title: Perturbation of FliL interferes with Proteus mirabilis swarmer cell gene expression and differentiation.
abstract: Proteus mirabilis is a dimorphic, motile bacterium often associated with urinary tract infections. Colonization of urinary tract surfaces is aided by swarmer cell differentiation, which is initiated by inhibition of flagellar rotation when the bacteria first contact a surface. Mutations in fliL, encoding a flagellar structural protein with an enigmatic function, result in the inappropriate production of differentiated swarmer cells, called pseudoswarmer cells, under noninducing conditions, indicating involvement of FliL in the surface sensing pathway. In the present study, we compared the fliL transcriptome with that of wild-type swarmer cells and showed that nearly all genes associated with motility (flagellar class II and III genes) and chemotaxis are repressed. In contrast, spontaneous motile revertants of fliL cells that regained motility yet produced differentiated swarmer cells under noninducing conditions transcribed flagellar class II promoters at consistent levels. Expression of umoA (a known regulator of swarmer cells), flgF, and flgI increased significantly in both swarmer and pseudoswarmer cells, as did genes in a degenerate prophage region situated immediately adjacent to the Rcs phosphorelay system. Unlike swarmer cells, pseudoswarmers displayed increased activity, rather than transcription, of the flagellar master regulatory protein, FlhD(4)C(2), and analyses of the fliL parent strain and its motile revertants showed that they result from mutations altering the C-terminal 14 amino acids of FliL. Collectively, the data suggest a functional role for the C terminus of FliL in surface sensing and implicate UmoA as part of the signal relay leading to the master flagellar regulator FlhD(4)C(2), which ultimately controls swarmer cell differentiation.
authors.affiliation: Department of Microbiology, The University of Tennessee, Knoxville, Tennessee, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Cusick
authors.forename: Yi-Ying
authors.initials: YY
authors.lastname: Lee
authors.forename: Brian
authors.initials: B
authors.lastname: Youchak
authors.forename: Robert
authors.initials: R
authors.lastname: Belas
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D005947:Glucose; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D009876:Operon; D011513:Proteus mirabilis / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D012329:RNA, Bacterial; C074426:FliL protein, Bacteria; D005947:Glucose
references.citation: Bioinformatics. 2009 Jul 15;25(14):1754-60
references.pmid: 19451168
references.citation: Microbes Infect. 2000 Oct;2(12):1497-505
references.pmid: 11099936
references.citation: Infect Immun. 2010 Jun;78(6):2834-45
references.pmid: 20368347
references.citation: Anal Biochem. 2003 Oct 15;321(2):226-35
references.pmid: 14511688
references.citation: Mol Microbiol. 2008 Apr;68(2):328-41
references.pmid: 18284590
references.citation: J Bacteriol. 2005 Oct;187(19):6789-803
references.pmid: 16166542
references.citation: Methods Enzymol. 2001;336:29-40
references.pmid: 11398406
references.citation: J Bacteriol. 2008 Jan;190(2):463-75
references.pmid: 17993515
references.citation: Bioessays. 2008 Nov;30(11-12):1084-95
references.pmid: 18937343
references.citation: J Bacteriol. 2010 Dec;192(24):6477-81
references.pmid: 20935096
references.citation: J Bacteriol. 1998 Dec;180(23):6126-39
references.pmid: 9829920
references.citation: J Gen Microbiol. 1975 Jul;89(1):199-202
references.pmid: 1097593
references.citation: J Bacteriol. 1990 Feb;172(2):741-7
references.pmid: 2404955
references.citation: Nat Biotechnol. 2010 May;28(5):511-5
references.pmid: 20436464
references.citation: Nucleic Acids Res. 2002 Jan 1;30(1):207-10
references.pmid: 11752295
references.citation: J Bacteriol. 1997 Sep;179(17):5585-8
references.pmid: 9287017
references.citation: Mol Microbiol. 2004 Apr;52(1):169-87
references.pmid: 15049819
references.citation: Biochim Biophys Acta. 1979 May 16;584(3):389-97
references.pmid: 378265
references.citation: J Bacteriol. 1995 Feb;177(3):823-8
references.pmid: 7836320
references.citation: J Bacteriol. 2008 Jun;190(11):4027-37
references.pmid: 18375554
references.citation: J Bacteriol. 2010 Dec;192(23):6230-9
references.pmid: 20889747
references.citation: Mol Syst Biol. 2007;3:128
references.pmid: 17667950
references.citation: Nat Rev Microbiol. 2010 Sep;8(9):634-44
references.pmid: 20694026
references.citation: J Mol Biol. 2006 Dec 15;364(5):921-37
references.pmid: 17052729
references.citation: Mol Microbiol. 2010 Dec;78(6):1416-30
references.pmid: 21143315
references.citation: J Bacteriol. 1982 Apr;150(1):16-26
references.pmid: 7037746
references.citation: EMBO J. 2001 Sep 3;20(17):4854-62
references.pmid: 11532949
references.citation: Genome Biol. 2010;11(10):R106
references.pmid: 20979621
references.citation: Mol Microbiol. 1999 May;32(4):825-36
references.pmid: 10361285
references.citation: Bioinformatics. 2009 May 1;25(9):1105-11
references.pmid: 19289445
references.citation: Mol Microbiol. 1998 Aug;29(3):741-51
references.pmid: 9723914
references.citation: EMBO J. 1995 Apr 3;14(7):1430-8
references.pmid: 7729419
references.citation: Mol Microbiol. 2008 Jul;69(2):548-58
references.pmid: 18630347
references.citation: Mol Microbiol. 1995 Feb;15(4):761-9
references.pmid: 7783646
references.citation: Mol Microbiol. 1992 Jun;6(12):1583-91
references.pmid: 1495387
references.citation: Genome Biol. 2003;4(4):R28
references.pmid: 12702209
references.citation: In Silico Biol. 2005;5(4):419-23
references.pmid: 16268787
references.citation: Mol Microbiol. 2004 Jan;51(2):437-46
references.pmid: 14756784
references.citation: Nucleic Acids Res. 2001 May 1;29(9):e45
references.pmid: 11328886
references.citation: Biochemistry. 2001 Oct 2;40(39):11938-45
references.pmid: 11570895
references.citation: J Bacteriol. 1994 Dec;176(23):7169-81
references.pmid: 7961488
references.citation: Nat Methods. 2008 Jul;5(7):621-8
references.pmid: 18516045
references.citation: J Bacteriol. 1982 May;150(2):900-4
references.pmid: 6279575
references.citation: J Bacteriol. 1994 Apr;176(8):2308-11
references.pmid: 8157599
references.citation: Mol Microbiol. 2003 Dec;50(5):1665-82
references.pmid: 14651646
references.citation: Methods. 2001 Dec;25(4):402-8
references.pmid: 11846609
references.citation: J Bacteriol. 2008 Apr;190(8):2966-71
references.pmid: 18296526
references.citation: Proc Natl Acad Sci U S A. 2007 Mar 6;104(10):4112-7
references.pmid: 17360486
references.citation: Mol Microbiol. 1995 Sep;17(6):1167-75
references.pmid: 8594335
references.citation: FEMS Microbiol Rev. 2010 Sep;34(5):753-63
references.pmid: 20497230
references.citation: Curr Opin Microbiol. 1999 Dec;2(6):630-5
references.pmid: 10607626
references.citation: Mol Microbiol. 2011 May;80(4):886-99
references.pmid: 21244534
references.citation: J Bacteriol. 2006 Sep;188(18):6703-8
references.pmid: 16952964
references.citation: BMC Bioinformatics. 2005 Jul 05;6:168
references.pmid: 15998470
references.citation: J Bacteriol. 1996 Nov;178(22):6525-38
references.pmid: 8932309
references.citation: Clin Microbiol Rev. 2008 Jan;21(1):26-59
references.pmid: 18202436
references.citation: J Bacteriol. 2008 Jul;190(14):4979-88
references.pmid: 18469103
references.citation: J Bacteriol. 1991 Oct;173(19):6289-93
references.pmid: 1655704
references.citation: Infect Immun. 1992 Nov;60(11):4740-6
references.pmid: 1398984