Localisation and protein-protein interactions of the Helicobacter pylori taxis sensor TlpD and their connection to metabolic functions
Localisation and protein-protein interactions of the Helicobacter pylori taxis sensor TlpD and their connection to metabolic functions
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DOI：
10.1038/srep23582
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发表时间：
2016-04-05
影响因子：
4.6
通讯作者：
Josenhans, Christine
中科院分区：
文献类型：
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作者：
Behrens, Wiebke;Schweinitzer, Tobias;Josenhans, Christine
幽门螺杆菌能量传感器TlpD决定低能量条件下的策略行为，在体内很重要。我们探索了TlpD的蛋白-蛋白相互作用及其对TlpD定位和功能的影响。对标记的TlpD进行下拉，鉴定出TlpD的蛋白相互作用伙伴，包括趋化组氨酸激酶CheAY2、中心代谢酶乌头碱酶（AcnB）和解毒酶过氧化氢酶（KatA）。我们证实了KatA和AcnB与TlpD的物理相互作用。虽然在稳态行为分析中，相互作用突变体katA和acnB的tlpd依赖性行为反应似乎没有受到影响，但丙酮羧化酶亚基（acxC）突变体的行为发生了改变。在高能介质中，TlpD以双极亚细胞模式定位。我们观察到，在cheAY2-、过氧化氢酶或乌头酸酶缺乏的细菌中，或在低能量条件下（包括氧化应激或呼吸抑制）培养的细菌中，TlpD向细胞体的定位发生了显著变化。tlpD失活导致对铁限制和氧化应激的敏感性增加，并影响幽门螺杆菌转录组。氧化应激、铁限制和铁硫修复系统nifSU的过表达改变了tlpd依赖行为。我们认为，TlpD的定位受代谢活动和蛋白质相互作用的指导，其感觉活动与铁硫簇完整性有关。
The Helicobacter pylori energy sensor TlpD determines tactic behaviour under low energy conditions and is important in vivo. We explored protein-protein interactions of TlpD and their impact on TlpD localisation and function. Pull-down of tagged TlpD identified protein interaction partners of TlpD, which included the chemotaxis histidine kinase CheAY2, the central metabolic enzyme aconitase (AcnB) and the detoxifying enzyme catalase (KatA). We confirmed that KatA and AcnB physically interact with TlpD. While the TlpD-dependent behavioural response appeared not influenced in the interactor mutants katA and acnB in steady-state behavioural assays, acetone carboxylase subunit (acxC) mutant behaviour was altered. TlpD was localised in a bipolar subcellular pattern in media of high energy. We observed a significant change in TlpD localisation towards the cell body in cheAY2-, catalase-or aconitase-deficient bacteria or in bacteria incubated under low energy conditions, including oxidative stress or respiratory inhibition. Inactivation of tlpD resulted in an increased sensitivity to iron limitation and oxidative stress and influenced the H. pylori transcriptome. Oxidative stress, iron limitation and overexpressing the iron-sulfur repair system nifSU altered TlpD-dependent behaviour. We propose that TlpD localisation is instructed by metabolic activity and protein interactions, and its sensory activity is linked to iron-sulfur cluster integrity.