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51.
Huiyun Seo In-Seon Lee Jae Eun Park Sung Goo Park Do Hee Lee Byoung Chul Park Sayeon Cho 《PloS one》2013,8(11)
Protein tyrosine phosphatases play key roles in a diverse range of cellular processes such as differentiation, cell proliferation, apoptosis, immunological signaling, and cytoskeletal function. Protein tyrosine phosphatase non-receptor type 7 (PTPN7), a member of the phosphatase family, specifically inactivates mitogen-activated protein kinases (MAPKs). Here, we report that PTPN7 acts as a regulator of pro-inflammatory TNF-α production in RAW 264.7 cells that are stimulated with lipopolysaccharide (LPS) that acts as an endotoxin and elicits strong immune responses in animals. Stimulation of RAW 264.7 cells with LPS leads to a transient decrease in the levels of PTPN7 mRNA and protein. The overexpression of PTPN7 inhibits LPS-stimulated production of TNF-α. In addition, small interfering RNA (siRNA) analysis showed that knock-down of PTPN7 in RAW 264.7 cells increased TNF-α production. PTPN7 has a negative regulatory function to extracellular signal regulated kinase 1/2 (ERK1/2) and p38 that increase LPS-induced TNF-α production in macrophages. Thus, our data presents PTPN7 as a negative regulator of TNF-α expression and the inflammatory response in macrophages. 相似文献
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53.
Won-Kyung Hong Sun-Yeon Heo Baek-Rock Oh Chul Ho Kim Jung-Hoon Sohn Ji-Won Yang Akihiko Kondo Jeong-Woo Seo 《Bioprocess and biosystems engineering》2013,36(9):1191-1197
In the present study, we established a genetic system for manipulating the oleaginous heterotrophic microalgae Aurantiochytrium sp. KRS101, using cycloheximide resistance as the selectable marker. The gene encoding ribosomal protein L44 (RPL44) of Aurantiochytrium sp. KRS101 was first identified and characterized. Proline 56 was replaced with glutamine, affording cycloheximide resistance to strains encoding the mutant protein. This resistance served as a novel selection marker. The gene encoding the Δ12-fatty acid desaturase of Mortierella alpina, used as a reporter, was successfully introduced into chromosomal DNA of Aurantiochytrium sp. KRS101 via 18S rDNA-targeted homologous recombination. Enzymatic conversion of oleic acid (C18:1) to linoleic acid (C18:2) was detected in transformants but not in the wild-type strain. 相似文献
54.
Jung Ok Park Do‐Young Choi Dong‐Sic Choi Hee Joung Kim Jeong Won Kang Jae Hun Jung Jeong Hwa Lee Jayoung Kim Michael R. Freeman Kye Young Lee Yong Song Gho Kwang Pyo Kim 《Proteomics》2013,13(14):2125-2134
Microvesicles (MVs, also known as exosomes, ectosomes, microparticles) are released by various cancer cells, including lung, colorectal, and prostate carcinoma cells. MVs released from tumor cells and other sources accumulate in the circulation and in pleural effusion. Although recent studies have shown that MVs play multiple roles in tumor progression, the potential pathological roles of MV in pleural effusion, and their protein composition, are still unknown. In this study, we report the first global proteomic analysis of highly purified MVs derived from human nonsmall cell lung cancer (NSCLC) pleural effusion. Using nano‐LC–MS/MS following 1D SDS‐PAGE separation, we identified a total of 912 MV proteins with high confidence. Three independent experiments on three patients showed that MV proteins from PE were distinct from MV obtained from other malignancies. Bioinformatics analyses of the MS data identified pathologically relevant proteins and potential diagnostic makers for NSCLC, including lung‐enriched surface antigens and proteins related to epidermal growth factor receptor signaling. These findings provide new insight into the diverse functions of MVs in cancer progression and will aid in the development of novel diagnostic tools for NSCLC. 相似文献
55.
Martina Bielaszewska Christian Rüter Lisa Kunsmann Lilo Greune Andreas Bauwens Wenlan Zhang Thorsten Kuczius Kwang Sik Kim Alexander Mellmann M. Alexander Schmidt Helge Karch 《PLoS pathogens》2013,9(12)
Enterohemorrhagic Escherichia coli (EHEC) strains cause diarrhea and hemolytic uremic syndrome resulting from toxin-mediated microvascular endothelial injury. EHEC hemolysin (EHEC-Hly), a member of the RTX (repeats-in-toxin) family, is an EHEC virulence factor of increasingly recognized importance. The toxin exists as free EHEC-Hly and as EHEC-Hly associated with outer membrane vesicles (OMVs) released by EHEC during growth. Whereas the free toxin is lytic towards human endothelium, the biological effects of the OMV-associated EHEC-Hly on microvascular endothelial and intestinal epithelial cells, which are the major targets during EHEC infection, are unknown. Using microscopic, biochemical, flow cytometry and functional analyses of human brain microvascular endothelial cells (HBMEC) and Caco-2 cells we demonstrate that OMV-associated EHEC-Hly does not lyse the target cells but triggers their apoptosis. The OMV-associated toxin is internalized by HBMEC and Caco-2 cells via dynamin-dependent endocytosis of OMVs and trafficked with OMVs into endo-lysosomal compartments. Upon endosome acidification and subsequent pH drop, EHEC-Hly is separated from OMVs, escapes from the lysosomes, most probably via its pore-forming activity, and targets mitochondria. This results in decrease of the mitochondrial transmembrane potential and translocation of cytochrome c to the cytosol, indicating EHEC-Hly-mediated permeabilization of the mitochondrial membranes. Subsequent activation of caspase-9 and caspase-3 leads to apoptotic cell death as evidenced by DNA fragmentation and chromatin condensation in the intoxicated cells. The ability of OMV-associated EHEC-Hly to trigger the mitochondrial apoptotic pathway in human microvascular endothelial and intestinal epithelial cells indicates a novel mechanism of EHEC-Hly involvement in the pathogenesis of EHEC diseases. The OMV-mediated intracellular delivery represents a newly recognized mechanism for a bacterial toxin to enter host cells in order to target mitochondria. 相似文献
56.
Jina Park Jeongmi Lee Jaewon Shim Woongsu Han Jinu Lee Yong Chul Bae Yun Doo Chung Chul Hoon Kim Seok Jun Moon 《PLoS genetics》2013,9(9)
Mechanically gated ion channels convert sound into an electrical signal for the sense of hearing. In Drosophila melanogaster, several transient receptor potential (TRP) channels have been implicated to be involved in this process. TRPN (NompC) and TRPV (Inactive) channels are localized in the distal and proximal ciliary zones of auditory receptor neurons, respectively. This segregated ciliary localization suggests distinct roles in auditory transduction. However, the regulation of this localization is not fully understood. Here we show that the Drosophila Tubby homolog, King tubby (hereafter called dTULP) regulates ciliary localization of TRPs. dTULP-deficient flies show uncoordinated movement and complete loss of sound-evoked action potentials. Inactive and NompC are mislocalized in the cilia of auditory receptor neurons in the dTulp mutants, indicating that dTULP is required for proper cilia membrane protein localization. This is the first demonstration that dTULP regulates TRP channel localization in cilia, and suggests that dTULP is a protein that regulates ciliary neurosensory functions. 相似文献
57.
The somatotropic axis, the control system for growth hormone (GH) secretion and its endogenous factors involved in the regulation of metabolism and energy partitioning, has promising potentials for producing economically valuable traits in farm animals. Here we investigated single nucleotide polymorphisms (SNPs) of the genes of factors involved in the somatotropic axis for growth hormone (GH1), growth hormone receptor (GHR), ghrelin (GHRL), insulin-like growth factor 1 (IGF-I) and leptin (LEP), using polymerase chain reaction–single-strand conformation polymorphism (PCR–SSCP) and DNA sequencing methods in 452 individual Mehraban sheep. A nonradioactive method to allow SSCP detection was used for genomic DNA and PCR amplification of six fragments: exons 4 and 5 of GH1; exon 10 of GH receptor (GHR); exon 1 of ghrelin (GHRL); exon 1 of insulin-like growth factor-I (IGF-I), and exon 3 of leptin (LEP). Polymorphisms were detected in five of the six PCR products. Two electrophoretic patterns were detected for GH1 exon 4. Five conformational patterns were detected for GH1 exon 5 and LEP exon 3, and three for IGF-I exon 1. Only GHR and GHRL were monomorphic. Changes in protein structures due to variable SNPs were also analyzed. The results suggest that Mehraban sheep, a major breed that is important for the animal industry in Middle East countries, has high genetic variability, opening interesting prospects for future selection programs and preservation strategies. 相似文献
58.
Kyung‐Min Lee Yeon‐Joo Choi Sun‐Hye Shin Min‐Kyung Choi Hyeon‐Je Song Heung‐Chul Kim Terry A. Klein Allen L. Richards Kyung‐Hee Park Won‐Jong Jang 《Microbiology and immunology》2013,57(7):487-495
Rickettsia monacensis, a spotted fever group rickettsia, was isolated from Ixodes nipponensis ticks collected from live‐captured small mammals in South Jeolla province, Korea in 2006. Homogenates of tick tissues were inoculated into L929 and Vero cell monolayers using shell vial assays. After several passages, Giemsa staining revealed rickettsia‐like organisms in the inoculated Vero cells, but not the L929 cells. Sequencing analysis revealed that the ompA‐small part (25–614 bp region), ompA‐large part (2849–4455 bp region), nearly full‐length ompB (58–4889 bp region) and gltA (196–1236 bp region) of the isolates had similarities of 100%, 99.8%, 99.3% and 99.5%, respectively, to those of R. monacensis. Furthermore, phylogenetic analysis showed that the isolate was grouped into the cluster in the same way as R. monacensis in the trees of all genes examined. These results strongly suggest that the isolate is closely related to R. monacensis. As far as is known, this is the first report of isolation of R. monacensis from ticks in Korea. 相似文献
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60.
Abstract We have performed NPT molecular dynamics simulations (Langevin Piston Method) on two types of solvated proteins-‘denaturation-unfavorable’ protein (insulin) and ‘denaturation-favorable protein’ (ribonuclease A) at high pressure (from 1 bar up to 20 kbar). The method is based on the extended system formalism introduced by Andersen, where the deterministic equations of motion for the piston degree of freedom are replaced by Langevin equation. We report the structural changes of proteins (ribonuclease A and insulin) and water molecules through radius of gyration, solvent accessible surface area, hydrogen bond pattern, and the topology of water clusters connected by the hydrogen bonded circular network. The solvent accessibility of ribonuclease A is mainly decreased by hydrophilic residues rather than hydrophobic residues under high pressure. From the results of hydrogen bond analysis, we have found that α-helix is more stable than β-sheet under high pressure. In addition, from the analysis of the water cluster, we have observed that for ribonuclease A, 5-membered ring structure is more favorable than 6-membered ring at higher pressure. However, for insulin, the ratio of 5 to 6-ring is constant over the pressure ranges for which we have performed MD simulation. This indicates that the water structure around insulin does not change under high pressure. 相似文献