title: A p53-like transcription factor similar to Ndt80 controls the response to nutrient stress in the filamentous fungus, Aspergillus nidulans.
abstract: The Aspergillus nidulans xprG gene encodes a putative transcriptional activator that is a member of the Ndt80 family in the p53-like superfamily of proteins. Previous studies have shown that XprG controls the production of extracellular proteases in response to starvation. We undertook transcriptional profiling to investigate whether XprG has a wider role as a global regulator of the carbon nutrient stress response. Our microarray data showed that the expression of a large number of genes, including genes involved in secondary metabolism, development, high-affinity glucose uptake and autolysis, were altered in an xprG Δ null mutant. Many of these genes are known to be regulated in response to carbon starvation. We confirmed that sterigmatocystin and penicillin production is reduced in xprG (-) mutants. The loss of fungal mass and secretion of pigments that accompanies fungal autolysis in response to nutrient depletion was accelerated in an xprG1 gain-of-function mutant and decreased or absent in an xprG (-) mutant. The results support the hypothesis that XprG plays a major role in the response to carbon limitation and that nutrient sensing may represent one of the ancestral roles for the p53-like superfamily. Disruption of the AN6015 gene, which encodes a second Ndt80-like protein, showed that it is required for sexual reproduction in A. nidulans.
authors.affiliation: Department of Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia.
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Katz
authors.affiliation: Department of Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Braunberger
authors.affiliation: Department of Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia ; Current address: Nanjing Hospital for Women & Children's Health, Nanjing Medical University, Nanjing City, 210004, China.
authors.forename: Gauncai
authors.initials: G
authors.lastname: Yi
authors.affiliation: Department of Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Cooper
authors.affiliation: Department of Molecular and Cellular Biology, University of New England, Armidale, NSW 2351, Australia.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Nonhebel
authors.affiliation: The Centre for Genetic Analysis and Applications, University of New England, Armidale, NSW 2351, Australia.
authors.forename: Cedric
authors.initials: C
authors.lastname: Gondro