title: Nucleolar localization of Aspergillus fumigatus CgrA is temperature-dependent.
abstract: Pathogenic fungi must adapt to multiple adverse environmental conditions during the transition from the environment to a mammalian host, one of which is temperature. The ability of Aspergillus fumigatus to grow optimally under conditions of thermal stress requires the nucleolar protein CgrA. In this study, we have determined how temperature affects the intracellular localization of CgrA in A. fumigatus using a green fluorescent protein (GFP)-tagging approach. At 22 degrees C, CgrA was almost exclusively in the nucleolus, with a ratio of nucleolar to cytoplasmic fluorescence of 10:1. At 37 degrees C, the ratio of nucleolar to cytoplasmic fluorescence was reduced fivefold, and increased correspondingly in the cytoplasm. This effect was not seen with the nucleolar protein NopA in wild-type A. fumigatus. However, in a DeltacgrA mutant NopA was delocalized from the nucleolus at 37 degrees C but not at 22 degrees C. These results provide evidence for a temperature-dependent mechanism of intracellular localization for CgrA, and suggest that CgrA facilitates nucleolar compartmentalization of NopA at higher temperature.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0529, USA.
authors.forename: Ruchi
authors.initials: R
authors.lastname: Bhabhra
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Judith C
authors.initials: JC
authors.lastname: Rhodes
authors.forename: David S
authors.initials: DS
authors.lastname: Askew
mesh_terms: D001232:Aspergillus fumigatus / Q000378:metabolism / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D016601:RNA-Binding Proteins; D013696:Temperature
chemical_list: C433726:CGRA protein, Aspergillus fumigatus; D005656:Fungal Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins