Posttranslational, translational, and transcriptional responses to nitric oxide stress in Cryptococcus neoformans: implications for virulence.
The ability of the fungal pathogen Cryptococcus neoformans to evade the mammalian innate immune response and cause disease is partially due to its ability to respond to and survive nitrosative stress. In this study, we use proteomic and genomic approaches to elucidate the response of C. neoformans to nitric oxide stress. This nitrosative stress response involves both transcriptional, translational, and posttranslational regulation. Proteomic and genomic analyses reveal changes in expression of stress response genes. In addition, genes involved in cell wall organization, respiration, signal transduction, transport, transcriptional control, and metabolism show altered expression under nitrosative conditions. Posttranslational modifications of transaldolase (Tal1), aconitase (Aco1), and the thiol peroxidase, Tsa1, are regulated during nitrosative stress. One stress-related protein up-regulated in the presence of nitric oxide stress is glutathione reductase (Glr1). To further investigate its functional role during nitrosative stress, a deletion mutant was generated. We show that this glr1Delta mutant is sensitive to nitrosative stress and macrophage killing in addition to being avirulent in mice. These studies define the response to nitrosative stress in this important fungal pathogen.
Missall
Tricia A
TA
Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, 1402 S. Grand Blvd., St. Louis, MO 63104, USA.
Pusateri
Mary Ellen
ME
Donlin
Maureen J
MJ
Chambers
Kari T
KT
Corbett
John A
JA
Lodge
Jennifer K
JK
D000154:Aconitate Hydratase / Q000096:biosynthesis / Q000235:genetics; D000818:Animals; D003455:Cryptococcus neoformans / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D004305:Dose-Response Relationship, Drug; D005260:Female; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D023281:Genomics; D051379:Mice; D008808:Mice, Inbred CBA; D009569:Nitric Oxide / Q000494:pharmacology* / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects*; D010544:Peroxidases / Q000096:biosynthesis / Q000235:genetics; D011499:Protein Processing, Post-Translational; D040901:Proteomics; D014153:Transaldolase / Q000096:biosynthesis / Q000235:genetics; D014158:Transcription, Genetic; D014774:Virulence
D009569:Nitric Oxide; D010544:Peroxidases; D014153:Transaldolase; D000154:Aconitate Hydratase