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1.
Kyung Suk Lee Amanda B. Marciel Alexander G. Kozlov Charles M. Schroeder Timothy M. Lohman Taekjip Ha 《Journal of molecular biology》2014
Single-stranded DNA binding proteins (SSBs) selectively bind single-stranded DNA (ssDNA) and facilitate recruitment of additional proteins and enzymes to their sites of action on DNA. SSB can also locally diffuse on ssDNA, which allows it to quickly reposition itself while remaining bound to ssDNA. In this work, we used a hybrid instrument that combines single-molecule fluorescence and force spectroscopy to directly visualize the movement of Escherichia coli SSB on long polymeric ssDNA. Long ssDNA was synthesized without secondary structure that can hinder quantitative analysis of SSB movement. The apparent diffusion coefficient of E. coli SSB thus determined ranged from 70,000 to 170,000 nt2/s, which is at least 600 times higher than that determined from SSB diffusion on short ssDNA oligomers, and is within the range of values reported for protein diffusion on double-stranded DNA. Our work suggests that SSB can also migrate via a long-range intersegment transfer on long ssDNA. The force dependence of SSB movement on ssDNA further supports this interpretation. 相似文献
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Tamara Utermark Fabienne Schmit Sang Hyun Lee Xueliang Gao Brian S. Schaffhausen Thomas M. Roberts 《Journal of virology》2014,88(18):10673-10679
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Do-Soon Park Sung-Jin Na Shin Hyeong Cho Kyung Ja June Young-Chae Cho Young-Ha Lee 《The Korean journal of parasitology》2014,52(4):391-397
We evaluated the status of Clonorchis sinensis infection and potential risk factors among residents of riverside areas (Geumgang) in Muju-gun, Jeollabuk-do (Province), Korea. From January to February 2010, a total of 349 (171 males, 178 females) stool samples were collected and examined by the formalin-ether concentration technique. Also, village residents were interviewed using questionnaires to obtain information about C. sinensis infection-related risk factors. Overall egg-positive rate of C. sinensis was 13.2%. Egg-positive rates were significantly higher in males, farmers, and residents who had lived there more than 20 years, and in residents who had eaten raw freshwater fish than in opposite groups, respectively. However, there was no significant difference between age groups, education levels, cigarette smoking, alcohol drinking, health status, past history of infection, and experience of clonorchiasis medication and examination. Logistic regression analysis was performed to determine risk factors for clonorchiasis. On univariate analysis, the odds ratios for males, farmers, those who had lived there more than 20 years, and who had eaten raw freshwater fish were 2.41, 4.44, 3.16, and 4.88 times higher than those of the opposites, respectively. On multivariate analysis, the odds ratio of residents who had eaten raw freshwater fish was 3.2-fold higher than that of those who had not. These results indicate that residents living in Muju-gun, along the Geum River, Korea, have relatively high C. sinensis egg-positive rates, and the habit of eating raw freshwater fish was the major factor for the maintenance of clonorchiasis. 相似文献
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Hye-In Kim Fu-Shi Quan Ji-Eun Kim Na-Rae Lee Hyun Ji Kim Su Ji Jo Chae-Min Lee Dae Sik Jang Kyung-Soo Inn 《Biochemical and biophysical research communications》2014
Extracts of Prunella vulgaris have been shown to exert antiestrogenic effects. To identify the compounds responsible for these actions, we isolated the constituents of P. vulgaris and tested their individual antiestrogenic effects. Rosmarinic acid, caffeic acid, ursolic acid (UA), oleanolic acid, hyperoside, rutin and betulinic acid (BA) were isolated from the flower stalks of P. vulgaris var. lilacina Nakai (Labiatae). Among these constituents, UA and BA showed significant antiestrogenic effects, measured as a decrease in the mRNA level of GREB1, an estrogen-responsive protein; the effects of BA were stronger than those of UA. UA and BA were capable of suppressing estrogen response element (ERE)-dependent luciferase activity and expression of estrogen-responsive genes in response to exposure to estradiol, further supporting the suppressive role of these compounds in estrogen-induced signaling. However, neither UA nor BA was capable of suppressing estrogen signaling in cells ectopically overexpressing estrogen receptor α (ERα). Furthermore, both mRNA and protein levels of ERα were reduced by treatment with UA or BA, suggesting that UA and BA inhibit estrogen signaling by suppressing the expression of ERα. Interestingly, both compounds enhanced prostate-specific antigen promoter activity. Collectively, these findings demonstrate that UA and BA are responsible for the antiestrogenic effects of P. vulgaris and suggest their potential use as therapeutic agents against estrogen-dependent tumors. 相似文献
7.
TRPML3 is a Ca2+ permeable cation channel expressed in multiple intracellular compartments. Although TRPML3 is implicated in autophagy, how TRPML3 can regulate autophagy is not understood. To search interacting proteins with TRPML3 in autophagy, we performed split-ubiquitin membrane yeast two-hybrid (MY2H) screening with TRPML3-loop as a bait and identified GATE16, a mammalian ATG8 homologue. GST pull-down assay revealed that TRPML3 and TRPML3-loop specifically bind to GATE16, not to LC3B. Co-immunoprecipitation (co-IP) experiments showed that TRPML3 and TRPML3-loop pull down only the lipidated form of GATE16, indicating that the interaction occurs exclusively at the organellar membrane. The interaction of TRPML3 with GATE16 and GATE16-positive vesicle formation were increased in starvation induced autophagy, suggesting that the interaction facilitates the function of GATE16 in autophagosome formation. However, GATE16 was not required for TRPML3 trafficking to autophagosomes. Experiments using dominant-negative (DN) TRPML3(D458K) showed that GATE16 is localized not only in autophagosomes but also in extra-autophagosomal compartments, by contrast with LC3B. Since GATE16 acts at a later stage of the autophagosome biogenesis, our results suggest that TRPML3 plays a role in autophagosome maturation through the interaction with GATE16, by providing Ca2+ in the fusion process. 相似文献
8.
An Appropriate Cutoff Value for Determining the Colonization of Helicobacter pylori by the Pyrosequencing Method: Comparison with Conventional Methods 下载免费PDF全文
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Hyun Woong Lee Dong-Yeop Chang Hong Ju Moon Hye Young Chang Eui-Cheol Shin June Sung Lee Kyung-Ah Kim Hyung Joon Kim 《PloS one》2015,10(6)