Profiling the outer membrane proteome during growth and development of the social bacterium Myxococcus xanthus by selective biotinylation and analyses of outer membrane vesicles.
Social behavior in the bacterium Myxococcus xanthus relies on contact-dependent activities involving cell-cell and cell-substratum interactions. To identify outer membrane proteins that have a role in these activities, we profiled the outer membrane proteome of growing and starving cells using two strategies. First, outer membrane proteins were enriched by biotinylation of intact cells using the reagent NHS (N-hydroxysuccinimide)-PEO(12) (polyethylene oxide)-biotin with subsequent membrane solubilization and affinity chromatography. Second, the proteome of outer membrane vesicles (OMV) was determined. Comparisons of detected proteins show that these methods have different detection profiles and together provide a comprehensive view of the outer membrane proteome. From 362 proteins identified, 274 (76%) were cell envelope proteins including 64 integral outer membrane proteins and 85 lipoproteins. The majority of these proteins were of unknown function. Among integral outer membrane proteins with homologues of known function, TonB-dependent transporters comprise the largest group. Our data suggest novel functions for these transporters. Among lipoproteins with homologues of known function, proteins with hydrolytic functions comprise the largest group. The luminal load of OMV was enriched for proteins with hydrolytic functions. Our data suggest that OMV have functions in predation and possibly in transfer of intercellular signaling molecules between cells.
Kahnt
Jörg
J
Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str., Marburg, Germany.
Aguiluz
Kryssia
K
Koch
Jürgen
J
Treuner-Lange
Anke
A
Konovalova
Anna
A
Huntley
Stuart
S
Hoppert
Michael
M
Søgaard-Andersen
Lotte
L
Hedderich
Reiner
R
D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis*; D019921:Biotinylation; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002846:Chromatography, Affinity; D008854:Microscopy, Electron; D016941:Myxococcus xanthus / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D001425:Bacterial Outer Membrane Proteins; D020543:Proteome