• Title/Summary/Keyword: Sun:activity

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2-Undecanone derived from Pseudomonas aeruginosa modulates the neutrophil activity

  • Jeong, Yu Sun;Huh, Sunghyun;Kim, Ji Cheol;Park, Ji Ye;Lee, ChaeEun;Kim, Min-Sik;Koo, JaeHyung;Bae, Yoe-Sik
    • BMB Reports
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    • v.55 no.8
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    • pp.395-400
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    • 2022
  • Pseudomonas aeruginosa (P. aeruginosa) is a well-known Gramnegative opportunistic pathogen. Neutrophils play key roles in mediating host defense against P. aeruginosa infection. In this study, we identified a metabolite derived from P. aeruginosa that regulates neutrophil activities. Using gas chromatography-mass spectrometry, a markedly increased level of 2-undecanone was identified in the peritoneal fluid of P. aeruginosa-infected mice. 2-Undecanone elicited the activation of neutrophils in a Gαi-phospholipase C pathway. However, 2-undecanone strongly inhibited responses to lipopolysaccharide and bactericidal activity of neutrophils against P. aeruginosa by inducing apoptosis. Our results demonstrate that 2-undecanone from P. aeruginosa limits the innate defense activity of neutrophils, suggesting that the production of inhibitory metabolites is a strategy of P. aeruginosa for escaping the host immune system.

SOLAR ACTIVITY AND LATITUDINAL DISTRIBUTION OF SUNSPOTS

  • Chang, Heon-Young
    • Journal of The Korean Astronomical Society
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    • v.55 no.5
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    • pp.139-148
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    • 2022
  • We explore the latitudinal distribution of sunspots and pursue to establish a correlation between the statistical parameters of the latitudinal distribution of sunspots and characteristics of solar activity. For this purpose, we have statistically analyzed the daily sunspot areas and latitudes observed from May in 1874 to September in 2016. As results, we confirm that the maximum of the monthly averaged International Sunspot Number (ISN) strongly correlates with the mean number of sunspots per day, while the maximum ISN strongly anti-correlates with the number of spotless days. We find that both the maximum ISN and the mean number of sunspots per day strongly correlate with the the average latitude, the standard deviation, the skewness of the the latitudinal distribution of sunspots, while they appears to marginally correlate with the kurtosis. It is also found that the northern and southern hemispheres seem to show a correlated behavior in a different way when sunspots appearing in the northern and southern hemispheres are examined separately.

Mediation of Rubradirin Resistance by ABC Transporters (RubT1) from Streptomyces achromogenes var. rubradiris NRRL3061

  • Lamichhane, Janardan;Oh, Tae-Jin;Lee, Hei-Chan;Liou, Kwang-Kyoung;Kim, Chun-Gyu;Sohng, Jae-Kyung
    • Journal of Microbiology and Biotechnology
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    • v.16 no.12
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    • pp.1928-1934
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    • 2006
  • The rubradirin biosynthetic gene cluster harbors 58 ORFs within a 105.6-kb sequence, which includes all of the genes responsible for the synthesis of rubradirin, as well as the primary genes relevant to regulatory, resistance, and transport functions. This gene cluster also harbors a resistance-mediating ABC transporter, RubT1, which is located at the most upstream position in the cluster. In the present study, RubT1 was expressed heterologously in E. coli, and the resistance affinity of RubT1 was determined by an antibacterial activity test, as well as by HPLC and ESI-MS analyses. Evidence clearly demonstrates that RubTl mediates rubradirin resistance as an ABC transporter.