Analysis of outer membrane vesicle associated proteins isolated from the plant pathogenic bacterium Xanthomonas campestris pv. campestris.
BACKGROUND
Outer membrane vesicles (OMVs) are released from the outer membrane of many Gram-negative bacteria. These extracellular compartments are known to transport compounds involved in cell-cell signalling as well as virulence associated proteins, e.g. the cytolysine from enterotoxic E. coli.


RESULTS
We have demonstrated that Xanthomonas campestris pv. campestris (Xcc) releases OMVs into the culture supernatant during growth. A proteome study identified 31 different proteins that associate with the OMV fraction of which half are virulence-associated. A comparison with the most abundant outer membrane (OM) proteins revealed that some proteins are enriched in the OMV fraction. This may be connected to differences in the LPS composition between the OMVs and the OM. Furthermore, a comparison of the OMV proteomes from two different culture media indicated that the culture conditions have an impact on the protein composition. Interestingly, the proteins that are common to both culture conditions are mainly involved in virulence.


CONCLUSIONS
Outer membrane vesicles released from the OM of Xcc contain membrane- and virulence-associated proteins. Future experiments will prove whether these structures can serve as "vehicles" for the transport of virulence factors into the host membrane.
Dep.7 Proteome and Metabolome Research, Faculty of Biology, Bielefeld University, POB 10 01 31, D-33501 Bielefeld, Germany. Vishaldeep.Kaur.Sidhu@Genetik.Uni-Bielefeld.DE
Vishaldeep K
VK
Sidhu
Frank-Jörg
FJ
Vorhölter
Karsten
K
Niehaus
Steven A
SA
Watt
D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology*; D021381:Protein Transport; D020543:Proteome / Q000737:chemistry / Q000378:metabolism; D016959:Xanthomonas campestris / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure*
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D003470:Culture Media; D020543:Proteome