Pto Kinase Binds Two Domains of AvrPtoB and Its Proximity to the Effector E3 Ligase Determines if It Evades Degradation and Activates Plant Immunity

English version České info

Plant pathogenic bacteria inject effector proteins into plant cells to suppress immune responses and cause disease. The causal agent of bacterial speck, Pseudomonas syringae pv. tomato, is an important pathogen of tomato and a model system to study molecular plant-pathogen interactions. Here we report new insights into how the AvrPtoB effector can be recognized by the tomato kinase Pto to activate immunity. AvrPtoB is an active E3 ligase that is able to ubiquitinate host proteins and target them for degradation. The ability of Pto to resist ubiquitination and activate immunity has been attributed to its capacity to phosphorylate and inactivate the E3 ligase domain of AvrPtoB. Here we report that Pto can bind two distinct domains of AvrPtoB. Pto bound to the domain near the E3 ligase is degraded, whereas the distally bound Pto escapes ubiquitination. Furthermore, a kinase-inactive variant of Pto is fully capable of activating immunity in response to AvrPtoB, showing that proximity to the E3 ligase domain and not effector phosphorylation determines Pto recalcitrance to degradation. Our study provides further insight into the mechanism evolved by tomato to counteract a pathogenicity determinant of a bacterial pathogen, allowing it to activate an effective immune response.

Vyšlo v časopise: Pto Kinase Binds Two Domains of AvrPtoB and Its Proximity to the Effector E3 Ligase Determines if It Evades Degradation and Activates Plant Immunity. PLoS Pathog 10(7): e32767. doi:10.1371/journal.ppat.1004227
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.ppat.1004227

Souhrn

Zdroje

1. BollerT, HeSY (2009) Innate immunity in plants: an arms race between pattern recognition receptors in plants and effectors in microbial pathogens. Science 324: 742–744.

2. MonaghanJ, ZipfelC (2012) Plant pattern recognition receptor complexes at the plasma membrane. Curr Opin Plant Biol 15: 349–357.

3. RosliHG, ZhengY, PomboMA, ZhongS, BombarelyA, et al. (2013) Transcriptomics-based screen for genes induced by flagellin and repressed by pathogen effectors identifies a cell wall-associated kinase involved in plant immunity. Genome Biology 14: R139.

4. LindebergM, CunnacS, CollmerA (2012) Pseudomonas syringae type III effector repertoires: last words in endless arguments. Trends Microbiol 20: 199–208.

5. CunnacS, ChakravarthyS, KvitkoBH, RussellAB, MartinGB, et al. (2011) Genetic disassembly and combinatorial reassembly identify a minimal functional repertoire of type III effectors in Pseudomonas syringae. Proc Natl Acad Sci U S A 108: 2975–2980.

6. BaltrusDA, NishimuraMT, RomanchukA, ChangJH, MukhtarMS, et al. (2011) Dynamic evolution of pathogenicity revealed by sequencing and comparative genomics of 19 Pseudomonas syringae isolates. PLoS Pathog 7: e1002132.

7. FengF, ZhouJM (2012) Plant-bacterial pathogen interactions mediated by type III effectors. Curr Opin Plant Biol 15: 469–476.

8. MoffettP (2009) Mechanisms of recognition in dominant R gene-mediated resistance. Advances Virus Res 75: 1–33.

9. MaekawaT, KuferTA, Schulze-LefertP (2011) NLR functions in plant and animal immune systems: so far and yet so close. Nature Immunol 12: 817–826.

10. DoddsPN, RathjenJP (2010) Plant immunity: towards an integrated view of plant-pathogen interactions. Nat Rev Genet 11: 539–548.

11. OhCS, MartinGB (2011) Effector-triggered immunity mediated by the Pto kinase. Trends Plant Sci 16: 132–140.

12. CaplanJ, PadmanabhanM, Dinesh-KumarSP (2008) Plant NB-LRR immune receptors: from recognition to transcriptional reprogramming. Cell Host Microbe 3: 126–135.

13. TsudaK, SatoM, StoddardT, GlazebrookJ, KatagiriF (2009) Network properties of robust immunity in plants. PLoS Genet 5: e1000772.

14. PedleyKF, MartinGB (2003) Molecular basis of Pto-mediated resistance to bacterial speck disease in tomato. Annual Review of Phytopathology 41: 215–243.

15. Martin GB (2012) Suppression and activation of the plant immune system by Pseudomonas syringae effectors AvrPto and AvrPtoB. In: Martin F, Kamoun S, editors.Effectors in Plant-Microbe Interactions: Wiley-Blackwell. pp. 123–154.

16. XingW, ZouY, LiuQ, LiuJ, LuoX, et al. (2007) The structural basis for activation of plant immunity by bacterial effector protein AvrPto. Nature 449: 243–247.

17. DongJ, XiaoF, FanF, GuL, CangH, et al. (2009) Crystal structure of the complex between Pseudomonas effector AvrPtoB and the tomato Pto kinase reveals both a shared and a unique interface compared with AvrPto-Pto. Plant Cell 21: 1846–1859.

18. GutierrezJR, BalmuthAL, NtoukakisV, MucynTS, Gimenez-IbanezS, et al. (2010) Prf immune complexes of tomato are oligomeric and contain multiple Pto-like kinases that diversify effector recognition. Plant J 61: 507–518.

19. MucynTS, WuAJ, BalmuthAL, ArastehJM, RathjenJP (2009) Regulation of tomato Prf by Pto-like protein kinases. Mol Plant Microbe Interact 22: 391–401.

20. LinNC, MartinGB (2007) Pto- and Prf-mediated recognition of AvrPto and AvrPtoB restricts the ability of diverse Pseudomonas syringae pathovars to infect tomato. Mol Plant Microbe Interact 20: 806–815.

21. SalmeronJM, OldroydGED, RommensCMT, ScofieldSR, KimH-S, et al. (1996) Tomato Prf is a member of the leucine-rich repeat class of plant disease resistance genes and lies embedded within the Pto kinase gene cluster. Cell 86: 123–133.

22. RosebrockTR, ZengL, BradyJJ, AbramovitchRB, XiaoF, et al. (2007) A bacterial E3 ubiquitin ligase targets a host protein kinase to disrupt plant immunity. Nature 448: 370–374.

23. MartinGB, BrommonschenkelSH, ChunwongseJ, FraryA, GanalMW, et al. (1993) Map-based cloning of a protein kinase gene conferring disease resistance in tomato. Science 262: 1432–1436.

24. AbramovitchRB, KimY-J, ChenS, DickmanMB, MartinGB (2003) Pseudomonas type III effector AvrPtoB induces plant disease susceptibility by inhibition of host programmed cell death. EMBO J 22: 60–69.

25. ChengW, MunkvoldKR, GaoH, MathieuJ, SchwizerS, et al. (2011) Structural analysis of Pseudomonas syringae AvrPtoB bound to host BAK1 reveals two similar kinase-interacting domains in a type III effector. Cell Host Microbe 10: 616–626.

26. JanjusevicR, AbramovitchRB, MartinGB, StebbinsCE (2006) A bacterial inhibitor of host programmed cell death defenses is an E3 ubiquitin ligase. Science 311: 222–226.

27. AbramovitchRB, JanjusevicR, StebbinsCE, MartinGB (2006) Type III effector AvrPtoB requires intrinsic E3 ubiquitin ligase activity to suppress plant cell death and immunity. Proc Natl Acad Sci USA 103: 2851–2856.

28. NtoukakisV, MucynTS, Gimenez-IbanezS, ChapmanHC, GutierrezJR, et al. (2009) Host inhibition of a bacterial virulence effector triggers immunity to infection. Science 324: 784–787.

29. XiaoF, HeP, AbramovitchRB, DawsonJE, NicholsonLK, et al. (2007) The N-terminal region of Pseudomonas type III effector AvrPtoB elicits Pto-dependent immunity and has two distinct virulence determinants. Plant J 52: 595–614.

30. ZengL, VelasquezAC, MunkvoldKR, ZhangJ, MartinGB (2012) A tomato LysM receptor-like kinase promotes immunity and its kinase activity is inhibited by AvrPtoB. Plant J 69: 92–103.

31. ShanL, HeP, LiJ, HeeseA, PeckSC, et al. (2008) Bacterial effectors target the common signaling partner BAK1 to disrupt multiple MAMP receptor-signaling complexes and impede plant immunity. Cell Host Microbe 4: 17–27.

32. XiaoF, GiavaliscoP, MartinGB (2007) Pseudomonas syringae type III effector AvrPtoB is phosphorylated in plant cells on serine 258, promoting its virulence activity. J Biol Chem 282: 30737–30744.

33. MucynTS, ClementeA, AndriotisVM, BalmuthAL, OldroydGE, et al. (2006) The tomato NBARC-LRR protein Prf interacts with Pto kinase in vivo to regulate specific plant immunity. Plant Cell 18: 2792–2806.

34. LohY-T, MartinGB (1995) The disease resistance gene Pto and the fenthion-sensitivity gene Fen encode closely related, functional protein kinases. Proc Natl Acad Sci USA 92: 4181–4184.

35. LohY-T, MartinGB (1995) The Pto bacterial resistance gene and the Fen insecticide sensitivity gene encode functional protein kinases with serine/threonine specificity. Plant Physiol 108: 1735–1739.

36. ZhouJ, LohYT, BressanRA, MartinGB (1995) The tomato gene Pti1 encodes a serine/threonine kinase that is phosphorylated by Pto and is involved in the hypersensitive response. Cell 83: 925–935.

37. JiaY, LohY-T, ZhouJ, MartinGB (1997) Alleles of Pto and Fen occur in bacterial speck-susceptible and fenthion-insensitive tomato and encode active protein kinases. Plant Cell 9: 61–73.

38. FischerBE, HaringUK, TriboletR, SigelH (1979) Metal ion/buffer interactions. Stability of binary and ternary complexes containing 2-amino-2(hydroxymethyl)-1,3-propanediol (Tris) and adenosine 5′-triphosphate (ATP). Eur J Biochem 94: 523–530.

39. TaylorI, SeitzK, BennewitzS, WalkerJC (2013) A simple in vitro method to measure autophosphorylation of protein kinases. Plant Methods 9: 22.

40. XiaoF, LuM, LiJ, ZhaoT, YiSY, et al. (2003) Pto mutants differentially activate Prf-dependent, avrPto-independent resistance and gene-for-gene resistance. Plant Physiol 131: 1239–1249.

41. Hanks SK, Hunter T (1995) The eukaryotic protein kinase superfamily. In: Hardie G, Hanks S, editors.The Protein Kinase Facts Book: Protein Serine Kinases.San Diego, CA: Harcourt Brace & Co. pp. 7–47.

42. NtoukakisV, BalmuthAL, MucynTS, GutierrezJR, JonesAM, et al. (2013) The tomato Prf complex is a molecular trap for bacterial effectors based on Pto transphosphorylation. PLoS Pathog 9: e1003123.

43. BombarelyA, RosliHG, VrebalovJ, MoffettP, MuellerLA, et al. (2012) A draft genome sequence of Nicotiana benthamiana to enhance molecular plant-microbe biology research. Mol Plant-Microbe Interact 25: 1523–1530.

44. LinNC, MartinGB (2005) An avrPto/avrPtoB mutant of Pseudomonas syringae pv. tomato DC3000 does not elicit Pto-mediated resistance and is less virulent on tomato. Mol Plant Microbe Interact 18: 43–51.