title: Mhp182 (P102) binds fibronectin and contributes to the recruitment of plasmin(ogen) to the Mycoplasma hyopneumoniae cell surface.
abstract: Mycoplasma hyopneumoniae is a major, economically damaging respiratory pathogen. Although M. hyopneumoniae cells bind plasminogen, the identification of plasminogen-binding surface proteins and the biological ramifications of acquiring plasminogen requires further investigation. mhp182 encodes a highly expressed 102 kDa protein (P102) that undergoes proteolytic processing to generate surface-located N-terminal 60 kDa (P60) and C-terminal 42 kDa (P42) proteins of unknown function. We show that recombinant P102 (rP102) binds plasminogen at physiologically relevant concentrations (K(D) ~ 76 nM) increasing the susceptibility of plasmin(ogen) to activation by tissue-specific plasminogen activator (tPA). Recombinant proteins constructed to mimic P60 (rP60) and P42 (rP42) also bound plasminogen at physiologically significant levels. M. hyopneumoniae surface-bound plasminogen was activated by tPA and is able to degrade fibrinogen, demonstrating the biological functionality of M. hyopneumoniae-bound plasmin(ogen) upon activation. Plasmin(ogen) was readily detected in porcine ciliated airways and plasmin levels were consistently higher in bronchoalveolar lavage fluid from M. hyopneumoniae-infected animals. Additionally, rP102 and rP42 bind fibronectin with K(D) s of 26 and 33 nM respectively and recombinant P102 proteins promote adherence to porcine kidney epithelial-like cells. The multifunctional binding ability of P102 and activation of M. hyopneumoniae-sequestered plasmin(ogen) by an exogenous activator suggests P102 plays an important role in virulence.
authors.affiliation: School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Seymour
authors.forename: Cheryl
authors.initials: C
authors.lastname: Jenkins
authors.forename: Ania T
authors.initials: AT
authors.lastname: Deutscher
authors.forename: Benjamin B A
authors.initials: BB
authors.lastname: Raymond
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Padula
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Tacchi
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Bogema
authors.forename: Graeme J
authors.initials: GJ
authors.lastname: Eamens
authors.forename: Lauren K
authors.initials: LK
authors.lastname: Woolley
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Dixon
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Walker
authors.forename: Steven P
authors.initials: SP
authors.lastname: Djordjevic
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001422:Bacterial Adhesion; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism; D005341:Fibrinolysin / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D008969:Molecular Sequence Data; D045705:Mycoplasma hyopneumoniae / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D010958:Plasminogen / Q000378:metabolism*; D045729:Pneumonia of Swine, Mycoplasmal / Q000382:microbiology; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D013552:Swine
chemical_list: D018829:Adhesins, Bacterial; D005353:Fibronectins; D011994:Recombinant Proteins; D010958:Plasminogen; D005341:Fibrinolysin