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Shimogawa MM, Jonnalagadda K, Hill KL. FAP20 is required for flagellum assembly in Trypanosoma brucei. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.19.576295. [PMID: 38293126 PMCID: PMC10827224 DOI: 10.1101/2024.01.19.576295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Trypanosoma brucei is a human and animal pathogen that depends on flagellar motility for transmission and infection. The trypanosome flagellum is built around a canonical "9+2" axoneme, containing nine doublet microtubules (DMTs) surrounding two singlet microtubules. Each DMT contains a 13-protofilament A-tubule and a 10-protofilament B-tubule, connected to the A-tubule by a conserved, non-tubulin inner junction (IJ) filament made up of alternating PACRG and FAP20 subunits. Here we investigate FAP20 in procyclic form T. brucei. A FAP20-NeonGreen fusion protein localized to the axoneme as expected. Surprisingly, FAP20 knockdown led to a catastrophic failure in flagellum assembly and concomitant lethal cell division defect. This differs from other organisms, where FAP20 is required for normal flagellum motility, but generally dispensable for flagellum assembly and viability. Transmission electron microscopy demonstrates failed flagellum assembly in FAP20 mutants is associated with a range of DMT defects and defective assembly of the paraflagellar rod, a lineage-specific flagellum filament that attaches to DMT 4-7 in trypanosomes. Our studies reveal a lineage-specific requirement for FAP20 in trypanosomes, offering insight into adaptations for flagellum stability and motility in these parasites and highlighting pathogen versus host differences that might be considered for therapeutic intervention in trypanosome diseases.
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Affiliation(s)
- Michelle M. Shimogawa
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Keya Jonnalagadda
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Kent L. Hill
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA
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Shimogawa MM, Wijono AS, Wang H, Zhang J, Sha J, Szombathy N, Vadakkan S, Pelayo P, Jonnalagadda K, Wohlschlegel J, Zhou ZH, Hill KL. FAP106 is an interaction hub for assembling microtubule inner proteins at the cilium inner junction. Nat Commun 2023; 14:5225. [PMID: 37633952 PMCID: PMC10460401 DOI: 10.1038/s41467-023-40230-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 07/14/2023] [Indexed: 08/28/2023] Open
Abstract
Motility of pathogenic protozoa depends on flagella (synonymous with cilia) with axonemes containing nine doublet microtubules (DMTs) and two singlet microtubules. Microtubule inner proteins (MIPs) within DMTs influence axoneme stability and motility and provide lineage-specific adaptations, but individual MIP functions and assembly mechanisms are mostly unknown. Here, we show in the sleeping sickness parasite Trypanosoma brucei, that FAP106, a conserved MIP at the DMT inner junction, is required for trypanosome motility and functions as a critical interaction hub, directing assembly of several conserved and lineage-specific MIPs. We use comparative cryogenic electron tomography (cryoET) and quantitative proteomics to identify MIP candidates. Using RNAi knockdown together with fitting of AlphaFold models into cryoET maps, we demonstrate that one of these candidates, MC8, is a trypanosome-specific MIP required for parasite motility. Our work advances understanding of MIP assembly mechanisms and identifies lineage-specific motility proteins that are attractive targets to consider for therapeutic intervention.
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Affiliation(s)
- Michelle M Shimogawa
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Angeline S Wijono
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Hui Wang
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Jiayan Zhang
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Jihui Sha
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Natasha Szombathy
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Sabeeca Vadakkan
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Paula Pelayo
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Keya Jonnalagadda
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - James Wohlschlegel
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Z Hong Zhou
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA.
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA.
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA.
| | - Kent L Hill
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, 90095, USA.
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA.
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, 90095, USA.
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Godar S, Oristian J, Hinsch V, Wentworth K, Lopez E, Amlashi P, Enverso G, Markley S, Alper JD. Light chain 2 is a Tctex-type related axonemal dynein light chain that regulates directional ciliary motility in Trypanosoma brucei. PLoS Pathog 2022; 18:e1009984. [PMID: 36155669 PMCID: PMC9536576 DOI: 10.1371/journal.ppat.1009984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/06/2022] [Accepted: 08/26/2022] [Indexed: 01/04/2023] Open
Abstract
Flagellar motility is essential for the cell morphology, viability, and virulence of pathogenic kinetoplastids. Trypanosoma brucei flagella beat with a bending wave that propagates from the flagellum's tip to its base, rather than base-to-tip as in other eukaryotes. Thousands of dynein motor proteins coordinate their activity to drive ciliary bending wave propagation. Dynein-associated light and intermediate chains regulate the biophysical mechanisms of axonemal dynein. Tctex-type outer arm dynein light chain 2 (LC2) regulates flagellar bending wave propagation direction, amplitude, and frequency in Chlamydomonas reinhardtii. However, the role of Tctex-type light chains in regulating T. brucei motility is unknown. Here, we used a combination of bioinformatics, in-situ molecular tagging, and immunofluorescence microscopy to identify a Tctex-type light chain in the procyclic form of T. brucei (TbLC2). We knocked down TbLC2 expression using RNAi in both wild-type and FLAM3, a flagellar attachment zone protein, knockdown cells and quantified TbLC2's effects on trypanosome cell biology and biophysics. We found that TbLC2 knockdown reduced the directional persistence of trypanosome cell swimming, induced an asymmetric ciliary bending waveform, modulated the bias between the base-to-tip and tip-to-base beating modes, and increased the beating frequency. Together, our findings are consistent with a model of TbLC2 as a down-regulator of axonemal dynein activity that stabilizes the forward tip-to-base beating ciliary waveform characteristic of trypanosome cells. Our work sheds light on axonemal dynein regulation mechanisms that contribute to pathogenic kinetoplastids' unique tip-to-base ciliary beating nature and how those mechanisms underlie dynein-driven ciliary motility more generally.
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Affiliation(s)
- Subash Godar
- Department of Physics and Astronomy, College of Science, Clemson University, Clemson, South Carolina, United States of America
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
| | - James Oristian
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Genetics and Biochemistry, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Valerie Hinsch
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Genetics and Biochemistry, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Katherine Wentworth
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Ethan Lopez
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Genetics and Biochemistry, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Parastoo Amlashi
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Gerald Enverso
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Samantha Markley
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, United States of America
| | - Joshua Daniel Alper
- Department of Physics and Astronomy, College of Science, Clemson University, Clemson, South Carolina, United States of America
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
- Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, United States of America
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Niziolek M, Bicka M, Osinka A, Samsel Z, Sekretarska J, Poprzeczko M, Bazan R, Fabczak H, Joachimiak E, Wloga D. PCD Genes-From Patients to Model Organisms and Back to Humans. Int J Mol Sci 2022; 23:ijms23031749. [PMID: 35163666 PMCID: PMC8836003 DOI: 10.3390/ijms23031749] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/25/2022] [Accepted: 01/31/2022] [Indexed: 01/27/2023] Open
Abstract
Primary ciliary dyskinesia (PCD) is a hereditary genetic disorder caused by the lack of motile cilia or the assembxly of dysfunctional ones. This rare human disease affects 1 out of 10,000-20,000 individuals and is caused by mutations in at least 50 genes. The past twenty years brought significant progress in the identification of PCD-causative genes and in our understanding of the connections between causative mutations and ciliary defects observed in affected individuals. These scientific advances have been achieved, among others, due to the extensive motile cilia-related research conducted using several model organisms, ranging from protists to mammals. These are unicellular organisms such as the green alga Chlamydomonas, the parasitic protist Trypanosoma, and free-living ciliates, Tetrahymena and Paramecium, the invertebrate Schmidtea, and vertebrates such as zebrafish, Xenopus, and mouse. Establishing such evolutionarily distant experimental models with different levels of cell or body complexity was possible because both basic motile cilia ultrastructure and protein composition are highly conserved throughout evolution. Here, we characterize model organisms commonly used to study PCD-related genes, highlight their pros and cons, and summarize experimental data collected using these models.
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Affiliation(s)
- Michal Niziolek
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Marta Bicka
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Faculty of Chemistry, University of Warsaw, 1 Pasteur Street, 02-093 Warsaw, Poland
| | - Anna Osinka
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Zuzanna Samsel
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Justyna Sekretarska
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Martyna Poprzeczko
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Laboratory of Immunology, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawinskiego Street, 02-106 Warsaw, Poland
| | - Rafal Bazan
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Hanna Fabczak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Correspondence: (E.J.); (D.W.); Tel.: +48-22-58-92-338 (E.J. & D.W.)
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Correspondence: (E.J.); (D.W.); Tel.: +48-22-58-92-338 (E.J. & D.W.)
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APEX2 Proximity Proteomics Resolves Flagellum Subdomains and Identifies Flagellum Tip-Specific Proteins in Trypanosoma brucei. mSphere 2021; 6:6/1/e01090-20. [PMID: 33568455 PMCID: PMC8141408 DOI: 10.1128/msphere.01090-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Sleeping sickness is a neglected tropical disease caused by the protozoan parasite Trypanosoma brucei. The disease disrupts the sleep-wake cycle, leading to coma and death if left untreated. T. brucei motility, transmission, and virulence depend on its flagellum (cilium), which consists of several different specialized subdomains. Trypanosoma brucei is the protozoan parasite responsible for sleeping sickness, a lethal vector-borne disease. T. brucei has a single flagellum (cilium) that plays critical roles in transmission and pathogenesis. An emerging concept is that the flagellum is organized into subdomains, each having specialized composition and function. The overall flagellum proteome has been well studied, but a critical knowledge gap is the protein composition of individual subdomains. We have tested whether APEX-based proximity proteomics could be used to examine the protein composition of T. brucei flagellum subdomains. As APEX-based labeling has not previously been described in T. brucei, we first fused APEX2 to the DRC1 subunit of the nexin-dynein regulatory complex, a well-characterized axonemal complex. We found that DRC1-APEX2 directs flagellum-specific biotinylation, and purification of biotinylated proteins yields a DRC1 “proximity proteome” having good overlap with published proteomes obtained from purified axonemes. Having validated the use of APEX2 in T. brucei, we next attempted to distinguish flagellar subdomains by fusing APEX2 to a flagellar membrane protein that is restricted to the flagellum tip, AC1, and another one that is excluded from the tip, FS179. Fluorescence microscopy demonstrated subdomain-specific biotinylation, and principal-component analysis showed distinct profiles between AC1-APEX2 and FS179-APEX2. Comparing these two profiles allowed us to identify an AC1 proximity proteome that is enriched for tip proteins, including proteins involved in signaling. Our results demonstrate that APEX2-based proximity proteomics is effective in T. brucei and can be used to resolve the proteome composition of flagellum subdomains that cannot themselves be readily purified. IMPORTANCE Sleeping sickness is a neglected tropical disease caused by the protozoan parasite Trypanosoma brucei. The disease disrupts the sleep-wake cycle, leading to coma and death if left untreated. T. brucei motility, transmission, and virulence depend on its flagellum (cilium), which consists of several different specialized subdomains. Given the essential and multifunctional role of the T. brucei flagellum, there is need for approaches that enable proteomic analysis of individual subdomains. Our work establishes that APEX2 proximity labeling can, indeed, be implemented in the biochemical environment of T. brucei and has allowed identification of proximity proteomes for different flagellar subdomains that cannot be purified. This capacity opens the possibility to study the composition and function of other compartments. We expect this approach may be extended to other eukaryotic pathogens and will enhance the utility of T. brucei as a model organism to study ciliopathies, heritable human diseases in which cilium function is impaired.
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Abstract
Almost all living things need to be able to move, whether it is toward desirable environments or away from danger. For vector-borne parasites, successful transmission and infection require that these organisms be able to sense where they are and use signals from their environment to direct where they go next, a process known as chemotaxis. Here, we show that Trypanosoma brucei, the deadly protozoan parasite that causes African sleeping sickness, can sense and move toward an attractive cue. To our knowledge, this is the first report of positive chemotaxis in these organisms. In addition to describing a new behavior in T. brucei, our findings enable future studies of how chemotaxis works in these pathogens, which will lead to deeper understanding of how they move through their hosts and may lead to new therapeutic or transmission-blocking strategies. To complete its infectious cycle, the protozoan parasite Trypanosoma brucei must navigate through diverse tissue environments in both its tsetse fly and mammalian hosts. This is hypothesized to be driven by yet unidentified chemotactic cues. Prior work has shown that parasites engaging in social motility in vitro alter their trajectory to avoid other groups of parasites, an example of negative chemotaxis. However, movement of T. brucei toward a stimulus, positive chemotaxis, has so far not been reported. Here, we show that upon encountering Escherichia coli, socially behaving T. brucei parasites exhibit positive chemotaxis, redirecting group movement toward the neighboring bacterial colony. This response occurs at a distance from the bacteria and involves active changes in parasite motility. By developing a quantitative chemotaxis assay, we show that the attractant is a soluble, diffusible signal dependent on actively growing E. coli. Time-lapse and live video microscopy revealed that T. brucei chemotaxis involves changes in both group and single cell motility. Groups of parasites change direction of group movement and accelerate as they approach the source of attractant, and this correlates with increasingly constrained movement of individual cells within the group. Identification of positive chemotaxis in T. brucei opens new opportunities to study mechanisms of chemotaxis in these medically and economically important pathogens. This will lead to deeper insights into how these parasites interact with and navigate through their host environments. IMPORTANCE Almost all living things need to be able to move, whether it is toward desirable environments or away from danger. For vector-borne parasites, successful transmission and infection require that these organisms be able to sense where they are and use signals from their environment to direct where they go next, a process known as chemotaxis. Here, we show that Trypanosoma brucei, the deadly protozoan parasite that causes African sleeping sickness, can sense and move toward an attractive cue. To our knowledge, this is the first report of positive chemotaxis in these organisms. In addition to describing a new behavior in T. brucei, our findings enable future studies of how chemotaxis works in these pathogens, which will lead to deeper understanding of how they move through their hosts and may lead to new therapeutic or transmission-blocking strategies.
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Soares H, Sunter JD, Wloga D, Joachimiak E, Miceli C. Trypanosoma, Paramecium and Tetrahymena: From genomics to flagellar and ciliary structures and cytoskeleton dynamics. Eur J Protistol 2020; 76:125722. [PMID: 32679518 DOI: 10.1016/j.ejop.2020.125722] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/06/2020] [Accepted: 05/11/2020] [Indexed: 02/06/2023]
Abstract
Cilia and flagella play an important role in motility, sensory perception, and the life cycles of eukaryotes, from protists to humans. However, much critical information concerning cilia structure and function remains elusive. The vast majority of ciliary and flagellar proteins analyzed so far are evolutionarily conserved and play a similar role in protozoa and vertebrates. This makes protozoa attractive biological models for studying cilia biology. Research conducted on ciliated or flagellated protists may improve our general understanding of cilia protein composition, of cilia beating, and can shed light on the molecular basis of the human disorders caused by motile cilia dysfunction. The Symposium "From genomics to flagellar and ciliary structures and cytoskeleton dynamics" at ECOP2019 in Rome presented the latest discoveries about cilia biogenesis and the molecular mechanisms of ciliary and flagellum motility based on studies in Paramecium, Tetrahymena, and Trypanosoma. Here, we review the most relevant aspects presented and discussed during the symposium and add our perspectives for future research.
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Affiliation(s)
- Helena Soares
- Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal; Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Lisboa, Portugal
| | - Jack D Sunter
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Cristina Miceli
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy.
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Lorès P, Dacheux D, Kherraf ZE, Nsota Mbango JF, Coutton C, Stouvenel L, Ialy-Radio C, Amiri-Yekta A, Whitfield M, Schmitt A, Cazin C, Givelet M, Ferreux L, Fourati Ben Mustapha S, Halouani L, Marrakchi O, Daneshipour A, El Khouri E, Do Cruzeiro M, Favier M, Guillonneau F, Chaudhry M, Sakheli Z, Wolf JP, Patrat C, Gacon G, Savinov SN, Hosseini SH, Robinson DR, Zouari R, Ziyyat A, Arnoult C, Dulioust E, Bonhivers M, Ray PF, Touré A. Mutations in TTC29, Encoding an Evolutionarily Conserved Axonemal Protein, Result in Asthenozoospermia and Male Infertility. Am J Hum Genet 2019; 105:1148-1167. [PMID: 31735292 DOI: 10.1016/j.ajhg.2019.10.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 10/11/2019] [Indexed: 12/30/2022] Open
Abstract
In humans, structural or functional defects of the sperm flagellum induce asthenozoospermia, which accounts for the main sperm defect encountered in infertile men. Herein we focused on morphological abnormalities of the sperm flagellum (MMAF), a phenotype also termed "short tails," which constitutes one of the most severe sperm morphological defects resulting in asthenozoospermia. In previous work based on whole-exome sequencing of a cohort of 167 MMAF-affected individuals, we identified bi-allelic loss-of-function mutations in more than 30% of the tested subjects. In this study, we further analyzed this cohort and identified five individuals with homozygous truncating variants in TTC29, a gene preferentially and highly expressed in the testis, and encoding a tetratricopeptide repeat-containing protein related to the intraflagellar transport (IFT). One individual carried a frameshift variant, another one carried a homozygous stop-gain variant, and three carried the same splicing variant affecting a consensus donor site. The deleterious effect of this last variant was confirmed on the corresponding transcript and protein product. In addition, we produced and analyzed TTC29 loss-of-function models in the flagellated protist T. brucei and in M. musculus. Both models confirmed the importance of TTC29 for flagellar beating. We showed that in T. brucei the TPR structural motifs, highly conserved between the studied orthologs, are critical for TTC29 axonemal localization and flagellar beating. Overall our work demonstrates that TTC29 is a conserved axonemal protein required for flagellar structure and beating and that TTC29 mutations are a cause of male sterility due to MMAF.
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Affiliation(s)
- Patrick Lorès
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Denis Dacheux
- Université de Bordeaux, Microbiologie Fondamentale et Pathogénicité, CNRS UMR 5234, Bordeaux, France; Institut Polytechnique de Bordeaux, Microbiologie Fondamentale et Pathogénicité, UMR-CNRS 5234, 33000 Bordeaux, France
| | - Zine-Eddine Kherraf
- INSERM U1209, CNRS UMR 5309, Université Grenoble Alpes, 38000 Grenoble, France; CHU de Grenoble, UM GI-DPI, Grenoble 38000, France
| | - Jean-Fabrice Nsota Mbango
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Charles Coutton
- INSERM U1209, CNRS UMR 5309, Université Grenoble Alpes, 38000 Grenoble, France; CHU Grenoble Alpes, UM de Génétique Chromosomique, Grenoble, France
| | - Laurence Stouvenel
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Come Ialy-Radio
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Amir Amiri-Yekta
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Marjorie Whitfield
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Alain Schmitt
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Caroline Cazin
- INSERM U1209, CNRS UMR 5309, Université Grenoble Alpes, 38000 Grenoble, France
| | - Maëlle Givelet
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Lucile Ferreux
- Laboratoire d'Histologie Embryologie - Biologie de la Reproduction - CECOS Groupe Hospitalier Universitaire Paris Centre, Assistance Publique-Hôpitaux de Paris, Paris 75014, France
| | - Selima Fourati Ben Mustapha
- Histologie Embryologie et Biologie de la Reproduction, Centre de Promotion des Sciences de la Reproduction, Polyclinique les Jasmins, Centre Urbain Nord, 1003 Tunis, Tunisia
| | - Lazhar Halouani
- Histologie Embryologie et Biologie de la Reproduction, Centre de Promotion des Sciences de la Reproduction, Polyclinique les Jasmins, Centre Urbain Nord, 1003 Tunis, Tunisia
| | - Ouafi Marrakchi
- Histologie Embryologie et Biologie de la Reproduction, Centre de Promotion des Sciences de la Reproduction, Polyclinique les Jasmins, Centre Urbain Nord, 1003 Tunis, Tunisia
| | - Abbas Daneshipour
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Elma El Khouri
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Marcio Do Cruzeiro
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Maryline Favier
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - François Guillonneau
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Marhaba Chaudhry
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Zeinab Sakheli
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Jean-Philippe Wolf
- INSERM U1016, Institut Cochin, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France; Laboratoire d'Histologie Embryologie - Biologie de la Reproduction - CECOS Groupe Hospitalier Universitaire Paris Centre, Assistance Publique-Hôpitaux de Paris, Paris 75014, France
| | - Catherine Patrat
- INSERM U1016, Institut Cochin, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France; Laboratoire d'Histologie Embryologie - Biologie de la Reproduction - CECOS Groupe Hospitalier Universitaire Paris Centre, Assistance Publique-Hôpitaux de Paris, Paris 75014, France
| | - Gérard Gacon
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France
| | - Sergey N Savinov
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Seyedeh Hanieh Hosseini
- Department of Andrology, Reproductive Biomedicine Research Center, Royan Institutefor Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Derrick R Robinson
- Université de Bordeaux, Microbiologie Fondamentale et Pathogénicité, CNRS UMR 5234, Bordeaux, France
| | - Raoudha Zouari
- Histologie Embryologie et Biologie de la Reproduction, Centre de Promotion des Sciences de la Reproduction, Polyclinique les Jasmins, Centre Urbain Nord, 1003 Tunis, Tunisia
| | - Ahmed Ziyyat
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France; Laboratoire d'Histologie Embryologie - Biologie de la Reproduction - CECOS Groupe Hospitalier Universitaire Paris Centre, Assistance Publique-Hôpitaux de Paris, Paris 75014, France
| | - Christophe Arnoult
- INSERM U1209, CNRS UMR 5309, Université Grenoble Alpes, 38000 Grenoble, France
| | - Emmanuel Dulioust
- INSERM U1016, Institut Cochin, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France; Laboratoire d'Histologie Embryologie - Biologie de la Reproduction - CECOS Groupe Hospitalier Universitaire Paris Centre, Assistance Publique-Hôpitaux de Paris, Paris 75014, France
| | - Mélanie Bonhivers
- Université de Bordeaux, Microbiologie Fondamentale et Pathogénicité, CNRS UMR 5234, Bordeaux, France
| | - Pierre F Ray
- INSERM U1209, CNRS UMR 5309, Université Grenoble Alpes, 38000 Grenoble, France; CHU de Grenoble, UM GI-DPI, Grenoble 38000, France
| | - Aminata Touré
- INSERM U1016, Institut Cochin, Paris 75014, France; Centre National de la Recherche Scientifique UMR8104, Paris 75014, France; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris 75014, France.
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9
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de Heuvel E, Singh AK, Boronat P, Kooistra AJ, van der Meer T, Sadek P, Blaazer AR, Shaner NC, Bindels DS, Caljon G, Maes L, Sterk GJ, Siderius M, Oberholzer M, de Esch IJ, Brown DG, Leurs R. Alkynamide phthalazinones as a new class of TbrPDEB1 inhibitors (Part 2). Bioorg Med Chem 2019; 27:4013-4029. [DOI: 10.1016/j.bmc.2019.06.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 06/12/2019] [Accepted: 06/14/2019] [Indexed: 01/27/2023]
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10
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Zhang Y, Ceylan Koydemir H, Shimogawa MM, Yalcin S, Guziak A, Liu T, Oguz I, Huang Y, Bai B, Luo Y, Luo Y, Wei Z, Wang H, Bianco V, Zhang B, Nadkarni R, Hill K, Ozcan A. Motility-based label-free detection of parasites in bodily fluids using holographic speckle analysis and deep learning. LIGHT, SCIENCE & APPLICATIONS 2018; 7:108. [PMID: 30564314 PMCID: PMC6290798 DOI: 10.1038/s41377-018-0110-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 11/25/2018] [Accepted: 11/25/2018] [Indexed: 05/08/2023]
Abstract
Parasitic infections constitute a major global public health issue. Existing screening methods that are based on manual microscopic examination often struggle to provide sufficient volumetric throughput and sensitivity to facilitate early diagnosis. Here, we demonstrate a motility-based label-free computational imaging platform to rapidly detect motile parasites in optically dense bodily fluids by utilizing the locomotion of the parasites as a specific biomarker and endogenous contrast mechanism. Based on this principle, a cost-effective and mobile instrument, which rapidly screens ~3.2 mL of fluid sample in three dimensions, was built to automatically detect and count motile microorganisms using their holographic time-lapse speckle patterns. We demonstrate the capabilities of our platform by detecting trypanosomes, which are motile protozoan parasites, with various species that cause deadly diseases affecting millions of people worldwide. Using a holographic speckle analysis algorithm combined with deep learning-based classification, we demonstrate sensitive and label-free detection of trypanosomes within spiked whole blood and artificial cerebrospinal fluid (CSF) samples, achieving a limit of detection of ten trypanosomes per mL of whole blood (~five-fold better than the current state-of-the-art parasitological method) and three trypanosomes per mL of CSF. We further demonstrate that this platform can be applied to detect other motile parasites by imaging Trichomonas vaginalis, the causative agent of trichomoniasis, which affects 275 million people worldwide. With its cost-effective, portable design and rapid screening time, this unique platform has the potential to be applied for sensitive and timely diagnosis of neglected tropical diseases caused by motile parasites and other parasitic infections in resource-limited regions.
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Affiliation(s)
- Yibo Zhang
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
- Bioengineering Department, University of California, Los Angeles, CA 90095 USA
- California NanoSystems Institute, University of California, Los Angeles, CA 90095 USA
| | - Hatice Ceylan Koydemir
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
- Bioengineering Department, University of California, Los Angeles, CA 90095 USA
- California NanoSystems Institute, University of California, Los Angeles, CA 90095 USA
| | - Michelle M. Shimogawa
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA 90095 USA
| | - Sener Yalcin
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
| | - Alexander Guziak
- Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 USA
| | - Tairan Liu
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
- Bioengineering Department, University of California, Los Angeles, CA 90095 USA
- California NanoSystems Institute, University of California, Los Angeles, CA 90095 USA
| | - Ilker Oguz
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
| | - Yujia Huang
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
| | - Bijie Bai
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
| | - Yilin Luo
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
| | - Yi Luo
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
- Bioengineering Department, University of California, Los Angeles, CA 90095 USA
- California NanoSystems Institute, University of California, Los Angeles, CA 90095 USA
| | - Zhensong Wei
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
| | - Hongda Wang
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
- Bioengineering Department, University of California, Los Angeles, CA 90095 USA
- California NanoSystems Institute, University of California, Los Angeles, CA 90095 USA
| | - Vittorio Bianco
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
| | - Bohan Zhang
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
| | - Rohan Nadkarni
- Bioengineering Department, University of California, Los Angeles, CA 90095 USA
| | - Kent Hill
- California NanoSystems Institute, University of California, Los Angeles, CA 90095 USA
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA 90095 USA
- Molecular Biology Institute, University of California, Los Angeles, CA 90095 USA
| | - Aydogan Ozcan
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA
- Bioengineering Department, University of California, Los Angeles, CA 90095 USA
- California NanoSystems Institute, University of California, Los Angeles, CA 90095 USA
- Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, CA 90095 USA
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11
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A Homozygous Ancestral SVA-Insertion-Mediated Deletion in WDR66 Induces Multiple Morphological Abnormalities of the Sperm Flagellum and Male Infertility. Am J Hum Genet 2018; 103:400-412. [PMID: 30122540 DOI: 10.1016/j.ajhg.2018.07.014] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 07/18/2018] [Indexed: 01/04/2023] Open
Abstract
Multiple morphological abnormalities of the sperm flagellum (MMAF) is a severe form of male infertility defined by the presence of a mosaic of anomalies, including short, bent, curled, thick, or absent flagella, resulting from a severe disorganization of the axoneme and of the peri-axonemal structures. Mutations in DNAH1, CFAP43, and CFAP44, three genes encoding axoneme-related proteins, have been described to account for approximately 30% of the MMAF cases reported so far. Here, we searched for pathological copy-number variants in whole-exome sequencing data from a cohort of 78 MMAF-affected subjects to identify additional genes associated with MMAF. In 7 of 78 affected individuals, we identified a homozygous deletion that removes the two penultimate exons of WDR66 (also named CFAP251), a gene coding for an axonemal protein preferentially localized in the testis and described to localize to the calmodulin- and spoke-associated complex at the base of radial spoke 3. Sequence analysis of the breakpoint region revealed in all deleted subjects the presence of a single chimeric SVA (SINE-VNTR-Alu) at the breakpoint site, suggesting that the initial deletion event was potentially mediated by an SVA insertion-recombination mechanism. Study of Trypanosoma WDR66's ortholog (TbWDR66) highlighted high sequence and structural analogy with the human protein and confirmed axonemal localization of the protein. Reproduction of the human deletion in TbWDR66 impaired flagellar movement, thus confirming WDR66 as a gene associated with the MMAF phenotype and highlighting the importance of the WDR66 C-terminal region.
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12
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Parasite motility is critical for virulence of African trypanosomes. Sci Rep 2018; 8:9122. [PMID: 29904094 PMCID: PMC6002391 DOI: 10.1038/s41598-018-27228-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 05/23/2018] [Indexed: 12/19/2022] Open
Abstract
African trypanosomes, Trypanosoma brucei spp., are lethal pathogens that cause substantial human suffering and limit economic development in some of the world's most impoverished regions. The name Trypanosoma ("auger cell") derives from the parasite's distinctive motility, which is driven by a single flagellum. However, despite decades of study, a requirement for trypanosome motility in mammalian host infection has not been established. LC1 is a conserved dynein subunit required for flagellar motility. Prior studies with a conditional RNAi-based LC1 mutant, RNAi-K/R, revealed that parasites with defective motility could infect mice. However, RNAi-K/R retained residual expression of wild-type LC1 and residual motility, thus precluding definitive interpretation. To overcome these limitations, here we generate constitutive mutants in which both LC1 alleles are replaced with mutant versions. These double knock-in mutants show reduced motility compared to RNAi-K/R and are viable in culture, but are unable to maintain bloodstream infection in mice. The virulence defect is independent of infection route but dependent on an intact host immune system. By comparing different mutants, we also reveal a critical dependence on the LC1 N-terminus for motility and virulence. Our findings demonstrate that trypanosome motility is critical for establishment and maintenance of bloodstream infection, implicating dynein-dependent flagellar motility as a potential drug target.
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13
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Vincensini L, Blisnick T, Bertiaux E, Hutchinson S, Georgikou C, Ooi CP, Bastin P. Flagellar incorporation of proteins follows at least two different routes in trypanosomes. Biol Cell 2017; 110:33-47. [DOI: 10.1111/boc.201700052] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 10/19/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Laetitia Vincensini
- Trypanosome Cell Biology Unit; Institut Pasteur & INSERM U1201; Paris 75015 France
| | - Thierry Blisnick
- Trypanosome Cell Biology Unit; Institut Pasteur & INSERM U1201; Paris 75015 France
| | - Eloïse Bertiaux
- Trypanosome Cell Biology Unit; Institut Pasteur & INSERM U1201; Paris 75015 France
| | - Sebastian Hutchinson
- Trypanosome Cell Biology Unit; Institut Pasteur & INSERM U1201; Paris 75015 France
| | - Christina Georgikou
- Trypanosome Cell Biology Unit; Institut Pasteur & INSERM U1201; Paris 75015 France
| | - Cher-Pheng Ooi
- Trypanosome Cell Biology Unit; Institut Pasteur & INSERM U1201; Paris 75015 France
| | - Philippe Bastin
- Trypanosome Cell Biology Unit; Institut Pasteur & INSERM U1201; Paris 75015 France
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14
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Mittra B, Laranjeira-Silva MF, Miguel DC, Perrone Bezerra de Menezes J, Andrews NW. The iron-dependent mitochondrial superoxide dismutase SODA promotes Leishmania virulence. J Biol Chem 2017; 292:12324-12338. [PMID: 28550086 DOI: 10.1074/jbc.m116.772624] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 05/25/2017] [Indexed: 12/17/2022] Open
Abstract
Leishmaniasis is one of the leading globally neglected diseases, affecting millions of people worldwide. Leishmania infection depends on the ability of insect-transmitted metacyclic promastigotes to invade mammalian hosts, differentiate into amastigotes, and replicate inside macrophages. To counter the hostile oxidative environment inside macrophages, these protozoans contain anti-oxidant systems that include iron-dependent superoxide dismutases (SODs) in mitochondria and glycosomes. Increasing evidence suggests that in addition to this protective role, Leishmania mitochondrial SOD may also initiate H2O2-mediated redox signaling that regulates gene expression and metabolic changes associated with differentiation into virulent forms. To investigate this hypothesis, we examined the specific role of SODA, the mitochondrial SOD isoform in Leishmania amazonensis Our inability to generate L. amazonensis SODA null mutants and the lethal phenotype observed following RNAi-mediated silencing of the Trypanosoma brucei SODA ortholog suggests that SODA is essential for trypanosomatid survival. L. amazonensis metacyclic promastigotes lacking one SODA allele failed to replicate in macrophages and were severely attenuated in their ability to generate cutaneous lesions in mice. Reduced expression of SODA also resulted in mitochondrial oxidative damage and failure of SODA/ΔsodA promastigotes to differentiate into axenic amastigotes. SODA expression above a critical threshold was also required for the development of metacyclic promastigotes, as SODA/ΔsodA cultures were strongly depleted in this infective form and more susceptible to reactive oxygen species (ROS)-induced stress. Collectively, our data suggest that SODA promotes Leishmania virulence by protecting the parasites against mitochondrion-generated oxidative stress and by initiating ROS-mediated signaling mechanisms required for the differentiation of infective forms.
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Affiliation(s)
- Bidyottam Mittra
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815
| | | | - Danilo Ciccone Miguel
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815
| | | | - Norma W Andrews
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815.
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15
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Mittra B, Laranjeira-Silva MF, Perrone Bezerra de Menezes J, Jensen J, Michailowsky V, Andrews NW. A Trypanosomatid Iron Transporter that Regulates Mitochondrial Function Is Required for Leishmania amazonensis Virulence. PLoS Pathog 2016; 12:e1005340. [PMID: 26741360 PMCID: PMC4704735 DOI: 10.1371/journal.ppat.1005340] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/22/2015] [Indexed: 11/20/2022] Open
Abstract
Iron, an essential co-factor of respiratory chain proteins, is critical for mitochondrial function and maintenance of its redox balance. We previously reported a role for iron uptake in differentiation of Leishmania amazonensis into virulent amastigotes, by a mechanism that involves reactive oxygen species (ROS) production and is independent of the classical pH and temperature cues. Iron import into mitochondria was proposed to be essential for this process, but evidence supporting this hypothesis was lacking because the Leishmania mitochondrial iron transporter was unknown. Here we describe MIT1, a homolog of the mitochondrial iron importer genes mrs3 (yeast) and mitoferrin-1 (human) that is highly conserved among trypanosomatids. MIT1 expression was essential for the survival of Trypanosoma brucei procyclic but not bloodstream forms, which lack functional respiratory complexes. L. amazonensis LMIT1 null mutants could not be generated, suggesting that this mitochondrial iron importer is essential for promastigote viability. Promastigotes lacking one LMIT1 allele (LMIT1/Δlmit1) showed growth defects and were more susceptible to ROS toxicity, consistent with the role of iron as the essential co-factor of trypanosomatid mitochondrial superoxide dismutases. LMIT1/Δlmit1 metacyclic promastigotes were unable to replicate as intracellular amastigotes after infecting macrophages or cause cutaneous lesions in mice. When induced to differentiate axenically into amastigotes, LMIT1/Δlmit1 showed strong defects in iron content and function of mitochondria, were unable to upregulate the ROS-regulatory enzyme FeSOD, and showed mitochondrial changes suggestive of redox imbalance. Our results demonstrate the importance of mitochondrial iron uptake in trypanosomatid parasites, and highlight the role of LMIT1 in the iron-regulated process that orchestrates differentiation of L. amazonensis into infective amastigotes. Leishmaniasis is a serious parasitic disease that affects 12 million people worldwide, with clinical manifestations ranging from self-healing cutaneous lesions to deadly visceralizing disease. A vaccine is not available, and new and less toxic drugs against this protozoan parasite are urgently needed. Following introduction into vertebrate hosts during a sand fly blood meal, Leishmania parasites undergo extensive changes in morphology and metabolism that are critical for adaptation to life inside host macrophages and replication as amastigotes. Earlier studies identified major events that occur during amastigote differentiation, but the signaling mechanism initiating this process remained poorly understood. Previously we demonstrated a novel role for the reactive oxygen species (ROS) H2O2 in initiating amastigote differentiation, a process proposed to be dependent on iron availability inside the parasite’s mitochondria. In this study we identify LMIT1, a Leishmania transmembrane protein that functions as a mitochondrial iron transporter and is conserved in other trypanosomatid protozoan parasites. Reduced LMIT1 expression impairs mitochondrial function in the infective amastigote stage, abolishing parasite virulence. Our findings identify LMIT1 as a promising new drug target, and support the conclusion that iron-dependent ROS signals generated in the mitochondria regulate differentiation of virulent Leishmania amastigotes.
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Affiliation(s)
- Bidyottam Mittra
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
| | | | - Juliana Perrone Bezerra de Menezes
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
- Laboratório de Patologia e Biointervenção, CPqGM, FIOCRUZ, Candeal, Salvador, Bahia, Brazil
| | - Jennifer Jensen
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
| | - Vladimir Michailowsky
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
- Faculdade de Medicina, Setor Parasitologia, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
| | - Norma W. Andrews
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
- * E-mail:
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16
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Wilson CS, Chang AJ, Greene R, Machado S, Parsons MW, Takats TA, Zambetti LJ, Springer AL. Knockdown of Inner Arm Protein IC138 in Trypanosoma brucei Causes Defective Motility and Flagellar Detachment. PLoS One 2015; 10:e0139579. [PMID: 26555902 PMCID: PMC4640498 DOI: 10.1371/journal.pone.0139579] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 09/15/2015] [Indexed: 12/23/2022] Open
Abstract
Motility in the protozoan parasite Trypanosoma brucei is conferred by a single flagellum, attached alongside the cell, which moves the cell forward using a beat that is generated from tip-to-base. We are interested in characterizing components that regulate flagellar beating, in this study we extend the characterization of TbIC138, the ortholog of a dynein intermediate chain that regulates axonemal inner arm dynein f/I1. TbIC138 was tagged In situ-and shown to fractionate with the inner arm components of the flagellum. RNAi knockdown of TbIC138 resulted in significantly reduced protein levels, mild growth defect and significant motility defects. These cells tended to cluster, exhibited slow and abnormal motility and some cells had partially or fully detached flagella. Slight but significant increases were observed in the incidence of mis-localized or missing kinetoplasts. To document development of the TbIC138 knockdown phenotype over time, we performed a detailed analysis of flagellar detachment and motility changes over 108 hours following induction of RNAi. Abnormal motility, such as slow twitching or irregular beating, was observed early, and became progressively more severe such that by 72 hours-post-induction, approximately 80% of the cells were immotile. Progressively more cells exhibited flagellar detachment over time, but this phenotype was not as prevalent as immotility, affecting less than 60% of the population. Detached flagella had abnormal beating, but abnormal beating was also observed in cells with no flagellar detachment, suggesting that TbIC138 has a direct, or primary, effect on the flagellar beat, whereas detachment is a secondary phenotype of TbIC138 knockdown. Our results are consistent with the role of TbIC138 as a regulator of motility, and has a phenotype amenable to more extensive structure-function analyses to further elucidate its role in the control of flagellar beat in T. brucei.
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Affiliation(s)
- Corinne S. Wilson
- Department of Biology, Siena College, Loudonville, New York, United States of America
| | - Alex J. Chang
- Department of Biology, Amherst College, Amherst, Massachusetts, United States of America
| | - Rebecca Greene
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Sulynn Machado
- Department of Biology, Amherst College, Amherst, Massachusetts, United States of America
| | - Matthew W. Parsons
- Department of Biology, Amherst College, Amherst, Massachusetts, United States of America
| | - Taylor A. Takats
- Department of Biology, Siena College, Loudonville, New York, United States of America
| | - Luke J. Zambetti
- Department of Biology, Amherst College, Amherst, Massachusetts, United States of America
| | - Amy L. Springer
- Department of Biology, Siena College, Loudonville, New York, United States of America
- * E-mail:
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17
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Shimogawa MM, Saada EA, Vashisht AA, Barshop WD, Wohlschlegel JA, Hill KL. Cell Surface Proteomics Provides Insight into Stage-Specific Remodeling of the Host-Parasite Interface in Trypanosoma brucei. Mol Cell Proteomics 2015; 14:1977-88. [PMID: 25963835 DOI: 10.1074/mcp.m114.045146] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Indexed: 02/05/2023] Open
Abstract
African trypanosomes are devastating human and animal pathogens transmitted by tsetse flies between mammalian hosts. The trypanosome surface forms a critical host interface that is essential for sensing and adapting to diverse host environments. However, trypanosome surface protein composition and diversity remain largely unknown. Here, we use surface labeling, affinity purification, and proteomic analyses to describe cell surface proteomes from insect-stage and mammalian bloodstream-stage Trypanosoma brucei. The cell surface proteomes contain most previously characterized surface proteins. We additionally identify a substantial number of novel proteins, whose functions are unknown, indicating the parasite surface proteome is larger and more diverse than generally appreciated. We also show stage-specific expression for individual paralogs within several protein families, suggesting that fine-tuned remodeling of the parasite surface allows adaptation to diverse host environments, while still fulfilling universally essential cellular needs. Our surface proteome analyses complement existing transcriptomic, proteomic, and in silico analyses by highlighting proteins that are surface-exposed and thereby provide a major step forward in defining the host-parasite interface.
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Affiliation(s)
- Michelle M Shimogawa
- From the ‡Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, 90095
| | - Edwin A Saada
- From the ‡Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, 90095
| | - Ajay A Vashisht
- §Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California 90095
| | - William D Barshop
- §Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California 90095
| | - James A Wohlschlegel
- §Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California 90095; ¶Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095
| | - Kent L Hill
- From the ‡Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, 90095; ¶Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095
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18
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Santi-Rocca J, Chenouard N, Fort C, Lagache T, Olivo-Marin JC, Bastin P. Imaging intraflagellar transport in trypanosomes. Methods Cell Biol 2015; 127:487-508. [PMID: 25837405 DOI: 10.1016/bs.mcb.2015.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Trypanosoma brucei is a flagellated eukaryotic pathogen responsible for sleeping sickness in central Africa. Because of the presence of a long motile flagellum (>20 μm) and its amenity to genetic manipulation, it is becoming an attractive model to study the assembly and the functions of cilia and flagella. In recent years, several aspects have been investigated, especially intraflagellar transport (IFT) that has been exhaustively characterized at the light microscopy level. In this manuscript, we review various methods to express fluorescent fusion proteins and to record IFT in living trypanosomes in normal or mutant contexts. We present an approach for separating anterograde and retrograde IFT, hence facilitating quantification of train speed, frequency, and size. A statistical analysis to discriminate different subpopulations of IFT trains is also summarized. These methods have proven their efficiency for the study of IFT in trypanosomes and could be applied to any other organism.
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Affiliation(s)
- Julien Santi-Rocca
- Trypanosome Cell Biology Unit, Institut Pasteur & CNRS URA2581, Paris, France
| | - Nicolas Chenouard
- Bio Image Analysis Unit, Institut Pasteur & CNRS URA2582, Paris, France
| | - Cécile Fort
- Trypanosome Cell Biology Unit, Institut Pasteur & CNRS URA2581, Paris, France
| | - Thibault Lagache
- Bio Image Analysis Unit, Institut Pasteur & CNRS URA2582, Paris, France
| | | | - Philippe Bastin
- Trypanosome Cell Biology Unit, Institut Pasteur & CNRS URA2581, Paris, France
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Insect stage-specific adenylate cyclases regulate social motility in African trypanosomes. EUKARYOTIC CELL 2014; 14:104-12. [PMID: 25416239 DOI: 10.1128/ec.00217-14] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Sophisticated systems for cell-cell communication enable unicellular microbes to act as multicellular entities capable of group-level behaviors that are not evident in individuals. These group behaviors influence microbe physiology, and the underlying signaling pathways are considered potential drug targets in microbial pathogens. Trypanosoma brucei is a protozoan parasite that causes substantial human suffering and economic hardship in some of the most impoverished regions of the world. T. brucei lives on host tissue surfaces during transmission through its tsetse fly vector, and cultivation on surfaces causes the parasites to assemble into multicellular communities in which individual cells coordinate their movements in response to external signals. This behavior is termed "social motility," based on its similarities with surface-induced social motility in bacteria, and it demonstrates that trypanosomes are capable of group-level behavior. Mechanisms governing T. brucei social motility are unknown. Here we report that a subset of receptor-type adenylate cyclases (ACs) in the trypanosome flagellum regulate social motility. RNA interference-mediated knockdown of adenylate cyclase 6 (AC6), or dual knockdown of AC1 and AC2, causes a hypersocial phenotype but has no discernible effect on individual cells in suspension culture. Mutation of the AC6 catalytic domain phenocopies AC6 knockdown, demonstrating that loss of adenylate cyclase activity is responsible for the phenotype. Notably, knockdown of other ACs did not affect social motility, indicating segregation of AC functions. These studies reveal interesting parallels in systems that control social behavior in trypanosomes and bacteria and provide insight into a feature of parasite biology that may be exploited for novel intervention strategies.
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Insect stage-specific receptor adenylate cyclases are localized to distinct subdomains of the Trypanosoma brucei Flagellar membrane. EUKARYOTIC CELL 2014; 13:1064-76. [PMID: 24879126 DOI: 10.1128/ec.00019-14] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Increasing evidence indicates that the Trypanosoma brucei flagellum (synonymous with cilium) plays important roles in host-parasite interactions. Several studies have identified virulence factors and signaling proteins in the flagellar membrane of bloodstream-stage T. brucei, but less is known about flagellar membrane proteins in procyclic, insect-stage parasites. Here we report on the identification of several receptor-type flagellar adenylate cyclases (ACs) that are specifically upregulated in procyclic T. brucei parasites. Identification of insect stage-specific ACs is novel, as previously studied ACs were constitutively expressed or confined to bloodstream-stage parasites. We show that procyclic stage-specific ACs are glycosylated, surface-exposed proteins that dimerize and possess catalytic activity. We used gene-specific tags to examine the distribution of individual AC isoforms. All ACs examined localized to the flagellum. Notably, however, while some ACs were distributed along the length of the flagellum, others specifically localized to the flagellum tip. These are the first transmembrane domain proteins to be localized specifically at the flagellum tip in T. brucei, emphasizing that the flagellum membrane is organized into specific subdomains. Deletion analysis reveals that C-terminal sequences are critical for targeting ACs to the flagellum, and sequence comparisons suggest that differential subflagellar localization might be specified by isoform-specific C termini. Our combined results suggest insect stage-specific roles for a subset of flagellar adenylate cyclases and support a microdomain model for flagellar cyclic AMP (cAMP) signaling in T. brucei. In this model, cAMP production is compartmentalized through differential localization of individual ACs, thereby allowing diverse cellular responses to be controlled by a common signaling molecule.
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Nguyen HT, Sandhu J, Langousis G, Hill KL. CMF22 is a broadly conserved axonemal protein and is required for propulsive motility in Trypanosoma brucei. EUKARYOTIC CELL 2013; 12:1202-13. [PMID: 23851336 PMCID: PMC3811564 DOI: 10.1128/ec.00068-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 07/02/2013] [Indexed: 12/23/2022]
Abstract
The eukaryotic flagellum (or cilium) is a broadly conserved organelle that provides motility for many pathogenic protozoa and is critical for normal development and physiology in humans. Therefore, defining core components of motile axonemes enhances understanding of eukaryotic biology and provides insight into mechanisms of inherited and infectious diseases in humans. In this study, we show that component of motile flagella 22 (CMF22) is tightly associated with the flagellar axoneme and is likely to have been present in the last eukaryotic common ancestor. The CMF22 amino acid sequence contains predicted IQ and ATPase associated with a variety of cellular activities (AAA) motifs that are conserved among CMF22 orthologues in diverse organisms, hinting at the importance of these domains in CMF22 function. Knockdown by RNA interference (RNAi) and rescue with an RNAi-immune mRNA demonstrated that CMF22 is required for propulsive cell motility in Trypanosoma brucei. Loss of propulsive motility in CMF22-knockdown cells was due to altered flagellar beating patterns, rather than flagellar paralysis, indicating that CMF22 is essential for motility regulation and likely functions as a fundamental regulatory component of motile axonemes. CMF22 association with the axoneme is weakened in mutants that disrupt the nexin-dynein regulatory complex, suggesting potential interaction with this complex. Our results provide insight into the core machinery required for motility of eukaryotic flagella.
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Affiliation(s)
- HoangKim T. Nguyen
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Jaspreet Sandhu
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Gerasimos Langousis
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Kent L. Hill
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, USA
- Molecular Biology Institute, University of California, Los Angeles, California, USA
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22
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Dacheux D, Landrein N, Thonnus M, Gilbert G, Sahin A, Wodrich H, Robinson DR, Bonhivers M. A MAP6-related protein is present in protozoa and is involved in flagellum motility. PLoS One 2012; 7:e31344. [PMID: 22355359 PMCID: PMC3280300 DOI: 10.1371/journal.pone.0031344] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 01/06/2012] [Indexed: 12/25/2022] Open
Abstract
In vertebrates the microtubule-associated proteins MAP6 and MAP6d1 stabilize cold-resistant microtubules. Cilia and flagella have cold-stable microtubules but MAP6 proteins have not been identified in these organelles. Here, we describe TbSAXO as the first MAP6-related protein to be identified in a protozoan, Trypanosoma brucei. Using a heterologous expression system, we show that TbSAXO is a microtubule stabilizing protein. Furthermore we identify the domains of the protein responsible for microtubule binding and stabilizing and show that they share homologies with the microtubule-stabilizing Mn domains of the MAP6 proteins. We demonstrate, in the flagellated parasite, that TbSAXO is an axonemal protein that plays a role in flagellum motility. Lastly we provide evidence that TbSAXO belongs to a group of MAP6-related proteins (SAXO proteins) present only in ciliated or flagellated organisms ranging from protozoa to mammals. We discuss the potential roles of the SAXO proteins in cilia and flagella function.
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Affiliation(s)
- Denis Dacheux
- Microbiologie Fondamentale et Pathogénicité, Université de Bordeaux, UMR 5234, Bordeaux, France
- Microbiologie Fondamentale et Pathogénicité, CNRS, UMR 5234, Bordeaux, France
- Microbiologie Fondamentale et Pathogénicité, Institut Polytechnique de Bordeaux, UMR 5234, Bordeaux, France
| | - Nicolas Landrein
- Microbiologie Fondamentale et Pathogénicité, Université de Bordeaux, UMR 5234, Bordeaux, France
- Microbiologie Fondamentale et Pathogénicité, CNRS, UMR 5234, Bordeaux, France
| | - Magali Thonnus
- Microbiologie Fondamentale et Pathogénicité, Université de Bordeaux, UMR 5234, Bordeaux, France
- Microbiologie Fondamentale et Pathogénicité, CNRS, UMR 5234, Bordeaux, France
| | - Guillaume Gilbert
- Microbiologie Fondamentale et Pathogénicité, Université de Bordeaux, UMR 5234, Bordeaux, France
- Microbiologie Fondamentale et Pathogénicité, CNRS, UMR 5234, Bordeaux, France
| | - Annelise Sahin
- Microbiologie Fondamentale et Pathogénicité, Université de Bordeaux, UMR 5234, Bordeaux, France
- Microbiologie Fondamentale et Pathogénicité, CNRS, UMR 5234, Bordeaux, France
| | - Harald Wodrich
- Microbiologie Fondamentale et Pathogénicité, Université de Bordeaux, UMR 5234, Bordeaux, France
- Microbiologie Fondamentale et Pathogénicité, CNRS, UMR 5234, Bordeaux, France
| | - Derrick R. Robinson
- Microbiologie Fondamentale et Pathogénicité, Université de Bordeaux, UMR 5234, Bordeaux, France
- Microbiologie Fondamentale et Pathogénicité, CNRS, UMR 5234, Bordeaux, France
| | - Mélanie Bonhivers
- Microbiologie Fondamentale et Pathogénicité, Université de Bordeaux, UMR 5234, Bordeaux, France
- Microbiologie Fondamentale et Pathogénicité, CNRS, UMR 5234, Bordeaux, France
- * E-mail:
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24
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Hughes LC, Ralston KS, Hill KL, Zhou ZH. Three-dimensional structure of the Trypanosome flagellum suggests that the paraflagellar rod functions as a biomechanical spring. PLoS One 2012; 7:e25700. [PMID: 22235240 PMCID: PMC3250385 DOI: 10.1371/journal.pone.0025700] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 09/08/2011] [Indexed: 11/30/2022] Open
Abstract
Flagellum motility is critical for normal human development and for transmission of pathogenic protozoa that cause tremendous human suffering worldwide. Biophysical principles underlying motility of eukaryotic flagella are conserved from protists to vertebrates. However, individual cells exhibit diverse waveforms that depend on cell-specific elaborations on basic flagellum architecture. Trypanosoma brucei is a uniflagellated protozoan parasite that causes African sleeping sickness. The T. brucei flagellum is comprised of a 9+2 axoneme and an extra-axonemal paraflagellar rod (PFR), but the three-dimensional (3D) arrangement of the underlying structural units is poorly defined. Here, we use dual-axis electron tomography to determine the 3D architecture of the T. brucei flagellum. We define the T. brucei axonemal repeating unit. We observe direct connections between the PFR and axonemal dyneins, suggesting a mechanism by which mechanochemical signals may be transmitted from the PFR to axonemal dyneins. We find that the PFR itself is comprised of overlapping laths organized into distinct zones that are connected through twisting elements at the zonal interfaces. The overall structure has an underlying 57nm repeating unit. Biomechanical properties inferred from PFR structure lead us to propose that the PFR functions as a biomechanical spring that may store and transmit energy derived from axonemal beating. These findings provide insight into the structural foundations that underlie the distinctive flagellar waveform that is a hallmark of T. brucei cell motility.
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Affiliation(s)
- Louise C. Hughes
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, California, United States of America
| | - Katherine S. Ralston
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Kent L. Hill
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail: (ZZ); (KH)
| | - Z. Hong Zhou
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail: (ZZ); (KH)
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25
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Oberholzer M, Langousis G, Nguyen HT, Saada EA, Shimogawa MM, Jonsson ZO, Nguyen SM, Wohlschlegel JA, Hill KL. Independent analysis of the flagellum surface and matrix proteomes provides insight into flagellum signaling in mammalian-infectious Trypanosoma brucei. Mol Cell Proteomics 2011; 10:M111.010538. [PMID: 21685506 DOI: 10.1074/mcp.m111.010538] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The flagellum of African trypanosomes is an essential and multifunctional organelle that functions in motility, cell morphogenesis, and host-parasite interaction. Previous studies of the trypanosome flagellum have been limited by the inability to purify flagella without first removing the flagellar membrane. This limitation is particularly relevant in the context of studying flagellum signaling, as signaling requires surface-exposed proteins in the flagellar membrane and soluble signaling proteins in the flagellar matrix. Here we employ a combination of genetic and mechanical approaches to purify intact flagella from the African trypanosome, Trypanosoma brucei, in its mammalian-infectious stage. We combined flagellum purification with affinity-purification of surface-exposed proteins to conduct independent proteomic analyses of the flagellum surface and matrix fractions. The proteins identified encompass a broad range of molecular functionalities, including many predicted to function in signaling. Immunofluorescence and RNA interference studies demonstrate flagellum localization and function for proteins identified and provide insight into mechanisms of flagellum attachment and motility. The flagellum surface proteome includes many T. brucei-specific proteins and is enriched for proteins up-regulated in the mammalian-infectious stage of the parasite life-cycle. The combined results indicate that the flagellum surface presents a diverse and dynamic host-parasite interface that is well-suited for host-parasite signaling.
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Affiliation(s)
- Michael Oberholzer
- Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, CA 90095, USA
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Vincensini L, Blisnick T, Bastin P. [The importance of model organisms to study cilia and flagella biology]. Biol Aujourdhui 2011; 205:5-28. [PMID: 21501571 DOI: 10.1051/jbio/2011005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Indexed: 12/24/2022]
Abstract
Cilia and flagella are ubiquitous organelles that protrude from the surfaces of many cells, and whose architecture is highly conserved from protists to humans. These complex organelles, composed of over 500 proteins, can be either immotile or motile. They are involved in a myriad of biological processes, including sensing (non-motile cilia) and/or cell motility or movement of extracellular fluids (motile cilia). The ever-expanding list of human diseases linked to defective cilia illustrates the functional importance of cilia and flagella. These ciliopathies are characterised by an impressive diversity of symptoms and an often complex genetic etiology. A precise knowledge of cilia and flagella biology is thus critical to better understand these pathologies. However, multi-ciliated cells are terminally differentiated and difficult to manipulate, and a primary cilium is assembled only when the cell exits from the cell cycle. In this context the use of model organisms, that relies on the high degree of structural but also of molecular conservation of these organelles across evolution, is instrumental to decipher the many facets of cilia and flagella biology. In this review, we highlight the specific strengths of the main model organisms to investigate the molecular composition, mode of assembly, sensing and motility mechanisms and functions of cilia and flagella. Pioneering studies carried out in the green alga Chlamydomonas established the link between cilia and several genetic diseases. Moreover, multicellular organisms such as mouse, zebrafish, Xenopus, C. elegans or Drosophila, and protists like Paramecium, Tetrahymena and Trypanosoma or Leishmania each bring specific advantages to the study of cilium biology. For example, the function of genes involved in primary ciliary dyskinesia (due to defects in ciliary motility) can be efficiently assessed in trypanosomes.
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Affiliation(s)
- Laetitia Vincensini
- Unité de Biologie Cellulaire des Trypanosomes, Institut Pasteur et CNRS URA 2581, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France.
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Springer AL, Bruhn DF, Kinzel KW, Rosenthal NF, Zukas R, Klingbeil MM. Silencing of a putative inner arm dynein heavy chain results in flagellar immotility in Trypanosoma brucei. Mol Biochem Parasitol 2010; 175:68-75. [PMID: 20888370 DOI: 10.1016/j.molbiopara.2010.09.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 09/19/2010] [Accepted: 09/21/2010] [Indexed: 11/16/2022]
Abstract
The Trypanosoma brucei flagellum controls motility and is crucial for cell polarity and division. Unique features of trypanosome motility suggest that flagellar beat regulation in this organism is unusual and worthy of study. The flagellar axoneme, required for motility, has a structure that is highly conserved among eukaryotes. Of the several dyneins in the axonemal inner arm complex, dynein f is thought to control flagellar waveform shape. A T. brucei gene predicted to encode the dynein f alpha heavy chain, TbDNAH10, was silenced using RNA interference in procyclic T. brucei cells. This resulted in immotile flagella, showing no movement except for occasional slight twitches at the tips. Cell growth slowed dramatically and cells were found in large clusters. Microscopic analysis of silenced cultures showed many cells with detached flagella, sometimes entangled between multiple cells. DAPI staining showed an increased frequency of mis-positioned kinetoplasts and multinucleate cells, suggesting that these cells experience disruption at an early cell cycle stage, probably secondary to the motility defect. TEM images showed apparently normal axonemes and no discernable defects in inner arm structure. This study demonstrates the use of RNAi as an effective method to study very large genes such as dynein heavy chains (HCs), and the immotility phenotype of these dynein knockdowns suggests that an intact inner arm is necessary for flagellar beating in T. brucei. Since analogous mutants in Chlamydomonas reinhardtii retain motility, this phenotype likely reflects differences in requirements for motility and/or dynein assembly between the two organisms and these comparative studies will help elucidate the mechanisms of flagellar beat regulation.
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Affiliation(s)
- Amy L Springer
- Department of Biology, Amherst College, Amherst, MA, USA.
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Hill KL. Parasites in motion: flagellum-driven cell motility in African trypanosomes. Curr Opin Microbiol 2010; 13:459-65. [PMID: 20591724 DOI: 10.1016/j.mib.2010.05.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 05/21/2010] [Accepted: 05/27/2010] [Indexed: 10/19/2022]
Abstract
Motility of the sleeping sickness parasite, Trypanosoma brucei, impacts disease transmission and pathogenesis. Trypanosome motility is driven by a flagellum that harbors a canonical 9+2 axoneme, together with trypanosome-specific elaborations. Trypanosome flagellum biology and motility have been the object of intense research over the last two years. These studies have led to the discovery of a novel form of motility, termed social motility, and provided revision of long-standing models for cell propulsion. Recent work has also uncovered novel structural features and motor proteins associated with the flagellar apparatus and has identified candidate signaling molecules that are predicted to regulate flagellar motility. Together with earlier inventories of flagellar proteins from proteomic and genomic studies, the stage is now set to move forward with functional studies to elucidate molecular mechanisms and investigate parasite motility in the context of host-parasite interactions.
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Affiliation(s)
- Kent L Hill
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, 609 Charles E. Young Drive, Los Angeles, CA 90095, USA.
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