title: The purified and recombinant Legionella pneumophila chaperonin alters mitochondrial trafficking and microfilament organization.
abstract: A portion of the total cellular pool of the Legionella pneumophila chaperonin, HtpB, is found on the bacterial cell surface, where it can mediate invasion of nonphagocytic cells. HtpB continues to be abundantly produced and released by internalized L. pneumophila and may thus have postinvasion functions. We used here two functional models (protein-coated beads and expression of recombinant proteins in CHO cells) to investigate the competence of HtpB in mimicking early intracellular trafficking events of L. pneumophila, including the recruitment of mitochondria, cytoskeletal alterations, the inhibition of phagosome-lysosome fusion, and association with the endoplasmic reticulum. Microscopy and flow cytometry studies indicated that HtpB-coated beads recruited mitochondria in CHO cells and U937-derived macrophages and induced transient changes in the organization of actin microfilaments in CHO cells. Ectopic expression of HtpB in the cytoplasm of transfected CHO cells also led to modifications in actin microfilaments similar to those produced by HtpB-coated beads but did not change the distribution of mitochondria. Association of phagosomes containing HtpB-coated beads with the endoplasmic reticulum was not consistently detected by either fluorescence or electron microscopy studies, and only a modest delay in the fusion of TrOv-labeled lysosomes with phagosomes containing HtpB-coated beads was observed. HtpB is the first Legionella protein and the first chaperonin shown to, by means of our functional models, induce mitochondrial recruitment and microfilament rearrangements, two postinternalization events that typify the early trafficking of virulent L. pneumophila.
authors.affiliation: Department of Microbiology and Immunology, 5850 College Street, Sir Charles Tupper Medical Building, 7th Floor, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada.
authors.forename: Audrey
authors.initials: A
authors.lastname: Chong
authors.forename: Celia A
authors.initials: CA
authors.lastname: Lima
authors.forename: David S
authors.initials: DS
authors.lastname: Allan
authors.forename: Gheyath K
authors.initials: GK
authors.lastname: Nasrallah
authors.forename: Rafael A
authors.initials: RA
authors.lastname: Garduño
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D016466:CHO Cells; D018833:Chaperonins / Q000378:metabolism*; D006224:Cricetinae; D003412:Cricetulus; D005434:Flow Cytometry; D016952:Legionella pneumophila / Q000378:metabolism*; D008247:Lysosomes / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000378:metabolism*; D010588:Phagosomes / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D018833:Chaperonins
references.citation: Appl Environ Microbiol. 2006 Apr;72(4):2885-95
references.pmid: 16597995
references.citation: J Clin Invest. 1980 Sep;66(3):441-50
references.pmid: 7190579
references.citation: Appl Environ Microbiol. 2008 Apr;74(7):2187-99
references.pmid: 18245233
references.citation: Traffic. 2006 Mar;7(3):308-23
references.pmid: 16497225
references.citation: Infect Immun. 1990 Oct;58(10):3380-7
references.pmid: 2205580
references.citation: Appl Environ Microbiol. 2009 Apr;75(7):1826-37
references.pmid: 19201975
references.citation: J Exp Med. 1983 Dec 1;158(6):2108-26
references.pmid: 6644240
references.citation: Infect Immun. 1998 Mar;66(3):1252-7
references.pmid: 9488422
references.citation: J Gen Microbiol. 1985 Apr;131(4):697-706
references.pmid: 3989510
references.citation: Clin Microbiol Rev. 1988 Jan;1(1):60-81
references.pmid: 3060246
references.citation: Infect Immun. 2003 Nov;71(11):6256-63
references.pmid: 14573644
references.citation: J Clin Invest. 1993 Feb;91(2):717-23
references.pmid: 8432872
references.citation: Infect Immun. 1995 Sep;63(9):3609-20
references.pmid: 7642298
references.citation: Infect Immun. 2005 Jul;73(7):4370-80
references.pmid: 15972532
references.citation: J Bacteriol. 1990 May;172(5):2401-7
references.pmid: 2332403
references.citation: J Cell Sci. 2001 Dec;114(Pt 24):4637-50
references.pmid: 11792828
references.citation: J Biol Chem. 1982 Jan 25;257(2):1071-8
references.pmid: 7054166
references.citation: Cell Motil Cytoskeleton. 1998;40(4):368-78
references.pmid: 9712266
references.citation: Nature. 2001 May 3;411(6833):44
references.pmid: 11333970
references.citation: Mol Microbiol. 1998 May;28(3):663-74
references.pmid: 9632267
references.citation: Infect Immun. 1996 Jun;64(6):1968-76
references.pmid: 8675295
references.citation: J Histochem Cytochem. 1974 Dec;22(12):1077-83
references.pmid: 4374474
references.citation: J Exp Med. 1983 Oct 1;158(4):1319-31
references.pmid: 6619736
references.citation: J Exp Med. 1987 Nov 1;166(5):1310-28
references.pmid: 3681188
references.citation: Mol Microbiol. 1994 Nov;14(4):809-22
references.pmid: 7891566
references.citation: Nat Cell Biol. 1999 Nov;1(7):451-3
references.pmid: 10559990
references.citation: J Cell Biol. 1995 Dec;131(5):1315-26
references.pmid: 8522592
references.citation: Biotechniques. 1998 Nov;25(5):772-4, 776
references.pmid: 9821576
references.citation: Isr J Med Sci. 1986 Sep;22(9):678-89
references.pmid: 3793451
references.citation: Biochim Biophys Acta. 2006 May-Jun;1763(5-6):450-62
references.pmid: 16624426
references.citation: J Eukaryot Microbiol. 2004 Jan-Feb;51(1):81-7
references.pmid: 15068269
references.citation: Can J Microbiol. 1998 May;44(5):430-40
references.pmid: 9699298
references.citation: J Cell Sci. 1997 Sep;110 ( Pt 17):2117-28
references.pmid: 9378762
references.citation: J Exp Med. 1985 Feb 1;161(2):409-22
references.pmid: 3882879
references.citation: Methods Cell Biol. 1994;45:261-76
references.pmid: 7707990
references.citation: Nat Cell Biol. 2002 May;4(5):343-50
references.pmid: 11988737
references.citation: Nature. 2007 Nov 15;450(7168):365-9
references.pmid: 17952054
references.citation: Infect Immun. 2005 Aug;73(8):4494-504
references.pmid: 16040960
references.citation: J Exp Med. 2001 Oct 15;194(8):1081-96
references.pmid: 11602638
references.citation: Infect Immun. 2001 Aug;69(8):5157-61
references.pmid: 11447198
references.citation: Biochem J. 2004 Jan 15;377(Pt 2):327-37
references.pmid: 14521508
references.citation: Infect Immun. 2006 Mar;74(3):1683-91
references.pmid: 16495539
references.citation: Trends Microbiol. 2007 Aug;15(8):372-80
references.pmid: 17632005
references.citation: J Exp Med. 1987 Nov 1;166(5):1377-89
references.pmid: 3316470
references.citation: Exp Cell Res. 2001 May 15;266(1):11-20
references.pmid: 11339820
references.citation: J Infect Dis. 2004 May 1;189(9):1610-4
references.pmid: 15116296
references.citation: Cell Microbiol. 2008 Dec;10(12):2416-33
references.pmid: 18673369
references.citation: Infect Immun. 1998 Jun;66(6):2905-13
references.pmid: 9596766
references.citation: J Bacteriol. 1998 Feb;180(3):505-13
references.pmid: 9457851
references.citation: Dev Cell. 2006 Jul;11(1):47-56
references.pmid: 16824952
references.citation: Infect Immun. 1989 Jun;57(6):1731-9
references.pmid: 2566581
references.citation: Cell Microbiol. 2005 Jul;7(7):995-1007
references.pmid: 15953031
references.citation: Infect Immun. 1999 Sep;67(9):4427-34
references.pmid: 10456883
references.citation: J Cell Biol. 2001 Jul 9;154(1):95-108
references.pmid: 11448993
references.citation: J Cell Sci. 1983 May;61:87-105
references.pmid: 6350334
references.citation: J Mol Biol. 1987 Aug 20;196(4):947-50
references.pmid: 3681984
references.citation: Infect Immun. 2001 Jan;69(1):508-17
references.pmid: 11119544
references.citation: Proc Natl Acad Sci U S A. 1992 Oct 15;89(20):9607-11
references.pmid: 1409673
references.citation: J Cell Biol. 1984 Dec;99(6):1936-43
references.pmid: 6501409
references.citation: Immunology. 1996 Oct;89(2):281-8
references.pmid: 8943727
references.citation: J Bacteriol. 2006 Sep;188(17):6235-44
references.pmid: 16923890
references.citation: Nat Cell Biol. 2002 Dec;4(12):945-54
references.pmid: 12447391
references.citation: Infect Immun. 2004 May;72(5):3048-53
references.pmid: 15102819
references.citation: Infect Immun. 2007 Feb;75(2):592-603
references.pmid: 17101649
references.citation: Cell Microbiol. 2001 Feb;3(2):99-114
references.pmid: 11207624
references.citation: J Exp Med. 2000 Nov 6;192(9):1261-72
references.pmid: 11067875
references.citation: J Clin Invest. 1983 Jan;71(1):15-26
references.pmid: 6848556
references.citation: Cell. 1999 Jul 9;98(1):69-80
references.pmid: 10412982
references.citation: Proc Natl Acad Sci U S A. 1997 Mar 18;94(6):2192-7
references.pmid: 9122170
references.citation: Infect Immun. 1999 Sep;67(9):4490-8
references.pmid: 10456891
references.citation: Microbiology (Reading). 2000 Jun;146 ( Pt 6):1345-1359
references.pmid: 10846213
references.citation: J Exp Med. 2004 May 3;199(9):1201-11
references.pmid: 15117975
references.citation: Cell. 1984 Jan;36(1):27-33
references.pmid: 6692469
references.citation: J Electron Microsc (Tokyo). 1991 Oct;40(5):356-63
references.pmid: 1666645
references.citation: Cell Stress Chaperones. 2002 Oct;7(4):317-29
references.pmid: 12653476
references.citation: Science. 1999 Mar 26;283(5410):2092-5
references.pmid: 10092234
references.citation: J Bacteriol. 1988 Mar;170(3):1389-92
references.pmid: 3343223
references.citation: Infect Immun. 2004 Jan;72(1):38-45
references.pmid: 14688078
references.citation: Can J Microbiol. 1994 Oct;40(10):865-72
references.pmid: 8000965
references.citation: Ann N Y Acad Sci. 1996 Oct 25;797:271-2
references.pmid: 8993377
references.citation: Infect Immun. 1998 Oct;66(10):4602-10
references.pmid: 9746556
references.citation: Mol Microbiol. 1995 Jan;15(1):1-11
references.pmid: 7752884