Identification and characterization of the aspartate chemosensory receptor of Campylobacter jejuni
Identification and characterization of the aspartate chemosensory receptor of Campylobacter jejuni
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DOI：
10.1111/j.1365-2958.2009.07010.x
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发表时间：
2010-02-01
影响因子：
3.6
通讯作者：
Korolik, Victoria
中科院分区：
文献类型：
--
作者：
Hartley-Tassell, Lauren E.;Shewell, Lucy K.;Korolik, Victoria
空肠弯曲杆菌是一种高度能动的细菌，其通过趋化性对环境刺激作出反应，从而向有利条件迁移。先前对C.空肠菌株NCTC 11168基因组序列鉴定了10个开放阅读框，tlp 1 -10，其编码推定化学感受受体。我们描述了Tlp 1化学受体（Cj 1506 c）的作用和特异性的表征。在体外和体内模型被用来确定是否Tlp 1在宿主定植的作用。tlp 1同基因突变体在细胞培养中的粘附性更强，但在鸡体内的定殖能力降低。使用氨基酸阵列和饱和转移差分核磁共振光谱法鉴定了Tlp 1和L-天冬氨酸的纯化的感觉域之间的特异性相互作用。趋化性测定显示野生型C.空肠细胞和TLP 1-等基因突变体，特别是对天冬氨酸。此外，使用酵母双杂交和三杂交系统的蛋白质-蛋白质相互作用的分析，Tlp 1的细胞质信号结构域被发现优先与CheV相互作用，而不是CheW同源的趋化性信号通路，这种相互作用被证实使用免疫沉淀试验。这是第一次在大肠杆菌和鼠伤寒沙门氏菌以外的细菌中鉴定出天冬氨酸受体。
Campylobacter jejuni is a highly motile bacterium that responds via chemotaxis to environmental stimuli to migrate towards favourable conditions. Previous in silico analysis of the C. jejuni strain NCTC11168 genome sequence identified 10 open reading frames, tlp1-10, that encode putative chemosensory receptors. We describe the characterization of the role and specificity of the Tlp1 chemoreceptor (Cj1506c). In vitro and in vivo models were used to determine if Tlp1 had a role in host colonization. The tlp1- isogenic mutant was more adherent in cell culture, however, showed reduced colonization ability in chickens. Specific interactions between the purified sensory domain of Tlp1 and l-aspartate were identified using an amino acid array and saturation transfer difference nuclear magnetic resonance spectroscopy. Chemotaxis assays showed differences between migration of wild-type C. jejuni cells and that of a tlp1- isogenic mutant, specifically towards aspartate. Furthermore, using yeast two-hybrid and three-hybrid systems for analysis of protein-protein interactions, the cytoplasmic signalling domain of Tlp1 was found to preferentially interact with CheV, rather than the CheW homologue of the chemotaxis signalling pathway; this interaction was confirmed using immune precipitation assays. This is the first identification of an aspartate receptor in bacteria other than Escherichia coli and Salmonella enterica serovar Typhimurium.