title: RNA-seq reveals the critical role of OtpR in regulating Brucella melitensis metabolism and virulence under acidic stress.
abstract: The response regulator OtpR is critical for the growth, morphology and virulence of Brucella melitensis. Compared to its wild type strain 16 M, B. melitensis 16 MΔotpR mutant has decreased tolerance to acid stress. To analyze the genes regulated by OtpR under acid stress, we performed RNA-seq whole transcriptome analysis of 16 MΔotpR and 16 M. In total, 501 differentially expressed genes were identified, including 390 down-regulated and 111 up-regulated genes. Among these genes, 209 were associated with bacterial metabolism, including 54 genes involving carbohydrate metabolism, 13 genes associated with nitrogen metabolism, and seven genes associated with iron metabolism. The 16 MΔotpR also decreased capacity to utilize different carbon sources and to tolerate iron limitation in culture experiments. Notably, OtpR regulated many Brucella virulence factors essential for B. melitensis intracellular survival. For instance, the virB operon encoding type IV secretion system was significantly down-regulated, and 36 known transcriptional regulators (e.g., vjbR and blxR) were differentially expressed in 16 MΔotpR. Selected RNA-seq results were experimentally confirmed by RT-PCR and RT-qPCR. Overall, these results deciphered differential phenomena associated with virulence, environmental stresses and cell morphology in 16 MΔotpR and 16 M, which provided important information for understanding the detailed OtpR-regulated interaction networks and Brucella pathogenesis.
authors.affiliation: 1] Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China [2] Unit for Laboratory Animal Medicine and Department of Microbiology and Immunology, The University of Michigan Medical School, Ann Arbor, MI 48109 [3] Center for Computational Medicine and Bioinformatics, The University of Michigan Medical School, Ann Arbor, MI 48109 [4] Beijing Senkang Biotech Development Co., LTD, Beijing 101400, People's Republic of China.
authors.forename: Wenxiao
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Zoonosis Control, China Animal Disease Control Center, Beijing, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Dong
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
authors.forename: Qixing
authors.initials: Q
authors.lastname: Ou
authors.affiliation: Department of Veterinary Medicine, Zhengzhou College of Animal Husbandry Engineering, Zhengzhou 450046, People's Republic of China.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Lv
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Wang
authors.affiliation: Center for Computational Medicine and Bioinformatics, The University of Michigan Medical School, Ann Arbor, MI 48109.
authors.forename: Zuoshuang
authors.initials: Z
authors.lastname: Xiang
authors.affiliation: 1] Unit for Laboratory Animal Medicine and Department of Microbiology and Immunology, The University of Michigan Medical School, Ann Arbor, MI 48109 [2] Center for Computational Medicine and Bioinformatics, The University of Michigan Medical School, Ann Arbor, MI 48109.
authors.forename: Yongqun
authors.initials: Y
authors.lastname: He
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
authors.forename: Qingmin
authors.initials: Q
authors.lastname: Wu
mesh_terms: D000143:Acids / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D017347:Brucella melitensis / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D015536:Down-Regulation / Q000187:drug effects; D004734:Energy Metabolism; D012329:RNA, Bacterial / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA; D059467:Transcriptome / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000143:Acids; D001426:Bacterial Proteins; D012329:RNA, Bacterial; D037521:Virulence Factors