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Shi Y, Li X, Xue Y, Hu D, Song X. Cell cycle-regulated transcription factor AP2XII-9 is a key activator for asexual division and apicoplast inheritance in Toxoplasma gondii tachyzoite. mBio 2024:e0133624. [PMID: 39207100 DOI: 10.1128/mbio.01336-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 08/14/2024] [Indexed: 09/04/2024] Open
Abstract
Toxoplasma gondii is an intracellular parasitic protozoan that poses a significant risk to the fetus carried by a pregnant woman or to immunocompromised individuals. T. gondii tachyzoites duplicate rapidly in host cells during acute infection through endodyogeny. This highly regulated division process is accompanied by complex gene regulation networks. TgAP2XII-9 is a cell cycle-regulated transcription factor, but its specific role in the parasite cell cycle is not fully understood. In this study, we demonstrate that TgAP2XII-9 is identified as a nuclear transcription factor and is dominantly expressed during the S/M phase of the tachyzoite cell cycle. Cleavage Under Targets and Tagmentation (CUT&Tag) results indicate that TgAP2XII-9 targets key genes for the moving junction machinery (RON2, 4, and 8) and daughter cell inner membrane complex (IMC). TgAP2XII-9 deficiency resulted in a significant downregulation of rhoptry proteins and rhoptry neck proteins, leading to a severe defect in the invasion and egress efficiency of tachyzoites. Additionally, the loss of TgAP2XII-9 correlated with a substantial downregulation of multiple IMC and apicoplast proteins, leading to disorders of daughter bud formation and apicoplast inheritance and further contributing to the inability of cell division and intracellular proliferation. Our study reveals that TgAP2XII-9 acts as a critical S/M-phase regulator that orchestrates the endodyogeny and apicoplast division in T. gondii tachyzoites. This study contributes to a broader understanding of the complexity of the parasite's cell cycle and its key regulators. IMPORTANCE The intracellular apicoplast parasite Toxoplasma gondii poses a great threat to the public health. The acute infection of T. gondii tachyzoites relies on efficient invasion by forming a moving junction structure and also fast replication by highly regulated endodyogeny. This study shows that an ApiAP2 transcription factor, TgAP2XII-9, acts as an activator for the S/M-phase gene expression, including genes related to daughter buds and moving junction formation. Loss of TgAP2XII-9 results in significant growth defects and disorders in endodyogeny and apicoplast inheritance of the parasites. Our results provide valuable insights into the transcriptional regulation of the parasite cell cycle and invading machinery in T. gondii.
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Affiliation(s)
- Yuehong Shi
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Xuan Li
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Yingying Xue
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Dandan Hu
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, China
| | - Xingju Song
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, China
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Li TT, Zhao DY, Liang QL, Elsheikha HM, Wang M, Sun LX, Zhang ZW, Chen XQ, Zhu XQ, Wang JL. The antioxidant protein glutaredoxin 1 is essential for oxidative stress response and pathogenicity of Toxoplasma gondii. FASEB J 2023; 37:e22932. [PMID: 37115746 DOI: 10.1096/fj.202201275r] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 03/22/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023]
Abstract
Glutaredoxins (Grxs) are ubiquitous antioxidant proteins involved in many molecular processes to protect cells against oxidative damage. Here, we study the roles of Grxs in the pathogenicity of Toxoplasma gondii. We show that Grxs are localized in the mitochondria (Grx1), cytoplasm (Grx2), and apicoplast (Grx3, Grx4), while Grx5 had an undetectable level of expression. We generated Δgrx1-5 mutants of T. gondii type I RH and type II Pru strains using CRISPR-Cas9 system. No significant differences in the infectivity were detected between four Δgrx (grx2-grx5) strains and their respective wild-type (WT) strains in vitro or in vivo. Additionally, no differences were detected in the production of reactive oxygen species, total antioxidant capacity, superoxide dismutase activity, and sensitivity to external oxidative stimuli. Interestingly, RHΔgrx1 or PruΔgrx1 exhibited significant differences in all the investigated aspects compared to the other grx2-grx5 mutant and WT strains. Transcriptome analysis suggests that deletion of grx1 altered the expression of genes involved in transport and metabolic pathways, signal transduction, translation, and obsolete oxidation-reduction process. The data support the conclusion that grx1 supports T. gondii resistance to oxidative killing and is essential for the parasite growth in cultured cells and pathogenicity in mice and that the active site CGFS motif was necessary for Grx1 activity.
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Affiliation(s)
- Ting-Ting Li
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Gansu Province, Lanzhou, People's Republic of China
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Sichuan Province, Chengdu, People's Republic of China
| | - Dan-Yu Zhao
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Gansu Province, Lanzhou, People's Republic of China
| | - Qin-Li Liang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Gansu Province, Lanzhou, People's Republic of China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Loughborough, UK
| | - Meng Wang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Gansu Province, Lanzhou, People's Republic of China
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Sichuan Province, Chengdu, People's Republic of China
| | - Li-Xiu Sun
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Gansu Province, Lanzhou, People's Republic of China
| | - Zhi-Wei Zhang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Gansu Province, Lanzhou, People's Republic of China
| | - Xiao-Qing Chen
- Jiangxi Provincial Key Laboratory for Animal Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi Province, People's Republic of China
| | - Xing-Quan Zhu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi Province, People's Republic of China
- Key Laboratory of Veterinary Public Health of Yunnan Province, College of Veterinary Medicine, Yunnan Agricultural University, Kunming, Yunnan Province, People's Republic of China
| | - Jin-Lei Wang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Gansu Province, Lanzhou, People's Republic of China
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Sichuan Province, Chengdu, People's Republic of China
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Regulation of Mitochondrial Energy Metabolism by Glutaredoxin 5 in the Apicomplexan Parasite Neospora caninum. Microbiol Spectr 2023; 11:e0309122. [PMID: 36541793 PMCID: PMC9927405 DOI: 10.1128/spectrum.03091-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Iron-sulfur [Fe-S] clusters are one of the most ancient and functionally versatile natural biosynthetic prosthetic groups required by various proteins involved in important metabolic processes, including the oxidative phosphorylation of proteins, electron transfer, energy metabolism, DNA/RNA metabolism, and protein translation. Apicomplexan parasites harbor two possible [Fe-S] cluster assembly pathways: the iron-sulfur cluster (ISC) pathway in the mitochondria and the sulfur formation (SUF) pathway in the apicoplast. Glutaredoxin 5 (GRX5) is involved in the ISC pathway in many eukaryotes. However, the cellular roles of GRX5 in apicomplexan parasites remain to be explored. Here, we showed that Neospora caninum mitochondrial GRX5 (NcGRX5) deficiency resulted in aberrant mitochondrial ultrastructure and led to a significant reduction in parasite proliferation and virulence in mice, suggesting that NcGRX5 is important for parasite growth in vitro and in vivo. Comparative proteomics and energy metabolomics were used to investigate the effects of NcGRX5 on parasite growth and mitochondrial metabolism. The data showed that disruption of NcGRX5 downregulated the expression of mitochondrial electron transport chain (ETC) and tricarboxylic acid cycle (TCA) cycle proteins and reduced the corresponding metabolic fluxes. Subsequently, we identified 23 proteins that might be adjacent to or interact with NcGRX5 by proximity-based protein labeling techniques and proteomics. The interactions between NcGRX5 and two iron-sulfur cluster synthesis proteins (ISCS and ISCU1) were further confirmed by coimmunoprecipitation assays. In conclusion, NcGRX5 is important for parasite growth and may regulate mitochondrial energy metabolism by mediating the biosynthesis of iron-sulfur clusters. IMPORTANCE Iron-sulfur [Fe-S] clusters are among the oldest and most ubiquitous prosthetic groups, and they are required for a variety of proteins involved in important metabolic processes. The intracellular parasites in the phylum Apicomplexa, including Plasmodium, Toxoplasma gondii, and Neospora caninum, harbor the ISC pathway involved in the biosynthesis of [Fe-S] clusters in mitochondria. These cofactors are required for a variety of important biological processes. However, little is known about the role of oxidoreductase glutaredoxins in these parasites. Our data indicate that NcGRX5 is an essential protein that plays multiple roles in several biological processes of N. caninum. NcGRX5 interacts with the mitochondrial iron-sulfur cluster synthesis proteins ISCS and ISCU1 and also regulates parasite energy metabolism. These data provide an insider's view of the metabolic regulation and iron-sulfur cluster assembly processes in the apicomplexan parasites.
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Deleting ku80 improves the efficiency of targeted gene editing in Neospora caninum. Mol Biochem Parasitol 2022; 251:111508. [PMID: 35963548 DOI: 10.1016/j.molbiopara.2022.111508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 07/16/2022] [Accepted: 08/01/2022] [Indexed: 11/24/2022]
Abstract
CRISPR/Cas9 technology has been widely used for gene editing in organisms. Gene deletion of the ku80/ku70 complex can improve the efficiency of gene replacement in Arabidopsis thaliana, Cryptococcus neoformans, and Toxoplasma gondii, which remained elusive in Neospora caninum. Here, we knock out the ku80 gene in Nc1 strain by using CRISPR/Cas9, detect the growth rate and virulence of NcΔku80. Then we compare the efficiency of gene replacements between NcΔku80 and Nc1 strains by transfected with the same HA-tagged plasmids, and the percentage of HA-tagged parasites was investigated by IFA. The results showed that gene targeting efficiency was increased in the NcΔku80 strain via double crossover at several genetic loci, but its growth rate and virulence were unaffected. In conclusion, the NcΔku80 strain can be used as an effective strain for rapid gene editing of N. caninum.
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