#PAGE_PARAMS# #ADS_HEAD_SCRIPTS# #MICRODATA#

Structural Basis of Cytotoxicity Mediated by the Type III Secretion Toxin ExoU from


The type III secretion system (T3SS) is a complex macromolecular machinery employed by a number of Gram-negative pathogens to inject effectors directly into the cytoplasm of eukaryotic cells. ExoU from the opportunistic pathogen Pseudomonas aeruginosa is one of the most aggressive toxins injected by a T3SS, leading to rapid cell necrosis. Here we report the crystal structure of ExoU in complex with its chaperone, SpcU. ExoU folds into membrane-binding, bridging, and phospholipase domains. SpcU maintains the N-terminus of ExoU in an unfolded state, required for secretion. The phospholipase domain carries an embedded catalytic site whose position within ExoU does not permit direct interaction with the bilayer, which suggests that ExoU must undergo a conformational rearrangement in order to access lipids within the target membrane. The bridging domain connects catalytic domain and membrane-binding domains, the latter of which displays specificity to PI(4,5)P2. Both transfection experiments and infection of eukaryotic cells with ExoU-secreting bacteria show that ExoU ubiquitination results in its co-localization with endosomal markers. This could reflect an attempt of the infected cell to target ExoU for degradation in order to protect itself from its aggressive cytotoxic action.


Vyšlo v časopise: Structural Basis of Cytotoxicity Mediated by the Type III Secretion Toxin ExoU from. PLoS Pathog 8(4): e32767. doi:10.1371/journal.ppat.1002637
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.ppat.1002637

Souhrn

The type III secretion system (T3SS) is a complex macromolecular machinery employed by a number of Gram-negative pathogens to inject effectors directly into the cytoplasm of eukaryotic cells. ExoU from the opportunistic pathogen Pseudomonas aeruginosa is one of the most aggressive toxins injected by a T3SS, leading to rapid cell necrosis. Here we report the crystal structure of ExoU in complex with its chaperone, SpcU. ExoU folds into membrane-binding, bridging, and phospholipase domains. SpcU maintains the N-terminus of ExoU in an unfolded state, required for secretion. The phospholipase domain carries an embedded catalytic site whose position within ExoU does not permit direct interaction with the bilayer, which suggests that ExoU must undergo a conformational rearrangement in order to access lipids within the target membrane. The bridging domain connects catalytic domain and membrane-binding domains, the latter of which displays specificity to PI(4,5)P2. Both transfection experiments and infection of eukaryotic cells with ExoU-secreting bacteria show that ExoU ubiquitination results in its co-localization with endosomal markers. This could reflect an attempt of the infected cell to target ExoU for degradation in order to protect itself from its aggressive cytotoxic action.


Zdroje

1. WorrallLJLameignereEStrynadkaNC 2011 Structural overview of the bacteria injectisome. Curr Opin Microbiol 14 3 8

2. CornelisGR 2006 The type III secretion injectisome. Nat Rev Microbiol 4 811 825

3. IzoréTJobVDessenA 2011 Biogenesis, regulation, and targeting of the type III secretion system. Structure 19 603 612

4. HayesCSAokiSKLowDA 2010 Bacterial contact-dependent delivery systems. Annu Rev Genet 44 71 90

5. GalánJEWolf-WatzH 2006 Protein delivery into eukaryotic cells by type III secretion machines. Nature 444 567 573

6. MarlovitsTCStebbinsCE 2009 Type III secretion systems shape up as they ship out. Curr Opin Microbiol 13 1 6

7. BlockerAKomoriyaKAizawaS 2003 Type III secretion systems and bacterial flagella: insights into their function from structural similarities. Proc Natl Acad Sci USA 100 3027 3030

8. GalánJE 2009 Common themes in the design and function of bacterial effectors. Cell Host Microbe 5 571 579

9. El SolhAAAkinnusiMEWiener-KronishJPLynchSVPinedaLA 2008 Persistent infection with Pseudomonas aeruginosa in ventilator-associated pneumonia. Am J Respir Crit Care Med 178 513 519

10. HauserARCobbEBodiMMariscalDVallesJ 2002 Type III protein secretion is associated with poor clinical outcomes in patients with ventilator-associated pneumonia caused by Pseudomonas aeruginosa. Crit Care Med 30 521 528

11. EngelJBalachandranP 2009 Role of Pseudomonas aeruginosa type III effectors in disease. Curr Opin Microbiol 12 61 66

12. HauserAR 2009 The type III secretion system of Pseudomonas aeruginosa: infection by injection. Nat Rev Microbiol 7 654 665

13. FrankDW 1997 The enxoenzyme S regulon of Pseudomonas aeruginosa. Mol Microbiol 26 621 629

14. DengQBarbieriJT 2008 Modulation of host cell endocytosis by the type III cytotoxin, Pseudomonas ExoS. Traffic 9 1948 1957

15. Garrity-RyanLShafikhaniSBalachandranPNguyenLOzaJ 2004 The ADP ribosyltransferase domain of Pseudomonas aeruginosa ExoT contributes to its biological activities. Infect Immun 72 546 558

16. ShafikhaniSHMoralesCEngelJ 2008 The Pseudomonas aeruginosa type III secreted toxin ExoT is necessary and sufficient to induce apoptosis in epithelial cells. Cell Microbiol 10 994 1007

17. PielageJFPowellKRKalmanDEngelJN 2008 RNAi screen reveals an Abl kinase-dependent host cell pathway involved in Pseudomonas aeruginosa internalization. PLoS Pathog 4 e1000031

18. ShaverCMHauserAR 2004 Relative contributions of Pseudomonas aeruginosa ExoU, ExoS, and ExoT to virulence in the lung. Infect Immun 72 6969 6977

19. Frithz-LindstenEDuYRosqvistRForsbergA 1997 Intracellular targeting of exoenzyme S of Pseudomonas aeruginosa via type III-dependent translocation induces phagocytosis resistance, cytotoxicity and disruption of actin microfilaments. Mol Microbiol 25 1125 1139

20. CowellBAEvansDJFleiszigSM 2005 Actin cytoskeleton disruption by ExoY and its effects on Pseudomonas aeruginosa invasion. FEMS Microbiol Lett 250 71 76

21. YahrTLVallisAJHancockMKBarbieriJTFrankDW 1998 ExoY, an adenylate cyclase secreted by the Pseudomonas aeruginosa type III system. Proc Natl Acad Sci U S A 95 13899 13904

22. HritonenkoVMunJJTamCSimonNCBarbieriJT 2011 Adenylate cyclase activity of Pseudomonas aeruginosa ExoY can mediate bleb-niche formation in epithelial cells and contributes to virulence. Microb Pathog 51 305 312

23. Finck-BarbançonVYahrTLFrankDW 1998 Identification and characterization of SpcU, a chaperone required for efficient secretion of the ExoU cytotoxin. J Bacteriol 180 6224 6231

24. SatoHFrankDW 2004 ExoU is a potent intracellular phospholipase. Mol Microbiol 53 1279 1290

25. Finck-BarbançonVGoransonJZhuLSawaTWiener-KronishJP 1997 ExoU expression by Pseudomonas aeruginosa correlates with acute cytotoxicity and epithelial injury. Mol Microbiol 25 547 557

26. AlleweltMColemanFTGroutMPriebeGPPierGB 2000 Acquisition of expression of the Pseudomonas aeruginosa ExoU cytotoxin leads to increased bacterial virulence in a murine model of acute pneumoniae and systemic spread. Infect Immun 68 3998 4004

27. MachadoGBde AssisMCLeãoRSalibaAMSilvaMC 2010 ExoU-induced vascular hyperpermeability and platelet activation in the course of experimental Pseudomonas aeruginosa pneumosepsis. Shock 33 315 321

28. KurahashiKKajikawaOSawaTOharaMGropperM 1999 Pathogenesis of septic shock in Pseudomonas aeruginosa pneumonia. J Clin Invest 104 743 750

29. PankhaniyaRRTamuraMAllmondLRMoriyamaKAjayiT 2004 Pseudomonas aeruginosa causes acute lung injury via the catalytic activity of the patatin-like phospholipase domain of ExoU. Crit Care Med 32 2293 2299

30. Roy-BurmanASavelRHRacineSSwansonBLRevadigarNS 2001 Type III protein secretion is associated with death in lower respiratory and systemic Pseudomonas aeruginosa infections. J Infect Dis 183 1767 1774

31. RabinSDPHauserAR 2005 Functional regions of the Pseudomonas aeruginosa cytotoxin ExoU. Infect Immun 73 573 582

32. PhillipsRMSixDADennisEAGhoshP 2003 In vivo phospholipase activity of the Pseudomonas aeruginosa cytotoxin ExoU and protection of mammalian cells with phospholipase A2 inhibitors. J Biol Chem 278 41326 41332

33. SatoHFrankDWHillardCJFeixJBPankhaniyaRR 2003 The mechanism of action of the Pseudomonas aeruginosa-encoded type III cytotoxin, ExoU. EMBO J 22 2959 2969

34. MurakamiMTaketomiYSatoHYamamotoK 2011 Secreted phospholipase A2 revisited. J Biochem 150 233 255

35. GhoshMTuckerDEBurchettSALeslieCC 2006 Properties of the group IV phospholipase A2 family. Prog Lipid Res 45 487 510

36. BurkeJEDennisEA 2009 Phospholipase A2 structure/function, mechanism, and signaling. J Lipid Res 50 S237 S242

37. RabinSDPVeesenmeyerJLBiegingKTHauserAR 2006 A C-terminal domain targets the Pseudomonas aeruginosa cytotoxin ExoU to the plasma membrane of host cells. Infect Immun 74 2552 2561

38. VeesenmeyerJLHowellHHalavatyASAhrensSAndersonWF 2010 Role of the membrane localization domain of the Pseudomonas aeruginosa effector protein ExoU in cytotoxicity. Infect Immun 78 3346 3357

39. StirlingFRCuzickAKellySMOxleyDEvansTJE 2006 Eukaryotic localization, activation and ubiquitinylation of a bacterial type III secreted toxin. Cell Microbiol 8 1294 1309

40. SchmalzerKBensonMAFrankDW 2010 Activation of ExoU phospholipase activity requires specific C-terminal regions. J Bacteriol 192 1801 1812

41. SatoHFeixJBHillardCJ 2005 Characterization of phospholipase activity of the Pseudomonas aeruginosa type III cytotoxin, ExoU. J Bacteriol 187 1192 1195

42. SatoHFeixJBFrankDW 2006 Identification of superoxide dismutase as a cofactor for the Pseudomonas type III toxin, ExoU. Biochemistry 45 10368 10375

43. BensonMAKomasSMSchmalzerKCaseyMSFrankDW 2011 Induced conformational changes in the activation of the Pseudomonas aeruginosa type III toxin, ExoU. Biophys J 100 1335 1343

44. AndersonDMSchmalzerKMSatoHCaseyMTerhuneSS 2011 Ubiquitin and ubiquitin-modified proteins activate the Pseudomonas aeruginosa T3SS cytotoxin, ExoU. Mol Microbiol 82 1452 67

45. ParsotCHamiauxCPageA-L 2003 The various and varying roles of specific chaperones in type III secretion systems. Curr Opin Microbiol 6 7 14

46. LilicMVujanacMStebbinsCE 2006 A common structural motif in the binding of virulence factors to bacterial secretion chaperones. Mol Cell 21 653 664

47. BirtalanSCPhillipsRMGhoshP 2002 Three-dimensional secretional signals in chaperone-effector complexes of bacterial pathogens. Mol Cell 9 971 980

48. StebbinsCEGalánJE 2001 Maintenance of an unfolded polypeptide by a cognate chaperone in bacterial type III secretion. Nature 414 77 81

49. PhanJTropeaJEWaughDS 2004 Structure of the Yersinia pestis type III secretion chaperone SycH in complex with a stable fragment of YscM2. Acta Cryst Sect D 60 1591 1599

50. Finck-BarbançonVFrankDW 2001 Multiple domains are required for the toxic activity of Pseudomonas aeruginosa ExoU. J Bacteriol 183 4330 4344

51. DessenATangJSchmidtHStahlMClarkJD 1999 Crystal structure of human cytosolic phospholipase A2 reveals a novel topology and catalytic mechanism. Cell 97 349 360

52. KerppolaTK 2009 Visualization of molecular interactions using bimolecular fluorescence complementation analysis: characteristics of protein fragment complementation. Chem Soc Rev 38 2876 2886

53. LuoYBerteroMGFreyEAPfuetznerRAWenkMR 2001 Structural and biochemical characterization of the type III secretion chaperones CesT and SigE. Nat Struct Biol 8 1031 1036

54. AkedaYGalánJE 2005 Chaperone release and unfolding of substrates in type III secretion. Nature 437 911 915

55. JainMKBergOG 2006 Coupling of the i-face and the active site of phospholipase A2 for interfacial activation. Curr Opin Chem Biol 10 473 479

56. DennisEACaoJHsuY-HMagriotiVKokotosG 2011 Phospholipase A2 enzymes: physical structure, biological function, disease implication, chemical inhibition, and therapeutic intervention. Chem Rev 111 6130 6185

57. PiperRCLehnerPJ 2011 Endosomal transport via ubiquitination. Trends Cell Biol 21 647 655

58. KabschW 1993 Automatic processing of rotation diffraction data from crystals of initially unknown symmetry and cell constants. J Appl Cryst 26 795 800

59. AdamsPDAfoninePVBunkocziGChenVBDavisIW 2010 PHENIX: a comprehensive Python-based system for macromolecular structure solution. Acta Crystallogr D 66 213 221

60. CowtanK 2010 Recent developments in classical density modification. Acta Crystallogr D 66 470 478

61. CowtanK 2000 General quadratic functions in real and reciprocal space and their application to likelihood phasing. Acta Crystallogr D 56 1612 1621

62. CowtanK 2006 The Buccaneer software for automated model building. 1. Tracing protein chains. Acta Crystallogr D 62 1002 1111

63. EmsleyPCowtanK 2004 Coot: model-building tools for molecular graphics. Acta Crystallogr sect D 60 2126 2132

64. PerrakisAMorrisRMLamzinVS 1999 Automated protein model building combined with iterative structure refinement. Nat Struct Biol 6 458 463

65. MurshudovGVaginADodsonE 1997 Refinement of macromolecular structures by the maximum-likelihood method. Acta Crystallogr sect D 53 240 255

66. LaskowskiRAMacArthurMWMossDSThorntonJM 1993 PROCHECK: a program to check the stereo chemical quality of protein structures. J Appl Crystallog 26 283 291

67. KabschWSanderC 1983 Dictionary of protein secondary structure: pattern recognition of hydrogen-bonded and geometrical features. Biopolymers 22 2577 2637

68. ShyuYJHuCD 2008 Fluorescence complementation: an emerging tool for biological research. Trends Biotechnol 26 622 630

69. LinJWangNLiYTianSZhaoL 2011 LEC-BIFC: a new method for rapid assay of protein interaction. Biotech Histochem 86 272 279

70. BerthelotPAttreeIPlesiatPChabertJde BentzmannS 2003 Genotypic and phenotypic analysis of type III secretion system in a cohort of Pseudomonas aeruginosa bacteremia isolates: evidence for a possible association between O serotypes and exo genes. J Infect Dis 188 512 518

71. ChuanchuenRNarasakiCTSchweizerHP 2002 Benchtop and microcentrifuge preparation of Pseudomonas aeruginosa competent cells. Biotechniques 33 762 763

Štítky
Hygiena a epidemiológia Infekčné lekárstvo Laboratórium

Článok vyšiel v časopise

PLOS Pathogens


2012 Číslo 4
Najčítanejšie tento týždeň
Najčítanejšie v tomto čísle
Kurzy

Zvýšte si kvalifikáciu online z pohodlia domova

Získaná hemofilie - Povědomí o nemoci a její diagnostika
nový kurz

Eozinofilní granulomatóza s polyangiitidou
Autori: doc. MUDr. Martina Doubková, Ph.D.

Všetky kurzy
Prihlásenie
Zabudnuté heslo

Zadajte e-mailovú adresu, s ktorou ste vytvárali účet. Budú Vám na ňu zasielané informácie k nastaveniu nového hesla.

Prihlásenie

Nemáte účet?  Registrujte sa

#ADS_BOTTOM_SCRIPTS#