CPn0572, the C. pneumoniae ortholog of TarP, reorganizes the actin cytoskeleton via a newly identified F-actin binding domain and recruitment of vinculin
CPn0572, the C. pneumoniae ortholog of TarP, reorganizes the actin cytoskeleton via a newly identified F-actin binding domain and recruitment of vinculin
复制标题
DOI：
10.1371/journal.pone.0210403
复制
发表时间：
2019-01-10
期刊：
影响因子：
3.7
通讯作者：
Hegemann, Johannes H.
中科院分区：
文献类型：
--
作者：
Braun, Corinna;Alcazar-Roman, Abel R.;Hegemann, Johannes H.
肺炎衣原体是衣原体科的两个主要物种之一，对人类健康有深远的影响。C.肺炎与多种严重的急性及慢性上呼吸道及下呼吸道疾病有关，包括肺炎，哮喘，支气管炎，而该病原体的感染亦可能引致肺癌。粘附后，衣原体分泌效应蛋白进入宿主细胞质，调节肌动蛋白细胞骨架，促进内化和感染。保守的TarP蛋白家族的成员包括这样的效应蛋白，即，在C.沙眼衣原体TarP蛋白，已显示在发病机制中起关键作用。在以前的研究中，我们证明，在细菌入侵，C。肺炎支原体TarP家族成员CPn 0572分泌到宿主细胞质中，并通过TarP蛋白中保守的肌动蛋白结合结构域募集并与肌动蛋白缔合。我们现在已经扩展了我们对CPn 0572的分析，发现CPn 0572肌动蛋白结合和调节能力更加复杂。在裂殖酵母系统的帮助下，第二个肌动蛋白调节结构域被鉴定为独立于肌动蛋白结合结构域。表达不同CPn 0572缺失变体的HEp-2细胞的显微镜分析将该结构域定位到蛋白质的C末端部分，因为CPn 0572（536-755）在体外结合F-肌动蛋白，并且在体内与异常增厚的肌动蛋白缆共定位。最后，显微镜和生物信息学分析揭示了在CPn 0572中存在黏着斑蛋白结合序列。我们的研究结果有助于了解TarP家族的功能，并强调存在几个肌动蛋白结合域和黏着斑蛋白结合位点的宿主肌动蛋白调制。
Chlamydia pneumoniae is one of the two major species of the Chlamydiaceae family that have a profound effect on human health. C. pneumoniae is linked to a number of severe acute and chronic diseases of the upper and lower respiratory tract including pneumonia, asthma, bronchitis and infection by the pathogen might play a role in lung cancer. Following adhesion, Chlamydiae secrete effector proteins into the host cytoplasm that modulate the actin cytoskeleton facilitating internalization and infection. Members of the conserved TarP protein family comprise such effector proteins that polymerize actin, and in the case of the C. trachomatis TarP protein, has been shown to play a critical role in pathogenesis. In a previous study, we demonstrated that, upon bacterial invasion, the C. pneumoniae TarP family member CPn0572 is secreted into the host cytoplasm and recruits and associates with actin via an actin-binding domain conserved in TarP proteins. We have now extended our analysis of CPn0572 and found that the CPn0572 actin binding and modulating capability is more complex. With the help of the fission yeast system, a second actin modulating domain was identified independent of the actin binding domain. Microscopic analysis of HEp-2 cells expressing different CPn0572 deletion variants mapped this domain to the C-terminal part of the protein as CPn0572(536-755) binds F-actin in vitro and colocalizes with aberrantly thickened actin cables in vivo. Finally, microscopic and bioinformatic analysis revealed the existence of a vinculin binding sequence in CPn0572. Our findings contribute to the understanding of the function of the TarP family and underscore the existence of several actin binding domains and a vinculin binding site for host actin modulation.