scholarly journals Characterization of the Aspergillus fumigatus detoxification systems for reactive nitrogen intermediates and their impact on virulence

2014 ◽  
Vol 5 ◽  
Author(s):  
Katrin Lapp ◽  
Martin Vödisch ◽  
Kristin Kroll ◽  
Maria Strassburger ◽  
Olaf Kniemeyer ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Reactive Nitrogen ◽  
Detoxification Systems ◽  
Reactive Nitrogen Intermediates

CHARACTERIZATION OF REACTIVE NITROGEN TRANSPORT IN PITTSBURGH’S RIVERS

2017 ◽  
Author(s):  
Angela H. Chung ◽  
◽  
Emily M. Elliott ◽  
Carl Nim
Keyword(s):  
Reactive Nitrogen ◽  
Nitrogen Transport

scholarly journals Characterization of the mbsA Gene Encoding a Putative APSES Transcription Factor in Aspergillus fumigatus

2021 ◽  
Vol 22 (7) ◽  
pp. 3777
Author(s):  
Yong-Ho Choi ◽  
Sang-Cheol Jun ◽  
Min-Woo Lee ◽  
Jae-Hyuk Yu ◽  
Kwang-Soo Shin
Keyword(s):  
Aspergillus Fumigatus ◽  
Pathogenic Fungus ◽  
Hyphal Growth ◽  
Spore Wall ◽  
Mrna Levels ◽  
Chitin Synthesis ◽  
Helix Loop Helix ◽  
Growth Development ◽  
Opportunistic Pathogenic

The APSES family proteins are transcription factors (TFs) with a basic helix-loop-helix domain, known to regulate growth, development, secondary metabolism, and other biological processes in Aspergillus species. In the genome of the human opportunistic pathogenic fungus Aspergillus fumigatus, five genes predicted to encode APSES TFs are present. Here, we report the characterization of one of these genes, called mbsA (Afu7g05620). The deletion (Δ) of mbsA resulted in significantly decreased hyphal growth and asexual sporulation (conidiation), and lowered mRNA levels of the key conidiation genes abaA, brlA, and wetA. Moreover, ΔmbsA resulted in reduced spore germination rates, elevated sensitivity toward Nikkomycin Z, and significantly lowered transcripts levels of genes associated with chitin synthesis. The mbsA deletion also resulted in significantly reduced levels of proteins and transcripts of genes associated with the SakA MAP kinase pathway. Importantly, the cell wall hydrophobicity and architecture of the ΔmbsA asexual spores (conidia) were altered, notably lacking the rodlet layer on the surface of the ΔmbsA conidium. Comparative transcriptomic analyses revealed that the ΔmbsA mutant showed higher mRNA levels of gliotoxin (GT) biosynthetic genes, which was corroborated by elevated levels of GT production in the mutant. While the ΔmbsA mutant produced higher amount of GT, ΔmbsA strains showed reduced virulence in the murine model, likely due to the defective spore integrity. In summary, the putative APSES TF MbsA plays a multiple role in governing growth, development, spore wall architecture, GT production, and virulence, which may be associated with the attenuated SakA signaling pathway.

Cloning, Expression, and Enzyme Characterization of an Acid Heat-Stable Phytase from Aspergillus fumigatus WY-2

2007 ◽  
Vol 55 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Yan Wang ◽  
Xiaorong Gao ◽  
Qiao Su ◽  
Wei Wu ◽  
Lijia An
Keyword(s):  
Aspergillus Fumigatus ◽  
Enzyme Characterization ◽  
Heat Stable

scholarly journals The Contributions of Reactive Oxygen Intermediates and Reactive Nitrogen Intermediates to Listericidal Mechanisms Differ in Macrophages Activated Pre- and Postinfection

1998 ◽  
Vol 66 (9) ◽  
pp. 4043-4049 ◽  
Author(s):  
Satoshi Ohya ◽  
Yoshinari Tanabe ◽  
Masato Makino ◽  
Takamasa Nomura ◽  
Huabao Xiong ◽  
...  
Keyword(s):  
Specific Antigen ◽  
Reactive Oxygen ◽  
Reactive Nitrogen ◽  
Reactive Oxygen Intermediates ◽  
Intracellular Killing ◽  
Spleen Cells ◽  
Oxygen Intermediates ◽  
Normal Spleen ◽  
Reactive Nitrogen Intermediates ◽  
Immune Spleen Cells

ABSTRACT The contribution of reactive oxygen intermediates (ROI) and reactive nitrogen intermediates (RNI) to the killing of Listeria monocytogenes by macrophages activated by addition of spleen cells from listeria-immune mice plus specific antigen was examined. When macrophages were infected with L. monocytogenes and then spleen cells were added, there was not as big a difference in listericidal activity between macrophages cultured with normal spleen cells and those cultured with immune spleen cells as expected. In this culture system, RNI was mainly involved in the macrophage intracellular killing. In macrophages first activated and then infected, a significant level of enhanced killing was observed. Blockade of ROI production drastically affected the enhanced killing ability, while inhibition of RNI production had a negligible effect. Thus, the contributions of ROI and RNI to listericidal mechanisms of macrophages were different between macrophages activated at pre- and postinfection stages.

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