Chlamydia pneumoniae is a Gram-negative, obligate intracellular pathogen that causes community-acquired respiratory infections. After C. pneumoniae invades host cells, it disturbs the vesicle transport system to escape host lysosomal or autophagosomal degradation. By using a yeast mis-sorting assay, we found 10 C. pneumoniae candidate genes involved in aberrant vesicular trafficking in host cells. One of the candidate genes, CPj0783, was recognized by antibodies from C. pneumoniae-infected patients. The expression of CPj0783 was detected at mid to late-cycle time points and increased during the inclusion maturation. Two-hybrid screening in yeast cells revealed that CPj0783 interacted with Huntingtin-interacting protein 14 (HIP14). The specific interaction between CPj0783 and HIP14 could be demonstrated by an in vivo co-immunoprecipitation assay and an in vitro GST pull-down assay. It was also demonstrated that HIP14 was localized in the Golgi apparatus and colocalized with CPj0783. HIP14 has a palmitoyl transferase activity that is involved in the palmitoylation-dependent vesicular trafficking of several acylated proteins. These findings suggest that CPj0783 might cause abnormal vesicle-mediated transport by interacting with HIP14. [Int Microbiol 18(4):225-233 (2015)]

Keywords: Chlamydia pneumoniae · intracellular pathogens · yeast two-hybrid screening CPj0783–HIP14 · protein mis-sorting · vesicle transport