1
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Barrick JE, Yu DS, Yoon SH, Jeong H, Oh TK, Schneider D, Lenski RE, Kim JF. Genome evolution and adaptation in a long-term experiment with Escherichia coli. Nature 2009; 461:1243-7. [PMID: 19838166 DOI: 10.1038/nature08480] [Citation(s) in RCA: 805] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Accepted: 08/28/2009] [Indexed: 11/09/2022]
Abstract
The relationship between rates of genomic evolution and organismal adaptation remains uncertain, despite considerable interest. The feasibility of obtaining genome sequences from experimentally evolving populations offers the opportunity to investigate this relationship with new precision. Here we sequence genomes sampled through 40,000 generations from a laboratory population of Escherichia coli. Although adaptation decelerated sharply, genomic evolution was nearly constant for 20,000 generations. Such clock-like regularity is usually viewed as the signature of neutral evolution, but several lines of evidence indicate that almost all of these mutations were beneficial. This same population later evolved an elevated mutation rate and accumulated hundreds of additional mutations dominated by a neutral signature. Thus, the coupling between genomic and adaptive evolution is complex and can be counterintuitive even in a constant environment. In particular, beneficial substitutions were surprisingly uniform over time, whereas neutral substitutions were highly variable.
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Research Support, U.S. Gov't, Non-P.H.S. |
16 |
805 |
2
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Jeong H, Barbe V, Lee CH, Vallenet D, Yu DS, Choi SH, Couloux A, Lee SW, Yoon SH, Cattolico L, Hur CG, Park HS, Ségurens B, Kim SC, Oh TK, Lenski RE, Studier FW, Daegelen P, Kim JF. Genome sequences of Escherichia coli B strains REL606 and BL21(DE3). J Mol Biol 2009; 394:644-52. [PMID: 19786035 DOI: 10.1016/j.jmb.2009.09.052] [Citation(s) in RCA: 271] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 09/21/2009] [Indexed: 12/23/2022]
Abstract
Escherichia coli K-12 and B have been the subjects of classical experiments from which much of our understanding of molecular genetics has emerged. We present here complete genome sequences of two E. coli B strains, REL606, used in a long-term evolution experiment, and BL21(DE3), widely used to express recombinant proteins. The two genomes differ in length by 72,304 bp and have 426 single base pair differences, a seemingly large difference for laboratory strains having a common ancestor within the last 67 years. Transpositions by IS1 and IS150 have occurred in both lineages. Integration of the DE3 prophage in BL21(DE3) apparently displaced a defective prophage in the lambda attachment site of B. As might have been anticipated from the many genetic and biochemical experiments comparing B and K-12 over the years, the B genomes are similar in size and organization to the genome of E. coli K-12 MG1655 and have >99% sequence identity over approximately 92% of their genomes. E. coli B and K-12 differ considerably in distribution of IS elements and in location and composition of larger mobile elements. An unexpected difference is the absence of a large cluster of flagella genes in B, due to a 41 kbp IS1-mediated deletion. Gene clusters that specify the LPS core, O antigen, and restriction enzymes differ substantially, presumably because of horizontal transfer. Comparative analysis of 32 independently isolated E. coli and Shigella genomes, both commensals and pathogenic strains, identifies a minimal set of genes in common plus many strain-specific genes that constitute a large E. coli pan-genome.
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Research Support, Non-U.S. Gov't |
16 |
271 |
3
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Mitrophanous K, Yoon S, Rohll J, Patil D, Wilkes F, Kim V, Kingsman S, Kingsman A, Mazarakis N. Stable gene transfer to the nervous system using a non-primate lentiviral vector. Gene Ther 1999; 6:1808-18. [PMID: 10602376 DOI: 10.1038/sj.gt.3301023] [Citation(s) in RCA: 214] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have constructed a non-primate lentiviral vector system based on the equine infectious anaemia virus (EIAV). This system is able to transduce both dividing and non-dividing cells, including primary cultured hippocampal neurons and neurons and glia in the adult rat central nervous system (CNS), at efficiencies comparable with HIV-based vectors. We demonstrate that the only EIAV proteins required for this activity are gag/pol and that the only accessory protein required for vector production is rev. In addition, we show that the pol encoded dUTPase activity that is found in all non-primate lentiviruses is not required. The vectors can be pseudotyped with a range of envelopes including rabies G and MLV 4070A and can be concentrated to high titres. The ability of EIAV to infect mitotically inactive cells makes this vector an attractive alternative to the immunodeficiency viruses for gene therapy.
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26 |
214 |
4
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Horazdovsky BF, Davies BA, Seaman MN, McLaughlin SA, Yoon S, Emr SD. A sorting nexin-1 homologue, Vps5p, forms a complex with Vps17p and is required for recycling the vacuolar protein-sorting receptor. Mol Biol Cell 1997; 8:1529-41. [PMID: 9285823 PMCID: PMC276174 DOI: 10.1091/mbc.8.8.1529] [Citation(s) in RCA: 191] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A number of the Saccharomyces cerevisiae vacuolar protein-sorting (vps) mutants exhibit an altered vacuolar morphology. Unlike wild-type cells that contain 1-3 large vacuolar structures, the class B vps5 and vps17 mutant cells contain 10-20 smaller vacuole-like compartments. To explore the role of these VPS gene products in vacuole biogenesis, we cloned and sequenced VPS5 and characterized its protein products. The VPS5 gene is predicted to encode a very hydrophilic protein of 675 amino acids that shows significant sequence homology with mammalian sorting nexin-1. Polyclonal antiserum directed against the VPS5 gene product detects a single, cytoplasmic protein that is phosphorylated specifically on a serine residue(s). Subcellular fractionation studies indicate that Vps5p is associated peripherally with a dense membrane fraction distinct from Golgi, endosomal, and vacuolar membranes. This association was found to be dependent on the presence of another class B VPS gene product, Vps17p. Biochemical cross-linking studies demonstrated that Vps5p and Vps17p physically interact. Gene disruption experiments show that the VPS5 genes product is not essential for cell viability; however, cells carrying the null allele contain fragmented vacuoles and exhibit defects in vacuolar protein-sorting similar to vps17 null mutants. More than 95% of carboxypeptidase Y is secreted from these cells in its Golgi-modified p2 precursor form. Additionally, the Vps10p vacuolar protein-sorting receptor is mislocalized to the vacuole in vps5 mutant cells. On the basis of these and other observations, we propose that the Vps17p protein complex may participate in the intracellular trafficking of the Vps10p-sorting receptor, as well as other later-Golgi proteins.
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research-article |
28 |
191 |
5
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Winder WW, Wilson HA, Hardie DG, Rasmussen BB, Hutber CA, Call GB, Clayton RD, Conley LM, Yoon S, Zhou B. Phosphorylation of rat muscle acetyl-CoA carboxylase by AMP-activated protein kinase and protein kinase A. J Appl Physiol (1985) 1997; 82:219-25. [PMID: 9029219 DOI: 10.1152/jappl.1997.82.1.219] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
This study was designed to compare functional effects of phosphorylation of muscle acetyl-CoA carboxylase (ACC) by adenosine 3',5'-cyclic monophosphate-dependent protein kinase (PKA) and by AMP-activated protein kinase (AMPK). Muscle ACC (272 kDa) was phosphorylated and then subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography. Functional effects of phosphorylation were determined by measuring ACC activity at different concentrations of each of the substrates and of citrate, an activator of the enzyme. The maximal velocity (Vmax) and the Michaelis constants (Km) for ATP, acetyl-CoA, and bicarbonate were unaffected by phosphorylation by PKA. Phosphorylation by AMPK increased the Km for ATP and acetyl-CoA. Sequential phosphorylation by PKA and AMPK, first without label and second with label, appeared to reduce the extent of label incorporation, regardless of the order. The activation constant (Ka) for citrate activation was increased to the same extent by AMPK phosphorylation, regardless of previous or subsequent phosphorylation by PKA. Thus muscle ACC can be phosphorylated by PKA but with no apparent functional effects on the enzyme. AMPK appears to be the more important regulator of muscle ACC.
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28 |
157 |
6
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Yoon S, Bogdanov K, Kovalenko A, Wallach D. Necroptosis is preceded by nuclear translocation of the signaling proteins that induce it. Cell Death Differ 2015; 23:253-60. [PMID: 26184911 PMCID: PMC4716306 DOI: 10.1038/cdd.2015.92] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 05/19/2015] [Accepted: 06/01/2015] [Indexed: 12/15/2022] Open
Abstract
A signaling pathway that induces programmed necrotic cell death (necroptosis) was reported to be activated in cells by several cytokines and various pathogen components. The major proteins participating in that pathway are the protein kinases RIPK1 and RIPK3 and the pseudokinase mixed lineage kinase domain-like protein (MLKL). Recent studies have suggested that MLKL, once activated, mediates necroptosis by binding to cellular membranes, thereby triggering ion fluxes. However, our knowledge of both the sequence of molecular events leading to MLKL activation and the subcellular sites of these events is fragmentary. Here we report that the association of MLKL with the cell membrane in necroptotic death is preceded by the translocation of phosphorylated MLKL, along with RIPK1 and RIPK3, to the nucleus.
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Research Support, Non-U.S. Gov't |
10 |
124 |
7
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Yoon SH, Han MJ, Jeong H, Lee CH, Xia XX, Lee DH, Shim JH, Lee SY, Oh TK, Kim JF. Comparative multi-omics systems analysis of Escherichia coli strains B and K-12. Genome Biol 2012; 13:R37. [PMID: 22632713 PMCID: PMC3446290 DOI: 10.1186/gb-2012-13-5-r37] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 05/15/2012] [Accepted: 05/25/2012] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Elucidation of a genotype-phenotype relationship is critical to understand an organism at the whole-system level. Here, we demonstrate that comparative analyses of multi-omics data combined with a computational modeling approach provide a framework for elucidating the phenotypic characteristics of organisms whose genomes are sequenced. RESULTS We present a comprehensive analysis of genome-wide measurements incorporating multifaceted holistic data - genome, transcriptome, proteome, and phenome - to determine the differences between Escherichia coli B and K-12 strains. A genome-scale metabolic network of E. coli B was reconstructed and used to identify genetic bases of the phenotypes unique to B compared with K-12 through in silico complementation testing. This systems analysis revealed that E. coli B is well-suited for production of recombinant proteins due to a greater capacity for amino acid biosynthesis, fewer proteases, and lack of flagella. Furthermore, E. coli B has an additional type II secretion system and a different cell wall and outer membrane composition predicted to be more favorable for protein secretion. In contrast, E. coli K-12 showed a higher expression of heat shock genes and was less susceptible to certain stress conditions. CONCLUSIONS This integrative systems approach provides a high-resolution system-wide view and insights into why two closely related strains of E. coli, B and K-12, manifest distinct phenotypes. Therefore, systematic understanding of cellular physiology and metabolism of the strains is essential not only to determine culture conditions but also to design recombinant hosts.
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Comparative Study |
13 |
120 |
8
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Yoon SH, Han MJ, Lee SY, Jeong KJ, Yoo JS. Combined transcriptome and proteome analysis of Escherichia coli during high cell density culture. Biotechnol Bioeng 2003; 81:753-67. [PMID: 12557308 DOI: 10.1002/bit.10626] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Combined transcriptome and proteome analysis was carried out to understand metabolic and physiological changes of Escherichia coli during the high cell density cultivation (HCDC). The expression of genes of TCA cycle enzymes, NADH dehydrogenase and ATPase, was up-regulated during the exponential fed-batch period and was down-regulated afterward. However, expression of most of the genes involved in glycolysis and pentose phosphate pathway was up-regulated at the stationary phase. The expression of most of amino acid biosynthesis genes was down-regulated as cell density increased, which seems to be the major reason for the reduced specific productivity of recombinant proteins during HCDC. The expression of chaperone genes increased with cell density, suggesting that the high cell density condition itself can be stressful to the cells. Severe competition for oxygen at high cell density seemed to make cells use cytochrome bd, which is less efficient but has a high oxygen affinity than cytochrome bo(3). Population cell density itself strongly affected the expression of porin protein genes, especially ompF, and hence the permeability of the outer membrane. Expression of phosphate starvation genes was most strongly up-regulated toward the end of cultivation. It was also found that sigma(E) (rpoE) plays a more important role than sigma(S) (rpoS) at the stationary phase of HCDC. These findings should be invaluable in designing metabolic engineering and fermentation strategies for the production of recombinant proteins and metabolites by HCDC of E. coli.
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22 |
114 |
9
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Choi-Kwon S, Chung C, Kim H, Lee S, Yoon S, Kho H, Oh J, Lee S. Factors affecting the quality of life in patients with epilepsy in Seoul, South Korea. Acta Neurol Scand 2003; 108:428-34. [PMID: 14616296 DOI: 10.1046/j.1600-0404.2003.00151.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES The level of, and factors affecting the quality of life (QOL) in patients with epilepsy may be different in Korea where social prejudice toward them is still pronounced. However, these issues have not yet been addressed properly. METHODS We consecutively identified 154 epilepsy patients who visited the outpatient clinic at the Seoul National University Hospital. An interview was performed by two research nurses with the use of a standardized questionnaire, which included data pertaining to seizure characteristics, symptoms of depression/anxiety, social support, family life/social life satisfaction, and the activities of daily living (ADLs). The QOL was assessed with the use of QOL in Epilepsy Inventory (QOLIE-31). RESULTS Factors affecting the QOL were: age (P<0.01), education in years (P<0.01), employment status (P<0.05), employment type (P<0.05), current economic status (P<0.05), seizure frequency (P<0.01), the number of antiepileptic drugs (P<0.01), family life/social life dissatisfaction (P<0.01, respectively), social support (P<0.01), the symptoms of anxiety and depression (P<0.01, respectively) and ADL dysfunction (P<0.01). In multiple regression analysis, the symptom of anxiety was the most important factor in explaining lower QOL in patients with epilepsy, while depression (P<0.01), social life dissatisfaction (P<0.01), ADL dysfunction (P<0.05) and seizure frequency (P<0.05) were also significant factors. CONCLUSION Psycho-social factors outweighed the physical factors in determining QOL in Korean epilepsy patients. Recognition of these factors will lead health professionals to develop different strategies to improve the QOL of these patients.
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22 |
112 |
10
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Chuppa S, Tsai YS, Yoon S, Shackleford S, Rozales C, Bhat R, Tsay G, Matanguihan C, Konstantinov K, Naveh D. Fermentor temperature as a tool for control of high-density perfusion cultures of mammalian cells. Biotechnol Bioeng 2010; 55:328-38. [PMID: 18636491 DOI: 10.1002/(sici)1097-0290(19970720)55:2<328::aid-bit10>3.0.co;2-d] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Temperature is a key environmental variable whose potential in animal cell fermentor optimization is not yet fully utilized. The scarce literature data suggests that reduced fermentor temperature results in an improved viability and shear resistance, higher cell density and titer in batch cultures, and reduction in glucose/lactate metabolism. Due to the arrest of the cells in the G1 phase, the specific growth rate was found to decrease at temperatures below 37.0 degrees C. The response of the specific production rate was cell line dependent: in some cases it increased 2-to-3-fold, but decreased in other cases. The controlable slowdown of cell metabolism at lower temperature can be used in optimization of perfusion mammalian cell cultures with several potential advantages, including higher cell density in oxygen limited reactors, lower perfusion rate, improved product quality, simplified pH control, and others. To evaluate this strategy, a series of long-term experiments in 15 L perfusion bioreactors culturing recombinant hamster cells at 20.0 x 10(6) cells/mL were conducted. The temperature was changed over a range of set points, and maintained at each of these for a long period of time. Steady state process data was collected and analyzed. The effect of temperature on the following characteristics of the perfusion process was studied: cell growth, glucose/lactate metabolism, glutamine/ammonia metabolism, cell respiration, cell density at constant oxygen transfer rate, proteolytic activity, and product quality (glycosylation and molecule fragmentation). The results suggest that temperature is a variable with a significant potential in optimization of perfusion cultures. Properly selected temperature set point will contribute to the overall improvement of process performance. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 328-338, 1997.
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Journal Article |
15 |
111 |
11
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Kang BW, Seo AN, Yoon S, Bae HI, Jeon SW, Kwon OK, Chung HY, Yu W, Kang H, Kim JG. Prognostic value of tumor-infiltrating lymphocytes in Epstein-Barr virus-associated gastric cancer. Ann Oncol 2015; 27:494-501. [PMID: 26673353 DOI: 10.1093/annonc/mdv610] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 12/09/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND This study explored the prognostic impact of tumor-infiltrating lymphocytes (TILs) and investigated whether three histologic subtypes (lymphoepithelioma-like carcinoma, carcinoma with Crohn's disease-like lymphoid reaction, and conventional-type adenocarcinoma) could stratify a prognostic subset for patients with Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC). MATERIALS AND METHODS After reviewing 1318 consecutive cases of surgically resected or endoscopic submucosal dissected gastric cancers, 120 patients were identified as EBV-positive using EBV-encoded RNA in situ hybridization. The evaluation of the percentage of intratumoral (iTu-) and stromal (str-) TILs was carried out, and the cases were also subclassified into three histologic subtypes as noted above. RESULTS Among the 120 patients, 73 patients (60.8%) and 60 patients (50.0%) were determined as str-TIL-positive and iTu-TIL-positive, respectively. In a univariate analysis, str-TIL-positivity was significantly associated with longer recurrence-free survival (RFS; P = 0.002) and disease-free survival (DFS; P = 0.008), yet not overall survival (OS; P = 0.145). While iTu-TIL-positivity has a tendency of favorable outcome indicator for DFS and OS, but statistically significant differences were not shown, respectively (RFS, P = 0.058; DFS, P = 0.151; OS, P = 0.191). In a multivariate analysis using a Cox proportional hazard model adjusted for age, pTNM stage, lymphatic invasion, perineural invasion, and venous invasion; histologic subtype, WHO classification, and str-TIL-positivity were independently or tentatively associated with favorable RFS (hazard ratio [HR] = 12.193, 95% confidence interval [95% CI] 1.039-143.055, P = 0.047) or DFS (HR = 4.836, 95% CI 0.917-25.525, P = 0.063). CONCLUSION The histologic subclassification and TILs can be used to predict RFS and DFS for patients with EBVaGC.
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Research Support, Non-U.S. Gov't |
10 |
109 |
12
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Jeong H, Yim JH, Lee C, Choi SH, Park YK, Yoon SH, Hur CG, Kang HY, Kim D, Lee HH, Park KH, Park SH, Park HS, Lee HK, Oh TK, Kim JF. Genomic blueprint of Hahella chejuensis, a marine microbe producing an algicidal agent. Nucleic Acids Res 2005; 33:7066-73. [PMID: 16352867 PMCID: PMC1312362 DOI: 10.1093/nar/gki1016] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Harmful algal blooms, caused by rapid growth and accumulation of certain microalgae in the ocean, pose considerable impacts on marine environments, aquatic industries and even public health. Here, we present the 7.2-megabase genome of the marine bacterium Hahella chejuensis including genes responsible for the biosynthesis of a pigment which has the lytic activity against a red-tide dinoflagellate. H.chejuensis is the first sequenced species in the Oceanospiralles clade, and sequence analysis revealed its distant relationship to the Pseudomonas group. The genome was well equipped with genes for basic metabolic capabilities and contained a large number of genes involved in regulation or transport as well as with characteristics as a marine heterotroph. Sequence analysis also revealed a multitude of genes of functional equivalence or of possible foreign origin. Functions encoded in the genomic islands include biosynthesis of exopolysacchrides, toxins, polyketides or non-ribosomal peptides, iron utilization, motility, type III protein secretion and pigmentation. Molecular structure of the algicidal pigment, which was determined through LC-ESI-MS/MS and NMR analyses, indicated that it is prodigiosin. In conclusion, our work provides new insights into mitigating algal blooms in addition to genetic make-up, physiology, biotic interactions and biological roles in the community of a marine bacterium.
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Research Support, Non-U.S. Gov't |
20 |
101 |
13
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Yoon S, Tromp G, Vongpunsawad S, Ronkainen A, Juvonen T, Kuivaniemi H. Genetic analysis of MMP3, MMP9, and PAI-1 in Finnish patients with abdominal aortic or intracranial aneurysms. Biochem Biophys Res Commun 1999; 265:563-8. [PMID: 10558909 DOI: 10.1006/bbrc.1999.1721] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
MMP3, MMP9, and PAI-1 are present at increased levels in abdominal aortic aneurysms (AAAs). The promoters of these genes contain polymorphisms, with alleles that exhibit different transcriptional activities in vitro. Association studies were performed using these polymorphisms and DNA isolated from 47 AAA patients, 57 intracranial aneurysm (IA) patients, and 174 controls, all from Finland. PAI-1 and MMP9 genotypes did not associate with aneurysms. The frequency of the 5A MMP3 allele was somewhat higher in the AAA than that in the control group (P = 0.0609 after Bonferroni correction), whereas the MMP3 allele frequencies in the IA group did not differ from those of the controls (P = 0.9667). These findings suggest that the transcriptionally more active 5A MMP3 allele might be a genetic risk factor for AAA among Finns. They are in agreement with previous studies demonstrating higher level of MMP3 expression in AAA than in control tissues.
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26 |
100 |
14
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Lee IH, Sohn M, Lim HJ, Yoon S, Oh H, Shin S, Shin JH, Oh SH, Kim J, Lee DK, Noh DY, Bae DS, Seong JK, Bae YS. Ahnak functions as a tumor suppressor via modulation of TGFβ/Smad signaling pathway. Oncogene 2014; 33:4675-84. [PMID: 24662814 PMCID: PMC4180639 DOI: 10.1038/onc.2014.69] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 12/15/2013] [Accepted: 12/24/2013] [Indexed: 02/06/2023]
Abstract
We provide detailed mechanisms of Ahnak-mediated potentiation of transforming growth factor β (TGFβ) signaling, which leads to a negative regulation of cell growth. We show that Smad3 interacts with Ahnak through MH2 domain and that Ahnak stimulates Smad3 localization into nucleus leading to potentiating TGFβ-induced transcriptional activity of R-Smad. Moreover, overexpression of Ahnak resulted in growth retardation and cell cycle arrest through downregulation of c-Myc and cyclin D1/D2. We describe results from analyses of Ahnak−/− mouse model expressing middle T antigen in a mammary gland-specific manner (MMTVTg/+Ahnak−/−), which showed significantly progressed hyperplasia of mammary glands compared with MMTVTg/+Ahnak+/+. Finally, we screened multiple human breast cancer tissues and showed that the expression of Ahnak in cancer tissues is lower than that in control tissues by 50%. Taken together, these data indicate that Ahnak mediates a negative regulation of cell growth and acts as novel tumor suppressor through potentiation of TGFβ signaling.
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Research Support, Non-U.S. Gov't |
11 |
100 |
15
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Yoon SH, Park YK, Kim JF. PAIDB v2.0: exploration and analysis of pathogenicity and resistance islands. Nucleic Acids Res 2014; 43:D624-30. [PMID: 25336619 PMCID: PMC4384037 DOI: 10.1093/nar/gku985] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Pathogenicity is a complex multifactorial process confounded by the concerted activity of genetic regions associated with virulence and/or resistance determinants. Pathogenicity islands (PAIs) and resistance islands (REIs) are key to the evolution of pathogens and appear to play complimentary roles in the process of bacterial infection. While PAIs promote disease development, REIs give a fitness advantage to the host against multiple antimicrobial agents. The Pathogenicity Island Database (PAIDB, http://www.paidb.re.kr) has been the only database dedicated to providing comprehensive information on all reported PAIs and candidate PAIs in prokaryotic genomes. In this study, we present PAIDB v2.0, whose functionality is extended to incorporate REIs. PAIDB v2.0 contains 223 types of PAIs with 1331 accessions, and 88 types of REIs with 108 accessions. With an improved detection scheme, 2673 prokaryotic genomes were analyzed to locate candidate PAIs and REIs. With additional quantitative and qualitative advancements in database content and detection accuracy, PAIDB will continue to facilitate pathogenomic studies of both pathogenic and non-pathogenic organisms.
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Research Support, Non-U.S. Gov't |
11 |
91 |
16
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Yoon SH, Kim SK, Kim JF. Secretory production of recombinant proteins in Escherichia coli. Recent Pat Biotechnol 2010; 4:23-29. [PMID: 20201800 DOI: 10.2174/187220810790069550] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 09/08/2009] [Indexed: 05/28/2023]
Abstract
Extracellular production of heterologous proteins using the Escherichia coli cell factory offers several advantages over intracellular production and mammalian culture. Properly folded proteins can be rapidly accumulated in the culture media, and downstream processes for isolation and purification can be much simplified. Efforts to enhance the secretory production of target proteins can be largely classified as selection and modification of the signal peptide, co-expression of proteins to assist translocation and folding, improvement of periplasmic release, and protection of target proteins from degradation and contamination. Here, we review recent patents on the secretory production of recombinant proteins in E. coli.
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Review |
15 |
91 |
17
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Jeon TY, Han ME, Lee YW, Lee YS, Kim GH, Song GA, Hur GY, Kim JY, Kim HJ, Yoon S, Baek SY, Kim BS, Kim JB, Oh SO. Overexpression of stathmin1 in the diffuse type of gastric cancer and its roles in proliferation and migration of gastric cancer cells. Br J Cancer 2010; 102:710-718. [PMID: 20087351 PMCID: PMC2837578 DOI: 10.1038/sj.bjc.6605537] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 12/09/2009] [Accepted: 12/24/2009] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Stathmin1 is a microtubule-regulating protein that has an important role in the assembly and disassembly of the mitotic spindle. The roles of stathmin1 in carcinogenesis of various cancers, including prostate and breast cancer, have been explored. However, its expression and roles in gastric cancer have not yet been described. METHODS Stathmin1 expression in paraffin-embedded tissue sections from 226 patients was analysed by immunohistochemistry. Roles of stathmin1 were studied using a specific small interfering RNA (siRNA). RESULTS The expression of stathmin1 was positively correlated with lymph node metastasis, TNM stages and vascular invasion, and negatively with recurrence-free survival, in the diffuse type of gastric cancer. The median recurrence-free survival in patients with a negative and positive expression of stathmin1 was 17.0 and 7.0 months, respectively (P=0.009). When the expression of stathmin1 was knocked down using siRNA, the proliferation, migration and invasion of poorly differentiated gastric cancer cells in vitro were significantly inhibited. Moreover, stathmin1 siRNA transfection significantly slowed the growth of xenografts in nude mice. CONCLUSION These results suggest that stathmin1 can be a good prognostic factor for recurrence-free survival rate and is a therapeutic target in diffuse-type gastric cancer.
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research-article |
15 |
87 |
18
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Yoon S, Booth JG. Magnetic properties and structures of some ordered (FeMn)3Si alloys. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0305-4608/7/6/022] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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24 |
87 |
19
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Cui L, Yoon S, Schinazi RF, Sommadossi JP. Cellular and molecular events leading to mitochondrial toxicity of 1-(2-deoxy-2-fluoro-1-beta-D-arabinofuranosyl)-5-iodouracil in human liver cells. J Clin Invest 1995; 95:555-63. [PMID: 7860738 PMCID: PMC295512 DOI: 10.1172/jci117698] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We have explored the mechanism(s) related to FIAU-induced liver toxicity, particularly focusing on its effect on mitochondrial function in a human hepatoma cell line-HepG2. The potential role of FMAU and FAU, metabolites detected in FIAU-treated patients were also ascertained. FIAU and FMAU inhibited cell growth and were effectively phosphorylated. A substantial increase in lactic acid production in medium of cells incubated with 1-10 microM FIAU or FMAU was consistent with mitochondrial dysfunction. Slot blot analysis demonstrated that a two week exposure to 10 microM FIAU or FMAU was not associated with a decrease in total mitochondrial (mt) DNA content. However, FIAU and FMAU were incorporated into nuclear and mtDNA and relative values suggest that both compounds incorporate at a much higher rate into mtDNA. Electron micrographs of cells incubated with 10 microM FIAU or FMAU revealed the presence of enlarged mitochondria with higher cristae density and lipid vesicles. In conclusion, these data suggest that despite the lack of inhibition of mtDNA content, incorporation of FIAU and FMAU into mtDNA of HepG2 cells leads to marked mitochondrial dysfunction as evidenced by disturbance in cellular energy metabolism and detection of micro- and macrovesicular steatosis.
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MESH Headings
- Adenosine Triphosphate/metabolism
- Antiviral Agents/toxicity
- Arabinofuranosyluracil/analogs & derivatives
- Arabinofuranosyluracil/metabolism
- Arabinofuranosyluracil/toxicity
- Carcinoma, Hepatocellular
- Cell Division/drug effects
- Cell Nucleus/metabolism
- Chromatography, High Pressure Liquid
- DNA, Mitochondrial/biosynthesis
- DNA, Mitochondrial/drug effects
- DNA, Mitochondrial/isolation & purification
- DNA, Neoplasm/biosynthesis
- DNA, Neoplasm/drug effects
- DNA, Neoplasm/isolation & purification
- Humans
- Kinetics
- Liver Neoplasms
- Microscopy, Electron
- Mitochondria/drug effects
- Mitochondria/pathology
- Mitochondria/ultrastructure
- Mitochondria, Liver/drug effects
- Mitochondria, Liver/pathology
- Mitochondria, Liver/ultrastructure
- Time Factors
- Tumor Cells, Cultured
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research-article |
30 |
86 |
20
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Liu X, Lee JK, Yoon SH, Kessler MR. Characterization of diene monomers as healing agents for autonomic damage repair. J Appl Polym Sci 2006. [DOI: 10.1002/app.23245] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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19 |
83 |
21
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Konstantinov K, Chuppa S, Sajan E, Tsai Y, Yoon S, Golini F. Real-time biomass-concentration monitoring in animal-cell cultures. Trends Biotechnol 1994; 12:324-33. [PMID: 7765262 DOI: 10.1016/0167-7799(94)90049-3] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The accurate, on-line measurement of cell concentration in animal-cell cultures is an on-going problem in bioprocess engineering, and the development of new monitoring techniques is an area of intensive and fruitful research. This article summarizes the recent advances, trends and problems in this field and focuses, in particular, on optical sensors, including the latest laser and infrared probes. Alternative methods, such as multiple-extinction fluorimetry, real-time imaging and particle-size analysis, are also discussed. Although many of these techniques are still at an experimental stage, we believe that some of them have been developed sufficiently that we advocate their routine use in bioprocess monitoring and control.
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Review |
31 |
82 |
22
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Yoon SH, Lee JM, Cho HI, Kim EK, Kim HS, Park MY, Kim TG. Adoptive immunotherapy using human peripheral blood lymphocytes transferred with RNA encoding Her-2/neu-specific chimeric immune receptor in ovarian cancer xenograft model. Cancer Gene Ther 2008; 16:489-97. [PMID: 19096447 DOI: 10.1038/cgt.2008.98] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The current gene transfer technology for single chain (scFv)-based chimeric immune receptor (CIR) has relied on retrovirus and lentivirus vectors which require a long time to obtain sufficient number of transduced cells and stably incorporate into genome. To ameliorate these limitations, we applied RNA electroporation to human peripheral blood lymphocytes (PBLs) activated with anti-CD3 antibody and interleukin-2 (IL-2) for 3 days and assessed that PBL transiently expressing anti-Her-2/neu CIR (CIR-PBL) containing signaling portion of CD28 and CD3zeta could elicit strong cytotoxicity in vitro and antitumor responses in vivo. The CIR-PBL expressed high level of CIR in CD4+, CD8+ and CD56+ cells. Her-2/neu-specific stimulation induced secretion of type-I cytokines including interferon-gamma (IFN-gamma), IL-8 and granulocyte-macrophage colony-stimulating factor, and IFN-gamma secretion was mainly mediated by CD8+ T cells. CIR-PBL specifically killed SKOV3 cell line expressing Her-2/neu. Adoptive transfer of CIR-PBL in SKOV3 xenograft model led to significant inhibition of tumor growth compared with transfer of mock-transduced PBL and showed higher inhibition than those with Herceptin, humanized monoclonal antibody specific for Her-2/neu. These results provided evidence that electroporation of CIR RNA to human PBLs could be used for rapid generation and high number of therapeutic antigen-specific T cells for adoptive immunotherapy.
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Research Support, Non-U.S. Gov't |
17 |
78 |
23
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25 |
77 |
24
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Kim TH, Kwon JG, Yoon SH, Park HS, Kim MH, Cha JE. Numerical analysis of air-foil shaped fin performance in printed circuit heat exchanger in a supercritical carbon dioxide power cycle. NUCLEAR ENGINEERING AND DESIGN 2015. [DOI: 10.1016/j.nucengdes.2015.03.013] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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10 |
69 |
25
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Schweitzer EJ, Yoon S, Hart J, Anderson L, Barnes R, Evans D, Hartman K, Jaekels J, Johnson LB, Kuo PC, Hoehn-Saric E, Klassen DK, Weir MR, Bartlett ST. Increased living donor volunteer rates with a formal recipient family education program. Am J Kidney Dis 1997; 29:739-45. [PMID: 9159309 DOI: 10.1016/s0272-6386(97)90128-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We have generally encouraged living donation among our kidney recipients. However, an examination of our clinical practice revealed inconsistencies in the depth and content of information transmitted to kidney recipient families regarding living donation. We therefore initiated a structured education program, including an educational video, to ensure that all recipient families would receive a similar exposure to a standard block of information. After the program had been functioning for over a year, we compared the living donor (LD) volunteer rates between the 3-year period before (BEFORE) and the 18 months after (AFTER) initiation of the formal education program. There were 1,363 patients registered on our kidney transplantation waiting list during the 54-month study period (757 white [56%] and 580 black [43%]). We found that 33.4% of the kidney transplant candidates in the period BEFORE the LD education program had at least one potential LD tissue typed, compared with 39.4% in the period AFTER starting the program (P = 0.03). The increase in the proportion of patients with potential donors was greatest among the black (P < 0.05) and elderly (P < 0.01) registrants, which were the groups with the lowest volunteer rates before the program began. Among the registrants with at least one potential donor, the percentage of registrants who ultimately received an LD transplant was highly correlated with the number of donors (R = 0.98). The rate of LD kidney transplantation was significantly higher (P = 0.02) for the patients referred in the period AFTER initiation of the LD education program compared with the period BEFORE the program. The 1- and 3-year graft survival rates for the 170 LD transplants performed in these patients were 96.9% and 93.2%, respectively. These were significantly better than the corresponding 83.9% and 71.4% rates for the 341 kidney transplants from cadaver donors in these registrants (P < 0.001). Black recipients of LD transplants had graft survival rates comparable to whites; the 3-year graft survival rate for LD transplants was 93.9% in whites and 90.6% in blacks (P = NS). We conclude that living kidney donor volunteer rates can be improved by a formal family education program, especially for subgroups of patients with low volunteer rates. A substantial benefit is derived by black patients, who generally experience low graft survival rates with cadaver-donor kidneys. A local formal LD education program is a useful adjunct to national organ donation campaigns.
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Comparative Study |
28 |
68 |