title: Post-translational processing targets functionally diverse proteins in Mycoplasma hyopneumoniae.
abstract: Mycoplasma hyopneumoniae is a genome-reduced, cell wall-less, bacterial pathogen with a predicted coding capacity of less than 700 proteins and is one of the smallest self-replicating pathogens. The cell surface of M. hyopneumoniae is extensively modified by processing events that target the P97 and P102 adhesin families. Here, we present analyses of the proteome of M. hyopneumoniae-type strain J using protein-centric approaches (one- and two-dimensional GeLC-MS/MS) that enabled us to focus on global processing events in this species. While these approaches only identified 52% of the predicted proteome (347 proteins), our analyses identified 35 surface-associated proteins with widely divergent functions that were targets of unusual endoproteolytic processing events, including cell adhesins, lipoproteins and proteins with canonical functions in the cytosol that moonlight on the cell surface. Affinity chromatography assays that separately used heparin, fibronectin, actin and host epithelial cell surface proteins as bait recovered cleavage products derived from these processed proteins, suggesting these fragments interact directly with the bait proteins and display previously unrecognized adhesive functions. We hypothesize that protein processing is underestimated as a post-translational modification in genome-reduced bacteria and prokaryotes more broadly, and represents an important mechanism for creating cell surface protein diversity.
authors: The ithree Institute, University of Technology Sydney, PO Box 123, Broadway, New South Wales 2007, Australia.
authors: Jessica L
authors: JL
authors: Tacchi
authors: The ithree Institute, University of Technology Sydney, PO Box 123, Broadway, New South Wales 2007, Australia.
authors: Benjamin B A
authors: BB
authors: Raymond
authors: Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia.
authors: Paul A
authors: PA
authors: Haynes
authors: The ithree Institute, University of Technology Sydney, PO Box 123, Broadway, New South Wales 2007, Australia.
authors: Iain J
authors: IJ
authors: Berry
authors: The ithree Institute, University of Technology Sydney, PO Box 123, Broadway, New South Wales 2007, Australia.
authors: Michael
authors: M
authors: Widjaja
authors: The ithree Institute, University of Technology Sydney, PO Box 123, Broadway, New South Wales 2007, Australia NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, New South Wales 2568, Australia.
authors: Daniel R
authors: DR
authors: Bogema
authors: NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, New South Wales 2568, Australia School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia.
authors: Lauren K
authors: LK
authors: Woolley
authors: NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, New South Wales 2568, Australia.
authors: Cheryl
authors: C
authors: Jenkins
authors: Department of Veterinary Microbiology and Preventative Medicine, Iowa State University, Ames, IA 50011, USA.
authors: F Chris
authors: FC
authors: Minion
authors: The ithree Institute, University of Technology Sydney, PO Box 123, Broadway, New South Wales 2007, Australia Proteomics Core Facility, University of Technology Sydney, PO Box 123, Broadway, New South Wales 2007, Australia.
authors: Matthew P
authors: MP
authors: Padula
authors: The ithree Institute, University of Technology Sydney, PO Box 123, Broadway, New South Wales 2007, Australia Proteomics Core Facility, University of Technology Sydney, PO Box 123, Broadway, New South Wales 2007, Australia steven.djordjevic@uts.edu.au.
authors: Steven P
authors: SP
authors: Djordjevic
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D045705:Mycoplasma hyopneumoniae / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D059748:Proteolysis; D020543:Proteome; D040901:Proteomics / Q000379:methods
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; C093832:Mycoplasma protein 65-kDa; D020543:Proteome
keywords: adhesins; global proteome; processing; protein-centric; two-dimensional gels