Global gene expression profile of Orientia tsutsugamushi.
Orientia tsutsugamushi, an obligate intracellular bacterium, is the causative agent of Scrub typhus. The control mechanisms for bacterial gene expression are largely unknown. Here, the global gene expression of O. tsutsugamushi within eukaryotic cells was examined using a microarray and proteomic approaches for the first time. These approaches identified 643 genes, corresponding to approximately 30% of the genes encoded in the genome. The majority of expressed genes belonged to several functional categories including protein translation, protein processing/secretion, and replication/repair. We also searched the conserved sequence blocks (CSBs) in the O. tsutsugamushi genome which is unique in that up to 40% of its genome consists of dispersed repeated sequences. Although extensive shuffling of genomic sequences was observed between two different strains, 204 CSBs, covering 48% of the genome, were identified. When combining the data of CSBs and global gene expression, the CSBs correlates well with the location of expressed genes, suggesting the functional conservation between gene expression and genomic location. Finally, we compared the gene expression of the bacteria-infected fibroblasts and macrophages using microarray analysis. Some major changes were the downregulation of genes involved in translation, protein processing and secretion, which correlated with the reduction in bacterial translation rates and growth within macrophages.
Cho
Bon-A
BA
Department of Microbiology and Immunology, College of Medicine and Institute of Endemic Diseases, Seoul National University Medical Research Center, Seoul, Korea.
Cho
Nam-Hyuk
NH
Min
Chan-Ki
CK
Kim
Se-Yoon
SY
Yang
Jae-Seong
JS
Lee
Jung Rok
JR
Jung
Jin Woo
JW
Lee
Won-Chul
WC
Kim
Kijeong
K
Lee
Mi-Kyung
MK
Kim
Sanguk
S
Kim
Kwang Pyo
KP
Seong
Seung-Yong
SY
Choi
Myung-Sik
MS
Kim
Ik-Sang
IS
D000818:Animals; D002460:Cell Line; D017124:Conserved Sequence; D005347:Fibroblasts / Q000737:chemistry / Q000378:metabolism; D020869:Gene Expression Profiling; D016680:Genome, Bacterial; D008264:Macrophages / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D012285:Orientia tsutsugamushi / Q000235:genetics*; D020543:Proteome; D012333:RNA, Messenger / Q000235:genetics
D020543:Proteome; D012333:RNA, Messenger