Chlamydia interacts with the Golgi apparatus - understanding the underlying molecular mechanisms

衣原体属物种是专性细胞内细菌病原体。在真核宿主细胞内，它们存在于一个被称为内含物的膜结合区室中。关于这种细菌生态位和细胞隔室（包括高尔基体（GA））之间特定相互作用的分子基础知之甚少。我们最近证明，感染C。沙眼衣原体引起GA的片段化，这伴随着重要的细胞高尔基体基质蛋白（golgin-84）的加工。通过RNA干扰（RNAi）敲低两种GTP酶Rab 6A和Rab 11 A抑制衣原体诱导的和高尔基体蛋白-84依赖的高尔基体片段化，表明Rab蛋白和高尔基体蛋白-84在有助于高尔基体结构的通路中连接。此外，我们发表的数据支持这一假设，高尔基体片段化是必不可少的细菌脂质收购和衣原体生长。我们将通过共聚焦活细胞显微镜研究光活化Rab 6A，Rab 11 A和golgin-84融合蛋白的运输，以了解这些蛋白在感染细胞和对照细胞中的动态。Rab和golgin-84相互作用的合作伙伴（已知的和新的）通过生化手段和RNAi的表征将被用来阐明这些因素在衣原体诱导的高尔基体片段化，细菌脂质收购和发展的作用。该研究的目的是了解Rab蛋白和golgins在感染细胞中引起高尔基体片段化以确保衣原体脂质获得和生长的过程的分子基础。

Chlamydia spp. are obligate intracellular bacterial pathogens. Inside the eukaryotic host cell they are found in a membrane-bound compartment called the inclusion. Little is known about the molecular basis for specific interactions between this bacterial niche and cellular compartments, including the Golgi apparatus (GA). We have recently demonstrated that infection with C. trachomatis causes fragmentation of the GA, which is accompanied by processing of an important cellular Golgi matrix protein, golgin-84. Knockdown of the two GTPases, Rab6A and Rab11A, by RNA interference (RNAi) inhibited Chlamydia-induced and golgin-84-dependent Golgi fragmentation indicating that Rab proteins and golgin-84 are linked in a pathway that contributes to Golgi structure. Furthermore, our published data support the hypothesis that Golgi fragmentation is essential for bacterial lipid acquisition and Chlamydia growth. We will study trafficking of photoactivatable Rab6A, Rab11A and golgin-84 fusion proteins by confocal live cell microscopy to understand the dynamics of these proteins in infected and control cells. Characterization of Rab and golgin-84 interaction partners (known and novel) by biochemical means and RNAi will be used to elucidate the role of these factors in Chlamydia-induced Golgi fragmentation, bacterial lipid acquisition and development. The aim of the study is to understand the molecular basis of the processes by which Rab proteins and golgins cause Golgi fragmentation in infected cells to ensure Chlamydia lipid acquisition and growth.