title: The N terminus of type III secretion needle protein YscF from Yersinia pestis functions to modulate innate immune responses.
abstract: The type III secretion system is employed by many pathogens, including the genera Yersinia, Shigella, Pseudomonas, and Salmonella, to deliver effector proteins into eukaryotic cells. The injectisome needle is formed by the polymerization of a single protein, e.g., YscF (Yersinia pestis), PscF (Pseudomonas aeruginosa), PrgI (Salmonella enterica SPI-1), SsaG (Salmonella enterica SPI-2), or MxiH (Shigella flexneri). In this study, we demonstrated that the N termini of some needle proteins, particularly the N terminus of YscF from Yersinia pestis, influences host immune responses. The N termini of several needle proteins were truncated and tested for the ability to induce inflammatory responses in a human monocytic cell line (THP-1 cells). Truncated needle proteins induced proinflammatory cytokines to different magnitudes than the corresponding wild-type proteins, except SsaG. Notably, N-terminally truncated YscF induced significantly higher activation of NF-κB and/or AP-1 and higher induction of proinflammatory cytokines, suggesting that a function of the N terminus of YscF is interference with host sensing of YscF, consistent with Y. pestis pathogenesis. To directly test the ability of the N terminus of YscF to suppress cytokine induction, a YscF-SsaG chimera with 15 N-terminal amino acids from YscF added to SsaG was constructed. The chimeric YscF-SsaG induced lower levels of cytokines than wild-type SsaG. However, the addition of 15 random amino acids to SsaG had no effect on NF-κB/AP-1 activation. These results suggest that the N terminus of YscF can function to decrease cytokine induction, perhaps contributing to a favorable immune environment leading to survival of Y. pestis within the eukaryotic host.
authors: Department of Basic Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, North Dakota, USA.
authors: Patrick
authors: P
authors: Osei-Owusu
authors: Department of Basic Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, North Dakota, USA.
authors: Danielle L
authors: DL
authors: Jessen Condry
authors: Department of Basic Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, North Dakota, USA.
authors: Melody
authors: M
authors: Toosky
authors: Department of Basic Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, North Dakota, USA.
authors: William
authors: W
authors: Roughead
authors: Department of Basic Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, North Dakota, USA.
authors: David S
authors: DS
authors: Bradley
authors: Department of Basic Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, North Dakota, USA matthew.nilles@med.und.edu.
authors: Matthew L
authors: ML
authors: Nilles
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology* / Q000494:pharmacology; D058947:Bacterial Secretion Systems / Q000276:immunology; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D057131:Immune Evasion / Q000235:genetics; D007249:Inflammation / Q000276:immunology; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D009000:Monocytes / Q000276:immunology; D016328:NF-kappa B / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D019779:Salmonella enterica / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity; D016415:Sequence Alignment; D017384:Sequence Deletion / Q000235:genetics; D015398:Signal Transduction / Q000276:immunology; D018808:Transcription Factor AP-1 / Q000378:metabolism; D015010:Yersinia pestis / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D016207:Cytokines; D008565:Membrane Proteins; D016328:NF-kappa B; D011993:Recombinant Fusion Proteins; C440638:SPI-2 protein, Salmonella; D018808:Transcription Factor AP-1; C505708:YscF protein, Yersinia pestis
references: J Biol Chem. 2005 Oct 28;280(43):36293-300
references: 16115870
references: Mol Microbiol. 2005 Sep;57(6):1719-33
references: 16135236
references: J Biol Chem. 2005 Dec 30;280(52):42929-37
references: 16227202
references: J Immunol. 2006 Feb 15;176(4):2373-80
references: 16455995
references: Acta Crystallogr Sect F Struct Biol Cryst Commun. 2006 Mar 1;62(Pt 3):302-5
references: 16511329
references: J Mol Biol. 2006 Jun 2;359(2):322-30
references: 16631790
references: Microb Pathog. 2006 Jul;41(1):33-42
references: 16777370
references: Nat Rev Microbiol. 2006 Nov;4(11):811-25
references: 17041629
references: Nature. 2006 Nov 30;444(7119):567-73
references: 17136086
references: Immunol Cell Biol. 2007 Feb-Mar;85(2):119-29
references: 17213832
references: Proc Natl Acad Sci U S A. 2007 May 8;104(19):7803-8
references: 17470796
references: Cell Microbiol. 2007 Jun;9(6):1529-37
references: 17298393
references: J Mol Biol. 2007 Aug 31;371(5):1304-14
references: 17617421
references: J Mol Biol. 2008 Mar 28;377(3):819-30
references: 18281060
references: Proc Natl Acad Sci U S A. 2008 May 6;105(18):6507-13
references: 18458349
references: Proteins. 2008 Nov 15;73(3):632-43
references: 18491382
references: Biotechniques. 2010 Jun;48(6):463-5
references: 20569222
references: J Pharm Sci. 2010 Nov;99(11):4488-96
references: 20845448
references: Infect Immun. 2010 Dec;78(12):5314-23
references: 20937766
references: Microbiology. 2010 Dec;156(Pt 12):3689-98
references: 20817644
references: Nature. 2011 Apr 14;472(7342):179-80
references: 21490667
references: J Infect Dev Ctries. 2011 Sep;5(9):628-39
references: 21918303
references: Proc Natl Acad Sci U S A. 2012 Feb 21;109(8):3083-8
references: 22308352
references: Microbiology. 2012 May;158(Pt 5):1147-61
references: 22422755
references: Gut Microbes. 2012 Mar-Apr;3(2):62-70
references: 22198618
references: Nature. 2012 Jun 14;486(7402):276-9
references: 22699623
references: Infect Immun. 2012 Oct;80(10):3417-28
references: 22825445
references: Gut Microbes. 2013 Mar-Apr;4(2):140-5
references: 23333857
references: PLoS Pathog. 2013 Mar;9(3):e1003245
references: 23555258
references: Res Microbiol. 2013 Jul-Aug;164(6):605-19
references: 23541478
references: Trends Microbiol. 2013 Aug;21(8):430-41
references: 23870533
references: Front Cell Infect Microbiol. 2013;3:76
references: 24324933
references: J Struct Biol. 2014 Mar;185(3):440-7
references: 24361688
references: Infect Immun. 2014 Jun;82(6):2300-9
references: 24643544
references: Nature. 2000 Aug 17;406(6797):782-7
references: 10963608
references: J Biol Chem. 2004 Feb 13;279(7):5667-75
references: 14634022
references: Proc Natl Acad Sci U S A. 2001 Apr 10;98(8):4669-74
references: 11287645
references: J Immunol. 2001 Dec 15;167(12):7009-16
references: 11739521
references: J Biol Chem. 2002 Oct 25;277(43):40456-61
references: 12185085
references: Cell Microbiol. 2003 Aug;5(8):501-11
references: 12864810
references: Nat Immunol. 2003 Dec;4(12):1247-53
references: 14625549
references: Infect Immun. 2004 May;72(5):2879-88
references: 15102800
references: Infect Immun. 1986 Feb;51(2):445-54
references: 3002984
references: J Bacteriol. 1995 Jul;177(14):4121-30
references: 7608087
references: Mol Microbiol. 1995 Oct;18(2):343-55
references: 8709853
references: J Bacteriol. 1998 Jul;180(13):3410-20
references: 9642196
references: Protein Expr Purif. 2005 May;41(1):207-34
references: 15915565
references: Proc Natl Acad Sci U S A. 2005 Jun 28;102(26):9247-52
references: 15956202
references: BMC Microbiol. 2005;5:38
references: 15978133
references: J Mol Biol. 2005 Nov 25;354(2):206-11
references: 16243352