The Legionella pneumophila F-box protein Lpp2082 (AnkB) modulates ubiquitination of the host protein parvin B and promotes intracellular replication
The Legionella pneumophila F-box protein Lpp2082 (AnkB) modulates ubiquitination of the host protein parvin B and promotes intracellular replication
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DOI：
10.1111/j.1462-5822.2010.01467.x
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发表时间：
2010-09-01
影响因子：
3.4
通讯作者：
Buchrieser, C.
中科院分区：
文献类型：
--
作者：
Lomma, M.;Dervins-Ravault, D.;Buchrieser, C.
P>环境病原体嗜肺军团菌编码三种含有 F-box 结构域和额外的蛋白质-蛋白质相互作用结构域的蛋白质，让人想起真核 SCF 泛素-蛋白质连接酶。在这里，我们表明，嗜肺军团菌巴黎菌株的 F-box 蛋白是 Dot/Icm 效应子，参与与含军团菌液泡相关的泛素化蛋白的积累。 F-box 蛋白编码基因的单、双和三突变体在卡氏棘阿米巴、THP-1 巨噬细胞和人肺上皮细胞的感染中受损。 Lpp2082/AnkB 对于体内 A/J 小鼠肺部感染至关重要，并与哺乳动物细胞中 SCF 复合物的相互作用伴侣 Skp1 结合，类似于来自菌株 AA100/130b 的 AnkB。使用酵母双杂交筛选和免疫共沉淀分析，我们确定了 ParvB（一种存在于粘着斑和板状伪足中的蛋白质）作为靶标。免疫荧光分析证实异位表达的 Lpp2082/AnkB 与 ParvB 共定位于板状伪足的外围。出乎意料的是，泛素化测试显示 Lpp2082/AnkB 减少了 ParvB 的内源性泛素化。基于这些结果，我们提出嗜肺军团菌通过与真核E3连接酶竞争ParvB的特定蛋白质-蛋白质相互作用位点来调节ParvB的泛素化，从而揭示嗜肺军团菌可能利用易位效应蛋白来促进细菌存活的新机制。
P>The environmental pathogen Legionella pneumophila encodes three proteins containing F-box domains and additional protein-protein interaction domains, reminiscent of eukaryotic SCF ubiquitin-protein ligases. Here we show that the F-box proteins of L. pneumophila strain Paris are Dot/Icm effectors involved in the accumulation of ubiquitinated proteins associated with the Legionella-containing vacuole. Single, double and triple mutants of the F-box protein encoding genes were impaired in infection of Acanthamoeba castellanii, THP-1 macrophages and human lung epithelial cells. Lpp2082/AnkB was essential for infection of the lungs of A/J mice in vivo , and bound Skp1, the interaction partner of the SCF complex in mammalian cells, similar to AnkB from strain AA100/130b. Using a yeast two-hybrid screen and co-immunoprecipitation analysis we identified ParvB a protein present in focal adhesions and in lamellipodia, as a target. Immunofluorescence analysis confirmed that ectopically expressed Lpp2082/AnkB colocalized with ParvB at the periphery of lamellipodia. Unexpectedly, ubiquitination tests revealed that Lpp2082/AnkB diminishes endogenous ubiquitination of ParvB. Based on these results we propose that L. pneumophila modulates ubiquitination of ParvB by competing with eukaryotic E3 ligases for the specific protein-protein interaction site of ParvB, thereby revealing a new mechanism by which L. pneumophila may employ translocated effector proteins to promote bacterial survival.