Post-translational processing targets functionally diverse proteins in Mycoplasma hyopneumoniae

Jessica L Tacchi; Benjamin B A Raymond; Paul A Haynes; Iain J Berry; Michael Widjaja; Daniel R Bogema; Lauren K Woolley; Cheryl Jenkins; F Chris Minion; Matthew P Padula; Steven P Djordjevic

doi:10.1098/rsob.150210

Post-translational processing targets functionally diverse proteins in Mycoplasma hyopneumoniae

Open Biol. 2016 Feb;6(2):150210. doi: 10.1098/rsob.150210.

Affiliations

¹ The ithree Institute, University of Technology Sydney, PO Box 123, Broadway, New South Wales 2007, Australia.
² Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia.
³ 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.
⁴ 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.
⁵ NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, New South Wales 2568, Australia.
⁶ Department of Veterinary Microbiology and Preventative Medicine, Iowa State University, Ames, IA 50011, USA.
⁷ 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.
⁸ 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.

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.

Keywords: adhesins; global proteome; processing; protein-centric; two-dimensional gels.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
Bacterial Proteins / chemistry
Bacterial Proteins / metabolism*
Membrane Proteins / metabolism
Molecular Sequence Data
Mycoplasma hyopneumoniae / metabolism*
Protein Processing, Post-Translational*
Proteolysis
Proteome
Proteomics / methods

Substances

Bacterial Proteins
Membrane Proteins
Mycoplasma protein 65-kDa
Proteome