title: Secretion of TcpF by the Vibrio cholerae toxin-coregulated pilus biogenesis apparatus requires an N-terminal determinant.
abstract: Type IV pili are important for microcolony formation, biofilm formation, twitching motility, and attachment. We and others have shown that type IV pili are important for protein secretion across the outer membrane, similar to type II secretion systems. This study explored the relationship between protein secretion and pilus formation in Vibrio cholerae. The toxin-coregulated pilus (TCP), a type IV pilus required for V. cholerae pathogenesis, is necessary for the secretion of the colonization factor TcpF (T. J. Kirn, N. Bose, and R. K. Taylor, Mol. Microbiol. 49:81-92, 2003). This phenomenon is not unique to V. cholerae; secreted virulence factors that are dependent on the presence of components of the type IV pilus biogenesis apparatus for secretion have been reported with Dichelobacter nodosus (R. M. Kennan, O. P. Dhungyel, R. J. Whittington, J. R. Egerton, and J. I. Rood, J. Bacteriol. 183:4451-4458, 2001) and Francisella tularensis (A. J. Hager et al., Mol. Microbiol. 62:227-237, 2006). Using site-directed mutagenesis, we demonstrated that the secretion of TcpF is dependent on the presence of selected amino acid R groups at position five. We were unable to find other secretion determinants, suggesting that Y5 is the major secretion determinant within TcpF. We also report that proteins secreted in a type IV pilus biogenesis apparatus-dependent manner have a YXS motif within the first 15 amino acids following the Sec cleavage site. The YXS motif is not present in proteins secreted by type II secretion systems, indicating that this is unique to type IV pilus-mediated secretion. Moreover, we show that TcpF interacts with the pilin TcpA, suggesting that these proteins are secreted by the type IV pilus biogenesis system. These data provide a starting point for understanding how type IV pili can mediate secretion of virulence factors important for bacterial pathogenesis.
authors.affiliation: Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
authors.forename: Christina J
authors.initials: CJ
authors.lastname: Megli
authors.forename: Ronald K
authors.initials: RK
authors.lastname: Taylor
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D058947:Bacterial Secretion Systems; D010861:Fimbriae, Bacterial / Q000378:metabolism / Q000502:physiology*; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014734:Vibrio cholerae / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D050505:Mutant Proteins; D014157:Transcription Factors; C075626:tcpN protein, Vibrio cholerae
references.citation: Infect Disord Drug Targets. 2007 Mar;7(1):19-27
references.pmid: 17346208
references.citation: J Bacteriol. 2011 Feb;193(4):979-88
references.pmid: 21169492
references.citation: J Bacteriol. 2007 Jul;189(14):5022-33
references.pmid: 17513472
references.citation: Gene. 1997 Jun 11;192(1):63-70
references.pmid: 9224875
references.citation: FEMS Microbiol Lett. 2007 Jan;266(2):129-37
references.pmid: 17156122
references.citation: J Bacteriol. 2009 Mar;191(6):1961-73
references.pmid: 19151143
references.citation: Infect Immun. 2005 Aug;73(8):4461-70
references.pmid: 16040956
references.citation: PLoS Pathog. 2010 Sep 16;6(9):e1001102
references.pmid: 20862321
references.citation: J Bacteriol. 2010 Jul;192(14):3809-21
references.pmid: 20472801
references.citation: FEMS Microbiol Lett. 2006 Feb;255(2):175-86
references.pmid: 16448494
references.citation: J Bacteriol. 1997 Nov;179(22):6994-7003
references.pmid: 9371445
references.citation: Channels (Austin). 2011 May-Jun;5(3):215-8
references.pmid: 21406971
references.citation: Gene. 1993 Apr 15;126(1):43-9
references.pmid: 8097177
references.citation: J Exp Med. 1969 Jul 1;130(1):185-202
references.pmid: 4978880
references.citation: Structure. 2008 Jan;16(1):137-48
references.pmid: 18184591
references.citation: J Bacteriol. 2001 Jul;183(13):3825-32
references.pmid: 11395444
references.citation: J Mol Biol. 2010 May 7;398(3):444-61
references.pmid: 20338182
references.citation: Nature. 2009 Dec 24;462(7276):1011-5
references.pmid: 19946264
references.citation: Mol Microbiol. 2006 Oct;62(1):227-37
references.pmid: 16987180
references.citation: J Bacteriol. 2009 May;191(9):3149-61
references.pmid: 19251862
references.citation: J Bacteriol. 2003 May;185(9):2749-58
references.pmid: 12700254
references.citation: Nature. 1999 May 27;399(6734):375-9
references.pmid: 10360577
references.citation: Mol Microbiol. 2001 Apr;40(2):271-83
references.pmid: 11309111
references.citation: J Bacteriol. 2007 Jun;189(12):4401-9
references.pmid: 17434972
references.citation: J Bacteriol. 2009 Jun;191(11):3665-76
references.pmid: 19304855
references.citation: Nat Rev Microbiol. 2004 May;2(5):363-78
references.pmid: 15100690
references.citation: Mol Microbiol. 1993 Oct;10(2):233-43
references.pmid: 7934814
references.citation: J Bacteriol. 2005 Apr;187(7):2225-32
references.pmid: 15774863
references.citation: Mol Microbiol. 2011 Feb;79(3):786-98
references.pmid: 21255118
references.citation: Microbiology (Reading). 2008 Jul;154(Pt 7):2139-2150
references.pmid: 18599841
references.citation: Nat Struct Mol Biol. 2008 May;15(5):428-30
references.pmid: 18461043
references.citation: Mol Microbiol. 2001 May;40(3):542-54
references.pmid: 11359562
references.citation: Science. 1996 Jan 12;271(5246):163-8
references.pmid: 8539615
references.citation: J Bacteriol. 2001 Aug;183(15):4451-8
references.pmid: 11443078
references.citation: Biochim Biophys Acta. 2008 Sep;1778(9):1839-50
references.pmid: 18406342
references.citation: J Biol Chem. 2005 Sep 9;280(36):31378-89
references.pmid: 16012171
references.citation: J Mol Biol. 2012 May 25;419(1-2):110-24
references.pmid: 22387466
references.citation: J Exp Med. 1988 Oct 1;168(4):1487-92
references.pmid: 2902187
references.citation: Mol Microbiol. 2000 Feb;35(4):896-910
references.pmid: 10692166
references.citation: Future Microbiol. 2010 Aug;5(8):1203-18
references.pmid: 20722599
references.citation: Gene. 1996 Feb 22;169(1):47-52
references.pmid: 8635748
references.citation: EMBO J. 2001 Dec 3;20(23):6735-41
references.pmid: 11726509
references.citation: Mol Microbiol. 2003 Jul;49(1):81-92
references.pmid: 12823812
references.citation: J Mol Biol. 2011 Jun 3;409(2):146-58
references.pmid: 21440558
references.citation: Microbiology (Reading). 2008 Jan;154(Pt 1):114-126
references.pmid: 18174131
references.citation: J Struct Biol. 2010 Jan;169(1):75-80
references.pmid: 19747550
references.citation: Mol Cell. 2006 Sep 1;23(5):651-62
references.pmid: 16949362
references.citation: J Mol Microbiol Biotechnol. 2006;11(3-5):192-207
references.pmid: 16983195
references.citation: Proc Natl Acad Sci U S A. 1987 May;84(9):2833-7
references.pmid: 2883655
references.citation: Ann Sclavo Collana Monogr. 1986;3(1-2):51-61
references.pmid: 2892514
references.citation: EMBO J. 2000 May 15;19(10):2221-8
references.pmid: 10811613
references.citation: Cell Microbiol. 2009 Oct;11(10):1462-70
references.pmid: 19622097
references.citation: Infect Immun. 2001 Jun;69(6):3523-35
references.pmid: 11349009
references.citation: Mol Cell. 2003 May;11(5):1139-50
references.pmid: 12769840
references.citation: Nat Struct Mol Biol. 2010 Oct;17(10):1226-32
references.pmid: 20852644