Sidhu Vishaldeep K, Vorhölter Frank-Jörg, Niehaus Karsten, Watt Steven A
Dep.7 Proteome and Metabolome Research, Faculty of Biology, Bielefeld University, POB 10 01 31, D-33501 Bielefeld, Germany.
BMC Microbiol. 2008 Jun 2;8:87. doi: 10.1186/1471-2180-8-87.
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.
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.
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.
外膜囊泡（OMVs）从许多革兰氏阴性细菌的外膜释放。已知这些细胞外区室可运输参与细胞间信号传导的化合物以及与毒力相关的蛋白质，例如来自肠毒素性大肠杆菌的细胞溶素。
我们已证明野油菜黄单胞菌野油菜致病变种（Xcc）在生长过程中会将OMVs释放到培养上清液中。一项蛋白质组研究鉴定出31种与OMV组分相关的不同蛋白质，其中一半与毒力相关。与最丰富的外膜（OM）蛋白质进行比较发现，一些蛋白质在OMV组分中富集。这可能与OMVs和OM之间脂多糖组成的差异有关。此外，对来自两种不同培养基的OMV蛋白质组的比较表明，培养条件对蛋白质组成有影响。有趣的是，两种培养条件共有的蛋白质主要参与毒力作用。
从Xcc的OM释放的外膜囊泡含有与膜和毒力相关的蛋白质。未来的实验将证明这些结构是否可作为将毒力因子运输到宿主膜中的“载体”。
