Riedel Kathrin, Arevalo-Ferro Catalina, Reil Gerold, Görg Angelika, Lottspeich Friedrich, Eberl Leo
Department of Microbiology, Technical Univerisity of Munich, Am Hochanger 4, D-85350 Freising, Germany.
Electrophoresis. 2003 Feb;24(4):740-50. doi: 10.1002/elps.200390089.
Burkholderia cepacia H111, an important pathogen for persons suffering from cystic fibrosis, employs a quorum-sensing (QS) system, cep, to control expression of virulence factors as well as the formation of biofilms. The QS system is thought to ensure that pathogenic traits are only expressed when the bacterial population density is high enough to overwhelm the host before it is able to mount an efficient response. In this study, we compared the protein pattern of the intracellular, extracellular, and surface protein fractions of an AHL-deficient cepI mutant with the one of the parent strain H111 by means of two-dimensional gel electrophoresis (2-DE). Our analysis showed that 55 proteins out of 985 detected spots were differentially expressed; these are expected to represent QS-controlled gene products. Addition of the respective signal molecules to the growth medium of the cep mutant fully restored the wild-type protein expression profile. In total about 5% of the B. cepacia proteome was downregulated and 1% upregulated in the cepI mutant, indicating that quorum sensing represents a global regulatory system. Nineteen proteins were identified with high confidence by N-terminal sequence analysis.
洋葱伯克霍尔德菌H111是患有囊性纤维化患者的一种重要病原体，它利用群体感应（QS）系统cep来控制毒力因子的表达以及生物膜的形成。人们认为，群体感应系统可确保只有当细菌群体密度足够高，能够在宿主产生有效反应之前压倒宿主时，致病特性才会表达。在本研究中，我们通过二维凝胶电泳（2-DE）比较了AHL缺陷型cepI突变体与亲本菌株H111的细胞内、细胞外和表面蛋白组分的蛋白质图谱。我们的分析表明，在检测到的985个斑点中，有55种蛋白质表达存在差异；预计这些蛋白质代表群体感应控制的基因产物。向cep突变体的生长培养基中添加相应的信号分子可完全恢复野生型蛋白质表达谱。总体而言，在cepI突变体中，洋葱伯克霍尔德菌蛋白质组中约5%的蛋白质表达下调，1%的蛋白质表达上调，这表明群体感应代表一种全局调节系统。通过N端序列分析，有19种蛋白质被高度可靠地鉴定出来。
