title: Metabolic adaptation in Cryptococcus neoformans during early murine pulmonary infection.
abstract: The pathogenic fungus Cryptococcus neoformans generally initiates infection in mammalian lung tissue and subsequently disseminates to the brain. We performed serial analysis of gene expression (SAGE) on C. neoformans cells recovered from the lungs of mice and found elevated expression of genes for central carbon metabolism including functions for acetyl-CoA production and utilization. Deletion of the highly expressed ACS1 gene encoding acetyl-CoA synthetase revealed a requirement for growth on acetate and for full virulence. Transcripts for transporters (e.g. for monosaccharides, iron, copper and acetate) and for stress-response proteins were also elevated thus indicating a nutrient-limited and hostile host environment. The pattern of regulation was reminiscent of the control of alternative carbon source utilization and stress response by the Snf1 protein kinase in Saccharomyces cerevisiae. A snf1 mutant of C. neoformans showed defects in alternative carbon source utilization, the response to nitrosative stress, melanin production and virulence. However, loss of Snf1 did not influence the expression of a set of genes for carbon metabolism that were elevated upon lung infection. Taken together, the results reveal specific metabolic adaptations of C. neoformans during pulmonary infection and indicate a role for ACS1 and SNF1 in virulence.
authors.affiliation: Michael Smith Laboratories, The University of British Columbia, 2185 East Mall, Vancouver, BC, Canada.
authors.forename: Guanggan
authors.initials: G
authors.lastname: Hu
authors.forename: Po-Yan
authors.initials: PY
authors.lastname: Cheng
authors.forename: Anita
authors.initials: A
authors.lastname: Sham
authors.forename: John R
authors.initials: JR
authors.lastname: Perfect
authors.forename: James W
authors.initials: JW
authors.lastname: Kronstad
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D000222:Adaptation, Physiological; D000818:Animals; D002244:Carbon / Q000378:metabolism; D003066:Coenzyme A Ligases / Q000235:genetics / Q000378:metabolism; D003453:Cryptococcosis / Q000382:microbiology*; D003455:Cryptococcus neoformans / Q000378:metabolism* / Q000502:physiology*; D005260:Female; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D008168:Lung / Q000382:microbiology; D051379:Mice; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D037521:Virulence Factors; D002244:Carbon; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases; D003066:Coenzyme A Ligases; C561832:Acsl1 protein, rat; D019342:Acetic Acid