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Gewählte Publikation:

Schinko, T; Berger, H; Lee, W; Gallmetzer, A; Pirker, K; Pachlinger, R; Buchner, I; Reichenauer, T; Güldener, U; Strauss, J; .
(2010): Transcriptome analysis of nitrate assimilation in Aspergillus nidulans reveals connections to nitric oxide metabolism.
Mol Microbiol. 2010; 78(3):720-738 FullText FullText_BOKU

P>Nitrate is a dominant form of inorganic nitrogen (N) in soils and can be efficiently assimilated by bacteria, fungi and plants. We studied here the transcriptome of the short-term nitrate response using assimilating and non-assimilating strains of the model ascomycete Aspergillus nidulans. Among the 72 genes positively responding to nitrate, only 18 genes carry binding sites for the pathway-specific activator NirA. Forty-five genes were repressed by nitrate metabolism. Because nirA- strains are N-starved at nitrate induction conditions, we also compared the nitrate transcriptome with N-deprived conditions and found a partial overlap of differentially regulated genes between these conditions. Nitric oxide (NO)-metabolizing flavohaemoglobins were found to be co-regulated with nitrate assimilatory genes. Subsequent molecular characterization revealed that the strongly inducible FhbA is required for full activity of nitrate and nitrite reductase enzymes. The co-regulation of NO-detoxifying and nitrate/nitrite assimilating systems may represent a conserved mechanism, which serves to neutralize nitrosative stress imposed by an external NO source in saprophytic and pathogenic fungi. Our analysis using membrane-permeable NO donors suggests that signalling for NirA activation only indirectly depends on the nitrate transporters NrtA (CrnA) and NrtB (CrnB).
Autor*innen der BOKU Wien:
Pirker Katharina
Strauss Joseph
Find related publications in this database (using NML MeSH Indexing)
Anion Transport Proteins/genetics;Anion Transport Proteins/metabolism;Aspergillus nidulans/enzymology;Aspergillus nidulans/genetics*;Aspergillus nidulans/metabolism*;Fungal Proteins/genetics;Fungal Proteins/metabolism;Gene Expression Profiling*;Gene Expression Regulation, Fungal;Nitrate Reductase/genetics;Nitrate Reductase/metabolism;Nitrates/metabolism*;Nitric Oxide/metabolism*;Nitrite Reductases/genetics;Nitrite Reductases/metabolism;

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