1
|
Stürmer VS, Stopper S, Binder P, Klemmer A, Lichti NP, Becker NB, Guizetti J. Progeny counter mechanism in malaria parasites is linked to extracellular resources. PLoS Pathog 2023; 19:e1011807. [PMID: 38051755 PMCID: PMC10723702 DOI: 10.1371/journal.ppat.1011807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 12/15/2023] [Accepted: 11/07/2023] [Indexed: 12/07/2023] Open
Abstract
Malaria is caused by the rapid proliferation of Plasmodium parasites in patients and disease severity correlates with the number of infected red blood cells in circulation. Parasite multiplication within red blood cells is called schizogony and occurs through an atypical multinucleated cell division mode. The mechanisms regulating the number of daughter cells produced by a single progenitor are poorly understood. We investigated underlying regulatory principles by quantifying nuclear multiplication dynamics in Plasmodium falciparum and knowlesi using super-resolution time-lapse microscopy. This confirmed that the number of daughter cells was consistent with a model in which a counter mechanism regulates multiplication yet incompatible with a timer mechanism. P. falciparum cell volume at the start of nuclear division correlated with the final number of daughter cells. As schizogony progressed, the nucleocytoplasmic volume ratio, which has been found to be constant in all eukaryotes characterized so far, increased significantly, possibly to accommodate the exponentially multiplying nuclei. Depleting nutrients by dilution of culture medium caused parasites to produce fewer merozoites and reduced proliferation but did not affect cell volume or total nuclear volume at the end of schizogony. Our findings suggest that the counter mechanism implicated in malaria parasite proliferation integrates extracellular resource status to modify progeny number during blood stage infection.
Collapse
Affiliation(s)
- Vanessa S. Stürmer
- Heidelberg University Medical Faculty, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Sophie Stopper
- Heidelberg University Medical Faculty, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Patrick Binder
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
- Theoretical Systems Biology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Anja Klemmer
- Heidelberg University Medical Faculty, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Nicolas P. Lichti
- Heidelberg University Medical Faculty, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Nils B. Becker
- Theoretical Systems Biology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Julien Guizetti
- Heidelberg University Medical Faculty, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
2
|
Voß Y, Klaus S, Lichti NP, Ganter M, Guizetti J. Malaria parasite centrins can assemble by Ca2+-inducible condensation. PLoS Pathog 2023; 19:e1011899. [PMID: 38150475 PMCID: PMC10775985 DOI: 10.1371/journal.ppat.1011899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 01/09/2024] [Accepted: 12/13/2023] [Indexed: 12/29/2023] Open
Abstract
Centrins are small calcium-binding proteins that have a variety of roles and are universally associated with eukaryotic centrosomes. Rapid proliferation of the malaria-causing parasite Plasmodium falciparum in the human blood depends on a particularly divergent and acentriolar centrosome, which incorporates several essential centrins. Their precise mode of action, however, remains unclear. In this study calcium-inducible liquid-liquid phase separation is revealed as an evolutionarily conserved principle of assembly for multiple centrins from P. falciparum and other species. Furthermore, the disordered N-terminus and calcium-binding motifs are defined as essential features for reversible biomolecular condensation, and we demonstrate that certain centrins can form co-condensates. In vivo analysis using live cell STED microscopy shows liquid-like dynamics of centrosomal centrin. Additionally, implementation of an inducible protein overexpression system reveals concentration-dependent formation of extra-centrosomal centrin assemblies with condensate-like properties. The timing of foci formation and dissolution suggests that centrin assembly is regulated. This study thereby provides a new model for centrin accumulation at eukaryotic centrosomes.
Collapse
Affiliation(s)
- Yannik Voß
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
- German Center for Infection Research, partner site Heidelberg, Heidelberg, Germany
| | - Severina Klaus
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Nicolas P. Lichti
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Markus Ganter
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Julien Guizetti
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
3
|
Machado M, Klaus S, Klaschka D, Guizetti J, Ganter M. Plasmodium falciparum CRK4 links early mitotic events to the onset of S-phase during schizogony. mBio 2023; 14:e0077923. [PMID: 37345936 PMCID: PMC10470535 DOI: 10.1128/mbio.00779-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 05/03/2023] [Indexed: 06/23/2023] Open
Abstract
Plasmodium falciparum proliferates through schizogony in the clinically relevant blood stage of infection. During schizogony, consecutive rounds of DNA replication and nuclear division give rise to multinucleated stages before cellularization occurs. Although these nuclei reside in a shared cytoplasm, DNA replication and nuclear division occur asynchronously. Here, by mapping the proteomic context of the S-phase-promoting kinase PfCRK4, we show that it has a dual role for nuclear-cycle progression: PfCRK4 orchestrates not only DNA replication, but in parallel also the rearrangement of intranuclear microtubules from hemispindles into early mitotic spindles. Live-cell imaging of a reporter parasite showed that these microtubule rearrangements coincide with the onset of DNA replication. Together, our data render PfCRK4 a key factor for nuclear-cycle progression, linking entry into S-phase with the initiation of mitotic events. In part, such links may compensate for the absence of canonical cell cycle checkpoints in P. falciparum. IMPORTANCE The human malaria parasite Plasmodium falciparum proliferates in erythrocytes through schizogony, forming multinucleated stages before cellularization occurs. In marked contrast to the pattern of proliferation seen in most model organisms, P. falciparum nuclei multiply asynchronously despite residing in a shared cytoplasm. This divergent mode of replication is, thus, a good target for therapeutic interventions. To exploit this potential, we investigated a key regulator of the parasite's unusual cell cycle, the kinase PfCRK4 and found that this kinase regulated not only DNA replication but also in parallel the rearrangement of nuclear microtubules into early mitotic spindles. Since canonical cell cycle checkpoints have not been described in P. falciparum parasites, linking entry into S-phase and the initiation of mitotic events via a kinase, may be an alternative means to exert control, which is typically achieved by checkpoints.
Collapse
Affiliation(s)
- Marta Machado
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
- Graduate Program in Areas of Basic and Applied Biology, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Severina Klaus
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Darius Klaschka
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Julien Guizetti
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Markus Ganter
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
4
|
Wenz C, Simon CS, Romão TP, Stürmer VS, Machado M, Klages N, Klemmer A, Voß Y, Ganter M, Brochet M, Guizetti J. An Sfi1-like centrin-interacting centriolar plaque protein affects nuclear microtubule homeostasis. PLoS Pathog 2023; 19:e1011325. [PMID: 37130129 PMCID: PMC10180636 DOI: 10.1371/journal.ppat.1011325] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 05/12/2023] [Accepted: 03/28/2023] [Indexed: 05/03/2023] Open
Abstract
Malaria-causing parasites achieve rapid proliferation in human blood through multiple rounds of asynchronous nuclear division followed by daughter cell formation. Nuclear divisions critically depend on the centriolar plaque, which organizes intranuclear spindle microtubules. The centriolar plaque consists of an extranuclear compartment, which is connected via a nuclear pore-like structure to a chromatin-free intranuclear compartment. Composition and function of this non-canonical centrosome remain largely elusive. Centrins, which reside in the extranuclear part, are among the very few centrosomal proteins conserved in Plasmodium falciparum. Here we identify a novel centrin-interacting centriolar plaque protein. Conditional knock down of this Sfi1-like protein (PfSlp) caused a growth delay in blood stages, which correlated with a reduced number of daughter cells. Surprisingly, intranuclear tubulin abundance was significantly increased, which raises the hypothesis that the centriolar plaque might be implicated in regulating tubulin levels. Disruption of tubulin homeostasis caused excess microtubules and aberrant mitotic spindles. Time-lapse microscopy revealed that this prevented or delayed mitotic spindle extension but did not significantly interfere with DNA replication. Our study thereby identifies a novel extranuclear centriolar plaque factor and establishes a functional link to the intranuclear compartment of this divergent eukaryotic centrosome.
Collapse
Affiliation(s)
- Christoph Wenz
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | | | | | | | - Marta Machado
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
- Graduate Program in Areas of Basic and Applied Biology, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Natacha Klages
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Anja Klemmer
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Yannik Voß
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Markus Ganter
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Mathieu Brochet
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Julien Guizetti
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
5
|
Klaus S, Binder P, Kim J, Machado M, Funaya C, Schaaf V, Klaschka D, Kudulyte A, Cyrklaff M, Laketa V, Höfer T, Guizetti J, Becker NB, Frischknecht F, Schwarz US, Ganter M. Asynchronous nuclear cycles in multinucleated Plasmodium falciparum facilitate rapid proliferation. Sci Adv 2022; 8:eabj5362. [PMID: 35353560 PMCID: PMC8967237 DOI: 10.1126/sciadv.abj5362] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 02/10/2022] [Indexed: 05/20/2023]
Abstract
Malaria-causing parasites proliferate within erythrocytes through schizogony, forming multinucleated stages before cellularization. Nuclear multiplication does not follow a strict geometric 2n progression, and each proliferative cycle produces a variable number of progeny. Here, by tracking nuclei and DNA replication, we show that individual nuclei replicate their DNA at different times, despite residing in a shared cytoplasm. Extrapolating from experimental data using mathematical modeling, we provide strong indication that a limiting factor exists, which slows down the nuclear multiplication rate. Consistent with this prediction, our data show that temporally overlapping DNA replication events were significantly slower than partially overlapping or nonoverlapping events. Our findings suggest the existence of evolutionary pressure that selects for asynchronous DNA replication, balancing available resources with rapid pathogen proliferation.
Collapse
Affiliation(s)
- Severina Klaus
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Patrick Binder
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
- Theoretical Systems Biology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Juyeop Kim
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Marta Machado
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
- Graduate Program in Areas of Basic and Applied Biology, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Charlotta Funaya
- Electron Microscopy Core Facility, Heidelberg University, Heidelberg, Germany
| | - Violetta Schaaf
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Darius Klaschka
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Aiste Kudulyte
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Marek Cyrklaff
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Vibor Laketa
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Thomas Höfer
- Theoretical Systems Biology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Julien Guizetti
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Nils B. Becker
- Theoretical Systems Biology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Ulrich S. Schwarz
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
| | - Markus Ganter
- Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
6
|
Ganter M, Guizetti J, Kilian N. Visualization of Infected Red Blood Cell Surface Antigens by Fluorescence Microscopy. Methods Mol Biol 2022; 2470:425-433. [PMID: 35881363 DOI: 10.1007/978-1-0716-2189-9_31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Immunofluorescence labeling enables the detection and characterization of various parasite proteins presented on the surface of the infected red blood cell. Several approaches for immunofluorescence detection of red blood cell surface-presented proteins of Plasmodium spp. have been successfully established and published over the years. However, finding the right approach depends on the scientific question, and different protocols have different advantages. Here, we discuss some aspects that should be considered and present an easily applicable protocol for labeling parasite surface antigens, which subsequently can be analyzed by immunofluorescence microscopy (or flow cytometry).
Collapse
Affiliation(s)
- Markus Ganter
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany.
| | - Julien Guizetti
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Nicole Kilian
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
7
|
Simon CS, Funaya C, Bauer J, Voβ Y, Machado M, Penning A, Klaschka D, Cyrklaff M, Kim J, Ganter M, Guizetti J. An extended DNA-free intranuclear compartment organizes centrosome microtubules in malaria parasites. Life Sci Alliance 2021; 4:e202101199. [PMID: 34535568 PMCID: PMC8473725 DOI: 10.26508/lsa.202101199] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 08/31/2021] [Accepted: 09/03/2021] [Indexed: 11/24/2022] Open
Abstract
Proliferation of Plasmodium falciparum in red blood cells is the cause of malaria and is underpinned by an unconventional cell division mode, called schizogony. Contrary to model organisms, P. falciparum replicates by multiple rounds of nuclear divisions that are not interrupted by cytokinesis. Organization and dynamics of critical nuclear division factors remain poorly understood. Centriolar plaques, the centrosomes of P. falciparum, serve as microtubule organizing centers and have an acentriolar, amorphous structure. The small size of parasite nuclei has precluded detailed analysis of intranuclear microtubule organization by classical fluorescence microscopy. We apply recently developed super-resolution and time-lapse imaging protocols to describe microtubule reconfiguration during schizogony. Analysis of centrin, nuclear pore, and microtubule positioning reveals two distinct compartments of the centriolar plaque. Whereas centrin is extranuclear, we confirm by correlative light and electron tomography that microtubules are nucleated in a previously unknown and extended intranuclear compartment, which is devoid of chromatin but protein-dense. This study generates a working model for an unconventional centrosome and enables a better understanding about the diversity of eukaryotic cell division.
Collapse
Affiliation(s)
- Caroline S Simon
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Charlotta Funaya
- Electron Microscopy Core Facility, Heidelberg University, Heidelberg, Germany
| | - Johanna Bauer
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Yannik Voβ
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Marta Machado
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
- Graduate Program in Areas of Basic and Applied Biology, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Alexander Penning
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Darius Klaschka
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Marek Cyrklaff
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Juyeop Kim
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Markus Ganter
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Julien Guizetti
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
8
|
Soni K, Kempf G, Manalastas-Cantos K, Hendricks A, Flemming D, Guizetti J, Simon B, Frischknecht F, Svergun DI, Wild K, Sinning I. Structural analysis of the SRP Alu domain from Plasmodium falciparum reveals a non-canonical open conformation. Commun Biol 2021; 4:600. [PMID: 34017052 PMCID: PMC8137916 DOI: 10.1038/s42003-021-02132-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 04/22/2021] [Indexed: 12/25/2022] Open
Abstract
The eukaryotic signal recognition particle (SRP) contains an Alu domain, which docks into the factor binding site of translating ribosomes and confers translation retardation. The canonical Alu domain consists of the SRP9/14 protein heterodimer and a tRNA-like folded Alu RNA that adopts a strictly 'closed' conformation involving a loop-loop pseudoknot. Here, we study the structure of the Alu domain from Plasmodium falciparum (PfAlu), a divergent apicomplexan protozoan that causes human malaria. Using NMR, SAXS and cryo-EM analyses, we show that, in contrast to its prokaryotic and eukaryotic counterparts, the PfAlu domain adopts an 'open' Y-shaped conformation. We show that cytoplasmic P. falciparum ribosomes are non-discriminative and recognize both the open PfAlu and closed human Alu domains with nanomolar affinity. In contrast, human ribosomes do not provide high affinity binding sites for either of the Alu domains. Our analyses extend the structural database of Alu domains to the protozoan species and reveal species-specific differences in the recognition of SRP Alu domains by ribosomes.
Collapse
Affiliation(s)
- Komal Soni
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Georg Kempf
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | | | - Astrid Hendricks
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Dirk Flemming
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Julien Guizetti
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Bernd Simon
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany.
| |
Collapse
|
9
|
Simon CS, Stürmer VS, Guizetti J. How Many Is Enough? - Challenges of Multinucleated Cell Division in Malaria Parasites. Front Cell Infect Microbiol 2021; 11:658616. [PMID: 34026661 PMCID: PMC8137892 DOI: 10.3389/fcimb.2021.658616] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/21/2021] [Indexed: 12/12/2022] Open
Abstract
Regulating the number of progeny generated by replicative cell cycles is critical for any organism to best adapt to its environment. Classically, the decision whether to divide further is made after cell division is completed by cytokinesis and can be triggered by intrinsic or extrinsic factors. Contrarily, cell cycles of some species, such as the malaria-causing parasites, go through multinucleated cell stages. Hence, their number of progeny is determined prior to the completion of cell division. This should fundamentally affect how the process is regulated and raises questions about advantages and challenges of multinucleation in eukaryotes. Throughout their life cycle Plasmodium spp. parasites undergo four phases of extensive proliferation, which differ over three orders of magnitude in the amount of daughter cells that are produced by a single progenitor. Even during the asexual blood stage proliferation parasites can produce very variable numbers of progeny within one replicative cycle. Here, we review the few factors that have been shown to affect those numbers. We further provide a comparative quantification of merozoite numbers in several P. knowlesi and P. falciparum parasite strains, and we discuss the general processes that may regulate progeny number in the context of host-parasite interactions. Finally, we provide a perspective of the critical knowledge gaps hindering our understanding of the molecular mechanisms underlying this exciting and atypical mode of parasite multiplication.
Collapse
Affiliation(s)
| | | | - Julien Guizetti
- Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
10
|
Abstract
Apicomplexan parasites are defined by complex apical structures, which are necessary for interaction with incredibly diverse host cells. Two studies now amend a long-standing paradigm by showing conservation of an essential ring structure in the entire phylum.
Collapse
Affiliation(s)
- Julien Guizetti
- Parasitology, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Friedrich Frischknecht
- Parasitology, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
11
|
Mehnert AK, Simon CS, Guizetti J. Immunofluorescence staining protocol for STED nanoscopy of Plasmodium-infected red blood cells. Mol Biochem Parasitol 2019; 229:47-52. [PMID: 30831155 DOI: 10.1016/j.molbiopara.2019.02.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 02/20/2019] [Accepted: 02/25/2019] [Indexed: 12/12/2022]
Abstract
Immunofluorescence staining is the key technique for visualizing organization of endogenous cellular structures in single cells. Labeling and imaging of blood stage Plasmodium falciparum has always been challenging since it is a small intracellular parasite. A widely-used standard for parasite immunofluorescence is fixation in suspension with addition of minute amounts of glutaraldehyde to the paraformaldehyde-based solution. While this maintains red blood cell integrity, it has been postulated that antigenicity of the parasite proteins was, if at all, only slightly reduced. Here we show the deleterious effect that even these small quantities of glutaraldehyde can have on immunofluorescence staining quality and present an alternative cell seeding protocol that allows fixation with only paraformaldehyde. The highly improved signal intensity and staining efficiency enabled us to carry out RescueSTED nanoscopy on microtubules and nuclear pores and describe their organization in greater detail throughout the blood stage cycle.
Collapse
Affiliation(s)
- Ann-Kathrin Mehnert
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Caroline Sophie Simon
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Julien Guizetti
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany.
| |
Collapse
|
12
|
Müller LSM, Cosentino RO, Förstner KU, Guizetti J, Wedel C, Kaplan N, Janzen CJ, Arampatzi P, Vogel J, Steinbiss S, Otto TD, Saliba AE, Sebra RP, Siegel TN. Genome organization and DNA accessibility control antigenic variation in trypanosomes. Nature 2018; 563:121-125. [PMID: 30333624 PMCID: PMC6784898 DOI: 10.1038/s41586-018-0619-8] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 09/03/2018] [Indexed: 01/15/2023]
Abstract
Many evolutionarily distant pathogenic organisms have evolved similar survival strategies to evade the immune responses of their hosts. These include antigenic variation, through which an infecting organism prevents clearance by periodically altering the identity of proteins that are visible to the immune system of the host1. Antigenic variation requires large reservoirs of immunologically diverse antigen genes, which are often generated through homologous recombination, as well as mechanisms to ensure the expression of one or very few antigens at any given time. Both homologous recombination and gene expression are affected by three-dimensional genome architecture and local DNA accessibility2,3. Factors that link three-dimensional genome architecture, local chromatin conformation and antigenic variation have, to our knowledge, not yet been identified in any organism. One of the major obstacles to studying the role of genome architecture in antigenic variation has been the highly repetitive nature and heterozygosity of antigen-gene arrays, which has precluded complete genome assembly in many pathogens. Here we report the de novo haplotype-specific assembly and scaffolding of the long antigen-gene arrays of the model protozoan parasite Trypanosoma brucei, using long-read sequencing technology and conserved features of chromosome folding4. Genome-wide chromosome conformation capture (Hi-C) reveals a distinct partitioning of the genome, with antigen-encoding subtelomeric regions that are folded into distinct, highly compact compartments. In addition, we performed a range of analyses-Hi-C, fluorescence in situ hybridization, assays for transposase-accessible chromatin using sequencing and single-cell RNA sequencing-that showed that deletion of the histone variants H3.V and H4.V increases antigen-gene clustering, DNA accessibility across sites of antigen expression and switching of the expressed antigen isoform, via homologous recombination. Our analyses identify histone variants as a molecular link between global genome architecture, local chromatin conformation and antigenic variation.
Collapse
Affiliation(s)
- Laura S M Müller
- Department of Veterinary Sciences, Experimental Parasitology, Ludwig-Maximilians-Universität München, Munich, Germany
- Biomedical Center Munich, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Research Center for Infectious Diseases, University of Würzburg, Würzburg, Germany
| | - Raúl O Cosentino
- Department of Veterinary Sciences, Experimental Parasitology, Ludwig-Maximilians-Universität München, Munich, Germany
- Biomedical Center Munich, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Research Center for Infectious Diseases, University of Würzburg, Würzburg, Germany
| | - Konrad U Förstner
- ZB MED - Information Centre for Life Sciences, Cologne, Germany
- TH Köln, Faculty of Information Science and Communication Studies, Cologne, Germany
- Core Unit Systems Medicine, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Julien Guizetti
- Research Center for Infectious Diseases, University of Würzburg, Würzburg, Germany
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Carolin Wedel
- Research Center for Infectious Diseases, University of Würzburg, Würzburg, Germany
| | - Noam Kaplan
- Department of Physiology, Biophysics & Systems Biology, Rappaport Faculty of Medicine, Technion Israel Institute of Technology, Haifa, Israel
| | - Christian J Janzen
- Department of Cell & Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Panagiota Arampatzi
- Core Unit Systems Medicine, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Jörg Vogel
- Helmholtz Institute for RNA-based Infection Research, Würzburg, Germany
- RNA Biology Group, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | | | - Thomas D Otto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
- Centre of Immunobiology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | | | - Robert P Sebra
- Icahn Institute and Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - T Nicolai Siegel
- Department of Veterinary Sciences, Experimental Parasitology, Ludwig-Maximilians-Universität München, Munich, Germany.
- Biomedical Center Munich, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.
- Research Center for Infectious Diseases, University of Würzburg, Würzburg, Germany.
| |
Collapse
|
13
|
Guizetti J, Barcons-Simon A, Scherf A. Trans-acting GC-rich non-coding RNA at var expression site modulates gene counting in malaria parasite. Nucleic Acids Res 2016; 44:9710-9718. [PMID: 27466391 PMCID: PMC5175341 DOI: 10.1093/nar/gkw664] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 06/20/2016] [Accepted: 07/13/2016] [Indexed: 11/14/2022] Open
Abstract
Monoallelic expression of the var multigene family enables immune evasion of the malaria parasite Plasmodium falciparum in its human host. At a given time only a single member of the 60-member var gene family is expressed at a discrete perinuclear region called the 'var expression site'. However, the mechanism of var gene counting remains ill-defined. We hypothesize that activation factors associating specifically with the expression site play a key role in this process. Here, we investigate the role of a GC-rich non-coding RNA (ncRNA) gene family composed of 15 highly homologous members. GC-rich genes are positioned adjacent to var genes in chromosome-central gene clusters but are absent near subtelomeric var genes. Fluorescence in situ hybridization demonstrates that GC-rich ncRNA localizes to the perinuclear expression site of central and subtelomeric var genes in trans. Importantly, overexpression of distinct GC-rich ncRNA members disrupts the gene counting process at the single cell level and results in activation of a specific subset of var genes in distinct clones. We identify the first trans-acting factor targeted to the elusive perinuclear var expression site and open up new avenues to investigate ncRNA function in antigenic variation of malaria and other protozoan pathogens.
Collapse
Affiliation(s)
- Julien Guizetti
- Unité de Biologie des Interactions Hôte-Parasite, Institut Pasteur, Paris, 75724, France .,INSERM U1201, F-75724 Paris, France.,CNRS ERL9195, F-75724 Paris, France
| | - Anna Barcons-Simon
- Unité de Biologie des Interactions Hôte-Parasite, Institut Pasteur, Paris, 75724, France.,INSERM U1201, F-75724 Paris, France.,CNRS ERL9195, F-75724 Paris, France
| | - Artur Scherf
- Unité de Biologie des Interactions Hôte-Parasite, Institut Pasteur, Paris, 75724, France .,INSERM U1201, F-75724 Paris, France.,CNRS ERL9195, F-75724 Paris, France
| |
Collapse
|
14
|
Guizetti J, Scherf A. Silence, activate, poise and switch! Mechanisms of antigenic variation in Plasmodium falciparum. Cell Microbiol 2013; 15:718-26. [PMID: 23351305 PMCID: PMC3654561 DOI: 10.1111/cmi.12115] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/11/2013] [Accepted: 01/14/2013] [Indexed: 12/17/2022]
Abstract
Phenotypic variation in genetically identical malaria parasites is an emerging topic. Although antigenic variation is only part of a more global parasite strategy to create adaptation through epigenetically controlled transcriptional variability, it is the central mechanism enabling immune evasion and promoting pathogenesis. The var gene family is the best-studied example in a wide range of clonally variant gene families in Plasmodium falciparum. It is unique in its strict selection of a single member for activation, a process termed monoallelic expression. The conceptual advances that have emerged from studying var genes show striking common epigenetic features with many other clonally variant gene families or even single-copy genes that show a variegated expression in parasite populations. However, major mechanistic questions, such as the existence of a potential expression site and the identity of transcription factors or genetic elements driving singular gene choice, are still unanswered. In this review we discuss the recent findings in the molecular processes essential for clonal variation, namely silencing, activation, poising and switching. Integrating findings about all clonally variant gene families and other mutually exclusive expression systems will hopefully drive mechanistic understanding of antigenic variation.
Collapse
Affiliation(s)
- Julien Guizetti
- Unité de Biologie des Interactions Hôte-Parasite, Département de Parasitologie et Mycologie, Institut Pasteur, 25 Rue du Dr. Roux, Cedex 15, F-75724 Paris, France
| | | |
Collapse
|
15
|
Guizetti J, Schermelleh L, Mäntler J, Maar S, Poser I, Leonhardt H, Müller-Reichert T, Gerlich DW. Cortical constriction during abscission involves helices of ESCRT-III-dependent filaments. Science 2011; 331:1616-20. [PMID: 21310966 DOI: 10.1126/science.1201847] [Citation(s) in RCA: 359] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
After partitioning of cytoplasmic contents by cleavage furrow ingression, animal cells remain connected by an intercellular bridge, which subsequently splits by abscission. Here, we examined intermediate stages of abscission in human cells by using live imaging, three-dimensional structured illumination microscopy, and electron tomography. We identified helices of 17-nanometer-diameter filaments, which narrowed the cortex of the intercellular bridge to a single stalk. The endosomal sorting complex required for transport (ESCRT)-III co-localized with constriction zones and was required for assembly of 17-nanometer-diameter filaments. Simultaneous spastin-mediated removal of underlying microtubules enabled full constriction at the abscission site. The identification of contractile filament helices at the intercellular bridge has broad implications for the understanding of cell division and of ESCRT-III-mediated fission of large membrane structures.
Collapse
Affiliation(s)
- Julien Guizetti
- Institute of Biochemistry, Department of Biology, Swiss Federal Institute of Technology Zurich (ETHZ), Schafmattstrasse 18, Zurich, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Abstract
Cytokinesis leads to the separation of dividing cells, which in animal cells involves the contraction of an actin-myosin ring and subsequent fission during abscission. Abscission requires a series of dynamic events, including midbody-targeted vesicle secretion, specialization of plasma membrane domains, disassembly of midbody-associated microtubule bundles and plasma membrane fission. A large number of molecular factors required for abscission have been identified through localization, loss-of-function and proteomics studies, but their coordinate function in abscission is still poorly understood. Here, we review the structural elements and molecular factors known to contribute to abscission, and discuss their potential role in the context of proposed models for the abscission mechanism.
Collapse
Affiliation(s)
- Julien Guizetti
- Institute of Biochemistry, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich, Switzerland
| | | |
Collapse
|
17
|
Lacroix B, van Dijk J, Gold ND, Guizetti J, Aldrian-Herrada G, Rogowski K, Gerlich DW, Janke C. Tubulin polyglutamylation stimulates spastin-mediated microtubule severing. ACTA ACUST UNITED AC 2010; 189:945-54. [PMID: 20530212 PMCID: PMC2886356 DOI: 10.1083/jcb.201001024] [Citation(s) in RCA: 208] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Microtubules with long polyglutamylated C-terminal tails are more prone to severing by spastin, establishing the importance of tubulin posttranslational modifications. Posttranslational glutamylation of tubulin is present on selected subsets of microtubules in cells. Although the modification is expected to contribute to the spatial and temporal organization of the cytoskeleton, hardly anything is known about its functional relevance. Here we demonstrate that glutamylation, and in particular the generation of long glutamate side chains, promotes the severing of microtubules. In human cells, the generation of long side chains induces spastin-dependent microtubule disassembly and, consistently, only microtubules modified by long glutamate side chains are efficiently severed by spastin in vitro. Our study reveals a novel control mechanism for microtubule mass and stability, which is of fundamental importance to cellular physiology and might have implications for diseases related to microtubule severing.
Collapse
Affiliation(s)
- Benjamin Lacroix
- Centre de Recherche de Biochimie Macromoléculaire, Université Montpellier 2 and 1, Centre National de la Recherche Scientifique UMR 5237, Montpellier, France
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Lekomtsev S, Guizetti J, Pozniakovsky A, Gerlich DW, Petronczki M. Evidence that the tumor-suppressor protein BRCA2 does not regulate cytokinesis in human cells. J Cell Sci 2010; 123:1395-400. [DOI: 10.1242/jcs.068015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Germline mutations in the tumor-suppressor gene BRCA2 predispose to breast and ovarian cancer. BRCA2 plays a well-established role in maintaining genome stability by regulating homologous recombination. BRCA2 has more recently been implicated in cytokinesis, the final step of cell division, but the molecular basis for this remains unknown. We have used time-lapse microscopy, recently developed cytokinesis assays and BAC recombineering (bacterial artificial chromosome recombinogenic engineering) to investigate the function and localization of BRCA2 during cell division. Our analysis suggests that BRCA2 does not regulate cytokinesis in human cells. Thus, cytokinesis defects are unlikely to contribute to chromosomal instability and tumorigenesis in BRCA2-related cancers.
Collapse
Affiliation(s)
- Sergey Lekomtsev
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, Blanche Lane, South Mimms, Hertfordshire, EN6 3LD, UK
| | - Julien Guizetti
- Institute of Biochemistry, Swiss Federal Institute of Technology Zurich (ETHZ), Schafmattstrasse 18, CH-8093 Zurich, Switzerland
| | - Andrei Pozniakovsky
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany
| | - Daniel W. Gerlich
- Institute of Biochemistry, Swiss Federal Institute of Technology Zurich (ETHZ), Schafmattstrasse 18, CH-8093 Zurich, Switzerland
| | - Mark Petronczki
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, Blanche Lane, South Mimms, Hertfordshire, EN6 3LD, UK
| |
Collapse
|
19
|
Guizetti J, Mäntler J, Müller-Reichert T, Gerlich DW. Correlative time-lapse imaging and electron microscopy to study abscission in HeLa cells. Methods Cell Biol 2010; 96:591-601. [PMID: 20869539 DOI: 10.1016/s0091-679x(10)96024-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
HeLa cells are widely used as a model system to study cell division. The last step of cell division, abscission, occurs at an about 1 μm wide intercellular bridge that connects the post-mitotic sister cells. Abscission often occurs long after ingression of the cleavage furrow, and no efficient methods to synchronize cells to this stage are available. Here, we have developed a correlative fluorescence time-lapse imaging and electron microscopic approach using Aclar sheets with engraved grid patterns. This grid pattern, leaving a negative imprint on thin-layer embedded samples, allows identification of cells selected from the time-lapse imaging for serial-section electron microscopy. This method facilitates the ultrastructural analysis of specific stages of abscission.
Collapse
Affiliation(s)
- Julien Guizetti
- Institute of Biochemistry, Swiss Federal Institute of Technology Zurich (ETHZ), CH-8093 Zurich, Switzerland
| | | | | | | |
Collapse
|
20
|
Steigemann P, Wurzenberger C, Schmitz MHA, Held M, Guizetti J, Maar S, Gerlich DW. Aurora B-mediated abscission checkpoint protects against tetraploidization. Cell 2009; 136:473-84. [PMID: 19203582 DOI: 10.1016/j.cell.2008.12.020] [Citation(s) in RCA: 463] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 09/24/2008] [Accepted: 12/05/2008] [Indexed: 01/12/2023]
Abstract
Genomic abnormalities are often seen in tumor cells, and tetraploidization, which results from failures during cytokinesis, is presumed to be an early step in cancer formation. Here, we report a cell division control mechanism that prevents tetraploidization in human cells with perturbed chromosome segregation. First, we found that Aurora B inactivation promotes completion of cytokinesis by abscission. Chromosome bridges sustained Aurora B activity to posttelophase stages and thereby delayed abscission at stabilized intercellular canals. This was essential to suppress tetraploidization by furrow regression in a pathway further involving the phosphorylation of mitotic kinesin-like protein 1 (Mklp1). We propose that Aurora B is part of a sensor that responds to unsegregated chromatin at the cleavage site. Our study provides evidence that in human cells abscission is coordinated with the completion of chromosome segregation to protect against tetraploidization by furrow regression.
Collapse
Affiliation(s)
- Patrick Steigemann
- Institute of Biochemistry, Swiss Institute of Technology Zurich, ETHZ, Zurich, Switzerland
| | | | | | | | | | | | | |
Collapse
|