Metabolomics
·
2022
·Vol. 18
·期 11
·1-14
·
IF 4.747
Li Yongyu,Tian Sicheng,Yang Le,Bao Xiaoming,Su Lin,Zhang Xiang,Liu Sijing,Zhu Yalan,Yang Jiaxue,Lin Hua,Zhang Jing,Zeng Jumei,Wang Chuan,Tang Tian
Introduction Previous reports revealed the role played by Salmonella PhoP–PhoQ system in virulence activation, antimicrobial tolerance and intracellular survival, the impact of PhoP–PhoQ on cell metabolism has been less extensively described. Objectives The aim of this study is to address whether and how the PhoP–PhoQ system affects the cell metabolism of Salmonella. Methods We constructed a Salmonella phoP deletion mutant strain TT-81 (PhoP-OFF), a Salmonella PhoP constitutively expressed strain TT-82 (PhoP-ON) and a wild-type Salmonella PhoP strain TT-80 (PhoP-N), using P22-mediated generalized transduction or λ Red-mediated targeted mutagenesis. We then measured the in vitro growth kinetics of all test strains and determined their metabolomic and transcriptomic profiles using gas chromatography coupled with tandem mass spectrometry (GC–MS/MS) and RNA-seq technique, respectively. Results Low-Mg 2+ conditions impaired the growth of the phoP deletion mutant strain TT-81 (PhoP-OFF) dramatically. 42 metabolites in the wild-type PhoP strain TT-80 (PhoP-N) and 28 metabolites in the PhoP constitutively expressed strain TT-82 (PhoP-ON) changed by the absence of phoP . In contrast, the level of 19 compounds in TT-80 (PhoP-N) changed comparing to the PhoP constitutively expressed strain TT-82 (PhoP-N). The mRNA level of 95 genes in TT-80 (PhoP-N) changed when phoP was disrupted, wherein 78 genes downregulated and 17 genes upregulated. 106 genes were determined to be differentially expressed between TT-81 (PhoP-OFF) and TT-82 (PhoP-ON). While only 16 genes were found to differentially expressed between TT-82 (PhoP-ON) and TT-80 (PhoP-N). Conclusion Our findings confirmed the impact of PhoP–PhoQ system on lipopolysaccharide (LPS) modification, energy metabolism, and the biosynthesis or transport of amino acids. Most importantly, we demonstrated that the turnover of a given metabolite could respond differentially to the level of phoP . Taken together, the present study provided new insights into the adaptation of Salmonella to the host environment and helped to characterize the impact of the PhoP–PhoQ system on the cell metabolism.
研究领域:
微生物学
·
分子生物学
·
系统生物学
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DOI
PubMed
高影响因子
FISH & SHELLFISH IMMUNOLOGY
·
2025
·
IF 3.9
Meiqin Mao,Zhixia Zhuang,Xiaoru Wang,Huabin Huang,Jiaonan Zhang,Jiaolin Zhang,Qingpi Yan
Pseudomonas plecoglossicida is a significant pathogen in aquaculture, capable of infecting various teleost fish and causing visceral white spot disease, which leads to substantial economic losses. The PhoP/PhoQ two-component system plays a central role in virulence regulation in Gram-negative bacteria; however, its specific function in P. plecoglossicida remains unclear. To elucidate the role of the phoP gene in the pathogenicity of this bacterium, we used hybrid grouper ( Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) as an infection model to compare the pathogenicity and host immune responses among the wild-type (NZBD9), phoP deletion (Δ phoP ), and complemented (C-Δ phoP ) strains. In artificial infection experiments, the Δ phoP strain exhibited significantly attenuated virulence, with an LD 50 value of 4.082 × 10 4 , which was 13.7 times higher than that of the wild-type strain. Furthermore, the deletion of phoP reduced bacterial load in the spleen and alleviated histopathological damage in the spleen, head kidney, and intestine. RNA-seq analysis of spleen tissue at 4 days post-infection identified 1768 differentially expressed genes (DEGs), including 704 up-regulated and 1064 down-regulated genes. GO and KEGG enrichment analyses revealed that these DEGs were primarily involved in immune-related processes and pathways, including TLR signaling, NF-κB activation, PI3K-Akt signaling, cytokine-cytokine receptor interaction, and cell adhesion molecules. Temporal expression profiling via qRT-PCR demonstrated that key immune genes (including tlr1, tlr5 , tlr13 , traf5 , nf-κb , mcp1 , cd3 , and il10 ) were generally down-regulated or exhibited delayed and weakened activation in Δ phoP -infected fish, indicating a subdued and dysregulated immune response. These results suggest that the phoP gene is essential for maintaining full virulence in P. plecoglossicida , modulating host immunity by suppressing critical inflammatory and immune signaling pathways. Our study provides novel insights into the role of the PhoP/PhoQ system in host–pathogen interactions and lays a theoretical foundation for developing targeted control strategies against P. plecoglossicida infection in aquaculture.
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Jingyu Zhao,Huanhuan Sun,Gege Wang,Qi Wang,Yipeng Wang,Qingbin Li,Shuangyu Bi,Qingsheng Qi,Qian Wang
Two-component systems (TCSs) sensing and responding to various stimuli outside and inside cells are valuable resources for developing biosensors with synthetic biology applications. However, the use of TCS-based biosensors suffers from a limited effector spectrum, hypersensitivity, low dynamic range, and unwanted signal crosstalk. Here, we developed a tailor-made Escherichia coli whole-cell γ-aminobutyric acid (GABA) biosensor by engineering a chimeric GABA chemoreceptor PctC and TCS. By testing different TCSs, the chimeric PctC/PhoQ showed the response to GABA. Chimera-directed evolution and introduction of the insulated chimeric pair PctC/PhoQ*PhoP* produced biosensors with up to 3.50-fold dynamic range and good orthogonality. To further enhance the dynamic range and lower the basal leakage, three strategies, engineering of PhoP DNA binding sites, fine-tuning reporter expression by optimizing transcription/translation components, and a tobacco etch virus protease-controlled protein degradation, were integrated. This chimeric biosensor displayed a low basal leakage, a large dynamic range (15.8-fold), and a high threshold level (22.7 g L–1). Finally, the optimized biosensor was successfully applied in the high-throughput microdroplet screening of GABA-overproducing Corynebacterium glutamicum, demonstrating its desired properties for extracellular signal biosensing.
研究领域:
合成生物学
·
生物技术
·
分子生物学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
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