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Wang J.,Institute of Tuberculosis Control | Wang J.,Sun Yat Sen University | Wang J.,Guangzhou University | Huang C.,Institute of Tuberculosis Control | And 16 more authors.
Journal of Infection | Year: 2015

Objective: To explore the role of myeloid-related protein 8/14 in mycobacterial infection. Methods: The mRNA and protein expression levels of MRP8 or MRP14 were measured by real-time PCR and flow cytometry, respectively. Role of MRP8/14 was tested by overexpression or RNA interference assays. Flow cytometry and colony forming unit were used to test the phagocytosis and the survival of intracellular Mycobacterium bovis BCG (BCG), respectively. Autophagy mediated by MRP8/14 was detected by Western blot and immunofluorescence. The colocalization of BCG phagosomes with autophagosomes or lysosomes was by detected by confocal microscopy. ROS production was detected by flow cytometry. Results: MRP8/14 expressions were up-regulated in human monocytic THP1 cells and primary macrophages after mycobacterial challenge. Silencing of MRP8/14 suppressed bacterial killing, but had no influence on the phagocytosis of BCG. Importantly, silencing MRP8/14 decreased autophagy and BCG phagosome maturation in THP1-derived macrophages, thereby increasing the BCG survival. Additionally, we demonstrated that MRP8/14 promoted autophagy in a ROS-dependent manner. Conclusions: The present study revealed a novel role of MRP8/14 in the autophagy-mediated elimination of intracellular BCG by promoting ROS generation, which may provide a promising therapeutic target for tuberculosis and other intracellular bacterial infectious diseases. © 2014 The British Infection Association. Source

Gao Y.-R.,CAS Institute of Biophysics | Gao Y.-R.,University of Chinese Academy of Sciences | Feng N.,CAS Institute of Biophysics | Chen T.,Center for Tuberculosis Control of Guangdong Province | And 2 more authors.
Acta Crystallographica Section F:Structural Biology Communications | Year: 2015

Rv0880 from the pathogen Mycobacterium tuberculosis is classified as a MarR family protein in the Pfam database. It consists of 143 amino acids and has an isoelectric point of 10.9. Crystals of Rv0880 belonged to space group P1, with unit-cell parameters a = 54.97, b = 69.60, c = 70.32 Å, α = 103.71, β = 111.06, γ = 105.83°. The structure of the MarR family transcription regulator Rv0880 was solved at a resolution of 2.0 Å with an R cryst and R free of 21.2 and 24.9%, respectively. The dimeric structure resembles that of other MarR proteins, with each subunit comprising a winged helix-turn-helix domain connected to an α-helical dimerization domain. © 2015 International Union of Crystallography. Source

Lu F.,East China University of Science and Technology | Gao F.,CAS Institute of Biophysics | Li H.,East China University of Science and Technology | Gong W.,CAS Institute of Biophysics | And 2 more authors.
Acta Crystallographica Section F:Structural Biology Communications | Year: 2014

The conserved protein Rv3705c from Mycobacterium tuberculosis has been cloned, expressed, purified and crystallized by the sitting-drop vapour-diffusion method using PEG 3350 as a precipitant. The Rv3705c crystals exhibited space group P6122 or P6522, with unit-cell parameters a = b = 198.0, c = 364.1 Å, α = β = 90, γ = 120°, and diffracted to a resolution of 3.3 Å. © 2014 CrossMark. Source

Chen T.,CAS Institute of Biophysics | Chen T.,Center for Tuberculosis Control of Guangdong Province | Chen L.,Center for Tuberculosis Control of Guangdong Province | Li H.,Center for Tuberculosis Control of Guangdong Province | And 9 more authors.
Colloids and Surfaces B: Biointerfaces | Year: 2014

To overcome the undesirable side-effects of metronidazole (MTZ), ethylene glycol dimethacrylate is used as the cross-linker, and a series of poly(methacrylic acid) (PMAA) nanogels were prepared to load the MTZ. We investigated the morphology, size, in vitro release property in the simulated gastrointestinal medium, long-term antibacterial performance against Bacteroides fragilis, cytotoxicity, stability and activity of this novel MTZ/PMAA nanogel. The results indicate that the MTZ/PMAA nanogel sustained the release of MTZ in long-term antibacterial activity in the simulated gastrointestinal medium. This MTZ/PMAA nanogel exhibits less cytotoxicity than MTZ alone, suggesting that MTZ/PMAA nanogel is a more useful dosage form than MTZ for mild-to-moderate Clostridium difficile infections. The novel aspects of this study include the synthesis of a nanogel and the three-phase study of the release profile, which might be useful for other researchers in this field. © 2014 . Source

Zhou Y.,CAS Institute of Biophysics | Chen T.,Center for Tuberculosis Control of Guangdong Province | Zhou L.,Center for Tuberculosis Control of Guangdong Province | Fleming J.,CAS Institute of Biophysics | And 7 more authors.
FEMS microbiology letters | Year: 2015

Lysine acetylation is an important post-translational modification and is known to regulate many eukaryotic cellular processes. Little, however, is known about acetylated proteins in prokaryotes. Here, using immunoblotting, mass spectrometry and mutagenesis studies, we investigate the acetylation dynamics of the DNA repair protein Ku and its relationship with the deacetylase protein Sir2 and the non-homologous end joining (NHEJ) pathway in Mycobacterium smegmatis. We report that acetylation of Ku increases with growth, while NHEJ activity decreases, providing support for the hypothesis that acetylation of Ku may be involved in the DNA damage response in bacteria. Ku has multiple lysine sites. Our results indicate that K29 is an important acetylation site and that deficiency of Sir2 or mutation of K29 affects the quantity of Ku and its acetylation dynamics. Our findings expand knowledge of acetylation targets in prokaryotes and indicate a new direction for further research on bacterial DNA repair mechanisms. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. Source

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