The two-component sensor kinase TcsC and its role in stress resistance of the human-pathogenic mold Aspergillus fumigatus.

Abstract

Two-component signaling systems are widespread in bacteria, but also found in fungi. In this study, we have characterized TcsC, the only Group III two-component sensor kinase of Aspergillus fumigatus. TcsC is required for growth under hyperosmotic stress, but dispensable for normal growth, sporulation and conidial viability. A characteristic feature of the ΔtcsC mutant is its resistance to certain fungicides, like fludioxonil. Both hyperosmotic stress and treatment with fludioxonil result in a TcsC-dependent phosphorylation of SakA, the final MAP kinase in the high osmolarity glycerol (HOG) pathway, confirming a role for TcsC in this signaling pathway. In wild type cells fludioxonil induces a TcsC-dependent swelling and a complete, but reversible block of growth and cytokinesis. Several types of stress, such as hypoxia, exposure to farnesol or elevated concentrations of certain divalent cations, trigger a differentiation in A. fumigatus toward a "fluffy" growth phenotype resulting in white, dome-shaped colonies. The ΔtcsC mutant is clearly more susceptible to these morphogenetic changes suggesting that TcsC normally antagonizes this process. Although TcsC plays a role in the adaptation of A. fumigatus to hypoxia, it seems to be dispensable for virulence.

• Authors: Allison McCormick, Ilse D Jacobsen, Marzena Broniszewska, Julia Beck, Jürgen Heesemann, Frank Ebel
• Journal: PloS one (PLoS One) Vol. 7 Issue 6 Pg. e38262 ( 2012) ISSN: 1932-6203 [Electronic] United States
• PMID: 22675534 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Dioxoles
• Fungal Proteins
• Fungicides, Industrial
• Pyrroles
• Cyclic AMP
• Protein Kinases
• Histidine Kinase
• fludioxonil

Topics

• Animals
• Aspergillosis (microbiology, pathology)
• Aspergillus fumigatus (enzymology, genetics, growth & development, pathogenicity)
• Cyclic AMP (pharmacology)
• Dioxoles (pharmacology)
• Drug Resistance, Fungal (drug effects, radiation effects)
• Fungal Proteins (metabolism)
• Fungicides, Industrial (pharmacology)
• Histidine Kinase
• Humans
• Immunocompromised Host
• Light
• Mice
• Microbial Sensitivity Tests
• Models, Biological
• Mutation (genetics)
• Phenotype
• Phosphorylation (drug effects, radiation effects)
• Protein Kinases (metabolism)
• Pyrroles (pharmacology)
• Signal Transduction (drug effects, radiation effects)
• Stress, Physiological (drug effects, radiation effects)
• Virulence (drug effects, radiation effects)