Moonlighting proteins in <em>Mycoplasma hyopneumoniae</em>: Investigating a pathogenic role for glycolytic enzymes and their cleavage fragments. — ASN Events
  1. Schedule
  2. Lunch/Poster Session One
  3. Moonlighting proteins in Mycoplasma hyopneumoniae: Investigating a pathogenic role for glycolytic enzymes and their cleavage fragments.

Moonlighting proteins in Mycoplasma hyopneumoniae: Investigating a pathogenic role for glycolytic enzymes and their cleavage fragments. (#123)

Marcelo Moreno 1 2 , Benjamin B. A. Raymond 1 2 , Jessica L. Tacchi 1 2 , Iain J. Berry 1 2 , Michael Widjaja 1 2 , Matt P. Padula 1 2 , Steven P. Djordjevic 1 2
  1. UTS, Sydney, NSW, Australia
  2. the ithree institute, Sydney, NSW, Australia

Mycoplasma species are strictly parasitic bacteria from the Mollicutes class that are thought to have undergone extensive genomic reduction from a low G + C Firmicute ancestor. As such, Mycoplasma spp. lack genes for the TCA cycle and secretory mechanisms, and the biosynthesis of a cell wall, amino acids, nucleotides, and cholesterol. The pig pathogen Mycoplasma hyopneumoniae (Mhp) destroys mucociliary function in the respiratory tract and causes significant economic loss to pig production systems globally. Our surfaceome studies show that in addition to the P97 and P102 adhesin families, many lipoproteins and proteins with canonical cytosolic functions are surface-accessible targets of proteolytic processing events.

Proteins that do not contain known secretion motifs are often described on the surface of bacteria including metabolic enzymes, chaperones, and ribosomal proteins. The surface-expression of these proteins has been ignored for many years but has recently garnered widespread attention as their possible role in pathogenesis has developed. Many of these canonically cytosolic moonlighting proteins have since been shown to play important roles in binding to a functionally and structurally diverse array of host molecules and to activate host proteases such as plasminogen1. In Mycoplasma pneumoniae, subunits of the pyruvate dehydrogenase (PDH) complex are known to bind plasminogen and fibronectin2,3.

Here we report processing of the PDH complex subunits that are located on the surface of M. hyopneumoniae. We argue that proteolytic processing may be a mechanism to release new, functional domains and expand the adhesive capacity of this pathogen as it colonises the host. To assist with the identification of cleavage fragments, a series of affinity chromatography assays using host molecules (plasminogen, fibronectin, and others) as bait were applied. Protein cleavage fragments were mapped by combining 1D and 2D-SDS-PAGE and LC-MS/MS data and precise cleavage sites within these molecules identified by dimethyl labelling of neo-N-termini. These enrichment strategies are useful for mapping functionally relevant cleavage fragments and assist with the identification of novel binding domains.

  1. Kainulainen, V. and Korhonen, T. K., Dancing to another tune—adhesive moonlighting proteins in bacteria. Biology, 2014. 3(1): p. 178-204.
  2. Dallo, S.F., Kannan, T. R., Blaylock, M. W., Baseman, J. B., Elongation factor Tu and E1 β subunit of pyruvate dehydrogenase complex act as fibronectin binding proteins in Mycoplasma pneumoniae. Molecular Microbiology, 2002. 46(4): p. 1041-1051.
  3. Gründel, A., Friedrich, K., Pfeiffer, M., Jacobs, E., Dumke, R., Subunits of the Pyruvate Dehydrogenase Cluster of Mycoplasma pneumoniae Are Surface-Displayed Proteins that Bind and Activate Human Plasminogen. PLoS ONE, 2015. 10(5): e0126600