 2015 IEEE/ASME transactions on mechatronics Vol.20 No.6

<P>This paper shows that redundant actuation can reduce the energy consumption of parallel mechanisms, in some cases by a considerable margin. A theoretical analysis for the energy-saving mechanism is elucidated, and an energy consumption model for a servo-motor system is proposed. Our hypothesis is experimentally verified with a widely used two degree of freedom parallel mechanism design driven by three actuators. Experimental results show that redundant actuation can reduce the electrical energy consumption of the actuators by up to 45% compared to the corresponding nonredundantly actuated version of the mechanism.</P>

Association Between Leisure Time Physical Activity, Cardiopulmonary Fitness, Cardiovascular Risk Factors, and Cardiovascular Workload at Work in Firefighters

Clare C.W. Yu,Chun T. Au,Frank Y.F. Lee,Raymond C.H. So,John P.S. Wong,Gary Y.K. Mak,Eric P. Chien,Alison M. McManus 한국산업안전공단 산업안전보건연구원 2015 Safety and health at work Vol.6 No.3

Background: Overweight, obesity, and cardiovascular disease risk factors are prevalent among firefighters in some developed countries. It is unclear whether physical activity and cardiopulmonary fitness reduce cardiovascular disease risk and the cardiovascular workload at work in firefighters. The present study investigated the relationship between leisure-time physical activity, cardiopulmonary fitness, cardiovascular disease risk factors, and cardiovascular workload at work in firefighters in Hong Kong. Methods: Male firefighters (n ¼ 387) were randomly selected from serving firefighters in Hong Kong (n ¼ 5,370) for the assessment of cardiovascular disease risk factors (obesity, hypertension, diabetes mellitus, dyslipidemia, smoking, known cardiovascular diseases). One-third (Target Group) were randomly selected for the assessment of off-duty leisure-time physical activity using the short version of the International Physical Activity Questionnaire. Maximal oxygen uptake was assessed, as well as cardiovascular workload using heart rate monitoring for each firefighter for four “normal” 24-hour working shifts and during real-situation simulated scenarios. Results: Overall, 33.9% of the firefighters had at least two cardiovascular disease risk factors. In the Target Group, firefighters who had higher leisure-time physical activity had a lower resting heart rate and a lower average working heart rate, and spent a smaller proportion of time working at a moderateintensity cardiovascular workload. Firefighters who had moderate aerobic fitness and high leisuretime physical activity had a lower peak working heart rate during the mountain rescue scenario compared with firefighters who had low leisure-time physical activities. Conclusion: Leisure-time physical activity conferred significant benefits during job tasks of moderate cardiovascular workload in firefighters in Hong Kong.