1
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Davutoglu MG, Geyer VF, Niese L, Soltwedel JR, Zoccoler ML, Sabatino V, Haase R, Kröger N, Diez S, Poulsen N. Gliding motility of the diatom Craspedostauros australis coincides with the intracellular movement of raphid-specific myosins. Commun Biol 2024; 7:1187. [PMID: 39313522 PMCID: PMC11420354 DOI: 10.1038/s42003-024-06889-w] [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: 04/23/2024] [Accepted: 09/12/2024] [Indexed: 09/25/2024] Open
Abstract
Raphid diatoms are one of the few eukaryotes capable of gliding motility, which is remarkably fast and allows for quasi-instantaneous directional reversals. Besides other mechanistic models, it has been suggested that an actomyosin system provides the force for diatom gliding. However, in vivo data on the dynamics of actin and myosin in diatoms are lacking. In this study, we demonstrate that the raphe-associated actin bundles required for diatom movement do not exhibit a directional turnover of subunits and thus their dynamics do not contribute directly to force generation. By phylogenomic analysis, we identified four raphid diatom-specific myosins in Craspedostauros australis (CaMyo51A-D) and investigated their in vivo localization and dynamics through GFP-tagging. Only CaMyo51B-D but not CaMyo51A exhibited coordinated movement during gliding, consistent with a role in force generation. The characterization of raphid diatom-specific myosins lays the foundation for unraveling the molecular mechanisms that underlie the gliding motility of diatoms.
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Affiliation(s)
- Metin G Davutoglu
- B CUBE - Center for Molecular Bioengineering, TUD Dresden University of Technology, Dresden, Germany
| | - Veikko F Geyer
- B CUBE - Center for Molecular Bioengineering, TUD Dresden University of Technology, Dresden, Germany
| | - Lukas Niese
- B CUBE - Center for Molecular Bioengineering, TUD Dresden University of Technology, Dresden, Germany
| | - Johannes R Soltwedel
- Cluster of Excellence Physics of Life, TUD Dresden University of Technology, Dresden, Germany
| | - Marcelo L Zoccoler
- Cluster of Excellence Physics of Life, TUD Dresden University of Technology, Dresden, Germany
| | - Valeria Sabatino
- B CUBE - Center for Molecular Bioengineering, TUD Dresden University of Technology, Dresden, Germany
| | - Robert Haase
- Cluster of Excellence Physics of Life, TUD Dresden University of Technology, Dresden, Germany
- Center for Scalable Data Analytics and Artificial Intelligence, Faculty of Mathematics and Computer Science, Leipzig University, Leipzig, Germany
| | - Nils Kröger
- B CUBE - Center for Molecular Bioengineering, TUD Dresden University of Technology, Dresden, Germany
- Cluster of Excellence Physics of Life, TUD Dresden University of Technology, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, TUD Dresden University of Technology, Dresden, Germany
| | - Stefan Diez
- B CUBE - Center for Molecular Bioengineering, TUD Dresden University of Technology, Dresden, Germany.
- Cluster of Excellence Physics of Life, TUD Dresden University of Technology, Dresden, Germany.
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
| | - Nicole Poulsen
- B CUBE - Center for Molecular Bioengineering, TUD Dresden University of Technology, Dresden, Germany.
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2
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Liffner B, Absalon S. Expansion microscopy of apicomplexan parasites. Mol Microbiol 2024; 121:619-635. [PMID: 37571814 DOI: 10.1111/mmi.15135] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 07/15/2023] [Accepted: 07/20/2023] [Indexed: 08/13/2023]
Abstract
Apicomplexan parasites comprise significant pathogens of humans, livestock and wildlife, but also represent a diverse group of eukaryotes with interesting and unique cell biology. The study of cell biology in apicomplexan parasites is complicated by their small size, and historically this has required the application of cutting-edge microscopy techniques to investigate fundamental processes like mitosis or cell division in these organisms. Recently, a technique called expansion microscopy has been developed, which rather than increasing instrument resolution like most imaging modalities, physically expands a biological sample. In only a few years since its development, a derivative of expansion microscopy known as ultrastructure-expansion microscopy (U-ExM) has been widely adopted and proven extremely useful for studying cell biology of Apicomplexa. Here, we review the insights into apicomplexan cell biology that have been enabled through the use of U-ExM, with a specific focus on Plasmodium, Toxoplasma and Cryptosporidium. Further, we summarize emerging expansion microscopy modifications and modalities and forecast how these may influence the field of parasite cell biology in future.
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Affiliation(s)
- Benjamin Liffner
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Sabrina Absalon
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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3
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Reber S, Singer M, Frischknecht F. Cytoskeletal dynamics in parasites. Curr Opin Cell Biol 2024; 86:102277. [PMID: 38048658 DOI: 10.1016/j.ceb.2023.102277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/12/2023] [Accepted: 10/17/2023] [Indexed: 12/06/2023]
Abstract
Cytoskeletal dynamics are essential for cellular homeostasis and development for both metazoans and protozoans. The function of cytoskeletal elements in protozoans can diverge from that of metazoan cells, with microtubules being more stable and actin filaments being more dynamic. This is particularly striking in protozoan parasites that evolved to enter metazoan cells. Here, we review recent progress towards understanding cytoskeletal dynamics in protozoan parasites, with a focus on divergent properties compared to classic model organisms.
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Affiliation(s)
- Simone Reber
- Max Planck Institute for Infection Biology, 10117 Berlin, Germany; University of Applied Sciences Berlin, 13353 Berlin, Germany
| | - Mirko Singer
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical Faculty, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; German Center for Infection Research, DZIF Partner Site Heidelberg, Heidelberg, Germany.
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical Faculty, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; German Center for Infection Research, DZIF Partner Site Heidelberg, Heidelberg, Germany
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4
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Wagner M, Song Y, Jiménez-Ruiz E, Härtle S, Meissner M. The SUN-like protein TgSLP1 is essential for nuclear division in the apicomplexan parasite Toxoplasma gondii. J Cell Sci 2023; 136:jcs260337. [PMID: 37815466 PMCID: PMC10629696 DOI: 10.1242/jcs.260337] [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: 06/14/2022] [Accepted: 09/22/2023] [Indexed: 10/11/2023] Open
Abstract
Connections between the nucleus and the cytoskeleton are important for positioning and division of the nucleus. In most eukaryotes, the linker of nucleoskeleton and cytoskeleton (LINC) complex spans the outer and inner nuclear membranes and connects the nucleus to the cytoskeleton. In opisthokonts, it is composed of Klarsicht, ANC-1 and Syne homology (KASH) domain proteins and Sad1 and UNC-84 (SUN) domain proteins. Given that the nucleus is positioned at the posterior pole of Toxoplasma gondii, we speculated that apicomplexan parasites must have a similar mechanism that integrates the nucleus and the cytoskeleton. Here, we identified three UNC family proteins in the genome of the apicomplexan parasite T. gondii. Whereas the UNC-50 protein TgUNC1 localised to the Golgi and appeared to be not essential for the parasite, the SUN domain protein TgSLP2 showed a diffuse pattern throughout the parasite. The second SUN domain protein, TgSLP1, was expressed in a cell cycle-dependent manner and was localised close to the mitotic spindle and, more detailed, at the kinetochore. We demonstrate that conditional knockout of TgSLP1 leads to failure of nuclear division and loss of centrocone integrity.
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Affiliation(s)
- Mirjam Wagner
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, 82152, Planegg, Germany
| | - Yuan Song
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, 82152, Planegg, Germany
| | - Elena Jiménez-Ruiz
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, 82152, Planegg, Germany
| | - Sonja Härtle
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, 82152, Planegg, Germany
| | - Markus Meissner
- Experimental Parasitology, Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, LMU, Munich, 82152, Planegg, Germany
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5
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Tengganu IF, Arias Padilla LF, Munera Lopez J, Liu J, Brown PT, Murray JM, Hu K. The cortical microtubules of Toxoplasma gondii underlie the helicity of parasite movement. J Cell Sci 2023; 136:jcs261270. [PMID: 37675776 PMCID: PMC10499027 DOI: 10.1242/jcs.261270] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 08/04/2023] [Indexed: 09/08/2023] Open
Abstract
Motility is essential for apicomplexan parasites to infect their hosts. In a three-dimensional (3D) environment, the apicomplexan parasite Toxoplasma gondii moves along a helical path. The cortical microtubules, which are ultra-stable and spirally arranged, have been considered to be a structure that guides the long-distance movement of the parasite. Here, we address the role of the cortical microtubules in parasite motility, invasion and egress by utilizing a previously generated mutant (dubbed 'TKO') in which these microtubules are destabilized in mature parasites. We found that the cortical microtubules in ∼80% of the non-dividing (i.e. daughter-free) TKO parasites are much shorter than normal. The extent of depolymerization was further exacerbated upon commencement of daughter formation or cold treatment, but parasite replication was not affected. In a 3D Matrigel matrix, the TKO mutant moved directionally over long distances, but along trajectories that were significantly more linear (i.e. less helical) than those of wild-type parasites. Interestingly, this change in trajectory did not impact either movement speed in the matrix or the speed and behavior of the parasite during entry into and egress from the host cell.
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Affiliation(s)
- Isadonna F. Tengganu
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, AZ 85284, USA
| | - Luisa F. Arias Padilla
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, AZ 85284, USA
| | - Jonathan Munera Lopez
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, AZ 85284, USA
| | - Jun Liu
- Department of Biology, Indiana University, Bloomington, ID 47405, USA
| | - Peter T. Brown
- Department of Physics and Center for Biological Physics, Arizona State University, Tempe, AZ 85284, USA
| | - John M. Murray
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, AZ 85284, USA
| | - Ke Hu
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, AZ 85284, USA
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6
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Midya J, Auth T, Gompper G. Membrane-Mediated Interactions Between Nonspherical Elastic Particles. ACS NANO 2023; 17:1935-1945. [PMID: 36669092 PMCID: PMC9933614 DOI: 10.1021/acsnano.2c05801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
The transport of particles across lipid-bilayer membranes is important for biological cells to exchange information and material with their environment. Large particles often get wrapped by membranes, a process which has been intensively investigated in the case of hard particles. However, many particles in vivo and in vitro are deformable, e.g., vesicles, filamentous viruses, macromolecular condensates, polymer-grafted nanoparticles, and microgels. Vesicles may serve as a generic model system for deformable particles. Here, we study nonspherical vesicles with various sizes, shapes, and elastic properties at initially planar lipid-bilayer membranes. Using the Helfrich Hamiltonian, triangulated membranes, and energy minimization, we predict the interplay of vesicle shapes and wrapping states. Increasing particle softness enhances the stability of shallow-wrapped and deep-wrapped states over nonwrapped and complete-wrapped states. The free membrane mediates an interaction between partial-wrapped vesicles. For the pair interaction between deep-wrapped vesicles, we predict repulsion. For shallow-wrapped vesicles, we predict attraction for tip-to-tip orientation and repulsion for side-by-side orientation. Our predictions may guide the design and fabrication of deformable particles for efficient use in medical applications, such as targeted drug delivery.
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Affiliation(s)
- Jiarul Midya
- Theoretical Physics of Living Matter,
Institute for Biological Information Processing and Institute for
Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Thorsten Auth
- Theoretical Physics of Living Matter,
Institute for Biological Information Processing and Institute for
Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Gerhard Gompper
- Theoretical Physics of Living Matter,
Institute for Biological Information Processing and Institute for
Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
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7
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Yee M, Walther T, Frischknecht F, Douglas RG. Divergent Plasmodium actin residues are essential for filament localization, mosquito salivary gland invasion and malaria transmission. PLoS Pathog 2022; 18:e1010779. [PMID: 35998188 PMCID: PMC9439217 DOI: 10.1371/journal.ppat.1010779] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 09/02/2022] [Accepted: 07/29/2022] [Indexed: 11/18/2022] Open
Abstract
Actin is one of the most conserved and ubiquitous proteins in eukaryotes. Its sequence has been highly conserved for its monomers to self-assemble into filaments that mediate essential cell functions such as trafficking, cell shape and motility. The malaria-causing parasite, Plasmodium, expresses a highly sequence divergent actin that is critical for its rapid motility at different stages within its mammalian and mosquito hosts. Each of Plasmodium actin’s four subdomains have divergent regions compared to canonical vertebrate actins. We previously identified subdomains 2 and 3 as providing critical contributions for parasite actin function as these regions could not be replaced by subdomains of vertebrate actins. Here we probed the contributions of individual divergent amino acid residues in these subdomains on parasite motility and progression. Non-lethal changes in these subdomains did not affect parasite development in the mammalian host but strongly affected progression through the mosquito with striking differences in transmission to and through the insect. Live visualization of actin filaments showed that divergent amino acid residues in subdomains 2 and 4 enhanced localization associated with filaments, while those in subdomain 3 negatively affected actin filaments. This suggests that finely tuned actin dynamics are essential for efficient organ entry in the mosquito vector affecting malaria transmission. This work provides residue level insight on the fundamental requirements of actin in highly motile cells. Actin is one of the most abundant and conserved proteins known. Actin monomers can join together to form long filaments. The malaria-causing parasite is transmitted by mosquitoes and needs actin to move very rapidly. An actin from the parasite is different to other actins: its amino acid sequence has relatively high amounts of changes compared to animal species and the actin tends to form only short filaments. We previously identified two large parts of the protein that were critical for the parasite since these large parts could not be exchanged with the equivalent regions of other species. In this study, we focused in on these regions by making more discrete mutations. Most mutations of the actin sequence were tolerated by the parasite in the blood stages. However, these mutants has striking defects in progressing through mosquitoes, especially in invading its salivary glands. We used a new filament labeler to visualize how these mutations affect the actin filaments and found surprisingly different effects. Taken together, small changes to the sequence can have large consequences for the parasite, which ultimately affects its ability to transmit to a new host.
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Affiliation(s)
- Michelle Yee
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
| | - Tobias Walther
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
- German Centre for Infection Research, DZIF, partner site Heidelberg, Heidelberg, Germany
- * E-mail: (FF); (RGD)
| | - Ross G. Douglas
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
- Biochemistry and Molecular Biology, Interdisciplinary Research Centre and Molecular Infection Biology, Biomedical Research Centre Seltersberg, Justus Liebig University Giessen, Giessen, Germany
- * E-mail: (FF); (RGD)
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8
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Munera Lopez J, Tengganu IF, Liu J, Murray JM, Arias Padilla LF, Zhang Y, Brown PT, Florens L, Hu K. An apical protein, Pcr2, is required for persistent movement by the human parasite Toxoplasma gondii. PLoS Pathog 2022; 18:e1010776. [PMID: 35994509 PMCID: PMC9436145 DOI: 10.1371/journal.ppat.1010776] [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: 05/20/2022] [Revised: 09/01/2022] [Accepted: 07/28/2022] [Indexed: 11/18/2022] Open
Abstract
The phylum Apicomplexa includes thousands of species of unicellular parasites that cause a wide range of human and animal diseases such as malaria and toxoplasmosis. To infect, the parasite must first initiate active movement to disseminate through tissue and invade into a host cell, and then cease moving once inside. The parasite moves by gliding on a surface, propelled by an internal cortical actomyosin-based motility apparatus. One of the most effective invaders in Apicomplexa is Toxoplasma gondii, which can infect any nucleated cell and any warm-blooded animal. During invasion, the parasite first makes contact with the host cell "head-on" with the apical complex, which features an elaborate cytoskeletal apparatus and associated structures. Here we report the identification and characterization of a new component of the apical complex, Preconoidal region protein 2 (Pcr2). Pcr2 knockout parasites replicate normally, but they are severely diminished in their capacity for host tissue destruction due to significantly impaired invasion and egress, two vital steps in the lytic cycle. When stimulated for calcium-induced egress, Pcr2 knockout parasites become active, and secrete effectors to lyse the host cell. Calcium-induced secretion of the major adhesin, MIC2, also appears to be normal. However, the movement of the Pcr2 knockout parasite is spasmodic, which drastically compromises egress. In addition to faulty motility, the ability of the Pcr2 knockout parasite to assemble the moving junction is impaired. Both defects likely contribute to the poor efficiency of invasion. Interestingly, actomyosin activity, as indicated by the motion of mEmerald tagged actin chromobody, appears to be largely unperturbed by the loss of Pcr2, raising the possibility that Pcr2 may act downstream of or in parallel with the actomyosin machinery.
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Affiliation(s)
- Jonathan Munera Lopez
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Isadonna F. Tengganu
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Jun Liu
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - John M. Murray
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Luisa F. Arias Padilla
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Ying Zhang
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Peter T. Brown
- Department of Physics and Center for Biological Physics, Arizona State University, Tempe, Arizona, United States of America
| | - Laurence Florens
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Ke Hu
- Biodesign Center for Mechanisms of Evolution/School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- * E-mail:
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9
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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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10
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Ultrastructure of Myzocytosis and Cyst Formation, and the Role of Actin in Tubular Tether Formation in Colpodella sp. (ATCC 50594). Pathogens 2022; 11:pathogens11040455. [PMID: 35456130 PMCID: PMC9027189 DOI: 10.3390/pathogens11040455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/06/2022] [Accepted: 04/06/2022] [Indexed: 02/04/2023] Open
Abstract
Free-living relatives of the Apicomplexa such as Colpodella species, Alphamonas species, and Voromonas pontica are predators that prey on ciliate, bodonid, and algal prey using the process of myzocytosis. During myzocytosis, the pseudoconoid is used to attach to the prey leading to aspiration of cytoplasmic contents of the prey into a posterior food vacuole formed in the predator, aided by secretions from the apical complex organelles. The conoid and associated proteins are conserved among the apicomplexa. However, the organization and function of the pseudoconoid during myzocytosis are not well understood. In this study, we investigated the morphology and ultrastructure of Colpodella sp. (ATCC 50594) during the stages of myzocytosis and cyst formation in the life cycle using light microscopy and transmission electron microscopy (TEM) in order to identify the organization of the tubular tether involved in nutrient aspiration by Colpodella sp. Tubular tethers of varying lengths were identified by light microscopy. We report that initial contact by Colpodella sp. trophozoites with Parabodo caudatus prey is by an area posterior to the apical tip of the rostrum that engulfs the membrane of the prey pulling it into the cytoplasm of the predator. The tubular tether that forms contains membranes of both predator and prey and is facilitated by microtubule organization and the cytoskeleton at the point of contact. Cytochalasin D treatment of diprotist cultures resulted in morphological distortions of trophozoites and the tubular tether suggesting a role of actin in the formation of the tubular tether. This mechanism of predation may provide insight into the mode of invasion observed in pathogenic apicomplexan zoites during host cell entry.
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11
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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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12
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Menard KL, Bu L, Denkers EY. Transcriptomics analysis of Toxoplasma gondii-infected mouse macrophages reveals coding and noncoding signatures in the presence and absence of MyD88. BMC Genomics 2021; 22:130. [PMID: 33622246 PMCID: PMC7903719 DOI: 10.1186/s12864-021-07437-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 02/11/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Toxoplasma gondii is a globally distributed protozoan parasite that establishes life-long asymptomatic infection in humans, often emerging as a life-threatening opportunistic pathogen during immunodeficiency. As an intracellular microbe, Toxoplasma establishes an intimate relationship with its host cell from the outset of infection. Macrophages are targets of infection and they are important in early innate immunity and possibly parasite dissemination throughout the host. Here, we employ an RNA-sequencing approach to identify host and parasite transcriptional responses during infection of mouse bone marrow-derived macrophages (BMDM). We incorporated into our analysis infection with the high virulence Type I RH strain and the low virulence Type II strain PTG. Because the well-known TLR-MyD88 signaling axis is likely of less importance in humans, we examined transcriptional responses in both MyD88+/+ and MyD88-/- BMDM. Long noncoding (lnc) RNA molecules are emerging as key regulators in infection and immunity, and were, therefore, included in our analysis. RESULTS We found significantly more host genes were differentially expressed in response to the highly virulent RH strain rather than with the less virulent PTG strain (335 versus 74 protein coding genes for RH and PTG, respectively). Enriched in these protein coding genes were subsets associated with the immune response as well as cell adhesion and migration. We identified 249 and 83 non-coding RNAs as differentially expressed during infection with RH and PTG strains, respectively. Although the majority of these are of unknown function, one conserved lncRNA termed mir17hg encodes the mir17 microRNA gene cluster that has been implicated in down-regulating host cell apoptosis during T. gondii infection. Only a minimal number of transcripts were differentially expressed between MyD88 knockout and wild type cells. However, several immune genes were among the differences. While transcripts for parasite secretory proteins were amongst the most highly expressed T. gondii genes during infection, no differentially expressed parasite genes were identified when comparing infection in MyD88 knockout and wild type host BMDM. CONCLUSIONS The large dataset presented here lays the groundwork for continued studies on both the MyD88-independent immune response and the function of lncRNAs during Toxoplasma gondii infection.
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Affiliation(s)
- Kayla L Menard
- Center for Evolutionary and Theoretical Immunology and Department of Biology, University of New Mexico, Albuquerque, NM, USA.
| | - Lijing Bu
- Center for Evolutionary and Theoretical Immunology and Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Eric Y Denkers
- Center for Evolutionary and Theoretical Immunology and Department of Biology, University of New Mexico, Albuquerque, NM, USA.
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13
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Blake TCA, Haase S, Baum J. Actomyosin forces and the energetics of red blood cell invasion by the malaria parasite Plasmodium falciparum. PLoS Pathog 2020; 16:e1009007. [PMID: 33104759 PMCID: PMC7644091 DOI: 10.1371/journal.ppat.1009007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/05/2020] [Accepted: 09/28/2020] [Indexed: 11/29/2022] Open
Abstract
All symptoms of malaria disease are associated with the asexual blood stages of development, involving cycles of red blood cell (RBC) invasion and egress by the Plasmodium spp. merozoite. Merozoite invasion is rapid and is actively powered by a parasite actomyosin motor. The current accepted model for actomyosin force generation envisages arrays of parasite myosins, pushing against short actin filaments connected to the external milieu that drive the merozoite forwards into the RBC. In Plasmodium falciparum, the most virulent human malaria species, Myosin A (PfMyoA) is critical for parasite replication. However, the precise function of PfMyoA in invasion, its regulation, the role of other myosins and overall energetics of invasion remain unclear. Here, we developed a conditional mutagenesis strategy combined with live video microscopy to probe PfMyoA function and that of the auxiliary motor PfMyoB in invasion. By imaging conditional mutants with increasing defects in force production, based on disruption to a key PfMyoA phospho-regulation site, the absence of the PfMyoA essential light chain, or complete motor absence, we define three distinct stages of incomplete RBC invasion. These three defects reveal three energetic barriers to successful entry: RBC deformation (pre-entry), mid-invasion initiation, and completion of internalisation, each requiring an active parasite motor. In defining distinct energetic barriers to invasion, these data illuminate the mechanical challenges faced in this remarkable process of protozoan parasitism, highlighting distinct myosin functions and identifying potential targets for preventing malaria pathogenesis.
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Affiliation(s)
- Thomas C. A. Blake
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
| | - Silvia Haase
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
| | - Jake Baum
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
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14
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The Riveting Cellular Structures of Apicomplexan Parasites. Trends Parasitol 2020; 36:979-991. [PMID: 33011071 DOI: 10.1016/j.pt.2020.09.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/31/2020] [Accepted: 09/03/2020] [Indexed: 12/21/2022]
Abstract
Parasitic protozoa of the phylum Apicomplexa cause a range of human and animal diseases. Their complex life cycles - often heteroxenous with sexual and asexual phases in different hosts - rely on elaborate cytoskeletal structures to enable morphogenesis and motility, organize cell division, and withstand diverse environmental forces. This review primarily focuses on studies using Toxoplasma gondii and Plasmodium spp. as the best studied apicomplexans; however, many cytoskeletal adaptations are broadly conserved and predate the emergence of the parasitic phylum. After decades cataloguing the constituents of such structures, a dynamic picture is emerging of the assembly and maintenance of apicomplexan cytoskeletons, illuminating how they template and orient critical processes during infection. These observations impact our view of eukaryotic diversity and offer future challenges for cell biology.
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15
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Pavlou G, Touquet B, Vigetti L, Renesto P, Bougdour A, Debarre D, Balland M, Tardieux I. Coupling Polar Adhesion with Traction, Spring, and Torque Forces Allows High-Speed Helical Migration of the Protozoan Parasite Toxoplasma. ACS NANO 2020; 14:7121-7139. [PMID: 32432851 DOI: 10.1021/acsnano.0c01893] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Among the eukaryotic cells that navigate through fully developed metazoan tissues, protozoans from the Apicomplexa phylum have evolved motile developmental stages that move much faster than the fastest crawling cells owing to a peculiar substrate-dependent type of motility, known as gliding. Best-studied models are the Plasmodium sporozoite and the Toxoplasma tachyzoite polarized cells for which motility is vital to achieve their developmental programs in the metazoan hosts. The gliding machinery is shared between the two parasites and is largely characterized. Localized beneath the cell surface, it includes actin filaments, unconventional myosin motors housed within a multimember glideosome unit, and apically secreted transmembrane adhesins. In contrast, less is known about the force mechanisms powering cell movement. Pioneered biophysical studies on the sporozoite and phenotypic analysis of tachyzoite actin-related mutants have added complexity to the general view that force production for parasite forward movement directly results from the myosin-driven rearward motion of the actin-coupled adhesion sites. Here, we have interrogated how forces and substrate adhesion-de-adhesion cycles operate and coordinate to allow the typical left-handed helical gliding mode of the tachyzoite. By combining quantitative traction force and reflection interference microscopy with micropatterning and expansion microscopy, we unveil at the millisecond and nanometer scales the integration of a critical apical anchoring adhesion with specific traction and spring-like forces. We propose that the acto-myoA motor directs the traction force which allows transient energy storage by the microtubule cytoskeleton and therefore sets the thrust force required for T. gondii tachyzoite vital helical gliding capacity.
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Affiliation(s)
- Georgios Pavlou
- Institute for Advanced Biosciences (IAB), Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR5309, INSERM U1209, Université Grenoble Alpes, 38700 Grenoble, France
| | - Bastien Touquet
- Institute for Advanced Biosciences (IAB), Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR5309, INSERM U1209, Université Grenoble Alpes, 38700 Grenoble, France
| | - Luis Vigetti
- Institute for Advanced Biosciences (IAB), Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR5309, INSERM U1209, Université Grenoble Alpes, 38700 Grenoble, France
| | - Patricia Renesto
- Institute for Advanced Biosciences (IAB), Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR5309, INSERM U1209, Université Grenoble Alpes, 38700 Grenoble, France
- TIMC-IMAG UMR 5525 - UGA CNRS, 38700 Grenoble, France
| | - Alexandre Bougdour
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions & Immunity to Infections, CNRS UMR5309, INSERM U1209, Université Grenoble Alpes, 38700 Grenoble, France
| | - Delphine Debarre
- Laboratoire Interdisciplinaire de Physique, UMR CNRS, 5588, Université Grenoble Alpes, Grenoble 38402, France
| | - Martial Balland
- Laboratoire Interdisciplinaire de Physique, UMR CNRS, 5588, Université Grenoble Alpes, Grenoble 38402, France
| | - Isabelle Tardieux
- Institute for Advanced Biosciences (IAB), Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR5309, INSERM U1209, Université Grenoble Alpes, 38700 Grenoble, France
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16
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Venugopal K, Chehade S, Werkmeister E, Barois N, Periz J, Lafont F, Tardieux I, Khalife J, Langsley G, Meissner M, Marion S. Rab11A regulates dense granule transport and secretion during Toxoplasma gondii invasion of host cells and parasite replication. PLoS Pathog 2020; 16:e1008106. [PMID: 32463830 PMCID: PMC7255593 DOI: 10.1371/journal.ppat.1008106] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 02/10/2020] [Indexed: 12/31/2022] Open
Abstract
Toxoplasma gondii possesses an armada of secreted virulent factors that enable parasite invasion and survival into host cells. These factors are contained in specific secretory organelles, the rhoptries, micronemes and dense granules that release their content upon host cell recognition. Dense granules are secreted in a constitutive manner during parasite replication and play a crucial role in modulating host metabolic and immune responses. While the molecular mechanisms triggering rhoptry and microneme release upon host cell adhesion have been well studied, constitutive secretion remains a poorly explored aspect of T. gondii vesicular trafficking. Here, we investigated the role of the small GTPase Rab11A, a known regulator of exocytosis in eukaryotic cells. Our data revealed an essential role of Rab11A in promoting the cytoskeleton driven transport of dense granules and the release of their content into the vacuolar space. Rab11A also regulates transmembrane protein trafficking and localization during parasite replication, indicating a broader role of Rab11A in cargo exocytosis at the plasma membrane. Moreover, we found that Rab11A also regulates extracellular parasite motility and adhesion to host cells. In line with these findings, MIC2 secretion was altered in Rab11A-defective parasites, which also exhibited severe morphological defects. Strikingly, by live imaging we observed a polarized accumulation of Rab11A-positive vesicles and dense granules at the apical pole of extracellular motile and invading parasites suggesting that apically polarized Rab11A-dependent delivery of cargo regulates early secretory events during parasite entry into host cells. Toxoplasma gondii (T. gondii) is a highly prevalent parasite infecting a wide range of animals as well as humans. T. gondii secretes numerous virulent factors contained in specific organelles, termed the rhoptries, micronemes and dense granules. These factors are released upon host cell recognition and enable parasite invasion and subsequent development into an intracellular vacuole. In particular, dense granules contain critical effectors that modulate intrinsic defenses of infected host cells ensuring parasite survival and dissemination. The mechanisms regulating dense granule secretion have not been elucidated. In this study, we unraveled a novel role for the T. gondii GTPase Rab11A in promoting dense granule transport along the parasite cytoskeleton and their content release into the vacuolar space during parasite replication. We also found that T. gondii Rab11A regulates extracellular parasite motility and adhesion to host cells suggesting a broader role in distinct secretory pathways essential for parasite virulence.
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Affiliation(s)
- Kannan Venugopal
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, Lille, France
| | - Sylia Chehade
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, Lille, France
| | - Elisabeth Werkmeister
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, Lille, France
| | - Nicolas Barois
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, Lille, France
| | - Javier Periz
- Department of Veterinary Sciences, Experimental Parasitology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Frank Lafont
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, Lille, France
| | - Isabelle Tardieux
- Institute for Advanced Biosciences (IAB), Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR5309, INSERM U1209, Université Grenoble Alpes, Grenoble, France
| | - Jamal Khalife
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, Lille, France
| | - Gordon Langsley
- Laboratoire de Biologie Comparative des Apicomplexes, Faculté de Médicine, Université Paris Descartes—Sorbonne Paris Cité, France, INSERM U1016, CNRS UMR8104, Institut Cochin, Paris, France
| | - Markus Meissner
- Department of Veterinary Sciences, Experimental Parasitology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Sabrina Marion
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, Lille, France
- * E-mail:
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17
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Del Rosario M, Periz J, Pavlou G, Lyth O, Latorre‐Barragan F, Das S, Pall GS, Stortz JF, Lemgruber L, Whitelaw JA, Baum J, Tardieux I, Meissner M. Apicomplexan F-actin is required for efficient nuclear entry during host cell invasion. EMBO Rep 2019; 20:e48896. [PMID: 31584242 PMCID: PMC6893294 DOI: 10.15252/embr.201948896] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 08/21/2019] [Accepted: 09/11/2019] [Indexed: 12/16/2022] Open
Abstract
The obligate intracellular parasites Toxoplasma gondii and Plasmodium spp. invade host cells by injecting a protein complex into the membrane of the targeted cell that bridges the two cells through the assembly of a ring-like junction. This circular junction stretches while the parasites apply a traction force to pass through, a step that typically concurs with transient constriction of the parasite body. Here we analyse F-actin dynamics during host cell invasion. Super-resolution microscopy and real-time imaging highlighted an F-actin pool at the apex of pre-invading parasite, an F-actin ring at the junction area during invasion but also networks of perinuclear and posteriorly localised F-actin. Mutant parasites with dysfunctional acto-myosin showed significant decrease of junctional and perinuclear F-actin and are coincidently affected in nuclear passage through the junction. We propose that the F-actin machinery eases nuclear passage by stabilising the junction and pushing the nucleus through the constriction. Our analysis suggests that the junction opposes resistance to the passage of the parasite's nucleus and provides the first evidence for a dual contribution of actin-forces during host cell invasion by apicomplexan parasites.
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Affiliation(s)
- Mario Del Rosario
- Wellcome Centre For Integrative ParasitologyInstitute of InfectionImmunity & Inflammation, Glasgow Biomedical Research CentreUniversity of GlasgowGlasgowUK
| | - Javier Periz
- Wellcome Centre For Integrative ParasitologyInstitute of InfectionImmunity & Inflammation, Glasgow Biomedical Research CentreUniversity of GlasgowGlasgowUK
| | - Georgios Pavlou
- Institute for Advanced BiosciencesCNRS, UMR5309, INSERM U1209Université Grenoble AlpesGrenobleFrance
| | - Oliver Lyth
- Department of Life SciencesImperial College LondonLondonUK
| | - Fernanda Latorre‐Barragan
- Wellcome Centre For Integrative ParasitologyInstitute of InfectionImmunity & Inflammation, Glasgow Biomedical Research CentreUniversity of GlasgowGlasgowUK
- Faculty of Science, Food Engineering and BiotechnologyTechnical University of AmbatoAmbatoEcuador
| | - Sujaan Das
- Wellcome Centre For Integrative ParasitologyInstitute of InfectionImmunity & Inflammation, Glasgow Biomedical Research CentreUniversity of GlasgowGlasgowUK
| | - Gurman S Pall
- Wellcome Centre For Integrative ParasitologyInstitute of InfectionImmunity & Inflammation, Glasgow Biomedical Research CentreUniversity of GlasgowGlasgowUK
| | - Johannes Felix Stortz
- Wellcome Centre For Integrative ParasitologyInstitute of InfectionImmunity & Inflammation, Glasgow Biomedical Research CentreUniversity of GlasgowGlasgowUK
| | - Leandro Lemgruber
- Wellcome Centre For Integrative ParasitologyInstitute of InfectionImmunity & Inflammation, Glasgow Biomedical Research CentreUniversity of GlasgowGlasgowUK
| | | | - Jake Baum
- Department of Life SciencesImperial College LondonLondonUK
| | - Isabelle Tardieux
- Institute for Advanced BiosciencesCNRS, UMR5309, INSERM U1209Université Grenoble AlpesGrenobleFrance
| | - Markus Meissner
- Wellcome Centre For Integrative ParasitologyInstitute of InfectionImmunity & Inflammation, Glasgow Biomedical Research CentreUniversity of GlasgowGlasgowUK
- Experimental ParasitologyDepartment for Veterinary SciencesLudwig‐Maximilians‐University Munich MunichGermany
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18
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Hunt A, Russell MRG, Wagener J, Kent R, Carmeille R, Peddie CJ, Collinson L, Heaslip A, Ward GE, Treeck M. Differential requirements for cyclase-associated protein (CAP) in actin-dependent processes of Toxoplasma gondii. eLife 2019; 8:e50598. [PMID: 31577230 PMCID: PMC6785269 DOI: 10.7554/elife.50598] [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: 07/30/2019] [Accepted: 09/26/2019] [Indexed: 12/26/2022] Open
Abstract
Toxoplasma gondii contains a limited subset of actin binding proteins. Here we show that the putative actin regulator cyclase-associated protein (CAP) is present in two different isoforms and its deletion leads to significant defects in some but not all actin dependent processes. We observe defects in cell-cell communication, daughter cell orientation and the juxtanuclear accumulation of actin, but only modest defects in synchronicity of division and no defect in the replication of the apicoplast. 3D electron microscopy reveals that loss of CAP results in a defect in formation of a normal central residual body, but parasites remain connected within the vacuole. This dissociates synchronicity of division and parasite rosetting and reveals that establishment and maintenance of the residual body may be more complex than previously thought. These results highlight the different spatial requirements for F-actin regulation in Toxoplasma which appear to be achieved by partially overlapping functions of actin regulators.
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Affiliation(s)
- Alex Hunt
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | | | - Jeanette Wagener
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Robyn Kent
- Department of Microbiology and Molecular GeneticsUniversity of Vermont Larner College of MedicineBurlingtonUnited States
| | - Romain Carmeille
- Department of Molecular and Cell BiologyUniversity of ConnecticutStorrsUnited States
| | - Christopher J Peddie
- Electron Microscopy Science Technology Platform, The Francis Crick InstituteLondonUnited Kingdom
| | - Lucy Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick InstituteLondonUnited Kingdom
| | - Aoife Heaslip
- Department of Molecular and Cell BiologyUniversity of ConnecticutStorrsUnited States
| | - Gary E Ward
- Department of Microbiology and Molecular GeneticsUniversity of Vermont Larner College of MedicineBurlingtonUnited States
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
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