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Identification of Functional Toxin/Immunity Genes Linked to Contact-Dependent Growth Inhibition (CDI) and Rearrangement Hotspot (Rhs) Systems


Bacterial contact-dependent growth inhibition (CDI) is mediated by the CdiA/CdiB family of two-partner secretion proteins. Each CdiA protein exhibits a distinct growth inhibition activity, which resides in the polymorphic C-terminal region (CdiA-CT). CDI+ cells also express unique CdiI immunity proteins that specifically block the activity of cognate CdiA-CT, thereby protecting the cell from autoinhibition. Here we show that many CDI systems contain multiple cdiA gene fragments that encode CdiA-CT sequences. These “orphan” cdiA-CT genes are almost always associated with downstream cdiI genes to form cdiA-CT/cdiI modules. Comparative genome analyses suggest that cdiA-CT/cdiI modules are mobile and exchanged between the CDI systems of different bacteria. In many instances, orphan cdiA-CT/cdiI modules are fused to full-length cdiA genes in other bacterial species. Examination of cdiA-CT/cdiI modules from Escherichia coli EC93, E. coli EC869, and Dickeya dadantii 3937 confirmed that these genes encode functional toxin/immunity pairs. Moreover, the orphan module from EC93 was functional in cell-mediated CDI when fused to the N-terminal portion of the EC93 CdiA protein. Bioinformatic analyses revealed that the genetic organization of CDI systems shares features with rhs (rearrangement hotspot) loci. Rhs proteins also contain polymorphic C-terminal regions (Rhs-CTs), some of which share significant sequence identity with CdiA-CTs. All rhs genes are followed by small ORFs representing possible rhsI immunity genes, and several Rhs systems encode orphan rhs-CT/rhsI modules. Analysis of rhs-CT/rhsI modules from D. dadantii 3937 demonstrated that Rhs-CTs have growth inhibitory activity, which is specifically blocked by cognate RhsI immunity proteins. Together, these results suggest that Rhs plays a role in intercellular competition and that orphan gene modules expand the diversity of toxic activities deployed by both CDI and Rhs systems.


Vyšlo v časopise: Identification of Functional Toxin/Immunity Genes Linked to Contact-Dependent Growth Inhibition (CDI) and Rearrangement Hotspot (Rhs) Systems. PLoS Genet 7(8): e32767. doi:10.1371/journal.pgen.1002217
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.pgen.1002217

Souhrn

Bacterial contact-dependent growth inhibition (CDI) is mediated by the CdiA/CdiB family of two-partner secretion proteins. Each CdiA protein exhibits a distinct growth inhibition activity, which resides in the polymorphic C-terminal region (CdiA-CT). CDI+ cells also express unique CdiI immunity proteins that specifically block the activity of cognate CdiA-CT, thereby protecting the cell from autoinhibition. Here we show that many CDI systems contain multiple cdiA gene fragments that encode CdiA-CT sequences. These “orphan” cdiA-CT genes are almost always associated with downstream cdiI genes to form cdiA-CT/cdiI modules. Comparative genome analyses suggest that cdiA-CT/cdiI modules are mobile and exchanged between the CDI systems of different bacteria. In many instances, orphan cdiA-CT/cdiI modules are fused to full-length cdiA genes in other bacterial species. Examination of cdiA-CT/cdiI modules from Escherichia coli EC93, E. coli EC869, and Dickeya dadantii 3937 confirmed that these genes encode functional toxin/immunity pairs. Moreover, the orphan module from EC93 was functional in cell-mediated CDI when fused to the N-terminal portion of the EC93 CdiA protein. Bioinformatic analyses revealed that the genetic organization of CDI systems shares features with rhs (rearrangement hotspot) loci. Rhs proteins also contain polymorphic C-terminal regions (Rhs-CTs), some of which share significant sequence identity with CdiA-CTs. All rhs genes are followed by small ORFs representing possible rhsI immunity genes, and several Rhs systems encode orphan rhs-CT/rhsI modules. Analysis of rhs-CT/rhsI modules from D. dadantii 3937 demonstrated that Rhs-CTs have growth inhibitory activity, which is specifically blocked by cognate RhsI immunity proteins. Together, these results suggest that Rhs plays a role in intercellular competition and that orphan gene modules expand the diversity of toxic activities deployed by both CDI and Rhs systems.


Zdroje

1. NadellCDBasslerBLLevinSA 2008 Observing bacteria through the lens of social evolution. J Biol 7 27

2. NgWLBasslerBL 2009 Bacterial quorum-sensing network architectures. Annu Rev Genet 43 197 222

3. LobedanzSSogaard-AndersenL 2003 Identification of the C-signal, a contact-dependent morphogen coordinating multiple developmental responses in Myxococcus xanthus. Genes Dev 17 2151 2161

4. AokiSKPammaRHerndayADBickhamJEBraatenBA 2005 Contact-dependent inhibition of growth in Escherichia coli. Science 309 1245 1248

5. AokiSKDinerEJt'Kint de RoodenbekeCBurgessBRPooleSJ 2010 A widespread family of polymorphic contact-dependent toxin delivery systems in bacteria. Nature 468 439 442

6. ChoiPSBernsteinHD 2010 Sequential translocation of an Escherchia coli two-partner secretion pathway exoprotein across the inner and outer membranes. Mol Microbiol 75 440 451

7. MazarJCotterPA 2007 New insight into the molecular mechanisms of two-partner secretion. Trends Microbiol 15 508 515

8. BaudCHodakHWilleryEDrobecqHLochtC 2009 Role of DegP for two-partner secretion in Bordetella. Mol Microbiol 74 315 329

9. ClantinBDelattreASRucktooaPSaintNMeliAC 2007 Structure of the membrane protein FhaC: a member of the Omp85-TpsB transporter superfamily. Science 317 957 961

10. CapageMHillCW 1979 Preferential unequal recombination in the glyS region of the Escherichia coli chromosome. J Mol Biol 127 73 87

11. LinRJCapageMHillCW 1984 A repetitive DNA sequence, rhs, responsible for duplications within the Escherichia coli K-12 chromosome. J Mol Biol 177 1 18

12. JacksonAPThomasGHParkhillJThomsonNR 2009 Evolutionary diversification of an ancient gene family (rhs) through C-terminal displacement. BMC Genomics 10 584

13. FosterSJ 1993 Molecular analysis of three major wall-associated proteins of Bacillus subtilis 168: evidence for processing of the product of a gene encoding a 258 kDa precursor two-domain ligand-binding protein. Mol Microbiol 8 299 310

14. McNultyCThompsonJBarrettBLordLAndersenC 2006 The cell surface expression of group 2 capsular polysaccharides in Escherichia coli: the role of KpsD, RhsA and a multi-protein complex at the pole of the cell. Mol Microbiol 59 907 922

15. YouderianPHartzellPL 2007 Triple mutants uncover three new genes required for social motility in Myxococcus xanthus. Genetics 177 557 566

16. KhachatryanARBesserTECallDR 2008 The streptomycin-sulfadiazine-tetracycline antimicrobial resistance element of calf-adapted Escherichia coli is widely distributed among isolates from Washington state cattle. Appl Environ Microbiol 74 391 395

17. McGinnessKEBakerTASauerRT 2006 Engineering controllable protein degradation. Mol Cell 22 701 707

18. AokiSKMalinverniJCJacobyKThomasBPammaR 2008 Contact-dependent growth inhibition requires the essential outer membrane protein BamA (YaeT) as the receptor and the inner membrane transport protein AcrB. Mol Microbiol 70 323 340

19. ZhaoSHillCW 1995 Reshuffling of Rhs components to create a new element. J Bacteriol 177 1393 1398

20. VlaznyDAHillCW 1995 A stationary-phase-dependent viability block governed by two different polypeptides from the RhsA genetic element of Escherichia coli K-12. J Bacteriol 177 2209 2213

21. MehtaPKattaKKrishnaswamyS 2004 HNH family subclassification leads to identification of commonality in the His-Me endonuclease superfamily. Protein Sci 13 295 300

22. BergthorssonUAnderssonDIRothJR 2007 Ohno's dilemma: evolution of new genes under continuous selection. Proc Natl Acad Sci U S A 104 17004 17009

23. ReamsABKofoidESavageauMRothJR 2010 Duplication frequency in a population of Salmonella enterica rapidly approaches steady state with or without recombination. Genetics 184 1077 1094

24. ZhangDIyerLMAravindL 2011 A novel immunity system for bacterial nucleic acid degrading toxins and its recruitment in various eukaryotic and DNA viral systems. Nucleic Acids Res 39 4532 4552

25. SistoACiprianiMGMoreaMLonigroSLValerioF 2010 An Rhs-like genetic element is involved in bacteriocin production by Pseudomonas savastanoi pv. savastanoi. Antonie Van Leeuwenhoek 98 505 517

26. WangYDZhaoSHillCW 1998 Rhs elements comprise three subfamilies which diverged prior to acquisition by Escherichia coli. J Bacteriol 180 4102 4110

27. PukatzkiSMaATRevelATSturtevantDMekalanosJJ 2007 Type VI secretion system translocates a phage tail spike-like protein into target cells where it cross-links actin. Proc Natl Acad Sci U S A 104 15508 15513

28. PukatzkiSMcAuleySBMiyataST 2009 The type VI secretion system: translocation of effectors and effector-domains. Curr Opin Microbiol 12 11 17

29. HoodRDSinghPHsuFGuvenerTCarlMA 2010 A type VI secretion system of Pseudomonas aeruginosa targets a toxin to bacteria. Cell Host Microbe 7 25 37

30. StavrinidesJNoAOchmanH 2010 A single genetic locus in the phytopathogen Pantoea stewartii enables gut colonization and pathogenicity in an insect host. Environ Microbiol 12 147 155

31. TuckerRPChiquet-EhrismannR 2006 Teneurins: a conserved family of transmembrane proteins involved in intercellular signaling during development. Dev Biol 290 237 245

32. YoungTRLeameyCA 2009 Teneurins: important regulators of neural circuitry. Int J Biochem Cell Biol 41 990 993

33. LovejoyDAAl ChawafACadinoucheMZ 2006 Teneurin C-terminal associated peptides: an enigmatic family of neuropeptides with structural similarity to the corticotropin-releasing factor and calcitonin families of peptides. Gen Comp Endocrinol 148 299 305

34. WangLRotzingerSAl ChawafAEliasCFBarsyte-LovejoyD 2005 Teneurin proteins possess a carboxy terminal sequence with neuromodulatory activity. Brain Res Mol Brain Res 133 253 265

35. Garza-SanchezFShojiSFredrickKHayesCS 2009 RNase II is important for A-site mRNA cleavage during ribosome pausing. Mol Microbiol 73 882 897

36. HayesCSBoseBSauerRT 2002 Proline residues at the C terminus of nascent chains induce SsrA tagging during translation termination. J Biol Chem 277 33825 33832

37. HayesCSSauerRT 2003 Cleavage of the A site mRNA codon during ribosome pausing provides a mechanism for translational quality control. Mol Cell 12 903 911

38. Garza-SánchezFJanssenBDHayesCS 2006 Prolyl-tRNAPro in the A-site of SecM-arrested ribosomes inhibits the recruitment of transfer-messenger RNA. J Biol Chem 281 34258 34268

39. GuzmanLMBelinDCarsonMJBeckwithJ 1995 Tight regulation, modulation, and high-level expression by vectors containing the arabinose PBAD promoter. J Bacteriol 177 4121 4130

40. EdwardsRAKellerLHSchifferliDM 1998 Improved allelic exchange vectors and their use to analyze 987P fimbria gene expression. Gene 207 149 157

41. PfafflMW 2001 A new mathematical model for relative quantification in real-time RT-PCR. Nucleic Acids Res 29 e45

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Genetika Reprodukčná medicína

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