@article{mbs:/content/journal/micro/10.1099/13500872-141-2-363, author = "Redd, Thomasina and Thompson, Herbert A.", title = "Secretion of proteins by Coxiella burnetii", journal= "Microbiology", year = "1995", volume = "141", number = "2", pages = "363-369", doi = "https://doi.org/10.1099/13500872-141-2-363", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/13500872-141-2-363", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "protein secretion", keywords = "intracellular bacteria", keywords = "Coxiella burnetii", abstract = "SUMMARY: ViableCoxiella burnetii organismswere isolated from the culture medium of persistently infected Baby Hamster Kidney (BHK-21) fibroblasts. When these organisms were incubated in host-cell-free medium at low pH, some of the de novo-synthesized protein made by the bacteria was translocated to the exterior of the cell. The exported protein was detectable after 2-7 h incubation at 37°C. No evidence was found to suggest that protein accumulation in the medium was due to leakiness caused by cell damage. Both DCCD (dicyclohexylcarbodiimide) and CCCP (carbonyl cyanide m-chlorophenylhydrazone) inhibited the process to some extent. Exported protein was represented largely by three polypeptides with molecular masses of 34, 24 and 12 kDa. De novo-synthesized proteins corresponding to these molecular masses were not detected in cytoplasmic fractions, but a membrane fraction might possess a similar form. It was concluded that a physiological process of protein translocation occurred in C. burnetii during acid activation in a defined medium. Organisms that were extracted directly from the cytoplasm of infected fibroblasts by a mechanical disruption procedure were also active in de novo protein synthesis; however they exported much less of the protein.", }