1
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Hu H, Kurasawa Y, Zhou Q, Li Z. A kinesin-13 family kinesin in Trypanosoma brucei regulates cytokinesis and cytoskeleton morphogenesis by promoting microtubule bundling. PLoS Pathog 2024; 20:e1012000. [PMID: 38300973 PMCID: PMC10863849 DOI: 10.1371/journal.ppat.1012000] [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: 09/28/2023] [Revised: 02/13/2024] [Accepted: 01/26/2024] [Indexed: 02/03/2024] Open
Abstract
The early branching eukaryote Trypanosoma brucei divides uni-directionally along the longitudinal cell axis from the cell anterior toward the cell posterior, and the cleavage furrow ingresses along the cell division plane between the new and the old flagella of a dividing bi-flagellated cell. Regulation of cytokinesis in T. brucei involves actomyosin-independent machineries and trypanosome-specific signaling pathways, but the molecular mechanisms underlying cell division plane positioning remain poorly understood. Here we report a kinesin-13 family protein, KIN13-5, that functions downstream of FPRC in the cytokinesis regulatory pathway and determines cell division plane placement. KIN13-5 localizes to multiple cytoskeletal structures, interacts with FPRC, and depends on FPRC for localization to the site of cytokinesis initiation. Knockdown of KIN13-5 causes loss of microtubule bundling at both ends of the cell division plane, leading to mis-placement of the cleavage furrow and unequal cytokinesis, and at the posterior cell tip, causing the formation of a blunt posterior. In vitro biochemical assays demonstrate that KIN13-5 bundles microtubules, providing mechanistic insights into the role of KIN13-5 in cytokinesis and posterior morphogenesis. Altogether, KIN13-5 promotes microtubule bundle formation to ensure cleavage furrow placement and to maintain posterior cytoskeleton morphology in T. brucei.
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Affiliation(s)
- Huiqing Hu
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Yasuhiro Kurasawa
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Qing Zhou
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
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2
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Hair M, Yanase R, Moreira-Leite F, Wheeler RJ, Sádlová J, Volf P, Vaughan S, Sunter JD. Whole cell reconstructions of Leishmania mexicana through the cell cycle. PLoS Pathog 2024; 20:e1012054. [PMID: 38416776 PMCID: PMC10927142 DOI: 10.1371/journal.ppat.1012054] [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: 12/15/2023] [Revised: 03/11/2024] [Accepted: 02/15/2024] [Indexed: 03/01/2024] Open
Abstract
The unicellular parasite Leishmania has a precisely defined cell architecture that is inherited by each subsequent generation, requiring a highly coordinated pattern of duplication and segregation of organelles and cytoskeletal structures. A framework of nuclear division and morphological changes is known from light microscopy, yet this has limited resolution and the intrinsic organisation of organelles within the cell body and their manner of duplication and inheritance is unknown. Using volume electron microscopy approaches, we have produced three-dimensional reconstructions of different promastigote cell cycle stages to give a spatial and quantitative overview of organelle positioning, division and inheritance. The first morphological indications seen in our dataset that a new cell cycle had begun were the assembly of a new flagellum, the duplication of the contractile vacuole and the increase in volume of the nucleus and kinetoplast. We showed that the progression of the cytokinesis furrow created a specific pattern of membrane indentations, while our analysis of sub-pellicular microtubule organisation indicated that there is likely a preferred site of new microtubule insertion. The daughter cells retained these indentations in their cell body for a period post-abscission. By comparing cultured and sand fly derived promastigotes, we found an increase in the number and overall volume of lipid droplets in the promastigotes from the sand fly, reflecting a change in their metabolism to ensure transmissibility to the mammalian host. Our insights into the cell cycle mechanics of Leishmania will support future molecular cell biology analyses of these parasites.
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Affiliation(s)
- Molly Hair
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
| | - Ryuji Yanase
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
| | - Flávia Moreira-Leite
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
| | - Richard John Wheeler
- Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
| | - Jovana Sádlová
- Department of Parasitology, Charles University, Prague, Czech Republic
| | - Petr Volf
- Department of Parasitology, Charles University, Prague, Czech Republic
| | - Sue Vaughan
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
| | - Jack Daniel Sunter
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
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3
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Tashyreva D, Týč J, Horák A, Lukeš J. Ultrastructure and 3D reconstruction of a diplonemid protist (Diplonemea) and its novel membranous organelle. mBio 2023; 14:e0192123. [PMID: 37737610 PMCID: PMC10653844 DOI: 10.1128/mbio.01921-23] [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: 07/25/2023] [Accepted: 07/26/2023] [Indexed: 09/23/2023] Open
Abstract
IMPORTANCE The knowledge of cell biology of a eukaryotic group is essential for correct interpretation of ecological and molecular data. Although diplonemid protists are one of the most species-rich lineages of marine eukaryotes, only very fragmentary information is available about the cellular architecture of this taxonomically diverse group. Here, a large serial block-face scanning electron microscopy data set complemented with light and fluorescence microscopy allowed the first detailed three-dimensional reconstruction of a diplonemid species. We describe numerous previously unknown peculiarities of the cellular architecture and cell division characteristic for diplonemid flagellates, and illustrate the obtained results with multiple three-dimensional models, comprehensible for non-specialists in protist ultrastructure.
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Affiliation(s)
- Daria Tashyreva
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Jiří Týč
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Aleš Horák
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Sciences, University of South Bohemia, České Budějovice, Czech Republic
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Sciences, University of South Bohemia, České Budějovice, Czech Republic
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4
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Campbell PC, de Graffenried CL. Morphogenesis in Trypanosoma cruzi epimastigotes proceeds via a highly asymmetric cell division. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.24.542100. [PMID: 37293088 PMCID: PMC10245916 DOI: 10.1101/2023.05.24.542100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Trypanosoma cruzi is a protist parasite that is the causative agent of Chagas' disease, a neglected tropical disease endemic to the Americas. T. cruzi cells are highly polarized and undergo morphological changes as they cycle within their insect and mammalian hosts. Work on related trypanosomatids has described cell division mechanisms in several life-cycle stages and identified a set of essential morphogenic proteins that serve as markers for key events during trypanosomatid division. Here, we use Cas9-based tagging of morphogenic genes, live-cell imaging, and expansion microscopy to study the cell division mechanism of the insect-resident epimastigote form of T. cruzi, which represents an understudied trypanosomatid morphotype. We find that T. cruzi epimastigote cell division is highly asymmetric, producing one daughter cell that is significantly smaller than the other. Daughter cell division rates differ by 4.9 h, which may be a consequence of this size disparity. Many of the morphogenic proteins identified in T. brucei have altered localization patterns in T. cruzi epimastigoes, which may reflect fundamental differences in the cell division mechanism of this life cycle stage, which widens and shortens the cell body to accommodate the duplicated organelles and cleavage furrow rather than elongating the cell body along the long axis of the cell, as is the case in life-cycle stages that have been studied in T. brucei. This work provides a foundation for further investigations of T. cruzi cell division and shows that subtle differences in trypansomatid cell morphology can alter how these parasites divide.
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Affiliation(s)
- Paul C. Campbell
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
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5
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Lee KJ, Zhou Q, Li Z. CRK2 controls cytoskeleton morphogenesis in Trypanosoma brucei by phosphorylating β-tubulin to regulate microtubule dynamics. PLoS Pathog 2023; 19:e1011270. [PMID: 36947554 PMCID: PMC10069784 DOI: 10.1371/journal.ppat.1011270] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 04/03/2023] [Accepted: 03/08/2023] [Indexed: 03/23/2023] Open
Abstract
Microtubules constitute a vital part of the cytoskeleton in eukaryotes by mediating cell morphogenesis, cell motility, cell division, and intracellular transport. The cytoskeleton of the parasite Trypanosoma brucei contains an array of subpellicular microtubules with their plus-ends positioned toward the posterior cell tip, where extensive microtubule growth and cytoskeleton remodeling take place during early cell cycle stages. However, the control mechanism underlying microtubule dynamics at the posterior cell tip remains elusive. Here, we report that the S-phase cyclin-dependent kinase-cyclin complex CRK2-CYC13 in T. brucei regulates microtubule dynamics by phosphorylating β-tubulin on multiple evolutionarily conserved serine and threonine residues to inhibit its incorporation into cytoskeletal microtubules and promote its degradation in the cytosol. Consequently, knockdown of CRK2 or CYC13 causes excessive microtubule extension and loss of microtubule convergence at the posterior cell tip, leading to cytoskeleton elongation and branching. These findings uncover a control mechanism for cytoskeletal microtubule dynamics by which CRK2 phosphorylates β-tubulin and fine-tunes cellular β-tubulin protein abundance to restrict excess microtubule extension for the maintenance of cytoskeleton architecture.
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Affiliation(s)
- Kyu Joon Lee
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Qing Zhou
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
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6
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de Liz LV, Stoco PH, Sunter JD. Cell-to-flagellum attachment and surface architecture in kinetoplastids. Trends Parasitol 2023; 39:332-344. [PMID: 36933967 DOI: 10.1016/j.pt.2023.02.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/20/2023] [Accepted: 02/20/2023] [Indexed: 03/18/2023]
Abstract
A key morphological feature of kinetoplastid parasites is the position and length of flagellum attachment to the cell body. This lateral attachment is mediated by the flagellum attachment zone (FAZ), a large complex cytoskeletal structure, which is essential for parasite morphogenesis and pathogenicity. Despite the complexity of the FAZ only two transmembrane proteins, FLA1 and FLA1BP, are known to interact and connect the flagellum to the cell body. Across the different kinetoplastid species, each only has a single FLA/FLABP pair, except in Trypanosoma brucei and Trypanosoma congolense where there has been an expansion of these genes. Here, we focus on the selection pressure behind the evolution of the FLA/FLABP proteins and the likely impact this will have on host-parasite interactions.
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Affiliation(s)
- Laryssa Vanessa de Liz
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Patrícia Hermes Stoco
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Jack Daniel Sunter
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK.
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7
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Smithson L, Ihuoma Akazue P, Findlater L, Gwira TM, Vaughan S, Sunter JD. Diversity in new flagellum tip attachment in bloodstream form African trypanosomes. Mol Microbiol 2022; 118:510-525. [PMID: 36056717 PMCID: PMC9826329 DOI: 10.1111/mmi.14979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 01/11/2023]
Abstract
The closely related parasites Trypanosoma brucei, T. congolense, and T. vivax cause neglected tropical diseases collectively known as African Trypanosomiasis. A characteristic feature of bloodstream form T. brucei is the flagellum that is laterally attached to the side of the cell body. During the cell cycle, the new flagellum is formed alongside the old flagellum, with the new flagellum tip embedded within a mobile transmembrane junction called the groove. The molecular composition of the groove is currently unknown, which limits the analysis of this junction and assessment of its conservation in related trypanosomatids. Here, we identified 13 proteins that localize to the flagellar groove through a small-scale tagging screen. Functional analysis of a subset of these proteins by RNAi and gene deletion revealed three proteins, FCP4/TbKin15, FCP7, and FAZ45, that are involved in new flagellum tip attachment to the groove. Despite possessing orthologues of all 13 groove proteins, T. congolense and T. vivax did not assemble a canonical groove around the new flagellum tip according to 3D electron microscopy. This diversity in new flagellum tip attachment points to the rapid evolution of membrane-cytoskeleton structures that can occur without large changes in gene complement and likely reflects the niche specialization of each species.
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Affiliation(s)
- Laura Smithson
- Department of Biological and Medical SciencesOxford Brookes UniversityOxfordUK
| | - Pearl Ihuoma Akazue
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied SciencesUniversity of GhanaAccraGhana,Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied SciencesUniversity of GhanaAccraGhana,Department of Biochemistry, Faculty of Life SciencesUniversity of BeninBenin CityNigeria
| | - Lucy Findlater
- Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
| | - Theresa Manful Gwira
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied SciencesUniversity of GhanaAccraGhana,Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied SciencesUniversity of GhanaAccraGhana
| | - Sue Vaughan
- Department of Biological and Medical SciencesOxford Brookes UniversityOxfordUK
| | - Jack D. Sunter
- Department of Biological and Medical SciencesOxford Brookes UniversityOxfordUK
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8
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Hegedűsová E, Maršalová V, Kulkarni S, Paris Z. Trafficking and/or division: Distinct roles of nucleoporins based on their location within the nuclear pore complex. RNA Biol 2022; 19:650-661. [PMID: 35491934 PMCID: PMC9067531 DOI: 10.1080/15476286.2022.2067711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The nuclear pore complex (NPC) facilitates the trafficking of proteins and RNA between the nucleus and cytoplasm. The role of nucleoporins (Nups) in transport in the context of the NPC is well established, yet their function in tRNA export has not been fully explored. We selected several nucleoporins from different parts of the NPC to investigate their potential role in tRNA trafficking in Trypanosoma brucei. We show that while all of the nucleoporins studied are essential for cell viability, only TbNup62 and TbNup53a function in tRNA export. In contrast to homologs in yeast TbNup144 and TbNup158, which are part of the inner and outer ring of the NPC, have no role in nuclear tRNA trafficking. Instead, TbNup144 plays a critical role in nuclear division, highlighting the role of nucleoporins beyond nucleocytoplasmic transport. These results suggest that the location of nucleoporins within the NPC is crucial to maintaining various cellular processes.
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Affiliation(s)
- Eva Hegedűsová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Veronika Maršalová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Sneha Kulkarni
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Zdeněk Paris
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
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9
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Gorilak P, Pružincová M, Vachova H, Olšinová M, Schmidt Cernohorska M, Varga V. Expansion microscopy facilitates quantitative super-resolution studies of cytoskeletal structures in kinetoplastid parasites. Open Biol 2021; 11:210131. [PMID: 34465213 PMCID: PMC8437234 DOI: 10.1098/rsob.210131] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Expansion microscopy (ExM) has become a powerful super-resolution method in cell biology. It is a simple, yet robust approach, which does not require any instrumentation or reagents beyond those present in a standard microscopy facility. In this study, we used kinetoplastid parasites Trypanosoma brucei and Leishmania major, which possess a complex, yet well-defined microtubule-based cytoskeleton, to demonstrate that this method recapitulates faithfully morphology of structures as previously revealed by a combination of sophisticated electron microscopy (EM) approaches. Importantly, we also show that due to the rapidness of image acquisition and three-dimensional reconstruction of cellular volumes ExM is capable of complementing EM approaches by providing more quantitative data. This is demonstrated on examples of less well-appreciated microtubule structures, such as the neck microtubule of T. brucei or the pocket, cytosolic and multivesicular tubule-associated microtubules of L. major. We further demonstrate that ExM enables identifying cell types rare in a population, such as cells in mitosis and cytokinesis. Three-dimensional reconstruction of an entire volume of these cells provided details on the morphology of the mitotic spindle and the cleavage furrow. Finally, we show that established antibody markers of major cytoskeletal structures function well in ExM, which together with the ability to visualize proteins tagged with small epitope tags will facilitate studies of the kinetoplastid cytoskeleton.
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Affiliation(s)
- Peter Gorilak
- Laboratory of Cell Motility, Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, Prague, 14220, Czech Republic,Charles University, Faculty of Science, Albertov 6, Prague, 128 00, Czech Republic
| | - Martina Pružincová
- Laboratory of Cell Motility, Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, Prague, 14220, Czech Republic
| | - Hana Vachova
- Laboratory of Cell Motility, Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, Prague, 14220, Czech Republic
| | - Marie Olšinová
- IMCF at BIOCEV, Faculty of Science, Charles University, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Marketa Schmidt Cernohorska
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, Prague, 14220, Czech Republic
| | - Vladimir Varga
- Laboratory of Cell Motility, Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, Prague, 14220, Czech Republic
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10
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Campbell PC, de Graffenried CL. Alternate histories of cytokinesis: lessons from the trypanosomatids. Mol Biol Cell 2021; 31:2631-2639. [PMID: 33180676 PMCID: PMC7927182 DOI: 10.1091/mbc.e19-12-0696] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Popular culture has recently produced several “alternate histories” that describe worlds where key historical events had different outcomes. Beyond entertainment, asking “could this have happened a different way?” and “what would the consequences be?” are valuable approaches for exploring molecular mechanisms in many areas of research, including cell biology. Analogous to alternate histories, studying how the evolutionary trajectories of related organisms have been selected to provide a range of outcomes can tell us about the plasticity and potential contained within the genome of the ancestral cell. Among eukaryotes, a group of model organisms has been employed with great success to identify a core, conserved framework of proteins that segregate the duplicated cellular organelles into two daughter cells during cell division, a process known as cytokinesis. However, these organisms provide relatively sparse sampling across the broad evolutionary distances that exist, which has limited our understanding of the true potential of the ancestral eukaryotic toolkit. Recent work on the trypanosomatids, a group of eukaryotic parasites, exemplifies alternate historical routes for cytokinesis that illustrate the range of eukaryotic diversity, especially among unicellular organisms.
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Affiliation(s)
- Paul C Campbell
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912
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11
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Sinclair AN, Huynh CT, Sladewski TE, Zuromski JL, Ruiz AE, de Graffenried CL. The Trypanosoma brucei subpellicular microtubule array is organized into functionally discrete subdomains defined by microtubule associated proteins. PLoS Pathog 2021; 17:e1009588. [PMID: 34010336 PMCID: PMC8168904 DOI: 10.1371/journal.ppat.1009588] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 06/01/2021] [Accepted: 04/25/2021] [Indexed: 11/19/2022] Open
Abstract
Microtubules are inherently dynamic cytoskeletal polymers whose length and organization can be altered to perform essential functions in eukaryotic cells, such as providing tracks for intracellular trafficking and forming the mitotic spindle. Microtubules can be bundled to create more stable structures that collectively propagate force, such as in the flagellar axoneme, which provides motility. The subpellicular microtubule array of the protist parasite Trypanosoma brucei, the causative agent of African sleeping sickness, is a remarkable example of a highly specialized microtubule bundle. It is comprised of a single layer of microtubules that are crosslinked to each other and to the overlying plasma membrane. The array microtubules appear to be highly stable and remain intact throughout the cell cycle, but very little is known about the pathways that tune microtubule properties in trypanosomatids. Here, we show that the subpellicular microtubule array is organized into subdomains that consist of differentially localized array-associated proteins at the array posterior, middle, and anterior. The array-associated protein PAVE1 stabilizes array microtubules at the cell posterior and is essential for maintaining its tapered shape. PAVE1 and the newly identified protein PAVE2 form a complex that binds directly to the microtubule lattice, demonstrating that they are a true kinetoplastid-specific MAP. TbAIR9, which localizes to the entirety of the subpellicular array, is necessary for maintaining the localization of array-associated proteins within their respective subdomains of the array. The arrangement of proteins within the array likely tunes the local properties of array microtubules and creates the asymmetric shape of the cell, which is essential for parasite viability.
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Affiliation(s)
- Amy N. Sinclair
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
| | - Christine T. Huynh
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
| | - Thomas E. Sladewski
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
| | - Jenna L. Zuromski
- Department of Pathology and Laboratory Medicine, Center for International Health Research, Brown University, Providence, Rhode Island, United States of America
| | - Amanda E. Ruiz
- Department of Pathology and Laboratory Medicine, Center for International Health Research, Brown University, Providence, Rhode Island, United States of America
| | - Christopher L. de Graffenried
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, United States of America
- * E-mail:
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12
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Calvo-Álvarez E, Bonnefoy S, Salles A, Benson FE, McKean PG, Bastin P, Rotureau B. Redistribution of FLAgellar Member 8 during the trypanosome life cycle: Consequences for cell fate prediction. Cell Microbiol 2021; 23:e13347. [PMID: 33896083 PMCID: PMC8459223 DOI: 10.1111/cmi.13347] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/17/2021] [Accepted: 04/22/2021] [Indexed: 11/28/2022]
Abstract
The single flagellum of African trypanosomes is essential in multiple aspects of the parasites' development. The FLAgellar Member 8 protein (FLAM8), localised to the tip of the flagellum in cultured insect forms of Trypanosoma brucei, was identified as a marker of the locking event that controls flagellum length. Here, we investigated whether FLAM8 could also reflect the flagellum maturation state in other parasite cycle stages. We observed that FLAM8 distribution extended along the entire flagellar cytoskeleton in mammalian‐infective forms. Then, a rapid FLAM8 concentration to the distal tip occurs during differentiation into early insect forms, illustrating the remodelling of an existing flagellum. In the tsetse cardia, FLAM8 further localises to the entire length of the new flagellum during an asymmetric division. Strikingly, in parasites dividing in the tsetse midgut and in the salivary glands, the amount and distribution of FLAM8 in the new flagellum were seen to predict the daughter cell fate. We propose and discuss how FLAM8 could be considered a meta‐marker of the flagellum stage and maturation state in trypanosomes.
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Affiliation(s)
- Estefanía Calvo-Álvarez
- Trypanosome Cell Biology Unit, Institut Pasteur and INSERM U1201, Paris, France.,Trypanosome Transmission Group, Institut Pasteur, Paris, France
| | - Serge Bonnefoy
- Trypanosome Cell Biology Unit, Institut Pasteur and INSERM U1201, Paris, France
| | - Audrey Salles
- Unit of Technology and Service Photonic BioImaging (UTechS PBI), C2RT, Institut Pasteur, Paris, France
| | - Fiona E Benson
- Division of Biomedical and Life Sciences, Lancaster University, Lancaster, UK
| | - Paul G McKean
- Division of Biomedical and Life Sciences, Lancaster University, Lancaster, UK
| | - Philippe Bastin
- Trypanosome Cell Biology Unit, Institut Pasteur and INSERM U1201, Paris, France
| | - Brice Rotureau
- Trypanosome Cell Biology Unit, Institut Pasteur and INSERM U1201, Paris, France.,Trypanosome Transmission Group, Institut Pasteur, Paris, France
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13
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A rapid approach for in locus overexpression of Trypanosoma brucei proteins. Mol Biochem Parasitol 2020; 239:111300. [PMID: 32682799 DOI: 10.1016/j.molbiopara.2020.111300] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/11/2020] [Accepted: 07/13/2020] [Indexed: 11/23/2022]
Abstract
Altering amounts of a protein in a cell has become a crucial tool for understanding its function. In many organisms, including the protozoan parasite Trypanosoma brucei, protein overexpression has been achieved by inserting a protein-coding sequence into an overexpression vector. Here, we have adapted the PCR only based system for tagging trypanosome proteins at their endogenous loci such that it in addition enables a tetracycline-inducible T7 RNA polymerase-mediated protein overexpression. Hence, this approach bypasses the need for molecular cloning, making it rapid and cost effective. We validated the approach for ten flagellum-associated proteins with molecular weights ranging from 40 to over 500 kDa. For a majority of the recombinant proteins a significant (3-50 fold) increase in the cellular amount was achieved upon induction of overexpression. Two of the largest proteins studied, the dynein heavy chains, were significantly overexpressed, while two were not. Our data suggest that this may reflect the extent of the T7 RNA polymerase processivity on the trypanosome genomic DNA. We further show that the overexpression is informative as to cellular functions of the studied proteins, and that these cultures can serve as an excellent source for purification of the overexpressed proteins. We believe that this rapid in locus overexpression system will become a valuable tool to interrogate cellular functions and biochemical activities of trypanosome proteins.
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