HacA-Independent Functions of the ER Stress Sensor IreA Synergize with the Canonical UPR to Influence Virulence Traits in
Endoplasmic reticulum (ER) stress is a condition in which the protein folding capacity of the ER becomes overwhelmed by an increased demand for secretion or by exposure to compounds that disrupt ER homeostasis. In yeast and other fungi, the accumulation of unfolded proteins is detected by the ER-transmembrane sensor IreA/Ire1, which responds by cleaving an intron from the downstream cytoplasmic mRNA HacA/Hac1, allowing for the translation of a transcription factor that coordinates a series of adaptive responses that are collectively known as the unfolded protein response (UPR). Here, we examined the contribution of IreA to growth and virulence in the human fungal pathogen Aspergillus fumigatus. Gene expression profiling revealed that A. fumigatus IreA signals predominantly through the canonical IreA-HacA pathway under conditions of severe ER stress. However, in the absence of ER stress IreA controls dual signaling circuits that are both HacA-dependent and HacA-independent. We found that a ΔireA mutant was avirulent in a mouse model of invasive aspergillosis, which contrasts the partial virulence of a ΔhacA mutant, suggesting that IreA contributes to pathogenesis independently of HacA. In support of this conclusion, we found that the ΔireA mutant had more severe defects in the expression of multiple virulence-related traits relative to ΔhacA, including reduced thermotolerance, decreased nutritional versatility, impaired growth under hypoxia, altered cell wall and membrane composition, and increased susceptibility to azole antifungals. In addition, full or partial virulence could be restored to the ΔireA mutant by complementation with either the induced form of the hacA mRNA, hacAi, or an ireA deletion mutant that was incapable of processing the hacA mRNA, ireAΔ10. Together, these findings demonstrate that IreA has both HacA-dependent and HacA-independent functions that contribute to the expression of traits that are essential for virulence in A. fumigatus.
Vyšlo v časopise:
HacA-Independent Functions of the ER Stress Sensor IreA Synergize with the Canonical UPR to Influence Virulence Traits in. PLoS Pathog 7(10): e32767. doi:10.1371/journal.ppat.1002330
Kategorie:
Research Article
prolekare.web.journal.doi_sk:
https://doi.org/10.1371/journal.ppat.1002330
Souhrn
Endoplasmic reticulum (ER) stress is a condition in which the protein folding capacity of the ER becomes overwhelmed by an increased demand for secretion or by exposure to compounds that disrupt ER homeostasis. In yeast and other fungi, the accumulation of unfolded proteins is detected by the ER-transmembrane sensor IreA/Ire1, which responds by cleaving an intron from the downstream cytoplasmic mRNA HacA/Hac1, allowing for the translation of a transcription factor that coordinates a series of adaptive responses that are collectively known as the unfolded protein response (UPR). Here, we examined the contribution of IreA to growth and virulence in the human fungal pathogen Aspergillus fumigatus. Gene expression profiling revealed that A. fumigatus IreA signals predominantly through the canonical IreA-HacA pathway under conditions of severe ER stress. However, in the absence of ER stress IreA controls dual signaling circuits that are both HacA-dependent and HacA-independent. We found that a ΔireA mutant was avirulent in a mouse model of invasive aspergillosis, which contrasts the partial virulence of a ΔhacA mutant, suggesting that IreA contributes to pathogenesis independently of HacA. In support of this conclusion, we found that the ΔireA mutant had more severe defects in the expression of multiple virulence-related traits relative to ΔhacA, including reduced thermotolerance, decreased nutritional versatility, impaired growth under hypoxia, altered cell wall and membrane composition, and increased susceptibility to azole antifungals. In addition, full or partial virulence could be restored to the ΔireA mutant by complementation with either the induced form of the hacA mRNA, hacAi, or an ireA deletion mutant that was incapable of processing the hacA mRNA, ireAΔ10. Together, these findings demonstrate that IreA has both HacA-dependent and HacA-independent functions that contribute to the expression of traits that are essential for virulence in A. fumigatus.
Zdroje
1. RavindranSBoothroydJC 2008 Secretion of proteins into host cells by Apicomplexan parasites. Traffic 9 647 656
2. Sam-YelloweTY 2009 The role of the Maurer's clefts in protein transport in Plasmodium falciparum. Trends Parasitol 25 277 284
3. FleckCBSchobelFBrockM 2011 Nutrient acquisition by pathogenic fungi: Nutrient availability, pathway regulation, and differences in substrate utilization. Int J Med Microbiol 301 400 407
4. NeofytosDFishmanJAHornDAnaissieEChangCH 2010 Epidemiology and outcome of invasive fungal infections in solid organ transplant recipients. Transpl Infect Dis 12 220 229
5. RomischK 2004 A cure for traffic jams: small molecule chaperones in the endoplasmic reticulum. Traffic 5 815 820
6. DobsonCM 2003 Protein folding and misfolding. Nature 426 884 890
7. MalhotraJDKaufmanRJ 2007 The endoplasmic reticulum and the unfolded protein response. Semin Cell Dev Biol 18 716 731
8. MoriK 2009 Signalling pathways in the unfolded protein response: development from yeast to mammals. J Biochem 146 743 750
9. SidrauskiCWalterP 1997 The transmembrane kinase Ire1p is a site-specific endonuclease that initiates mRNA splicing in the unfolded protein response. Cell 90 1031 1039
10. PincusDChevalierMWAragonTvan AnkenEVidalSE 2010 BiP binding to the ER-stress sensor Ire1 tunes the homeostatic behavior of the unfolded protein response. PLoS Biol 8 e1000415
11. CoxJSShamuCEWalterP 1993 Transcriptional induction of genes encoding endoplasmic reticulum resident proteins requires a transmembrane protein kinase. Cell 73 1197 1206
12. MoriKMaWGethingMJSambrookJ 1993 A transmembrane protein with a cdc2+/CDC28-related kinase activity is required for signaling from the ER to the nucleus. Cell 74 743 756
13. LiHKorennykhAVBehrmanSLWalterP 2010 Mammalian endoplasmic reticulum stress sensor IRE1 signals by dynamic clustering. Proc Natl Acad Sci U S A 107 16113 16118
14. BackSHSchroderMLeeKZhangKKaufmanRJ 2005 ER stress signaling by regulated splicing: IRE1/HAC1/XBP1. Methods 35 395 416
15. RichieDLHartlLAimaniandaVWintersMSFullerKK 2009 A role for the unfolded protein response (UPR) in virulence and antifungal susceptibility in Aspergillus fumigatus. PLoS Pathog 5 e1000258
16. LeeKPDeyMNeculaiDCaoCDeverTE 2008 Structure of the dual enzyme Ire1 reveals the basis for catalysis and regulation in nonconventional RNA splicing. Cell 132 89 100
17. LeeKTirasophonWShenXMichalakMPrywesR 2002 IRE1-mediated unconventional mRNA splicing and S2P-mediated ATF6 cleavage merge to regulate XBP1 in signaling the unfolded protein response. Genes Dev 16 452 466
18. MulderHJNikolaevI 2009 HacA-dependent transcriptional switch releases hacA mRNA from a translational block upon endoplasmic reticulum stress. Eukaryot Cell 8 665 675
19. SimsAHGentMELanthalerKDunn-ColemanNSOliverSG 2005 Transcriptome analysis of recombinant protein secretion by Aspergillus nidulans and the unfolded-protein response in vivo. Appl Environ Microbiol 71 2737 2747
20. GuillemetteTvan PeijNNGoosenTLanthalerKRobsonGD 2007 Genomic analysis of the secretion stress response in the enzyme-producing cell factory Aspergillus niger. BMC Genomics 8 158
21. ArvasMPakulaTLanthalerKSaloheimoMValkonenM 2006 Common features and interesting differences in transcriptional responses to secretion stress in the fungi Trichoderma reesei and Saccharomyces cerevisiae. BMC Genomics 7 32
22. MulderHJSaloheimoMPenttilaMMadridSM 2004 The transcription factor HACA mediates the unfolded protein response in Aspergillus niger, and up-regulates its own transcription. Mol Genet Genomics 271 130 140
23. TraversKJPatilCKWodickaLLockhartDJWeissmanJS 2000 Functional and genomic analyses reveal an essential coordination between the unfolded protein response and ER-associated degradation. Cell 101 249 258
24. WaltherTCBricknerJHAguilarPSBernalesSPantojaC 2006 Eisosomes mark static sites of endocytosis. Nature 439 998 1003
25. WangHXDouglasLMAimaniandaVLatgeJPKonopkaJB 2011 The Candida albicans Sur7 protein is needed for proper synthesis of the fibrillar component of the cell wall that confers strength. Eukaryot Cell 10 72 80
26. PakulaTMLaxellMHuuskonenAUusitaloJSaloheimoM 2003 The effects of drugs inhibiting protein secretion in the filamentous fungus Trichoderma reesei. Evidence for down-regulation of genes that encode secreted proteins in the stressed cells. J Biol Chem 278 45011 45020
27. BravoRVicencioJMParraVTroncosoRMunozJP 2011 Increased ER-mitochondrial coupling promotes mitochondrial respiration and bioenergetics during early phases of ER stress. J Cell Sci 124 2143 2152
28. HeleniusAAebiM 2004 Roles of N-linked glycans in the endoplasmic reticulum. Annu Rev Biochem 73 1019 1049
29. HartmannTSasseCSchedlerAHasenbergMGunzerM 2011 Shaping the fungal adaptome - Stress responses of Aspergillus fumigatus. Int J Med Microbiol 301 408 416
30. AraujoRRodriguesAG 2004 Variability of germinative potential among pathogenic species of Aspergillus. J Clin Microbiol 42 4335 4337
31. PaisleyDRobsonGDDenningDW 2005 Correlation between in vitro growth rate and in vivo virulence in Aspergillus fumigatus. Med Mycol 43 397 401
32. BhabhraRMileyMDMylonakisEBoettnerDFortwendelJ 2004 Disruption of the Aspergillus fumigatus gene encoding nucleolar protein CgrA impairs thermotolerant growth and reduces virulence. Infect Immun 72 4731 4740
33. WillgerSDPuttikamonkulSKimKHBurrittJBGrahlN 2008 A sterol-regulatory element binding protein is required for cell polarity, hypoxia adaptation, azole drug resistance, and virulence in Aspergillus fumigatus. PLoS Pathog 4 e1000200
34. Romero-RamirezLCaoHNelsonDHammondELeeAH 2004 XBP1 is essential for survival under hypoxic conditions and is required for tumor growth. Cancer Res 64 5943 5947
35. LatgeJP 2007 The cell wall: a carbohydrate armour for the fungal cell. Mol Microbiol 66 279 290
36. GasteboisAClavaudCAimaniandaVLatgeJP 2009 Aspergillus fumigatus: cell wall polysaccharides, their biosynthesis and organization. Future Microbiol 4 583 595
37. SturleySL 2000 Conservation of eukaryotic sterol homeostasis: new insights from studies in budding yeast. Biochim Biophys Acta 1529 155 163
38. Alcazar-FuoliLMelladoEGarcia-EffronGLopezJFGrimaltJO 2008 Ergosterol biosynthesis pathway in Aspergillus fumigatus. Steroids 73 339 347
39. JorgensenTRGoosenTHondelCARamAFIversenJJ 2009 Transcriptomic comparison of Aspergillus niger growing on two different sugars reveals coordinated regulation of the secretory pathway. BMC Genomics 10 44
40. WeinbergED 1999 The role of iron in protozoan and fungal infectious diseases. J Eukaryot Microbiol 46 231 238
41. SchrettlMBignellEKraglCJoechlCRogersT 2004 Siderophore biosynthesis but not reductive iron assimilation is essential for Aspergillus fumigatus virulence. J Exp Med 200 1213 1219
42. SchrettlMBeckmannNVargaJHeinekampTJacobsenID 2010 HapX-mediated adaption to iron starvation is crucial for virulence of Aspergillus fumigatus. PLoS Pathog 6 e1001124
43. BicknellAABabourAFederovitchCMNiwaM 2007 A novel role in cytokinesis reveals a housekeeping function for the unfolded protein response. J Cell Biol 177 1017 1027
44. ReadND 2011 Exocytosis and growth do not occur only at hyphal tips. Mol Microbiol 81 4 7
45. VinckATerlouMPestmanWRMartensEPRamAF 2005 Hyphal differentiation in the exploring mycelium of Aspergillus niger. Mol Microbiol 58 693 699
46. ShenXEllisRESakakiKKaufmanRJ 2005 Genetic interactions due to constitutive and inducible gene regulation mediated by the unfolded protein response in C. elegans. PLoS Genet 1 e37
47. HollienJLinJHLiHStevensNWalterP 2009 Regulated Ire1-dependent decay of messenger RNAs in mammalian cells. J Cell Biol 186 323 331
48. SprongHvan der SluijsPvan MeerG 2001 How proteins move lipids and lipids move proteins. Nat Rev Mol Cell Biol 2 504 513
49. SimoninHBeneyLGervaisP 2007 Cell death induced by mild physical perturbations could be related to transient plasma membrane modifications. J Membr Biol 216 37 47
50. McDonaghAFedorovaNDCrabtreeJYuYKimS 2008 Sub-telomere directed gene expression during initiation of invasive aspergillosis. PLoS Pathog 4 e1000154
51. PoytonROCastelloPRBallKAWooDKPanN 2009 Mitochondria and hypoxic signaling: a new view. Ann N Y Acad Sci 1177 48 56
52. PorterJRBurgJSEspenshadePJIglesiasPA 2010 Ergosterol regulates SREBP cleavage in fission yeast. J Biol Chem 285 41051 41061
53. WisemanRLZhangYLeeKPHardingHPHaynesCM 2010 Flavonol activation defines an unanticipated ligand-binding site in the kinase-RNase domain of IRE1. Mol Cell 38 291 304
54. JoubertASimoneauPCampionCBataille-SimoneauNIacomi-VasilescuB 2011 Impact of the unfolded protein response on the pathogenicity of the necrotrophic fungus Alternaria brassicicola. Mol Microbiol 79 1305 1324
55. CoveDJ 1966 The induction and repression of nitrate reductase in the fungus Aspergillus nidulans. Biochim Biophys Acta 113 51 56
56. ShangJLehrmanMA 2004 Discordance of UPR signaling by ATF6 and Ire1p-XBP1 with levels of target transcripts. Biochem Biophys Res Commun 317 390 396
57. NiermanWCPainAAndersonMJWortmanJRKimHS 2005 Genomic sequence of the pathogenic and allergenic filamentous fungus Aspergillus fumigatus. Nature 438 1151 1156
58. BoyleEIWengSGollubJJinHBotsteinD 2004 GO::TermFinder–open source software for accessing Gene Ontology information and finding significantly enriched Gene Ontology terms associated with a list of genes. Bioinformatics 20 3710 3715
59. KanehisaMGotoSKawashimaSOkunoYHattoriM 2004 The KEGG resource for deciphering the genome. Nucleic Acids Res 32 D277 280
60. EisenMBSpellmanPTBrownPOBotsteinD 1998 Cluster analysis and display of genome-wide expression patterns. Proc Natl Acad Sci U S A 95 14863 14868
61. SaldanhaAJ 2004 Java Treeview–extensible visualization of microarray data. Bioinformatics 20 3246 3248
62. FontaineTSimenelCDubreucqGAdamODelepierreM 2000 Molecular organization of the alkali-insoluble fraction of Aspergillus fumigatus cell wall. J Biol Chem 275 41528
Štítky
Hygiena a epidemiológia Infekčné lekárstvo LaboratóriumČlánok vyšiel v časopise
PLOS Pathogens
2011 Číslo 10
- Parazitičtí červi v terapii Crohnovy choroby a dalších zánětlivých autoimunitních onemocnění
- Očkování proti virové hemoragické horečce Ebola experimentální vakcínou rVSVDG-ZEBOV-GP
- Koronavirus hýbe světem: Víte jak se chránit a jak postupovat v případě podezření?
Najčítanejšie v tomto čísle
- Severe Acute Respiratory Syndrome Coronavirus Envelope Protein Regulates Cell Stress Response and Apoptosis
- The SARS-Coronavirus-Host Interactome: Identification of Cyclophilins as Target for Pan-Coronavirus Inhibitors
- Biochemical and Structural Insights into the Mechanisms of SARS Coronavirus RNA Ribose 2′-O-Methylation by nsp16/nsp10 Protein Complex
- Evolutionarily Divergent, Unstable Filamentous Actin Is Essential for Gliding Motility in Apicomplexan Parasites