Thermotolerance and virulence of Aspergillus fumigatus:: role of the fungal nucleolus

The ability to thrive at 37 degrees C is characteristic of all human pathogens and has long been suspected to play a role in the pathogenesis of aspergillosis. As a thermotolerant fungus, Aspergillus fumigatus is capable of growth at temperatures that approach the upper limit for all eukaryotes, suggesting that the organism has evolved unique mechanisms of stress resistance that may be relevant to its ability to adapt to the stress of growth in the host. High temperature is a strain on many biological systems, particularly those involved in complex macromolecular assemblies such as ribosomes. This review will discuss the relationship between thermotolerance and virulence in pathogenic fungi, emphasizing the link to ribosome biogenesis in A. fumigatus. Future work in this area will help determine how rapid growth is accomplished at elevated temperature and may offer new avenues for the development of novel antifungals that disrupt thermotolerant ribosome assembly.