| Title | Inhibition of eukaryotic translation by tetratricopeptide-repeat proteins of Orientia tsutsugamushi |
|---|---|
| Author | Sunyoung Bang1, Chan-Ki Min1,2, Na-Young Ha1,2, Myung-Sik Choi1, Ik-Sang Kim1, Yeon-Sook Kim3*, and Nam-Hyuk Cho1,2,4* |
| Address | 1Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea, 2Department of Biomedical Science, Seoul National University College of Medicine, Seoul 03080, Republic of Korea, 3Divisions of Infectious Diseases, Chungnam National University Hospital, Daejeon 35015, Republic of Korea, 4Institute of Endemic Disease, Seoul National University Medical Research Center and Bundang Hospital, Seoul 35015, Republic of Korea |
| Bibliography | Journal of Microbiology, 54(2),136-144, 2016, |
| DOI | 10.1007/s12275-016-5599-5 |
| Key Words | Orientia tsutsugamushi, tetratricopeptide proteins, DDX3, translation |
| Abstract | Orientia tsutsugamushi, an obligate intracellular bacterium, is the causative agent of scrub typhus. The genome of Orientia tsutsugamushi has revealed multiple ORFs encoding tetratricopeptide- repeat (TPR) proteins. The TPR protein family has been shown to be involved in a diverse spectrum of cellular functions such as cell cycle control, transcription, protein transport, and protein folding, especially in eukaryotic cells. However, little is known about the function of the TPR proteins in O. tsutsugamushi. To investigate the potential role of TPR proteins in host-pathogen interaction, two oriential TPR proteins were expressed in E. coli and applied for GSTpull down assay. DDX3, a DEAD-box containing RNA helicase, was identified as a specific eukaryotic target of the TPR proteins. Since the RNA helicase is involved in multiple RNAmodifying processes such as initiation of translation reaction, we performed in vitro translation assay in the presence of GST-TPR fusion proteins by using rabbit reticulocyte lysate system. The TPR proteins inhibited in vitro translation of a reporter luciferase in a dose dependent manner whereas the GST control proteins did not. These results suggested TPR proteins of O. tsutsugamushi might be involved in the modulation of eukarytotic translation through the interaction with DDX3 RNA helicase after secretion into host cytoplasm. |