1
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Reglero-Real N, Pérez-Gutiérrez L, Saleeb RS, Nourshargh S, Collinson L, Yoshimura A. Protocol for volume correlative light X-ray and electron microscopy of endothelial cells in mouse tissue. STAR Protoc 2024; 5:103257. [PMID: 39226173 PMCID: PMC11419916 DOI: 10.1016/j.xpro.2024.103257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 06/20/2024] [Accepted: 07/23/2024] [Indexed: 09/05/2024] Open
Abstract
Correlative light and electron microscopy (CLEM) greatly facilitate capturing the ultrastructure of spatially and/or temporally rare events. Here, we present a protocol for targeting regions of interests (ROIs) in tissue endothelial cells (ECs) using X-ray micro-computed tomography (μCT). We describe steps for ROI targeting guided by vasculature patterns and positions of EC nuclei visualized by light and X-ray microscopy. The protocol is applicable to thin or translucent tissues that contain defined landmarks visible in both light and X-ray microscopy. For complete details on the use and execution of this protocol, please refer to Reglero-Real et al.1.
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Affiliation(s)
- Natalia Reglero-Real
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK; Departamento e Instituto de Biología Molecular (IUBM, UAM), Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain.
| | - Lorena Pérez-Gutiérrez
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK; Cancer Immunology and Immunotherapy Lab, Center for Cooperative Research in Biosciences (CIC BioGUNE), Basque Research and Technology Alliance (BRTA), Derio, 48160 Bizkaia, Spain
| | - Rebeca S Saleeb
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK; Institute of Regeneration and Repair, University of Edinburgh, EH16 4UU Edinburgh, UK
| | - Sussan Nourshargh
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, EC1M 6BQ London, UK
| | - Lucy Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, NW1 1AT London, UK.
| | - Azumi Yoshimura
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, NW1 1AT London, UK; Graduate School of Medicine, Yamaguchi University, Ube 755-8505, Japan.
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2
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Marq JB, Gosetto M, Altenried A, Vadas O, Maco B, Dos Santos Pacheco N, Tosetti N, Soldati-Favre D, Lentini G. Cytokinetic abscission in Toxoplasma gondii is governed by protein phosphatase 2A and the daughter cell scaffold complex. EMBO J 2024; 43:3752-3786. [PMID: 39009675 PMCID: PMC11377541 DOI: 10.1038/s44318-024-00171-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 06/21/2024] [Accepted: 06/30/2024] [Indexed: 07/17/2024] Open
Abstract
Cytokinetic abscission marks the final stage of cell division, during which the daughter cells physically separate through the generation of new barriers, such as the plasma membrane or cell wall. While the contractile ring plays a central role during cytokinesis in bacteria, fungi and animal cells, the process diverges in Apicomplexa. In Toxoplasma gondii, two daughter cells are formed within the mother cell by endodyogeny. The mechanism by which the progeny cells acquire their plasma membrane during the disassembly of the mother cell, allowing daughter cells to emerge, remains unknown. Here we identify and characterize five T. gondii proteins, including three protein phosphatase 2A subunits, which exhibit a distinct and dynamic localization pattern during parasite division. Individual downregulation of these proteins prevents the accumulation of plasma membrane at the division plane, preventing the completion of cellular abscission. Remarkably, the absence of cytokinetic abscission does not hinder the completion of subsequent division cycles. The resulting progeny are able to egress from the infected cells but fail to glide and invade, except in cases of conjoined twin parasites.
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Affiliation(s)
- Jean-Baptiste Marq
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Margaux Gosetto
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Aline Altenried
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Oscar Vadas
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Bohumil Maco
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | | | - Nicolò Tosetti
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland.
| | - Gaëlle Lentini
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland.
- Institute of Cell Biology, University of Bern, Bern, Switzerland.
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3
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Huang Y, Li J, Pei S, You H, Liu H, Guo Y, Xu R, Li N, Feng Y, Xiao L. Optimization of a DiCre recombinase system with reduced leakage for conditional genome editing of Cryptosporidium. Parasit Vectors 2024; 17:352. [PMID: 39169430 PMCID: PMC11337648 DOI: 10.1186/s13071-024-06431-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2024] [Accepted: 08/02/2024] [Indexed: 08/23/2024] Open
Abstract
BACKGROUND The dimerizable Cre recombinase system (DiCre) exhibits increased leaky activity in Cryptosporidium, leading to unintended gene editing in the absence of induction. Therefore, optimization of the current DiCre technique is necessary for functional studies of essential Cryptosporidium genes. METHODS Based on the results of transcriptomic analysis of Cryptosporidium parvum stages, seven promoters with different transcriptional capabilities were screened to drive the expression of Cre fragments (FKBP-Cre59 and FRB-Cre60). Transient transfection was performed to assess the effect of promoter strength on leakage activity. In vitro and in vivo experiments were performed to evaluate the leaky activity and cleavage efficiency of the optimized DiCre system by polymerase chain reaction (PCR), nanoluciferase, and fluorescence analyses. RESULTS The use of promoters with lower transcriptional activity, such as pcgd6_4110 and pcgd3_260, as opposed to strong promoters such as pActin, pα-Tubulin, and pEnolase, reduced the leakage rate of the system from 35-75% to nearly undetectable levels, as verified by transient transfection. Subsequent in vitro and in vivo experiments using stable lines further demonstrated that the optimized DiCre system had no detectable leaky activity. The system achieved 71% cleavage efficiency in vitro. In mice, a single dose of the inducer resulted in a 10% conditional gene knockout and fluorescent protein expression in oocysts. These fluorescently tagged transgenic oocysts could be enriched by flow sorting for further infection studies. CONCLUSIONS A DiCre conditional gene knockout system for Cryptosporidium with good cleavage efficiency and reduced leaky activity has been successfully established.
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Affiliation(s)
- Yue Huang
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, 510642, China
| | - Jinli Li
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, 510642, China
| | - Shifeng Pei
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, 510642, China
| | - Heng You
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, 510642, China
| | - Huimin Liu
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, 510642, China
| | - Yaqiong Guo
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, 510642, China
| | - Rui Xu
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, 510642, China
| | - Na Li
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, 510642, China
| | - Yaoyu Feng
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, 510642, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China.
| | - Lihua Xiao
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, 510642, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China.
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4
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Ben Chaabene R, Martinez M, Bonavoglia A, Maco B, Chang YW, Lentini G, Soldati-Favre D. Toxoplasma gondii rhoptry discharge factor 3 is essential for invasion and microtubule-associated vesicle biogenesis. PLoS Biol 2024; 22:e3002745. [PMID: 39137211 PMCID: PMC11343613 DOI: 10.1371/journal.pbio.3002745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 08/23/2024] [Accepted: 07/10/2024] [Indexed: 08/15/2024] Open
Abstract
Rhoptries are specialized secretory organelles conserved across the Apicomplexa phylum, essential for host cell invasion and critical for subverting of host cellular and immune functions. They contain proteins and membranous materials injected directly into the host cells, participating in parasitophorous vacuole formation. Toxoplasma gondii tachyzoites harbor 8 to 12 rhoptries, 2 of which are docked to an apical vesicle (AV), a central element associated with a rhoptry secretory apparatus prior to injection into the host cell. This parasite is also equipped with 5 to 6 microtubule-associated vesicles, presumably serving as AV replenishment for iterative rhoptry discharge. Here, we characterized a rhoptry protein, rhoptry discharge factor 3 (RDF3), crucial for rhoptry discharge and invasion. RDF3 enters the secretory pathway, localizing near the AV and associated with the rhoptry bulb. Upon invasion, RDF3 dynamically delocalizes, suggesting a critical role at the time of rhoptry discharge. Cryo-electron tomography analysis of RDF3-depleted parasites reveals irregularity in microtubule-associated vesicles morphology, presumably impacting on their preparedness to function as an AV. Our findings suggest that RDF3 is priming the microtubule-associated vesicles for rhoptry discharge by a mechanism distinct from the rhoptry secretory apparatus contribution.
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Affiliation(s)
- Rouaa Ben Chaabene
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Matthew Martinez
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Alessandro Bonavoglia
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Bohumil Maco
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Yi-Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Gaëlle Lentini
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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5
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Guo X, Ji N, Guo Q, Wang M, Du H, Pan J, Xiao L, Gupta N, Feng Y, Xia N. Metabolic plasticity, essentiality and therapeutic potential of ribose-5-phosphate synthesis in Toxoplasma gondii. Nat Commun 2024; 15:2999. [PMID: 38589375 PMCID: PMC11001932 DOI: 10.1038/s41467-024-47097-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 03/11/2024] [Indexed: 04/10/2024] Open
Abstract
Ribose-5-phosphate (R5P) is a precursor for nucleic acid biogenesis; however, the importance and homeostasis of R5P in the intracellular parasite Toxoplasma gondii remain enigmatic. Here, we show that the cytoplasmic sedoheptulose-1,7-bisphosphatase (SBPase) is dispensable. Still, its co-deletion with transaldolase (TAL) impairs the double mutant's growth and increases 13C-glucose-derived flux into pentose sugars via the transketolase (TKT) enzyme. Deletion of the latter protein affects the parasite's fitness but is not lethal and is correlated with an increased carbon flux via the oxidative pentose phosphate pathway. Further, loss of TKT leads to a decline in 13C incorporation into glycolysis and the TCA cycle, resulting in a decrease in ATP levels and the inability of phosphoribosyl-pyrophosphate synthetase (PRPS) to convert R5P into 5'-phosphoribosyl-pyrophosphate and thereby contribute to the production of AMP and IMP. Likewise, PRPS is essential for the lytic cycle. Not least, we show that RuPE-mediated metabolic compensation is imperative for the survival of the ΔsbpaseΔtal strain. In conclusion, we demonstrate that multiple routes can flexibly supply R5P to enable parasite growth and identify catalysis by TKT and PRPS as critical enzymatic steps. Our work provides novel biological and therapeutic insights into the network design principles of intracellular parasitism in a clinically-relevant pathogen.
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Affiliation(s)
- Xuefang Guo
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Nuo Ji
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Qinghong Guo
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Mengting Wang
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Huiyu Du
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jiajia Pan
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Lihua Xiao
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Nishith Gupta
- Intracellular Parasite Education and Research Labs (iPEARL), Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS-P), Hyderabad, India.
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany.
| | - Yaoyu Feng
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
| | - Ningbo Xia
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
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6
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Kellermeier JA, Heaslip AT. Myosin F controls actin organization and dynamics in Toxoplasma gondii. Mol Biol Cell 2024; 35:ar57. [PMID: 38416592 PMCID: PMC11064658 DOI: 10.1091/mbc.e23-12-0510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/14/2024] [Accepted: 02/21/2024] [Indexed: 03/01/2024] Open
Abstract
Intracellular cargo transport is a ubiquitous cellular process in all eukaryotes. In many cell types, membrane bound cargo is associated with molecular motors which transport cargo along microtubule and actin tracks. In Toxoplasma gondii (T. gondii), an obligate intracellular parasite in the phylum Apicomplexa, organization of the endomembrane pathway depends on actin and an unconventional myosin motor, myosin F (MyoF). Loss of MyoF and actin disrupts vesicle transport, organelle positioning, and division of the apicoplast, a nonphotosynthetic plastid organelle. How this actomyosin system contributes to these cellular functions is still unclear. Using live-cell imaging, we observed that MyoF-EmeraldFP (MyoF-EmFP) displayed a dynamic and filamentous-like organization in the parasite cytosol, reminiscent of cytosolic actin filament dynamics. MyoF was not associated with the Golgi, apicoplast or dense granule surfaces, suggesting that it does not function using the canonical cargo transport mechanism. Instead, we found that loss of MyoF resulted in a dramatic rearrangement of the actin cytoskeleton in interphase parasites accompanied by significantly reduced actin dynamics. However, actin organization during parasite replication and motility was unaffected by the loss of MyoF. These findings revealed that MyoF is an actin organizing protein in Toxoplasma and facilitates cargo movement using an unconventional transport mechanism.
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Affiliation(s)
- Jacob A. Kellermeier
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269
| | - Aoife T. Heaslip
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269
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7
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Yang X, Yang J, Lyu M, Li Y, Liu A, Shen B. The α subunit of AMP-activated protein kinase is critical for the metabolic success and tachyzoite proliferation of Toxoplasma gondii. Microb Biotechnol 2024; 17:e14455. [PMID: 38635138 PMCID: PMC11025617 DOI: 10.1111/1751-7915.14455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/06/2024] [Accepted: 03/09/2024] [Indexed: 04/19/2024] Open
Abstract
Toxoplasma gondii is a zoonotic parasite infecting humans and nearly all warm-blooded animals. Successful parasitism in diverse hosts at various developmental stages requires the parasites to fine tune their metabolism according to environmental cues and the parasite's needs. By manipulating the β and γ subunits, we have previously shown that AMP-activated protein kinase (AMPK) has critical roles in regulating the metabolic and developmental programmes. However, the biological functions of the α catalytic subunit have not been established. T. gondii encodes a canonical AMPKα, as well as a KIN kinase whose kinase domain has high sequence similarities to those of classic AMPKα proteins. Here, we found that TgKIN is dispensable for tachyzoite growth, whereas TgAMPKα is essential. Depletion of TgAMPKα expression resulted in decreased ATP levels and reduced metabolic flux in glycolysis and the tricarboxylic acid cycle, confirming that TgAMPK is involved in metabolic regulation and energy homeostasis in the parasite. Sequential truncations at the C-terminus found an α-helix that is key for the function of TgAMPKα. The amino acid sequences of this α-helix are not conserved among various AMPKα proteins, likely because it is involved in interactions with TgAMPKβ, which only have limited sequence similarities to AMPKβ in other eukaryotes. The essential role of the less conserved C-terminus of TgAMPKα provides opportunities for parasite specific drug designs targeting TgAMPKα.
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Affiliation(s)
- Xuke Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
- Research Center for Infectious Diseases, Department of Pathogen Biology, School of Basic Medical SciencesAnhui Medical UniversityHefeiChina
| | - Jichao Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
| | - Mengyu Lyu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
| | - Yaqiong Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
| | - Anqi Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
- Hubei Hongshan LaboratoryWuhanHubei ProvinceChina
- Key Laboratory of Preventive Medicine in Hubei ProvinceHuazhong Agricultural UniversityWuhanHubei ProvinceChina
- Shenzhen Institute of Nutrition and HealthHuazhong Agricultural UniversityShenzhenGuangdong ProvinceChina
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8
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Liang QL, Nie LB, Elsheikha HM, Li TT, Sun LX, Zhang ZW, Wang M, Fu BQ, Zhu XQ, Wang JL. The Toxoplasma protein phosphatase 6 catalytic subunit (TgPP6C) is essential for cell cycle progression and virulence. PLoS Pathog 2023; 19:e1011831. [PMID: 38091362 PMCID: PMC10752510 DOI: 10.1371/journal.ppat.1011831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 12/27/2023] [Accepted: 11/16/2023] [Indexed: 12/28/2023] Open
Abstract
Protein phosphatases are post-translational regulators of Toxoplasma gondii proliferation, tachyzoite-bradyzoite differentiation and pathogenesis. Here, we identify the putative protein phosphatase 6 (TgPP6) subunits of T. gondii and elucidate their role in the parasite lytic cycle. The putative catalytic subunit TgPP6C and regulatory subunit TgPP6R likely form a complex whereas the predicted structural subunit TgPP6S, with low homology to the human PP6 structural subunit, does not coassemble with TgPP6C and TgPP6R. Functional studies showed that TgPP6C and TgPP6R are essential for parasite growth and replication. The ablation of TgPP6C significantly reduced the synchronous division of the parasite's daughter cells during endodyogeny, resulting in disordered rosettes. Moreover, the six conserved motifs of TgPP6C were required for efficient endodyogeny. Phosphoproteomic analysis revealed that ablation of TgPP6C predominately altered the phosphorylation status of proteins involved in the regulation of the parasite cell cycle. Deletion of TgPP6C significantly attenuated the parasite virulence in mice. Immunization of mice with TgPP6C-deficient type I RH strain induced protective immunity against challenge with a lethal dose of RH or PYS tachyzoites and Pru cysts. Taken together, the results show that TgPP6C contributes to the cell division, replication and pathogenicity in T. gondii.
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Affiliation(s)
- 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, Lanzhou, China
| | - Lan-Bi Nie
- 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, Lanzhou, China
| | - Hany M. Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Loughborough, United Kingdom
| | - 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, Lanzhou, China
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, 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, Lanzhou, 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, Lanzhou, China
| | - 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, Lanzhou, China
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
| | - Bao-Quan Fu
- 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, Lanzhou, China
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
| | - Xing-Quan Zhu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, 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, Lanzhou, China
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
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9
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Chan AW, Broncel M, Yifrach E, Haseley NR, Chakladar S, Andree E, Herneisen AL, Shortt E, Treeck M, Lourido S. Analysis of CDPK1 targets identifies a trafficking adaptor complex that regulates microneme exocytosis in Toxoplasma. eLife 2023; 12:RP85654. [PMID: 37933960 PMCID: PMC10629828 DOI: 10.7554/elife.85654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023] Open
Abstract
Apicomplexan parasites use Ca2+-regulated exocytosis to secrete essential virulence factors from specialized organelles called micronemes. Ca2+-dependent protein kinases (CDPKs) are required for microneme exocytosis; however, the molecular events that regulate trafficking and fusion of micronemes with the plasma membrane remain unresolved. Here, we combine sub-minute resolution phosphoproteomics and bio-orthogonal labeling of kinase substrates in Toxoplasma gondii to identify 163 proteins phosphorylated in a CDPK1-dependent manner. In addition to known regulators of secretion, we identify uncharacterized targets with predicted functions across signaling, gene expression, trafficking, metabolism, and ion homeostasis. One of the CDPK1 targets is a putative HOOK activating adaptor. In other eukaryotes, HOOK homologs form the FHF complex with FTS and FHIP to activate dynein-mediated trafficking of endosomes along microtubules. We show the FHF complex is partially conserved in T. gondii, consisting of HOOK, an FTS homolog, and two parasite-specific proteins (TGGT1_306920 and TGGT1_316650). CDPK1 kinase activity and HOOK are required for the rapid apical trafficking of micronemes as parasites initiate motility. Moreover, parasites lacking HOOK or FTS display impaired microneme protein secretion, leading to a block in the invasion of host cells. Taken together, our work provides a comprehensive catalog of CDPK1 targets and reveals how vesicular trafficking has been tuned to support a parasitic lifestyle.
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Affiliation(s)
- Alex W Chan
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Malgorzata Broncel
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Eden Yifrach
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | - Nicole R Haseley
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | | | - Elena Andree
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | - Alice L Herneisen
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Emily Shortt
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | - Moritz Treeck
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Sebastian Lourido
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
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10
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O’Shaughnessy WJ, Hu X, Henriquez SA, Reese ML. Toxoplasma ERK7 protects the apical complex from premature degradation. J Cell Biol 2023; 222:e202209098. [PMID: 37027006 PMCID: PMC10083718 DOI: 10.1083/jcb.202209098] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 02/01/2023] [Accepted: 03/17/2023] [Indexed: 04/08/2023] Open
Abstract
Accurate cellular replication balances the biogenesis and turnover of complex structures. In the apicomplexan parasite Toxoplasma gondii, daughter cells form within an intact mother cell, creating additional challenges to ensuring fidelity of division. The apical complex is critical to parasite infectivity and consists of apical secretory organelles and specialized cytoskeletal structures. We previously identified the kinase ERK7 as required for maturation of the apical complex in Toxoplasma. Here, we define the Toxoplasma ERK7 interactome, including a putative E3 ligase, CSAR1. Genetic disruption of CSAR1 fully suppresses loss of the apical complex upon ERK7 knockdown. Furthermore, we show that CSAR1 is normally responsible for turnover of maternal cytoskeleton during cytokinesis, and that its aberrant function is driven by mislocalization from the parasite residual body to the apical complex. These data identify a protein homeostasis pathway critical for Toxoplasma replication and fitness and suggest an unappreciated role for the parasite residual body in compartmentalizing processes that threaten the fidelity of parasite development.
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Affiliation(s)
| | - Xiaoyu Hu
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
| | - Sarah Ana Henriquez
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
| | - Michael L. Reese
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
- Department of Biochemistry, University of Texas, Southwestern Medical Center, Dallas, TX, USA
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11
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Butterworth S, Torelli F, Lockyer EJ, Wagener J, Song OR, Broncel M, Russell MRG, Moreira-Souza ACA, Young JC, Treeck M. Toxoplasma gondii virulence factor ROP1 reduces parasite susceptibility to murine and human innate immune restriction. PLoS Pathog 2022; 18:e1011021. [PMID: 36476844 PMCID: PMC9762571 DOI: 10.1371/journal.ppat.1011021] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/19/2022] [Accepted: 11/24/2022] [Indexed: 12/12/2022] Open
Abstract
Toxoplasma gondii is an intracellular parasite that can infect many host species and is a cause of significant human morbidity worldwide. T. gondii secretes a diverse array of effector proteins into the host cell which are critical for infection. The vast majority of these secreted proteins have no predicted functional domains and remain uncharacterised. Here, we carried out a pooled CRISPR knockout screen in the T. gondii Prugniaud strain in vivo to identify secreted proteins that contribute to parasite immune evasion in the host. We demonstrate that ROP1, the first-identified rhoptry protein of T. gondii, is essential for virulence and has a previously unrecognised role in parasite resistance to interferon gamma-mediated innate immune restriction. This function is conserved in the highly virulent RH strain of T. gondii and contributes to parasite growth in both murine and human macrophages. While ROP1 affects the morphology of rhoptries, from where the protein is secreted, it does not affect rhoptry secretion. Finally, we show that ROP1 co-immunoprecipitates with the host cell protein C1QBP, an emerging regulator of innate immune signaling. In summary, we identify putative in vivo virulence factors in the T. gondii Prugniaud strain and show that ROP1 is an important and previously overlooked effector protein that counteracts both murine and human innate immunity.
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Affiliation(s)
- Simon Butterworth
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Francesca Torelli
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Eloise J. Lockyer
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Jeanette Wagener
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Ok-Ryul Song
- High-Throughput Screening Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Malgorzata Broncel
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Matt R. G. Russell
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | | | - Joanna C. Young
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Moritz Treeck
- Signalling In Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
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12
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Niu Z, Ye S, Liu J, Lyu M, Xue L, Li M, Lyu C, Zhao J, Shen B. Two apicoplast dwelling glycolytic enzymes provide key substrates for metabolic pathways in the apicoplast and are critical for Toxoplasma growth. PLoS Pathog 2022; 18:e1011009. [PMID: 36449552 PMCID: PMC9744290 DOI: 10.1371/journal.ppat.1011009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 12/12/2022] [Accepted: 11/20/2022] [Indexed: 12/05/2022] Open
Abstract
Many apicomplexan parasites harbor a non-photosynthetic plastid called the apicoplast, which hosts important metabolic pathways like the methylerythritol 4-phosphate (MEP) pathway that synthesizes isoprenoid precursors. Yet many details in apicoplast metabolism are not well understood. In this study, we examined the physiological roles of four glycolytic enzymes in the apicoplast of Toxoplasma gondii. Many glycolytic enzymes in T. gondii have two or more isoforms. Endogenous tagging each of these enzymes found that four of them were localized to the apicoplast, including pyruvate kinase2 (PYK2), phosphoglycerate kinase 2 (PGK2), triosephosphate isomerase 2 (TPI2) and phosphoglyceraldehyde dehydrogenase 2 (GAPDH2). The ATP generating enzymes PYK2 and PGK2 were thought to be the main energy source of the apicoplast. Surprisingly, deleting PYK2 and PGK2 individually or simultaneously did not cause major defects on parasite growth or virulence. In contrast, TPI2 and GAPDH2 are critical for tachyzoite proliferation. Conditional depletion of TPI2 caused significant reduction in the levels of MEP pathway intermediates and led to parasite growth arrest. Reconstitution of another isoprenoid precursor synthesis pathway called the mevalonate pathway in the TPI2 depletion mutant partially rescued its growth defects. Similarly, knocking down the GAPDH2 enzyme that produces NADPH also reduced isoprenoid precursor synthesis through the MEP pathway and inhibited parasite proliferation. In addition, it reduced de novo fatty acid synthesis in the apicoplast. Together, these data suggest a model that the apicoplast dwelling TPI2 provides carbon source for the synthesis of isoprenoid precursor, whereas GAPDH2 supplies reducing power for pathways like MEP, fatty acid synthesis and ferredoxin redox system in T. gondii. As such, both enzymes are critical for parasite growth and serve as potential targets for anti-toxoplasmic intervention designs. On the other hand, the dispensability of PYK2 and PGK2 suggest additional sources for energy in the apicoplast, which deserves further investigation.
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Affiliation(s)
- Zhipeng Niu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
| | - Shu Ye
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
| | - Jiaojiao Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
| | - Mengyu Lyu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
| | - Lilan Xue
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
| | - Muxiao Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
| | - Congcong Lyu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei Province, PR China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei Province, PR China
- Hubei Hongshan Laboratory, Wuhan, Hubei Province, PR China
- Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Shenzhen, Guangdong Province, PR China
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, Guangdong Province, PR China
- * E-mail:
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13
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Benns HJ, Storch M, Falco JA, Fisher FR, Tamaki F, Alves E, Wincott CJ, Milne R, Wiedemar N, Craven G, Baragaña B, Wyllie S, Baum J, Baldwin GS, Weerapana E, Tate EW, Child MA. CRISPR-based oligo recombineering prioritizes apicomplexan cysteines for drug discovery. Nat Microbiol 2022; 7:1891-1905. [PMID: 36266336 PMCID: PMC9613468 DOI: 10.1038/s41564-022-01249-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/09/2022] [Indexed: 11/30/2022]
Abstract
Nucleophilic amino acids are important in covalent drug development yet underutilized as anti-microbial targets. Chemoproteomic technologies have been developed to mine chemically accessible residues via their intrinsic reactivity towards electrophilic probes but cannot discern which chemically reactive sites contribute to protein function and should therefore be prioritized for drug discovery. To address this, we have developed a CRISPR-based oligo recombineering (CORe) platform to support the rapid identification, functional prioritization and rational targeting of chemically reactive sites in haploid systems. Our approach couples protein sequence and function with biological fitness of live cells. Here we profile the electrophile sensitivity of proteinogenic cysteines in the eukaryotic pathogen Toxoplasma gondii and prioritize functional sites using CORe. Electrophile-sensitive cysteines decorating the ribosome were found to be critical for parasite growth, with target-based screening identifying a parasite-selective anti-malarial lead molecule and validating the apicomplexan translation machinery as a target for ongoing covalent ligand development.
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Affiliation(s)
- H J Benns
- Department of Life Sciences, Imperial College London, London, UK
- Department of Chemistry, Imperial College London, London, UK
| | - M Storch
- London Biofoundry, Imperial College Translation & Innovation Hub, London, UK
| | - J A Falco
- Department of Chemistry, Boston College, Boston, MA, USA
| | - F R Fisher
- Department of Life Sciences, Imperial College London, London, UK
| | - F Tamaki
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, UK
| | - E Alves
- Department of Life Sciences, Imperial College London, London, UK
| | - C J Wincott
- Department of Life Sciences, Imperial College London, London, UK
| | - R Milne
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, UK
| | - N Wiedemar
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, UK
| | - G Craven
- Department of Chemistry, Imperial College London, London, UK
| | - B Baragaña
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, UK
| | - S Wyllie
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, UK
| | - J Baum
- Department of Life Sciences, Imperial College London, London, UK
- School of Biomedical Sciences, UNSW, Sydney, NSW, Australia
| | - G S Baldwin
- Department of Life Sciences, Imperial College London, London, UK
| | - E Weerapana
- Department of Chemistry, Boston College, Boston, MA, USA
| | - E W Tate
- Department of Chemistry, Imperial College London, London, UK.
| | - M A Child
- Department of Life Sciences, Imperial College London, London, UK.
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14
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Nofal SD, Dominicus C, Broncel M, Katris NJ, Flynn HR, Arrizabalaga G, Botté CY, Invergo BM, Treeck M. A positive feedback loop mediates crosstalk between calcium, cyclic nucleotide and lipid signalling in calcium-induced Toxoplasma gondii egress. PLoS Pathog 2022; 18:e1010901. [PMID: 36265000 PMCID: PMC9624417 DOI: 10.1371/journal.ppat.1010901] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/01/2022] [Accepted: 09/29/2022] [Indexed: 11/25/2022] Open
Abstract
Fundamental processes that govern the lytic cycle of the intracellular parasite Toxoplasma gondii are regulated by several signalling pathways. However, how these pathways are connected remains largely unknown. Here, we compare the phospho-signalling networks during Toxoplasma egress from its host cell by artificially raising cGMP or calcium levels. We show that both egress inducers trigger indistinguishable signalling responses and provide evidence for a positive feedback loop linking calcium and cyclic nucleotide signalling. Using WT and conditional knockout parasites of the non-essential calcium-dependent protein kinase 3 (CDPK3), which display a delay in calcium inonophore-mediated egress, we explore changes in phosphorylation and lipid signalling in sub-minute timecourses after inducing Ca2+ release. These studies indicate that cAMP and lipid metabolism are central to the feedback loop, which is partly dependent on CDPK3 and allows the parasite to respond faster to inducers of egress. Biochemical analysis of 4 phosphodiesterases (PDEs) identified in our phosphoproteomes establishes PDE2 as a cAMP-specific PDE which regulates Ca2+ induced egress in a CDPK3-independent manner. The other PDEs display dual hydrolytic activity and play no role in Ca2+ induced egress. In summary, we uncover a positive feedback loop that enhances signalling during egress, thereby linking several signalling pathways.
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Affiliation(s)
- Stephanie D. Nofal
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Caia Dominicus
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Malgorzata Broncel
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
- Protein Analysis and Proteomics Platform, The Francis Crick Institute, London, United Kingdom
| | - Nicholas J. Katris
- Apicolipid Team, Institute for Advance Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Helen R. Flynn
- Protein Analysis and Proteomics Platform, The Francis Crick Institute, London, United Kingdom
| | - Gustavo Arrizabalaga
- University of Indianapolis, School of Medicine, Indianapolis, Indiana, United States of America
| | - Cyrille Y. Botté
- Apicolipid Team, Institute for Advance Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Brandon M. Invergo
- Translational Research Exchange at Exeter, University of Exeter, Exeter, United Kingdom
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
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15
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Xia N, Guo X, Guo Q, Gupta N, Ji N, Shen B, Xiao L, Feng Y. Metabolic flexibilities and vulnerabilities in the pentose phosphate pathway of the zoonotic pathogen Toxoplasma gondii. PLoS Pathog 2022; 18:e1010864. [PMID: 36121870 PMCID: PMC9521846 DOI: 10.1371/journal.ppat.1010864] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 09/29/2022] [Accepted: 09/08/2022] [Indexed: 11/18/2022] Open
Abstract
Metabolic pathways underpin the growth and virulence of intracellular parasites and are therefore promising antiparasitic targets. The pentose phosphate pathway (PPP) is vital in most organisms, providing a reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) and ribose sugar for nucleotide synthesis; however, it has not yet been studied in Toxoplasma gondii, a widespread intracellular pathogen and a model protozoan organism. Herein, we show that T. gondii has a functional PPP distributed in the cytoplasm and nucleus of its acutely-infectious tachyzoite stage. We produced eight parasite mutants disrupting seven enzymes of the PPP in T. gondii. Our data show that of the seven PPP proteins, the two glucose-6-phosphate dehydrogenases (TgG6PDH1, TgG6PDH2), one of the two 6-phosphogluconate dehydrogenases (Tg6PGDH1), ribulose-5-phosphate epimerase (TgRuPE) and transaldolase (TgTAL) are dispensable in vitro as well as in vivo, disclosing substantial metabolic plasticity in T. gondii. Among these, TgG6PDH2 plays a vital role in defense against oxidative stress by the pathogen. Further, we show that Tg6PGDH2 and ribulose-5-phosphate isomerase (TgRPI) are critical for tachyzoite growth. The depletion of TgRPI impairs the flux of glucose in central carbon pathways, and causes decreased expression of ribosomal, microneme and rhoptry proteins. In summary, our results demonstrate the physiological need of the PPP in T. gondii while unraveling metabolic flexibility and antiparasitic targets. Metabolic pathways are intimately associated with the survival and replication of parasitic Toxoplasma gondii and thus represent potential targets for antiparasitic strategies. Herein, we focused on the pentose phosphate pathway (PPP) in T. gondii and examined its roles in supporting the growth of this ubiquitous pathogen. We found that TgG6PDH1 and TgG6PDH2 were needed to defend oxidative stress but not for pentose synthesis. We revealed that inactivation of the Tg6PGDH2 and TgRPI severely impaired the asexual reproduction of tachyzoites. We also highlighted the remarkable metabolic plasticity in tachyzoites that enables them to acquire some of the PPP intermediates from multiple routes. This study provides significant insights into the carbon metabolism properties of Toxoplasma parasites, opening avenues for targeting this pathway to develop therapeutic interventions against toxoplasmosis.
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Affiliation(s)
- Ningbo Xia
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xuefang Guo
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Qinghong Guo
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Nishith Gupta
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (Hyderabad Campus), Hyderabad, India
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Nuo Ji
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- * E-mail: (BS); (LX); (YF)
| | - Lihua Xiao
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- * E-mail: (BS); (LX); (YF)
| | - Yaoyu Feng
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- * E-mail: (BS); (LX); (YF)
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16
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Zhang J, Fan F, Zhang L, Shen B. Nuclear Factor AP2X-4 Governs the Expression of Cell Cycle- and Life Stage-Regulated Genes and is Critical for Toxoplasma Growth. Microbiol Spectr 2022; 10:e0012022. [PMID: 35735977 PMCID: PMC9430314 DOI: 10.1128/spectrum.00120-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/06/2022] [Indexed: 11/21/2022] Open
Abstract
Toxoplasma gondii is a ubiquitous pathogen infecting one third of the world's population and diverse animals. It has a complex life cycle alternating among different developmental stages, which contributes to its transmission and pathogenesis. The parasite has a sophisticated gene regulation network that enables timely expression of genes at designated stages. However, little is known about the underlying regulatory mechanisms. Here, we identified an AP2 family transcription factor named TgAP2X-4, which was crucial for parasite growth during the acute infection stage. TgAP2X-4 deletion leads to reduced expression of many genes that are normally upregulated during the M phase of the cell cycle. These include genes that encode rhoptry neck proteins that are key for parasite invasion. As a result, the Δap2X-4 mutant displayed significantly decreased efficiency of host cell invasion. Transcriptomic analyses suggested that TgAP2X-4 also regulates a large group of genes that are typically induced during chronic infection, such as BAG1 and LDH2. Given the diverse impacts on gene expression, TgAP2X-4 inactivation results in severely impaired parasite growth, as well as drastic attenuation of parasite virulence and complete inability to form chronic infection. Therefore, TgAP2X-4 represents a candidate for antitoxoplasmic drug and vaccine designs. IMPORTANCE Toxoplasma gondii has a complicated gene regulation network that allows "just in time" expression of genes to cope with the physiological needs at each stage during the complex life cycle. However, how such regulation is achieved is largely unknown. Here, we identified a transcription factor named TgAP2X-4 that is critical for the growth and life cycle progression of the parasite. Detailed analyses found that TgAP2X-4 regulated the expression of many cell cycle-regulated genes, including a subset of rhoptry genes that were essential for the parasites to enter host cells. It also regulated the expression of many genes involved in the development of chronic infection. Because of the diverse impacts on gene expression, TgAP2X-4 inactivation caused reduced parasite growth in vitro and attenuated virulence in vivo. Therefore, it is a potential target for drug or vaccine designs against Toxoplasma infections.
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Affiliation(s)
- Jingwen Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
| | - Fuqiang Fan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
| | - Lihong Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
- Key Laboratory of Preventive Medicine in Hubei Province, Wuhan, Hubei Province, People’s Republic of China
- Hubei Hongshan Laboratory, Wuhan, Hubei Province, People’s Republic of China
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17
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Herneisen AL, Li ZH, Chan AW, Moreno SNJ, Lourido S. Temporal and thermal profiling of the Toxoplasma proteome implicates parasite Protein Phosphatase 1 in the regulation of Ca 2+-responsive pathways. eLife 2022; 11:e80336. [PMID: 35976251 PMCID: PMC9436416 DOI: 10.7554/elife.80336] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Apicomplexan parasites cause persistent mortality and morbidity worldwide through diseases including malaria, toxoplasmosis, and cryptosporidiosis. Ca2+ signaling pathways have been repurposed in these eukaryotic pathogens to regulate parasite-specific cellular processes governing the replicative and lytic phases of the infectious cycle, as well as the transition between them. Despite the presence of conserved Ca2+-responsive proteins, little is known about how specific signaling elements interact to impact pathogenesis. We mapped the Ca2+-responsive proteome of the model apicomplexan Taxoplasma gondii via time-resolved phosphoproteomics and thermal proteome profiling. The waves of phosphoregulation following PKG activation and stimulated Ca2+ release corroborate known physiological changes but identify specific proteins operating in these pathways. Thermal profiling of parasite extracts identified many expected Ca2+-responsive proteins, such as parasite Ca2+-dependent protein kinases. Our approach also identified numerous Ca2+-responsive proteins that are not predicted to bind Ca2+, yet are critical components of the parasite signaling network. We characterized protein phosphatase 1 (PP1) as a Ca2+-responsive enzyme that relocalized to the parasite apex upon Ca2+ store release. Conditional depletion of PP1 revealed that the phosphatase regulates Ca2+ uptake to promote parasite motility. PP1 may thus be partly responsible for Ca2+-regulated serine/threonine phosphatase activity in apicomplexan parasites.
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Affiliation(s)
- Alice L Herneisen
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Zhu-Hong Li
- Center for Tropical and Emerging Global Diseases, University of GeorgiaAthensUnited States
| | - Alex W Chan
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Center for Tropical and Emerging Global Diseases, University of GeorgiaAthensUnited States
| | - Silvia NJ Moreno
- Center for Tropical and Emerging Global Diseases, University of GeorgiaAthensUnited States
| | - Sebastian Lourido
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
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18
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Peddie CJ, Genoud C, Kreshuk A, Meechan K, Micheva KD, Narayan K, Pape C, Parton RG, Schieber NL, Schwab Y, Titze B, Verkade P, Aubrey A, Collinson LM. Volume electron microscopy. NATURE REVIEWS. METHODS PRIMERS 2022; 2:51. [PMID: 37409324 PMCID: PMC7614724 DOI: 10.1038/s43586-022-00131-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/10/2022] [Indexed: 07/07/2023]
Abstract
Life exists in three dimensions, but until the turn of the century most electron microscopy methods provided only 2D image data. Recently, electron microscopy techniques capable of delving deep into the structure of cells and tissues have emerged, collectively called volume electron microscopy (vEM). Developments in vEM have been dubbed a quiet revolution as the field evolved from established transmission and scanning electron microscopy techniques, so early publications largely focused on the bioscience applications rather than the underlying technological breakthroughs. However, with an explosion in the uptake of vEM across the biosciences and fast-paced advances in volume, resolution, throughput and ease of use, it is timely to introduce the field to new audiences. In this Primer, we introduce the different vEM imaging modalities, the specialized sample processing and image analysis pipelines that accompany each modality and the types of information revealed in the data. We showcase key applications in the biosciences where vEM has helped make breakthrough discoveries and consider limitations and future directions. We aim to show new users how vEM can support discovery science in their own research fields and inspire broader uptake of the technology, finally allowing its full adoption into mainstream biological imaging.
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Affiliation(s)
- Christopher J. Peddie
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, UK
| | - Christel Genoud
- Electron Microscopy Facility, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Anna Kreshuk
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Kimberly Meechan
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Present address: Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Kristina D. Micheva
- Department of Molecular and Cellular Physiology, Stanford University, Palo Alto, CA, USA
| | - Kedar Narayan
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Constantin Pape
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Robert G. Parton
- The Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
- Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Queensland, Australia
| | - Nicole L. Schieber
- Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Queensland, Australia
| | - Yannick Schwab
- Cell Biology and Biophysics Unit/ Electron Microscopy Core Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | | | - Paul Verkade
- School of Biochemistry, University of Bristol, Bristol, UK
| | - Aubrey Aubrey
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Lucy M. Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, UK
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19
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Kehrer J, Formaglio P, Muthinja JM, Weber S, Baltissen D, Lance C, Ripp J, Grech J, Meissner M, Funaya C, Amino R, Frischknecht F. Plasmodium
sporozoite disintegration during skin passage limits malaria parasite transmission. EMBO Rep 2022; 23:e54719. [PMID: 35403820 PMCID: PMC9253755 DOI: 10.15252/embr.202254719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 11/25/2022] Open
Abstract
During transmission of malaria‐causing parasites from mosquitoes to mammals, Plasmodium sporozoites migrate rapidly in the skin to search for a blood vessel. The high migratory speed and narrow passages taken by the parasites suggest considerable strain on the sporozoites to maintain their shape. Here, we show that the membrane‐associated protein, concavin, is important for the maintenance of the Plasmodium sporozoite shape inside salivary glands of mosquitoes and during migration in the skin. Concavin‐GFP localizes at the cytoplasmic periphery and concavin(−) sporozoites progressively round up upon entry of salivary glands. Rounded concavin(−) sporozoites fail to pass through the narrow salivary ducts and are rarely ejected by mosquitoes, while normally shaped concavin(−) sporozoites are transmitted. Strikingly, motile concavin(−) sporozoites disintegrate while migrating through the skin leading to parasite arrest or death and decreased transmission efficiency. Collectively, we suggest that concavin contributes to cell shape maintenance by riveting the plasma membrane to the subtending inner membrane complex. Interfering with cell shape maintenance pathways might hence provide a new strategy to prevent a malaria infection.
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Affiliation(s)
- Jessica Kehrer
- Integrative Parasitology Center for Infectious Diseases Heidelberg University Medical School Heidelberg Germany
- Infectious Diseases Imaging Platform Center for Infectious Diseases Heidelberg University Medical School Heidelberg Germany
| | - Pauline Formaglio
- Malaria Infection and Immunity Unit Department of Parasites and Insect Vectors Institut Pasteur Paris France
| | - Julianne Mendi Muthinja
- Integrative Parasitology Center for Infectious Diseases Heidelberg University Medical School Heidelberg Germany
| | - Sebastian Weber
- Electron Microscopy Core Facility Heidelberg University Heidelberg Germany
| | - Danny Baltissen
- Integrative Parasitology Center for Infectious Diseases Heidelberg University Medical School Heidelberg Germany
| | - Christopher Lance
- Integrative Parasitology Center for Infectious Diseases Heidelberg University Medical School Heidelberg Germany
| | - Johanna Ripp
- Integrative Parasitology Center for Infectious Diseases Heidelberg University Medical School Heidelberg Germany
| | - Janessa Grech
- Experimental Parasitology Ludwig Maximilian University Munich Planegg‐Martinsried Germany
| | - Markus Meissner
- Experimental Parasitology Ludwig Maximilian University Munich Planegg‐Martinsried Germany
| | - Charlotta Funaya
- Electron Microscopy Core Facility Heidelberg University Heidelberg Germany
| | - Rogerio Amino
- Malaria Infection and Immunity Unit Department of Parasites and Insect Vectors Institut Pasteur Paris France
| | - Friedrich Frischknecht
- Integrative Parasitology Center for Infectious Diseases Heidelberg University Medical School Heidelberg Germany
- German Center for Infection Research (DZIF), Partner Site Heidelberg Heidelberg Germany
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20
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Boisard J, Duvernois-Berthet E, Duval L, Schrével J, Guillou L, Labat A, Le Panse S, Prensier G, Ponger L, Florent I. Marine gregarine genomes reveal the breadth of apicomplexan diversity with a partially conserved glideosome machinery. BMC Genomics 2022; 23:485. [PMID: 35780080 PMCID: PMC9250747 DOI: 10.1186/s12864-022-08700-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 06/13/2022] [Indexed: 12/29/2022] Open
Abstract
Our current view of the evolutionary history, coding and adaptive capacities of Apicomplexa, protozoan parasites of a wide range of metazoan, is currently strongly biased toward species infecting humans, as data on early diverging apicomplexan lineages infecting invertebrates is extremely limited. Here, we characterized the genome of the marine eugregarine Porospora gigantea, intestinal parasite of Lobsters, remarkable for the macroscopic size of its vegetative feeding forms (trophozoites) and its gliding speed, the fastest so far recorded for Apicomplexa. Two highly syntenic genomes named A and B were assembled. Similar in size (~ 9 Mb) and coding capacity (~ 5300 genes), A and B genomes are 10.8% divergent at the nucleotide level, corresponding to 16-38 My in divergent time. Orthogroup analysis across 25 (proto)Apicomplexa species, including Gregarina niphandrodes, showed that A and B are highly divergent from all other known apicomplexan species, revealing an unexpected breadth of diversity. Phylogenetically these two species branch sisters to Cephaloidophoroidea, and thus expand the known crustacean gregarine superfamily. The genomes were mined for genes encoding proteins necessary for gliding, a key feature of apicomplexans parasites, currently studied through the molecular model called glideosome. Sequence analysis shows that actin-related proteins and regulatory factors are strongly conserved within apicomplexans. In contrast, the predicted protein sequences of core glideosome proteins and adhesion proteins are highly variable among apicomplexan lineages, especially in gregarines. These results confirm the importance of studying gregarines to widen our biological and evolutionary view of apicomplexan species diversity, and to deepen our understanding of the molecular bases of key functions such as gliding, well known to allow access to the intracellular parasitic lifestyle in Apicomplexa.
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Affiliation(s)
- Julie Boisard
- Département Adaptations du Vivant (AVIV), Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS), Muséum National d'Histoire Naturelle, CNRS, CP 52, 57 rue Cuvier, 75231 Cedex 05, Paris, France. .,Département Adaptations du Vivant (AVIV), Structure et instabilité des génomes (STRING UMR 7196 CNRS/INSERM U1154), Muséum National d'Histoire Naturelle, CNRS, INSERM, CP 26, 57 rue Cuvier, 75231 Cedex 05, Paris, France. .,Department of Biology, Lund University, Sölvegatan 35, 223 62, Lund, Sweden.
| | - Evelyne Duvernois-Berthet
- Département Adaptations du Vivant (AVIV), Physiologie Moléculaire et Adaptation (PhyMA UMR 7221 CNRS), Muséum national d'Histoire naturelle, CNRS, CP 32, 7 rue Cuvier, 75005, Paris, France
| | - Linda Duval
- Département Adaptations du Vivant (AVIV), Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS), Muséum National d'Histoire Naturelle, CNRS, CP 52, 57 rue Cuvier, 75231 Cedex 05, Paris, France
| | - Joseph Schrével
- Département Adaptations du Vivant (AVIV), Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS), Muséum National d'Histoire Naturelle, CNRS, CP 52, 57 rue Cuvier, 75231 Cedex 05, Paris, France
| | - Laure Guillou
- CNRS, UMR7144 Adaptation et Diversité en Milieu Marin, Ecology of Marine Plankton (ECOMAP), Station Biologique de Roscoff SBR, Sorbonne Université, 29680, Roscoff, France
| | - Amandine Labat
- Département Adaptations du Vivant (AVIV), Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS), Muséum National d'Histoire Naturelle, CNRS, CP 52, 57 rue Cuvier, 75231 Cedex 05, Paris, France
| | - Sophie Le Panse
- Plateforme d'Imagerie Merimage, FR2424, Centre National de la Recherche Scientifique, Station Biologique de Roscoff, 29680, Roscoff, France
| | - Gérard Prensier
- Cell biology and Electron Microscopy Laboratory, François Rabelais University, 10 Boulevard Tonnellé, 3223 Cedex, Tours, BP, France
| | - Loïc Ponger
- Département Adaptations du Vivant (AVIV), Structure et instabilité des génomes (STRING UMR 7196 CNRS/INSERM U1154), Muséum National d'Histoire Naturelle, CNRS, INSERM, CP 26, 57 rue Cuvier, 75231 Cedex 05, Paris, France.
| | - Isabelle Florent
- Département Adaptations du Vivant (AVIV), Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS), Muséum National d'Histoire Naturelle, CNRS, CP 52, 57 rue Cuvier, 75231 Cedex 05, Paris, France.
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21
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Smith TA, Lopez-Perez GS, Herneisen AL, Shortt E, Lourido S. Screening the Toxoplasma kinome with high-throughput tagging identifies a regulator of invasion and egress. Nat Microbiol 2022; 7:868-881. [PMID: 35484233 PMCID: PMC9167752 DOI: 10.1038/s41564-022-01104-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 03/11/2022] [Indexed: 12/26/2022]
Abstract
Protein kinases regulate fundamental aspects of eukaryotic cell biology, making them attractive chemotherapeutic targets in parasites like Plasmodium spp. and Toxoplasma gondii. To systematically examine the parasite kinome, we developed a high-throughput tagging (HiT) strategy to endogenously label protein kinases with an auxin-inducible degron and fluorophore. Hundreds of tagging vectors were assembled from synthetic sequences in a single reaction and used to generate pools of mutants to determine localization and function. Examining 1,160 arrayed clones, we assigned 40 protein localizations and associated 15 kinases with distinct defects. The fitness of tagged alleles was also measured by pooled screening, distinguishing delayed from acute phenotypes. A previously unstudied kinase, associated with a delayed phenotype, was shown to be a regulator of invasion and egress. We named the kinase Store Potentiating/Activating Regulatory Kinase (SPARK), based on its impact on intracellular Ca2+ stores. Despite homology to mammalian 3-phosphoinositide-dependent protein kinase-1 (PDK1), SPARK lacks a lipid-binding domain, suggesting a rewiring of the pathway in parasites. HiT screening extends genome-wide approaches into complex cellular phenotypes, providing a scalable and versatile platform to dissect parasite biology.
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Affiliation(s)
- Tyler A Smith
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Alice L Herneisen
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Emily Shortt
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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22
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Li W, Grech J, Stortz JF, Gow M, Periz J, Meissner M, Jimenez-Ruiz E. A splitCas9 phenotypic screen in Toxoplasma gondii identifies proteins involved in host cell egress and invasion. Nat Microbiol 2022; 7:882-895. [PMID: 35538310 DOI: 10.1038/s41564-022-01114-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 03/31/2022] [Indexed: 11/09/2022]
Abstract
Apicomplexan parasites, such as Toxoplasma gondii, have specific adaptations that enable invasion and exit from the host cell. Owing to the phylogenetic distance between apicomplexan parasites and model organisms, comparative genomics has limited capacity to infer gene functions. Further, although CRISPR/Cas9-based screens have assigned roles to some Toxoplasma genes, the functions of encoded proteins have proven difficult to assign. To overcome this problem, we devised a conditional Cas9-system in T. gondii that enables phenotypic screens. Using an indicator strain for F-actin dynamics and apicoplast segregation, we screened 320 genes to identify those required for defined steps in the asexual life cycle. The detailed characterization of two genes identified in our screen, through the generation of conditional knockout parasites using the DiCre-system, revealed that signalling linking factor (SLF) is an integral part of a signalling complex required for early induction of egress, and a novel conoid protein (conoid gliding protein, CGP) functions late during egress and is required for the activation of gliding motility. Establishing different indicator lines and applying our conditional Cas9 screen could enable the identification of genes involved in organellar biogenesis, parasite replication or maintenance of the endosymbiotic organelles in the future.
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Affiliation(s)
- Wei Li
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, Germany
| | - Janessa Grech
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, Germany
| | - Johannes Felix Stortz
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, UK.,Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Matthew Gow
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, Germany
| | - Javier Periz
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, Germany
| | - Markus Meissner
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, Germany. .,Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, UK.
| | - Elena Jimenez-Ruiz
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, Germany.
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23
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Briquet S, Gissot M, Silvie O. A toolbox for conditional control of gene expression in apicomplexan parasites. Mol Microbiol 2021; 117:618-631. [PMID: 34564906 PMCID: PMC9293482 DOI: 10.1111/mmi.14821] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 01/29/2023]
Abstract
Apicomplexan parasites encompass diverse pathogens for humans and animals, including the causative agents of malaria and toxoplasmosis, Plasmodium spp. and Toxoplasma gondii. Genetic manipulation of these parasites has become central to explore parasite biology, unravel gene function and identify new targets for therapeutic strategies. Tremendous progress has been achieved over the past years with the advent of next generation sequencing and powerful genome editing methods. In particular, various methods for conditional gene expression have been developed in both Plasmodium and Toxoplasma to knockout or knockdown essential genes, or for inducible expression of master developmental regulators or mutant versions of proteins. Conditional gene expression can be achieved at three distinct levels. At the DNA level, inducible site‐specific recombinases allow conditional genome editing. At the RNA level, regulation can be achieved during transcription, using stage‐specific or regulatable promoters, or post‐transcriptionally through alteration of mRNA stability or translation. At the protein level, several systems have been developed for inducible degradation or displacement of a protein of interest. In this review, we provide an overview of current systems for conditional control of gene expression in Plasmodium and Toxoplasma parasites, highlighting the advantages and limitations of each approach.
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Affiliation(s)
- Sylvie Briquet
- INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, Sorbonne Université, Paris, France
| | - Mathieu Gissot
- CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, Center for Infection and Immunity of Lille, CIIL, Univ. Lille, Lille, France
| | - Olivier Silvie
- INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, Sorbonne Université, Paris, France
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24
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Kloehn J, Lunghi M, Varesio E, Dubois D, Soldati-Favre D. Untargeted Metabolomics Uncovers the Essential Lysine Transporter in Toxoplasma gondii. Metabolites 2021; 11:metabo11080476. [PMID: 34436417 PMCID: PMC8399914 DOI: 10.3390/metabo11080476] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/09/2021] [Accepted: 07/20/2021] [Indexed: 12/15/2022] Open
Abstract
Apicomplexan parasites are responsible for devastating diseases, including malaria, toxoplasmosis, and cryptosporidiosis. Current treatments are limited by emerging resistance to, as well as the high cost and toxicity of existing drugs. As obligate intracellular parasites, apicomplexans rely on the uptake of many essential metabolites from their host. Toxoplasma gondii, the causative agent of toxoplasmosis, is auxotrophic for several metabolites, including sugars (e.g., myo-inositol), amino acids (e.g., tyrosine), lipidic compounds and lipid precursors (cholesterol, choline), vitamins, cofactors (thiamine) and others. To date, only few apicomplexan metabolite transporters have been characterized and assigned a substrate. Here, we set out to investigate whether untargeted metabolomics can be used to identify the substrate of an uncharacterized transporter. Based on existing genome- and proteome-wide datasets, we have identified an essential plasma membrane transporter of the major facilitator superfamily in T. gondii-previously termed TgApiAT6-1. Using an inducible system based on RNA degradation, TgApiAT6-1 was depleted, and the mutant parasite's metabolome was compared to that of non-depleted parasites. The most significantly reduced metabolite in parasites depleted in TgApiAT6-1 was identified as the amino acid lysine, for which T. gondii is predicted to be auxotrophic. Using stable isotope-labeled amino acids, we confirmed that TgApiAT6-1 is required for efficient lysine uptake. Our findings highlight untargeted metabolomics as a powerful tool to identify the substrate of orphan transporters.
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Affiliation(s)
- Joachim Kloehn
- Department of Microbiology and Molecular Medicine, University of Geneva, CMU, Rue Michel-Servet 1, 1211 Geneva, Switzerland; (M.L.); (D.D.)
- Correspondence: (J.K.); (D.S.-F.); Tel.: +41-22-379-57-16 (J.K.); +41-22-379-56-72 (D.S.-F.)
| | - Matteo Lunghi
- Department of Microbiology and Molecular Medicine, University of Geneva, CMU, Rue Michel-Servet 1, 1211 Geneva, Switzerland; (M.L.); (D.D.)
| | - Emmanuel Varesio
- Institute of Pharmaceutical Sciences of Western Switzerland, School of Pharmaceutical Sciences, Mass Spectrometry Core Facility (MZ 2.0), University of Geneva, 1211 Geneva, Switzerland;
| | - David Dubois
- Department of Microbiology and Molecular Medicine, University of Geneva, CMU, Rue Michel-Servet 1, 1211 Geneva, Switzerland; (M.L.); (D.D.)
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, University of Geneva, CMU, Rue Michel-Servet 1, 1211 Geneva, Switzerland; (M.L.); (D.D.)
- Correspondence: (J.K.); (D.S.-F.); Tel.: +41-22-379-57-16 (J.K.); +41-22-379-56-72 (D.S.-F.)
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25
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Das S, Stortz JF, Meissner M, Periz J. The multiple functions of actin in apicomplexan parasites. Cell Microbiol 2021; 23:e13345. [PMID: 33885206 DOI: 10.1111/cmi.13345] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/30/2021] [Accepted: 03/31/2021] [Indexed: 11/29/2022]
Abstract
The cytoskeletal protein actin is highly abundant and conserved in eukaryotic cells. It occurs in two different states- the globular (G-actin) form, which can polymerise into the filamentous (F-actin) form, fulfilling various critical functions including cytokinesis, cargo trafficking and cellular motility. In higher eukaryotes, there are several actin isoforms with nearly identical amino acid sequences. Despite the high level of amino acid identity, they display regulated expression patterns and unique non-redundant roles. The number of actin isoforms together with conserved sequences may reflect the selective pressure exerted by scores of actin binding proteins (ABPs) in higher eukaryotes. In contrast, in many protozoans such as apicomplexan parasites which possess only a few ABPs, the regulatory control of actin and its multiple functions are still obscure. Here, we provide a summary of the regulation and biological functions of actin in higher eukaryotes and compare it with the current knowledge in apicomplexans. We discuss future experiments that will help us understand the multiple, critical roles of this fascinating system in apicomplexans.
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Affiliation(s)
- Sujaan Das
- Faculty of Veterinary Medicine, Experimental Parasitology, Ludwig Maximilian University, Munich, Germany
| | - Johannes Felix Stortz
- Department Metabolism of Infection, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Markus Meissner
- Faculty of Veterinary Medicine, Experimental Parasitology, Ludwig Maximilian University, Munich, Germany
| | - Javier Periz
- Faculty of Veterinary Medicine, Experimental Parasitology, Ludwig Maximilian University, Munich, Germany
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26
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Carmeille R, Schiano Lomoriello P, Devarakonda PM, Kellermeier JA, Heaslip AT. Actin and an unconventional myosin motor, TgMyoF, control the organization and dynamics of the endomembrane network in Toxoplasma gondii. PLoS Pathog 2021; 17:e1008787. [PMID: 33529198 PMCID: PMC7880465 DOI: 10.1371/journal.ppat.1008787] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 02/12/2021] [Accepted: 01/07/2021] [Indexed: 12/25/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular parasite that relies on three distinct secretory organelles, the micronemes, rhoptries, and dense granules, for parasite survival and disease pathogenesis. Secretory proteins destined for these organelles are synthesized in the endoplasmic reticulum (ER) and sequentially trafficked through a highly polarized endomembrane network that consists of the Golgi and multiple post-Golgi compartments. Currently, little is known about how the parasite cytoskeleton controls the positioning of the organelles in this pathway, or how vesicular cargo is trafficked between organelles. Here we show that F-actin and an unconventional myosin motor, TgMyoF, control the dynamics and organization of the organelles in the secretory pathway, specifically ER tubule movement, apical positioning of the Golgi and post-Golgi compartments, apical positioning of the rhoptries, and finally, the directed transport of Rab6-positive and Rop1-positive vesicles. Thus, this study identifies TgMyoF and actin as the key cytoskeletal components that organize the endomembrane system in T. gondii. Endomembrane trafficking is a vital cellular process in all eukaryotic cells. In most cases the molecular motors myosin, kinesin, and dynein transport cargo including vesicles, organelles and transcripts along actin and microtubule filaments in a manner analogous to a train moving on its tracks. For the unicellular eukaryote Toxoplasma gondii, the accurate trafficking of proteins through the endomembrane system is vital for parasite survival and pathogenicity. However, the mechanisms of cargo transport in this parasite are poorly understood. In this study, we fluorescently labeled multiple endomembrane organelles and imaged their movements using live cell microscopy. We demonstrate that filamentous actin and an unconventional myosin motor named TgMyoF control both the positioning of organelles in this pathway and the movement of transport vesicles throughout the parasite cytosol. This data provides new insight into the mechanisms of cargo transport in this important pathogen and expands our understanding of the biological roles of actin in the intracellular phase of the parasite’s growth cycle.
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Affiliation(s)
- Romain Carmeille
- Department of Cell and Molecular Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Porfirio Schiano Lomoriello
- Department of Cell and Molecular Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Parvathi M. Devarakonda
- Department of Cell and Molecular Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Jacob A. Kellermeier
- Department of Cell and Molecular Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Aoife T. Heaslip
- Department of Cell and Molecular Biology, University of Connecticut, Storrs, Connecticut, United States of America
- * E-mail:
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27
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Abstract
Apicomplexans are obligate intracellular parasites harboring three sets of unique secretory organelles termed micronemes, rhoptries, and dense granules that are dedicated to the establishment of infection in the host cell. Apicomplexans rely on the endolysosomal system to generate the secretory organelles and to ingest and digest host cell proteins. These parasites also possess a metabolically relevant secondary endosymbiotic organelle, the apicoplast, which relies on vesicular trafficking for correct incorporation of nuclear-encoded proteins into the organelle. Here, we demonstrate that the trafficking and destination of vesicles to the unique and specialized parasite compartments depend on SNARE proteins that interact with tethering factors. Specifically, all secreted proteins depend on the function of SLY1 at the Golgi. In addition to a critical role in trafficking of endocytosed host proteins, TgVps45 is implicated in the biogenesis of the inner membrane complex (alveoli) in both Toxoplasma gondii and Plasmodium falciparum, likely acting in a coordinated manner with Stx16 and Stx6. Finally, Stx12 localizes to the endosomal-like compartment and is involved in the trafficking of proteins to the apical secretory organelles rhoptries and micronemes as well as to the apicoplast.IMPORTANCE The phylum of Apicomplexa groups medically relevant parasites such as those responsible for malaria and toxoplasmosis. As members of the Alveolata superphylum, these protozoans possess specialized organelles in addition to those found in all members of the eukaryotic kingdom. Vesicular trafficking is the major route of communication between membranous organelles. Neither the molecular mechanism that allows communication between organelles nor the vesicular fusion events that underlie it are completely understood in Apicomplexa. Here, we assessed the function of SEC1/Munc18 and SNARE proteins to identify factors involved in the trafficking of vesicles between these various organelles. We show that SEC1/Munc18 in interaction with SNARE proteins allows targeting of vesicles to the inner membrane complex, prerhoptries, micronemes, apicoplast, and vacuolar compartment from the endoplasmic reticulum, Golgi apparatus, or endosomal-like compartment. These data provide an exciting look at the "ZIP code" of vesicular trafficking in apicomplexans, essential for precise organelle biogenesis, homeostasis, and inheritance.
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28
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Harding CR, Sidik SM, Petrova B, Gnädig NF, Okombo J, Herneisen AL, Ward KE, Markus BM, Boydston EA, Fidock DA, Lourido S. Genetic screens reveal a central role for heme metabolism in artemisinin susceptibility. Nat Commun 2020; 11:4813. [PMID: 32968076 PMCID: PMC7511413 DOI: 10.1038/s41467-020-18624-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 09/03/2020] [Indexed: 01/26/2023] Open
Abstract
Artemisinins have revolutionized the treatment of Plasmodium falciparum malaria; however, resistance threatens to undermine global control efforts. To broadly explore artemisinin susceptibility in apicomplexan parasites, we employ genome-scale CRISPR screens recently developed for Toxoplasma gondii to discover sensitizing and desensitizing mutations. Using a sublethal concentration of dihydroartemisinin (DHA), we uncover the putative transporter Tmem14c whose disruption increases DHA susceptibility. Screens performed under high doses of DHA provide evidence that mitochondrial metabolism can modulate resistance. We show that disrupting a top candidate from the screens, the mitochondrial protease DegP2, lowers porphyrin levels and decreases DHA susceptibility, without significantly altering parasite fitness in culture. Deleting the homologous gene in P. falciparum, PfDegP, similarly lowers heme levels and DHA susceptibility. These results expose the vulnerability of heme metabolism to genetic perturbations that can lead to increased survival in the presence of DHA.
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Affiliation(s)
- Clare R Harding
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, UK
| | - Saima M Sidik
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Boryana Petrova
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Nina F Gnädig
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - John Okombo
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | | | - Kurt E Ward
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Benedikt M Markus
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
- Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA.
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Broncel M, Dominicus C, Vigetti L, Nofal SD, Bartlett EJ, Touquet B, Hunt A, Wallbank BA, Federico S, Matthews S, Young JC, Tate EW, Tardieux I, Treeck M. Profiling of myristoylation in Toxoplasma gondii reveals an N-myristoylated protein important for host cell penetration. eLife 2020; 9:e57861. [PMID: 32618271 PMCID: PMC7373427 DOI: 10.7554/elife.57861] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 06/27/2020] [Indexed: 12/26/2022] Open
Abstract
N-myristoylation is a ubiquitous class of protein lipidation across eukaryotes and N-myristoyl transferase (NMT) has been proposed as an attractive drug target in several pathogens. Myristoylation often primes for subsequent palmitoylation and stable membrane attachment, however, growing evidence suggests additional regulatory roles for myristoylation on proteins. Here we describe the myristoylated proteome of Toxoplasma gondii using chemoproteomic methods and show that a small-molecule NMT inhibitor developed against related Plasmodium spp. is also functional in Toxoplasma. We identify myristoylation on a transmembrane protein, the microneme protein 7 (MIC7), which enters the secretory pathway in an unconventional fashion with the myristoylated N-terminus facing the lumen of the micronemes. MIC7 and its myristoylation play a crucial role in the initial steps of invasion, likely during the interaction with and penetration of the host cell. Myristoylation of secreted eukaryotic proteins represents a substantial expansion of the functional repertoire of this co-translational modification.
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Affiliation(s)
- Malgorzata Broncel
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Caia Dominicus
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Luis Vigetti
- Institute for Advanced Biosciences, Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR5309, INSERM U1209, Université Grenoble AlpesGrenobleFrance
| | - Stephanie D Nofal
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Edward J Bartlett
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City CampusLondonUnited Kingdom
| | - Bastien Touquet
- Institute for Advanced Biosciences, Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR5309, INSERM U1209, Université Grenoble AlpesGrenobleFrance
| | - Alex Hunt
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Bethan A Wallbank
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Stefania Federico
- The Peptide Chemistry STP, The Francis Crick InstituteLondonUnited Kingdom
| | - Stephen Matthews
- Department of Life Sciences, Imperial College London, South KensingtonLondonUnited Kingdom
| | - Joanna C Young
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Edward W Tate
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City CampusLondonUnited Kingdom
| | - Isabelle Tardieux
- Institute for Advanced Biosciences, Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR5309, INSERM U1209, Université Grenoble AlpesGrenobleFrance
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
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Ancient MAPK ERK7 is regulated by an unusual inhibitory scaffold required for Toxoplasma apical complex biogenesis. Proc Natl Acad Sci U S A 2020; 117:12164-12173. [PMID: 32409604 PMCID: PMC7275706 DOI: 10.1073/pnas.1921245117] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Apicomplexan parasites include organisms that cause widespread and devastating human diseases such as malaria, cryptosporidiosis, and toxoplasmosis. These parasites are named for a structure, called the “apical complex,” that organizes their invasion and secretory machinery. We found that two proteins, apical cap protein 9 (AC9) and an enzyme called ERK7, work together to facilitate apical complex assembly. Intriguingly, ERK7 is an ancient molecule that is found throughout Eukaryota, though its regulation and function are poorly understood. AC9 is a scaffold that concentrates ERK7 at the base of the developing apical complex. In addition, AC9 binding likely confers substrate selectivity upon ERK7. This simple competitive regulatory model may be a powerful but largely overlooked mechanism throughout biology. Apicomplexan parasites use a specialized cilium structure called the apical complex to organize their secretory organelles and invasion machinery. The apical complex is integrally associated with both the parasite plasma membrane and an intermediate filament cytoskeleton called the inner-membrane complex (IMC). While the apical complex is essential to the parasitic lifestyle, little is known about the regulation of apical complex biogenesis. Here, we identify AC9 (apical cap protein 9), a largely intrinsically disordered component of the Toxoplasma gondii IMC, as essential for apical complex development, and therefore for host cell invasion and egress. Parasites lacking AC9 fail to successfully assemble the tubulin-rich core of their apical complex, called the conoid. We use proximity biotinylation to identify the AC9 interaction network, which includes the kinase extracellular signal-regulated kinase 7 (ERK7). Like AC9, ERK7 is required for apical complex biogenesis. We demonstrate that AC9 directly binds ERK7 through a conserved C-terminal motif and that this interaction is essential for ERK7 localization and function at the apical cap. The crystal structure of the ERK7–AC9 complex reveals that AC9 is not only a scaffold but also inhibits ERK7 through an unusual set of contacts that displaces nucleotide from the kinase active site. ERK7 is an ancient and autoactivating member of the mitogen-activated kinase (MAPK) family and its regulation is poorly understood in all organisms. We propose that AC9 dually regulates ERK7 by scaffolding and concentrating it at its site of action while maintaining it in an “off” state until the specific binding of a true substrate.
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31
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Molestina RE, Stedman TT. Update on BEI Resources for Parasitology and Arthropod Vector Research. Trends Parasitol 2020; 36:321-324. [PMID: 32035817 DOI: 10.1016/j.pt.2020.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/15/2020] [Accepted: 01/15/2020] [Indexed: 10/25/2022]
Abstract
BEI Resources has contributed to the advancement of parasitic diseases research for over 16 years. The accessibility of our reference strains and reagents is relevant to the development of new therapeutics and vaccines. Here we provide a resource update with emphasis on the new assets for toxoplasmosis and vector research.
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Affiliation(s)
- Robert E Molestina
- BEI Resources, American Type Culture Collection, Manassas, VA 20110, USA.
| | - Timothy T Stedman
- BEI Resources, American Type Culture Collection, Manassas, VA 20110, USA
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32
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Markus BM, Bell GW, Lorenzi HA, Lourido S. Optimizing Systems for Cas9 Expression in Toxoplasma gondii. mSphere 2019; 4:e00386-19. [PMID: 31243081 PMCID: PMC6595152 DOI: 10.1128/msphere.00386-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 01/26/2023] Open
Abstract
CRISPR-Cas9 technologies have enabled genome engineering in an unprecedented array of species, accelerating biological studies in both model and nonmodel systems. However, Cas9 can be inherently toxic, which has limited its use in some organisms. We previously described the serendipitous discovery of a single guide RNA (sgRNA) that helped overcome Cas9 toxicity in the apicomplexan parasite Toxoplasma gondii, enabling the first genome-wide loss-of-function screens in any apicomplexan. Even in the presence of the buffering sgRNA, low-level Cas9 toxicity persists and results in frequent loss of Cas9 expression, which can affect the outcome of these screens. Similar Cas9-mediated toxicity has also been described in other organisms. We therefore sought to define the requirements for stable Cas9 expression, comparing different expression constructs and characterizing the role of the buffering sgRNA to understand the basis of Cas9 toxicity. We find that viral 2A peptides can substantially improve the selection and stability of Cas9 expression. We also demonstrate that the sgRNA has two functions: primarily facilitating integration of the Cas9-expression construct following initial genome targeting and secondarily improving long-term parasite fitness by alleviating Cas9 toxicity. We define a set of guidelines for the expression of Cas9 with improved stability and selection stringency, which are directly applicable to a variety of genetic approaches in diverse organisms. Our work also emphasizes the need for further characterizing the effects of Cas9 expression.IMPORTANCE Toxoplasma gondii is an intracellular parasite that causes life-threatening disease in immunocompromised patients and affects the developing fetus when contracted during pregnancy. Closely related species cause malaria and severe diarrhea, thereby constituting leading causes for childhood mortality. Despite their importance to global health, this family of parasites has remained enigmatic. Given its remarkable experimental tractability, T. gondii has emerged as a model also for the study of related parasites. Genetic approaches are important tools for studying the biology of organisms, including T. gondii As such, the recent developments of CRISPR-Cas9-based techniques for genome editing have vastly expanded our ability to study the biology of numerous species. In some organisms, however, CRISPR-Cas9 has been difficult to implement due to its inherent toxicity. Our research characterizes the basis of the observed toxicity, using T. gondii as a model, allowing us to develop approaches to aid the use of CRISPR-Cas9 in diverse species.
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Affiliation(s)
- Benedikt M Markus
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, USA
- University of Freiburg, Faculty of Biology, Freiburg, Germany
| | - George W Bell
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, USA
| | | | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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