The Dot/Icm System Delivers a Unique Repertoire of Type IV Effectors into Host Cells and Is Required for Intracellular Replication

English version České info

Coxiella burnetii, the causative agent of human Q fever, is an intracellular pathogen that replicates in an acidified vacuole derived from the host lysosomal network. This pathogen encodes a Dot/Icm type IV secretion system that delivers bacterial proteins called effectors to the host cytosol. To identify new effector proteins, the functionally analogous Legionella pneumophila Dot/Icm system was used in a genetic screen to identify fragments of C. burnetii genomic DNA that when fused to an adenylate cyclase reporter were capable of directing Dot/Icm-dependent translocation of the fusion protein into mammalian host cells. This screen identified Dot/Icm effectors that were proteins unique to C. burnetii, having no overall sequence homology with L. pneumophila Dot/Icm effectors. A comparison of C. burnetii genome sequences from different isolates revealed diversity in the size and distribution of the genes encoding many of these effectors. Studies examining the localization and function of effectors in eukaryotic cells provided evidence that several of these proteins have an affinity for specific host organelles and can disrupt cellular functions. The identification of a transposon insertion mutation that disrupts the dot/icm locus was used to validate that this apparatus was essential for translocation of effectors. Importantly, this C. burnetii Dot/Icm-deficient mutant was found to be defective for intracellular replication. Thus, these data indicate that C. burnetii encodes a unique subset of bacterial effector proteins translocated into host cells by the Dot/Icm apparatus, and that the cumulative activities exerted by these effectors enables C. burnetii to successfully establish a niche inside mammalian cells that supports intracellular replication.

Vyšlo v časopise: The Dot/Icm System Delivers a Unique Repertoire of Type IV Effectors into Host Cells and Is Required for Intracellular Replication. PLoS Pathog 7(5): e32767. doi:10.1371/journal.ppat.1002056
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.ppat.1002056

Souhrn

Zdroje

1. MaurinMRaoultD 1999 Q fever. Clin Microbiol Rev 12 518 553

2. HackstadtTWilliamsJC 1981 Biochemical stratagem for obligate parasitism of eukaryotic cells by Coxiella burnetii. Proc Natl Acad Sci U S A 78 3240 3244

3. ColemanSAFischerERHoweDMeadDJHeinzenRA 2004 Temporal analysis of Coxiella burnetii morphological differentiation. J Bacteriol 186 7344 7352

4. HoweDMallaviaLP 2000 Coxiella burnetii exhibits morphological change and delays phagolysosomal fusion after internalization by J774A.1 cells. Infect Immun 68 3815 3821

5. HoweDHeinzenRA 2006 Coxiella burnetii inhabits a cholesterol-rich vacuole and influences cellular cholesterol metabolism. Cell Microbiol 8 496 507

6. RomanoPSGutierrezMGBeronWRabinovitchMColomboMI 2007 The autophagic pathway is actively modulated by phase II Coxiella burnetii to efficiently replicate in the host cell. Cell Microbiol 9 891 909

7. HoweDMelnicakovaJBarakIHeinzenRA 2003 Maturation of the Coxiella burnetii parasitophorous vacuole requires bacterial protein synthesis but not replication. Cell Microbiol 5 469 480

8. SeshadriRPaulsenITEisenJAReadTDNelsonKE 2003 Complete genome sequence of the Q-fever pathogen Coxiella burnetii. Proc Natl Acad Sci U S A 100 5455 5460

9. ZamboniDSMcGrathSRabinovitchMRoyCR 2003 Coxiella burnetii express type IV secretion system proteins that function similarly to components of the Legionella pneumophila Dot/Icm system. Mol Microbiol 49 965 976

10. ZusmanTYerushalmiGSegalG 2003 Functional similarities between the icm/dot pathogenesis systems of Coxiella burnetii and Legionella pneumophila. Infect Immun 71 3714 3723

11. SegalGShumanHA 1999 Legionella pneumophila utilizes the same genes to multiply within Acanthamoeba castellanii and human macrophages. Infect Immun 67 2117 2124

12. MarraABlanderSJHorwitzMAShumanHA 1992 Identification of a Legionella pneumophila locus required for intracellular multiplication in human macrophages. Proc Natl Acad Sci U S A 89 9607 9611

13. BergerKHIsbergRR 1993 Two distinct defects in intracellular growth complemented by a single genetic locus in Legionella pneumophila. Mol Microbiol 7 7 19

14. BrandBCSadoskyABShumanHA 1994 The Legionella pneumophila icm locus: a set of genes required for intracellular multiplication in human macrophages. Mol Microbiol 14 797 808

15. RoyCRBergerKHIsbergRR 1998 Legionella pneumophila DotA protein is required for early phagosome trafficking decisions that occur within minutes of bacterial uptake. Mol Microbiol 28 663 674

16. KaganJCRoyCR 2002 Legionella phagosomes intercept vesicular traffic from endoplasmic reticulum exit sites. Nat Cell Biol 4 945 954

17. KaganJCSteinMPPypaertMRoyCR 2004 Legionella subvert the functions of Rab1 and Sec22b to create a replicative organelle. J Exp Med 199 1201 1211

18. BursteinDZusmanTDegtyarEVinerRSegalG 2009 Genome-scale identification of Legionella pneumophila effectors using a machine learning approach. PLoS Pathog 5 e1000508

19. HuangLBoydDAmyotWMHempsteadADLuoZQ 2010 The E Block motif is associated with Legionella pneumophila translocated substrates. Cell Microbiol 13 227 245

20. MurataTDelpratoAIngmundsonAToomreDKLambrightDG 2006 The Legionella pneumophila effector protein DrrA is a Rab1 guanine nucleotide-exchange factor. Nat Cell Biol 8 971 977

21. MachnerMPIsbergRR 2006 Targeting of host Rab GTPase function by the intravacuolar pathogen Legionella pneumophila. Dev Cell 11 47 56

22. MullerMPPetersHBlumerJBlankenfeldtWGoodyRS 2010 The Legionella effector protein DrrA AMPylates the membrane traffic regulator Rab1b. Science 329 946 949

23. NagaiHKaganJCZhuXKahnRARoyCR 2002 A bacterial guanine nucleotide exchange factor activates ARF on Legionella phagosomes. Science 295 679 682

24. PanXLuhrmannASatohALaskowski-ArceMARoyCR 2008 Ankyrin repeat proteins comprise a diverse family of bacterial type IV effectors. Science 320 1651 1654

25. VothDEHoweDBearePAVogelJPUnsworthN 2009 The Coxiella burnetii ankyrin repeat domain-containing protein family is heterogeneous, with C-terminal truncations that influence Dot/Icm-mediated secretion. J Bacteriol 191 4232 4242

26. LuhrmannANogueiraCVCareyKLRoyCR 2010 Inhibition of pathogen-induced apoptosis by a Coxiella burnetii type IV effector protein. Proc Natl Acad Sci U S A 107 18997 19001

27. NagaiHCambronneEDKaganJCAmorJCKahnRA 2005 A C-terminal translocation signal required for Dot/Icm-dependent delivery of the Legionella RalF protein to host cells. Proc Natl Acad Sci U S A 102 826 831

28. JoinerKAFuhrmanSAMiettinenHMKasperLHMellmanI 1990 Toxoplasma gondii: fusion competence of parasitophorous vacuoles in Fc receptor-transfected fibroblasts. Science 249 641 646

29. LuoZQIsbergRR 2004 Multiple substrates of the Legionella pneumophila Dot/Icm system identified by interbacterial protein transfer. Proc Natl Acad Sci U S A 101 841 846

30. StoennerHGLackmanDB 1960 The biologic properties of Coxiella burnetii isolated from rodents collected in Utah. Am J Hyg 71 45 51

31. BearePAUnsworthNAndohMVothDEOmslandA 2009 Comparative genomics reveal extensive transposon-mediated genomic plasticity and diversity among potential effector proteins within the genus Coxiella. Infect Immun 77 642 656

32. CazaletCRusniokCBruggemannHZidaneNMagnierA 2004 Evidence in the Legionella pneumophila genome for exploitation of host cell functions and high genome plasticity. Nat Genet 36 1165 1173

33. SchultzJMilpetzFBorkPPontingCP 1998 SMART, a simple modular architecture research tool: identification of signaling domains. Proc Natl Acad Sci U S A 95 5857 5864

34. CirilloSLLumJCirilloJD 2000 Identification of novel loci involved in entry by Legionella pneumophila. Microbiology 146 1345 1359

35. LiuMConoverGMIsbergRR 2008 Legionella pneumophila EnhC is required for efficient replication in tumour necrosis factor alpha-stimulated macrophages. Cell Microbiol 10 1906 1923

36. NewtonHJSansomFMDaoJMcAlisterADSloanJ 2007 Sel1 repeat protein LpnE is a Legionella pneumophila virulence determinant that influences vacuolar trafficking. Infect Immun 75 5575 5585

37. CampodonicoEMChesnelLRoyCR 2005 A yeast genetic system for the identification and characterization of substrate proteins transferred into host cells by the Legionella pneumophila Dot/Icm system. Mol Microbiol 56 918 933

38. HeidtmanMChenEJMoyMYIsbergRR 2009 Large-scale identification of Legionella pneumophila Dot/Icm substrates that modulate host cell vesicle trafficking pathways. Cell Microbiol 11 230 248

39. de FelipeKSGloverRTCharpentierXAndersonORReyesM 2008 Legionella eukaryotic-like type IV substrates interfere with organelle trafficking. PLoS Pathog 4 e1000117

40. BearePAHoweDCockrellDCOmslandAHansenB 2009 Characterization of a Coxiella burnetii ftsZ mutant generated by Himar1 transposon mutagenesis. J Bacteriol 191 1369 1381

41. ChenCBangaSMertensKWeberMMGorbaslievaI 2010 Large-scale identification and translocation of type IV secretion substrates by Coxiella burnetii. Proc Natl Acad Sci U S A 107 21755 60

42. VothDEBearePAHoweDSharmaUMSamoilisG 2011 The Coxiella burnetii Cryptic Plasmid is Enriched in Genes Encoding Type IV Secretion System Substrates. J Bacteriol 193 1493 1503

43. CharpentierXGabayJEReyesMZhuJWWeissA 2009 Chemical genetics reveals bacterial and host cell functions critical for type IV effector translocation by Legionella pneumophila. PLoS Pathog 5 e1000501

44. HackstadtTWilliamsJC 1983 pH dependence of the Coxiella burnetii glutamate transport system. J Bacteriol 154 598 603

45. OmslandACockrellDCFischerERHeinzenRA 2008 Sustained axenic metabolic activity by the obligate intracellular bacterium Coxiella burnetii. J Bacteriol 190 3203 3212

46. ShinSCaseCLArcherKANogueiraCVKobayashiKS 2008 Type IV secretion-dependent activation of host MAP kinases induces an increased proinflammatory cytokine response to Legionella pneumophila. PLoS Pathog 4 e1000220

47. ArcherKARoyCR 2006 MyD88-dependent responses involving toll-like receptor 2 are important for protection and clearance of Legionella pneumophila in a mouse model of Legionnaires' disease. Infect Immun 74 3325 3333

48. OmslandACockrellDCHoweDFischerERVirtanevaK 2009 Host cell-free growth of the Q fever bacterium Coxiella burnetii. Proc Natl Acad Sci U S A 106 4430 4434

49. ZuckmanDMHungJBRoyCR 1999 Pore-forming activity is not sufficient for Legionella pneumophila phagosome trafficking and intracellular growth. Mol Microbiol 32 990 1001

50. FeeleyJCGibsonRJGormanGWLangfordNCRasheedJK 1979 Charcoal-yeast extract agar: primary isolation medium for Legionella pneumophila. J Clin Microbiol 10 437 441

51. SoryMPCornelisGR 1994 Translocation of a hybrid YopE-adenylate cyclase from Yersinia enterocolitica into HeLa cells. Mol Microbiol 14 583 594

52. SeshadriRHendrixLRSamuelJE 1999 Differential expression of translational elements by life cycle variants of Coxiella burnetii. Infect Immun 67 6026 6033