title: Subdomains N2N3 of fibronectin binding protein A mediate Staphylococcus aureus biofilm formation and adherence to fibrinogen using distinct mechanisms.
abstract: Health care-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) forms biofilm in vitro that is dependent on the surface-located fibronectin binding proteins A and B (FnBPA, FnBPB). Here we provide new insights into the requirements for FnBP-dependent biofilm formation by MRSA. We show that expression of FnBPs is sustained at high levels throughout the growth cycle in the HA-MRSA strain BH1CC in contrast to laboratory strain SH1000, where expression could be detected only in exponential phase. We found that FnBP-mediated biofilm accumulation required Zn(2+), while the removal of Zn(2+) had no effect on the ability of FnBPA to mediate bacterial adherence to fibrinogen. We also investigated the role of FnBPA expressed on the surface of S. aureus in promoting biofilm formation and bacterial adhesion to fibrinogen. The minimum part of FnBPA required for ligand binding has so far been defined only with recombinant proteins. Here we found that the N1 subdomain was not required for biofilm formation or for FnBPA to promote bacterial adherence to fibrinogen. Residues at the C terminus of subdomain N3 required for FnBPA to bind to ligands using the "dock, lock, and latch" mechanism were necessary for FnBPA to promote bacterial adherence to fibrinogen. However, these residues were not necessary to form biofilm, allowing us to localize the region of FnBPA required for biofilm accumulation to residues 166 to 498. Thus, FnBPA mediates biofilm formation and bacterial adhesion to fibrinogen using two distinct mechanisms. Finally, we identified a hitherto-unrecognized thrombin cleavage site close to the boundary between subdomains N1 and N2 of FnBPA.
authors.affiliation: Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin, Ireland. geoghegj@tcd.ie
authors.forename: Joan A
authors.initials: JA
authors.lastname: Geoghegan
authors.forename: Ian R
authors.initials: IR
authors.lastname: Monk
authors.forename: James P
authors.initials: JP
authors.lastname: O'Gara
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Foster
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001422:Bacterial Adhesion; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D005340:Fibrinogen / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007502:Iron Chelating Agents / Q000494:pharmacology; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D004369:Pentetic Acid / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins; D013203:Staphylococcal Infections / Q000382:microbiology*; D013917:Thrombin / Q000378:metabolism; D015032:Zinc / Q000378:metabolism
chemical_list: D018829:Adhesins, Bacterial; D005353:Fibronectins; D007502:Iron Chelating Agents; D008565:Membrane Proteins; D011994:Recombinant Proteins; C078635:fibronectin-binding proteins, bacterial; D004369:Pentetic Acid; D005340:Fibrinogen; D013917:Thrombin; D015032:Zinc
references.citation: Lancet. 2001 Jul 14;358(9276):135-8
references.pmid: 11463434
references.citation: PLoS One. 2009 Oct 23;4(10):e7567
references.pmid: 19851500
references.citation: Mol Microbiol. 1996 Jun;20(5):1083-91
references.pmid: 8809760
references.citation: mBio. 2012 Mar 20;3(2):
references.pmid: 22434850
references.citation: J Bacteriol. 2008 Jun;190(11):3835-50
references.pmid: 18375547
references.citation: J Biol Chem. 2001 Nov 30;276(48):44721-8
references.pmid: 11568183
references.citation: Infect Immun. 2003 Jul;71(7):4206-11
references.pmid: 12819120
references.citation: Infect Immun. 2009 Sep;77(9):3978-91
references.pmid: 19581398
references.citation: BMC Microbiol. 2010 Jun 01;10:160
references.pmid: 20515471
references.citation: J Biol Chem. 2001 Aug 10;276(32):29969-78
references.pmid: 11399757
references.citation: PLoS Pathog. 2008 Nov;4(11):e1000226
references.pmid: 19043557
references.citation: Cell Microbiol. 2004 Mar;6(3):269-75
references.pmid: 14764110
references.citation: Mol Microbiol. 2003 Jun;48(6):1429-49
references.pmid: 12791129
references.citation: EMBO J. 2002 Dec 16;21(24):6660-72
references.pmid: 12485987
references.citation: Nature. 2003 May 8;423(6936):177-81
references.pmid: 12736686
references.citation: N Engl J Med. 2004 Oct 14;351(16):1645-54
references.pmid: 15483283
references.citation: Mol Microbiol. 2007 Feb;63(3):711-23
references.pmid: 17302800
references.citation: Infect Immun. 1995 Feb;63(2):585-90
references.pmid: 7822026
references.citation: Curr Top Microbiol Immunol. 2006;306:251-8
references.pmid: 16909925
references.citation: J Clin Microbiol. 2007 May;45(5):1379-88
references.pmid: 17329452
references.citation: N Engl J Med. 1998 Aug 20;339(8):520-32
references.pmid: 9709046
references.citation: J Biol Chem. 2010 Feb 26;285(9):6208-16
references.pmid: 20007717
references.citation: J Med Microbiol. 2001 Jul;50(7):582-587
references.pmid: 11444767
references.citation: Mol Microbiol. 1995 Sep;17(6):1143-52
references.pmid: 8594333
references.citation: Eur J Biochem. 1991 Dec 18;202(3):1041-8
references.pmid: 1837266
references.citation: FEMS Microbiol Lett. 2006 Jun;259(2):260-8
references.pmid: 16734789
references.citation: Proc Natl Acad Sci U S A. 2008 Dec 9;105(49):19456-61
references.pmid: 19047636
references.citation: J Bacteriol. 2010 Nov;192(21):5663-73
references.pmid: 20817770
references.citation: Infect Immun. 2011 Mar;79(3):1153-65
references.pmid: 21189325
references.citation: Proc Natl Acad Sci U S A. 1989 Jan;86(2):699-703
references.pmid: 2521391
references.citation: FEBS J. 2011 Jul;278(13):2359-71
references.pmid: 21569203
references.citation: Cell. 2003 Oct 17;115(2):217-28
references.pmid: 14567919
references.citation: Infect Immun. 1997 Jul;65(7):2621-8
references.pmid: 9199429
references.citation: J Bacteriol. 2001 May;183(9):2888-96
references.pmid: 11292810
references.citation: J Biol Chem. 2011 Jul 22;286(29):25963-72
references.pmid: 21543319
references.citation: PLoS Pathog. 2010 Mar 12;6(3):e1000807
references.pmid: 20300605
references.citation: J Bacteriol. 2002 Oct;184(19):5457-67
references.pmid: 12218034
references.citation: BMC Microbiol. 2008 May 08;8:74
references.pmid: 18466610
references.citation: J Bacteriol. 2009 Feb;191(3):832-43
references.pmid: 19047354
references.citation: J Bacteriol. 1997 Sep;179(17):5259-63
references.pmid: 9286974