A Dot/Icm-translocated ankyrin protein of Legionella pneumophila is required for intracellular proliferation within human macrophages and protozoa.
A Dot/Icm-translocated ankyrin protein of Legionella pneumophila is required for intracellular proliferation within human macrophages and protozoa.
复制标题
DOI：
10.1111/j.1365-2958.2008.06453.x
复制
发表时间：
2008-11
影响因子：
3.6
通讯作者：
Abu Kwaik Y
中科院分区：
文献类型：
--
作者：
Al-Khodor S;Price CT;Habyarimana F;Kalia A;Abu Kwaik Y
嗜肺乳杆菌的Dot/ICM IV型分泌系统将大量的细菌效应物转移到宿主细胞内，对巨噬细胞和原生动物内的细菌增殖是必不可少的。我们最近发现嗜肺乳杆菌AA100/130b株含有11个基因，编码真核样锚蛋白(Ank)蛋白，Ank蛋白家族参与了真核细胞的各种重要过程。与大多数Dot/ICM输出的底物不同，大多数Dot/ICM输出的底物在细胞内增殖中几乎没有可检测到的作用，而ankB突变导致人单核细胞来源的巨噬细胞(HMDM)、U937巨噬细胞和棘阿米巴多噬细胞的细胞内复制存在严重的生长缺陷。对hMDM混合感染的单细胞分析表明，ankB突变体的胞内生长缺陷在含有野生型菌株的公共吞噬体内被完全挽救。有趣的是，与Dot/ICM结构突变体不同的是，ankB突变体也在不同吞噬小体中携带野生型菌株的细胞内反式拯救，表明AnkB是一种交易性分泌效应器。通过腺苷环化酶与AnkB的融合，我们证明了AnkB是通过Dot/ICM分泌系统以IcmSW依赖的方式转运到宿主细胞中的，最后3个C末端氨基酸残基是转运所必需的。与Dot/ICM结构突变体不同的是，含有ankB突变体的吞噬小体排除了晚期内体和溶酶体标记，它们的吞噬小体被RER重塑。我们发现，在后指数生长阶段，LetA/S和PmrA/B两个组分系统对ankB基因的表达起正向调节作用，而rpoS、LETE和relA则抑制其表达。我们的数据表明，类真核AnkB蛋白是Dot/ICM输出的效应蛋白，在巨噬细胞和原生动物内嗜肺杆菌的细胞内复制中发挥主要作用，其表达受指数后生长阶段的调控。
The Dot/Icm type IV secretion system of L. pneumophila translocates numerous bacterial effectors into the host cell and is essential for bacterial proliferation within macrophages and protozoa. We have recently shown that L. pneumophila strain AA100/130b harbors 11 genes encoding eukaryotic-like ankyrin (Ank) proteins, a family of proteins involved in various essential eukaryotic cellular processes. In contrast to most Dot/Icm-exported substrates, which have little or no detectable role in intracellular proliferation, a mutation in ankB results in a severe growth defect in intracellular replication within human monocyte-derived macrophages (hMDMs), U937 macrophages, and Acanthamoeba polyphaga. Single cell analyses of co-infections of hMDMs have shown that the intracellular growth defect of the ankB mutant is totally rescued in-cis within communal phagosomes harboring the wild type strain. Interestingly, distinct from dot/icm structural mutants, the ankB mutant is also rescued in-trans within cells harboring the wild type strain in a different phagosome, indicating that AnkB is a transacting secreted effector. Using adenylate cyclase fusions to AnkB, we show that AnkB is translocated into the host cell via the Dot/Icm secretion system in an IcmSW-dependent manner, and that the last 3 C-terminal amino acid residues are essential for translocation. Distinct from the dot/icm structural mutants, the ankB mutant-containing phagosomes exclude late endosomal and lysosomal markers and their phagosomes are remodeled by the RER. We show that at the post exponential phase of growth, the LetA/S and PmrA/B two component systems confer a positive regulation on expression of the ankB gene, whereas RpoS, LetE, and RelA suppress its expression. Our data show that the eukaryotic-like AnkB protein is a Dot/Icm-exported effector that plays a major role in intracellular replication of L. pneumophila within macrophages and protozoa, and its expression is temporally controlled by regulators of the post-exponential phase of growth.
登录
查看更多内容
影响因子：
3.6
作者：
Bachman, MA;Swanson, MS
通讯作者：
Swanson, MS
影响因子：
3.4
作者：
Bruggemann, Holger;Hagman, Arne;Buchrieser, Carmen
通讯作者：
Buchrieser, Carmen
影响因子：
3.2
作者：
Faulkner, G;Garduño, RA
通讯作者：
Garduño, RA
影响因子：
3.2
作者：
Feldman, Michal;Segal, Gil
通讯作者：
Segal, Gil
影响因子：
3.1
作者：
Byrne, B;Swanson, MS
通讯作者：
Swanson, MS