1
|
Albisetti AC, Douglas RL, Welch MD. FAZ assembly in bloodstream form Trypanosoma brucei requires kinesin KIN-E. Mol Biol Cell 2023; 34:ar103. [PMID: 37531263 PMCID: PMC10551704 DOI: 10.1091/mbc.e23-01-0022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 07/18/2023] [Accepted: 07/26/2023] [Indexed: 08/04/2023] Open
Abstract
Trypanosoma brucei, the causative agent of African sleeping sickness, uses its flagellum for movement, cell division, and signaling. The flagellum is anchored to the cell body membrane via the flagellum attachment zone (FAZ), a complex of proteins, filaments, and microtubules that spans two membranes with elements on both flagellum and cell body sides. How FAZ components are carried into place to form this complex is poorly understood. Here, we show that the trypanosome-specific kinesin KIN-E is required for building the FAZ in bloodstream-form parasites. KIN-E is localized along the flagellum with a concentration at its distal tip. Depletion of KIN-E by RNAi rapidly inhibits flagellum attachment and leads to cell death. A detailed analysis reveals that KIN-E depletion phenotypes include failure in cytokinesis completion, kinetoplast DNA missegregation, and transport vesicle accumulation. Together with previously published results in procyclic form parasites, these data suggest KIN-E plays a critical role in FAZ assembly in T. brucei.
Collapse
Affiliation(s)
- Anna C. Albisetti
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Robert L. Douglas
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Matthew D. Welch
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| |
Collapse
|
2
|
Briggs EM, Marques CA, Oldrieve GR, Hu J, Otto TD, Matthews KR. Profiling the bloodstream form and procyclic form Trypanosoma brucei cell cycle using single-cell transcriptomics. eLife 2023; 12:e86325. [PMID: 37166108 PMCID: PMC10212563 DOI: 10.7554/elife.86325] [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: 01/20/2023] [Accepted: 05/10/2023] [Indexed: 05/12/2023] Open
Abstract
African trypanosomes proliferate as bloodstream forms (BSFs) and procyclic forms in the mammal and tsetse fly midgut, respectively. This allows them to colonise the host environment upon infection and ensure life cycle progression. Yet, understanding of the mechanisms that regulate and drive the cell replication cycle of these forms is limited. Using single-cell transcriptomics on unsynchronised cell populations, we have obtained high resolution cell cycle regulated (CCR) transcriptomes of both procyclic and slender BSF Trypanosoma brucei without prior cell sorting or synchronisation. Additionally, we describe an efficient freeze-thawing protocol that allows single-cell transcriptomic analysis of cryopreserved T. brucei. Computational reconstruction of the cell cycle using periodic pseudotime inference allowed the dynamic expression patterns of cycling genes to be profiled for both life cycle forms. Comparative analyses identify a core cycling transcriptome highly conserved between forms, as well as several genes where transcript levels dynamics are form specific. Comparing transcript expression patterns with protein abundance revealed that the majority of genes with periodic cycling transcript and protein levels exhibit a relative delay between peak transcript and protein expression. This work reveals novel detail of the CCR transcriptomes of both forms, which are available for further interrogation via an interactive webtool.
Collapse
Affiliation(s)
- Emma M Briggs
- Institute for Immunology and Infection Research, School of Biological Sciences, University of EdinburghEdinburghUnited Kingdom
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, University of GlasgowGlasgowUnited Kingdom
| | - Catarina A Marques
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, University of GlasgowGlasgowUnited Kingdom
| | - Guy R Oldrieve
- Institute for Immunology and Infection Research, School of Biological Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Jihua Hu
- Institute for Immunology and Infection Research, School of Biological Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Thomas D Otto
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, University of GlasgowGlasgowUnited Kingdom
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of EdinburghEdinburghUnited Kingdom
| |
Collapse
|
3
|
Morales J, Ehret G, Poschmann G, Reinicke T, Maurya AK, Kröninger L, Zanini D, Wolters R, Kalyanaraman D, Krakovka M, Bäumers M, Stühler K, Nowack ECM. Host-symbiont interactions in Angomonas deanei include the evolution of a host-derived dynamin ring around the endosymbiont division site. Curr Biol 2023; 33:28-40.e7. [PMID: 36480982 DOI: 10.1016/j.cub.2022.11.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/09/2022] [Accepted: 11/09/2022] [Indexed: 12/12/2022]
Abstract
The trypanosomatid Angomonas deanei is a model to study endosymbiosis. Each cell contains a single β-proteobacterial endosymbiont that divides at a defined point in the host cell cycle and contributes essential metabolites to the host metabolism. Additionally, one endosymbiont gene, encoding an ornithine cyclodeaminase (OCD), was transferred by endosymbiotic gene transfer (EGT) to the nucleus. However, the molecular mechanisms mediating the intricate host/symbiont interactions are largely unexplored. Here, we used protein mass spectrometry to identify nucleus-encoded proteins that co-purify with the endosymbiont. Expression of fluorescent fusion constructs of these proteins in A. deanei confirmed seven host proteins to be recruited to specific sites within the endosymbiont. These endosymbiont-targeted proteins (ETPs) include two proteins annotated as dynamin-like protein and peptidoglycan hydrolase that form a ring-shaped structure around the endosymbiont division site that remarkably resembles organellar division machineries. The EGT-derived OCD was not among the ETPs, but instead localizes to the glycosome, likely enabling proline production in the glycosome. We hypothesize that recalibration of the metabolic capacity of the glycosomes that are closely associated with the endosymbiont helps to supply the endosymbiont with metabolites it is auxotrophic for and thus supports the integration of host and endosymbiont metabolic networks. Hence, scrutiny of endosymbiosis-induced protein re-localization patterns in A. deanei yielded profound insights into how an endosymbiotic relationship can stabilize and deepen over time far beyond the level of metabolite exchange.
Collapse
Affiliation(s)
- Jorge Morales
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Georg Ehret
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Gereon Poschmann
- Institute of Molecular Medicine, Proteome Research, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Tobias Reinicke
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Anay K Maurya
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Lena Kröninger
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Davide Zanini
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Rebecca Wolters
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Dhevi Kalyanaraman
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Michael Krakovka
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Miriam Bäumers
- Center for Advanced Imaging, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Kai Stühler
- Institute of Molecular Medicine, Proteome Research, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany; Molecular Proteomics Laboratory, Biological and Medical Research Centre (BMFZ), Heinrich Heine University Düsseldorf, Universitätsstr 1, 40225 Düsseldorf, Germany
| | - Eva C M Nowack
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
| |
Collapse
|
4
|
Orahoske CM, Afrin M, Li Y, Hanna J, Marbury M, Li B, Su B. Identification of Prazosin as a Potential Flagellum Attachment Zone 1(FAZ1) Inhibitor for the Treatment of Human African Trypanosomiasis. ACS Infect Dis 2022; 8:1711-1726. [PMID: 35894227 DOI: 10.1021/acsinfecdis.2c00331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human African trypanosomiasis (HAT) remains a health threat to sub-Saharan Africa. The current treatments suffer from drug resistance and life-threatening side effects, making drug discovery for HAT still important. A high-throughput screening of the library of pharmaceutically active compounds identified prazosin, an α-adrenoceptor antagonist, that showed selective activity toward Trypanosoma brucei brucei. Furthermore, a series of prazosin analogues were examined, and overall, the new analogues had improved activity and selectivity. To elucidate the binding partner, a biotin-conjugated probe was synthesized, and a protein pulldown assay combined with a proteomic analysis identified the flagellum attachment zone 1 (FAZ1) filament as an interacting partner. Additionally, prazosin treatment resulted in dysfunction of the flagellum of trypanosome cells, which is indicative of a FAZ1 irregularity. We also examined the drug distribution by utilizing immunofluorescence with a designed fluorescent analogue that showed partial colocalization with FAZ1. With the activity of the prazosin analogues, a structure-activity relationship (SAR) was summarized for future lead optimization. Our findings provide a new group of FAZ1 inhibitors as novel antitrypanosomal agents.
Collapse
Affiliation(s)
- Cody M Orahoske
- Department of Chemistry, Center for Gene Regulation in Health and Disease, College of Sciences & Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, Ohio 44115, United States
| | - Marjia Afrin
- Department of Biological, Geological, and Environmental Sciences, Center for Gene Regulation in Health and Disease, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, Ohio 44115, United States
| | - Yaxin Li
- Department of Chemistry, Center for Gene Regulation in Health and Disease, College of Sciences & Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, Ohio 44115, United States
| | - Jovana Hanna
- Department of Chemistry, Center for Gene Regulation in Health and Disease, College of Sciences & Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, Ohio 44115, United States
| | - Myah Marbury
- Department of Chemistry, Center for Gene Regulation in Health and Disease, College of Sciences & Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, Ohio 44115, United States
| | - Bibo Li
- Department of Biological, Geological, and Environmental Sciences, Center for Gene Regulation in Health and Disease, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, Ohio 44115, United States
| | - Bin Su
- Department of Chemistry, Center for Gene Regulation in Health and Disease, College of Sciences & Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, Ohio 44115, United States
| |
Collapse
|
5
|
Salari S, Bamorovat M, Sharifi I, Almani PGN. Global distribution of treatment resistance gene markers for leishmaniasis. J Clin Lab Anal 2022; 36:e24599. [PMID: 35808933 PMCID: PMC9396204 DOI: 10.1002/jcla.24599] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/19/2022] [Accepted: 06/28/2022] [Indexed: 01/02/2023] Open
Abstract
Background Pentavalent antimonials (Sb(V)) such as meglumine antimoniate (Glucantime®) and sodium stibogluconate (Pentostam®) are used as first‐line treatments for leishmaniasis, either alone or in combination with second‐line drugs such as amphotericin B (Amp B), miltefosine (MIL), methotrexate (MTX), or cryotherapy. Therapeutic aspects of these drugs are now challenged because of clinical resistance worldwide. Methods We reviewedthe recent original studies were assessed by searching in electronic databases such as Scopus, Pubmed, Embase, and Web of Science. Results Studies on molecular biomarkers involved in drug resistance are essential for monitoring the disease. We reviewed genes and mechanisms of resistance to leishmaniasis, and the geographical distribution of these biomarkers in each country has also been thoroughly investigated. Conclusion Due to the emergence of resistant genes mainly in anthroponotic Leishmania species such as L. donovani and L. tropica, as the causative agents of ACL and AVL, respectively, selection of an appropriate treatment modality is essential. Physicians should be aware of the presence of such resistance for the selection of proper treatment modalities in endemic countries.
Collapse
Affiliation(s)
- Samira Salari
- Medical Mycology and Bacteriology Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Mehdi Bamorovat
- Leishmaniasis Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Iraj Sharifi
- Leishmaniasis Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | | |
Collapse
|
6
|
Dewar CE, Oeljeklaus S, Mani J, Mühlhäuser WWD, von Känel C, Zimmermann J, Ochsenreiter T, Warscheid B, Schneider A. Mistargeting of aggregation prone mitochondrial proteins activates a nucleus-mediated posttranscriptional quality control pathway in trypanosomes. Nat Commun 2022; 13:3084. [PMID: 35654893 PMCID: PMC9163028 DOI: 10.1038/s41467-022-30748-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 05/02/2022] [Indexed: 12/25/2022] Open
Abstract
Mitochondrial protein import in the parasitic protozoan Trypanosoma brucei is mediated by the atypical outer membrane translocase, ATOM. It consists of seven subunits including ATOM69, the import receptor for hydrophobic proteins. Ablation of ATOM69, but not of any other subunit, triggers a unique quality control pathway resulting in the proteasomal degradation of non-imported mitochondrial proteins. The process requires a protein of unknown function, an E3 ubiquitin ligase and the ubiquitin-like protein (TbUbL1), which all are recruited to the mitochondrion upon ATOM69 depletion. TbUbL1 is a nuclear protein, a fraction of which is released to the cytosol upon triggering of the pathway. Nuclear release is essential as cytosolic TbUbL1 can bind mislocalised mitochondrial proteins and likely transfers them to the proteasome. Mitochondrial quality control has previously been studied in yeast and metazoans. Finding such a pathway in the highly diverged trypanosomes suggests such pathways are an obligate feature of all eukaryotes. Mitochondria import most of their proteins posttranslationally. Here, Dewar et al. characterize the mitochondrial quality control mechanism of Trypanosoma brucei. Through proteomics and functional studies, they show that only ablation of ATOM69, one of the seven subunits of its mitochondrial protein translocase, triggers a unique quality control pathway resulting in TbUbL1 release from the nucleus and subsequent proteasomal degradation of non-imported mitochondrial proteins.
Collapse
Affiliation(s)
- Caroline E Dewar
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern, CH-3012, Switzerland
| | - Silke Oeljeklaus
- Faculty of Chemistry and Pharmacy, Department of Biochemistry, Theodor Boveri-Institute, University of Würzburg, 97074, Würzburg, Germany.,Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Jan Mani
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern, CH-3012, Switzerland
| | - Wignand W D Mühlhäuser
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Corinne von Känel
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern, CH-3012, Switzerland
| | - Johannes Zimmermann
- Faculty of Chemistry and Pharmacy, Department of Biochemistry, Theodor Boveri-Institute, University of Würzburg, 97074, Würzburg, Germany
| | - Torsten Ochsenreiter
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, Bern, CH-3012, Switzerland
| | - Bettina Warscheid
- Faculty of Chemistry and Pharmacy, Department of Biochemistry, Theodor Boveri-Institute, University of Würzburg, 97074, Würzburg, Germany. .,Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany. .,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany.
| | - André Schneider
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern, CH-3012, Switzerland.
| |
Collapse
|
7
|
Wei R, Li X, Wang X, Zhang N, Wang Y, Zhang X, Gong P, Li J. Trypanosoma evansi evades host innate immunity by releasing extracellular vesicles to activate TLR2-AKT signaling pathway. Virulence 2021; 12:2017-2036. [PMID: 34348595 PMCID: PMC8344757 DOI: 10.1080/21505594.2021.1959495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Surra, one of the most important animal diseases with economic consequences in Asia and South America, is caused by Trypanosoma evansi. However, the mechanism of immune evasion by T. evansi has not been extensively studied. In the present study, T. evansi extracellular vesicles (TeEVs) were characterized and the role of TeEVs in T. evansi infection were examined. The results showed that T. evansi and TeEVs could activate TLR2-AKT pathway to inhibit the secretions of IL-12p40, IL-6, and TNF-α in mouse BMDMs. TLR2−/- mice and mice with a blocked AKT pathway were more resistant to T. evansi infection than wild type (WT) mice, with a significantly lower infection rate, longer survival time and less parasite load, as well as an increased secretion level of IL-12p40 and IFN-γ. Kinetoplastid membrane protein-11 (KMP-11) of TeEVs could activate AKT pathway and inhibit the productions of IL-12p40, TNF-α, and IL-6 in vitro. TeEVs and KMP-11 could inhibit the productions of IL-12p40 and IFN-γ, promote T. evansi proliferation and shorten the survival time of infected mice in vivo. In conclusion, T. evansi could escape host immune response through inhibiting the productions of inflammatory cytokines via secreting TeEVs to activate TLR2-AKT pathway. KMP-11 in TeEVs was involved in promoting T. evansi infection. Extracellular vesicles (EVs) secreted by Trypanosoma evansi (T. evansi) activate the TLR2-AKT signaling pathway to inhibit the production of inflammatory cytokines, thereby escaping the host’s immune response. Kinetoplastid membrane protein-11 (KMP-11) in EVs is related to the promotion of T.evansi infection via AKT pathway.
Collapse
Affiliation(s)
- Ran Wei
- Key Laboratory of Zoonosis Research, Ministry of Education; College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xin Li
- Key Laboratory of Zoonosis Research, Ministry of Education; College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xiaocen Wang
- Key Laboratory of Zoonosis Research, Ministry of Education; College of Veterinary Medicine, Jilin University, Changchun, China
| | - Nan Zhang
- Key Laboratory of Zoonosis Research, Ministry of Education; College of Veterinary Medicine, Jilin University, Changchun, China
| | - Yuru Wang
- Key Laboratory of Zoonosis Research, Ministry of Education; College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xichen Zhang
- Key Laboratory of Zoonosis Research, Ministry of Education; College of Veterinary Medicine, Jilin University, Changchun, China
| | - Pengtao Gong
- Key Laboratory of Zoonosis Research, Ministry of Education; College of Veterinary Medicine, Jilin University, Changchun, China
| | - Jianhua Li
- Key Laboratory of Zoonosis Research, Ministry of Education; College of Veterinary Medicine, Jilin University, Changchun, China
| |
Collapse
|
8
|
Casein kinase TbCK1.2 regulates division of kinetoplast DNA, and movement of basal bodies in the African trypanosome. PLoS One 2021; 16:e0249908. [PMID: 33861760 PMCID: PMC8051774 DOI: 10.1371/journal.pone.0249908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/26/2021] [Indexed: 01/15/2023] Open
Abstract
The single mitochondrial nucleoid (kinetoplast) of Trypanosoma brucei is found proximal to a basal body (mature (mBB)/probasal body (pBB) pair). Kinetoplast inheritance requires synthesis of, and scission of kinetoplast DNA (kDNA) generating two kinetoplasts that segregate with basal bodies into daughter cells. Molecular details of kinetoplast scission and the extent to which basal body separation influences the process are unavailable. To address this topic, we followed basal body movements in bloodstream trypanosomes following depletion of protein kinase TbCK1.2 which promotes kinetoplast division. In control cells we found that pBBs are positioned 0.4 um from mBBs in G1, and they mature after separating from mBBs by at least 0.8 um: mBB separation reaches ~2.2 um. These data indicate that current models of basal body biogenesis in which pBBs mature in close proximity to mBBs may need to be revisited. Knockdown of TbCK1.2 produced trypanosomes containing one kinetoplast and two nuclei (1K2N), increased the percentage of cells with uncleaved kDNA 400%, decreased mBB spacing by 15%, and inhibited cytokinesis 300%. We conclude that (a) separation of mBBs beyond a threshold of 1.8 um correlates with division of kDNA, and (b) TbCK1.2 regulates kDNA scission. We propose a Kinetoplast Division Factor hypothesis that integrates these data into a pathway for biogenesis of two daughter mitochondrial nucleoids.
Collapse
|
9
|
Pham KTM, Li Z. Regulated protein stabilization underpins the functional interplay among basal body components in Trypanosoma brucei. J Biol Chem 2020; 295:729-742. [PMID: 31819011 DOI: 10.1074/jbc.ra119.011352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/03/2019] [Indexed: 11/06/2022] Open
Abstract
The basal body in the human parasite Trypanosoma brucei is structurally equivalent to the centriole in animals and functions in the nucleation of axonemal microtubules in the flagellum. T. brucei lacks many evolutionarily conserved centriolar protein homologs and constructs the basal body through unknown mechanisms. Two evolutionarily conserved centriole/basal body cartwheel proteins, TbSAS-6 and TbBLD10, and a trypanosome-specific protein, BBP65, play essential roles in basal body biogenesis in T. brucei, but how they cooperate in the regulation of basal body assembly remains elusive. Here using RNAi, endogenous epitope tagging, immunofluorescence microscopy, and 3D-structured illumination super-resolution microscopy, we identified a new trypanosome-specific protein named BBP164 and found that it has an essential role in basal body biogenesis in T. brucei Further investigation of the functional interplay among BBP164 and the other three regulators of basal body assembly revealed that BBP164 and BBP65 are interdependent for maintaining their stability and depend on TbSAS-6 and TbBLD10 for their stabilization in the basal body. Additionally, TbSAS-6 and TbBLD10 are independent from each other and from BBP164 and BBP65 for maintaining their stability in the basal body. These findings demonstrate that basal body cartwheel proteins are required for stabilizing other basal body components and uncover that regulation of protein stability is an unusual control mechanism for assembly of the basal body in T. brucei.
Collapse
Affiliation(s)
- Kieu T M Pham
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030
| |
Collapse
|
10
|
Regulated protein stabilization underpins the functional interplay among basal body components in Trypanosoma brucei. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49931-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
11
|
Hammarton TC. Who Needs a Contractile Actomyosin Ring? The Plethora of Alternative Ways to Divide a Protozoan Parasite. Front Cell Infect Microbiol 2019; 9:397. [PMID: 31824870 PMCID: PMC6881465 DOI: 10.3389/fcimb.2019.00397] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/06/2019] [Indexed: 01/21/2023] Open
Abstract
Cytokinesis, or the division of the cytoplasm, following the end of mitosis or meiosis, is accomplished in animal cells, fungi, and amoebae, by the constriction of an actomyosin contractile ring, comprising filamentous actin, myosin II, and associated proteins. However, despite this being the best-studied mode of cytokinesis, it is restricted to the Opisthokonta and Amoebozoa, since members of other evolutionary supergroups lack myosin II and must, therefore, employ different mechanisms. In particular, parasitic protozoa, many of which cause significant morbidity and mortality in humans and animals as well as considerable economic losses, employ a wide diversity of mechanisms to divide, few, if any, of which involve myosin II. In some cases, cell division is not only myosin II-independent, but actin-independent too. Mechanisms employed range from primitive mechanical cell rupture (cytofission), to motility- and/or microtubule remodeling-dependent mechanisms, to budding involving the constriction of divergent contractile rings, to hijacking host cell division machinery, with some species able to utilize multiple mechanisms. Here, I review current knowledge of cytokinesis mechanisms and their molecular control in mammalian-infective parasitic protozoa from the Excavata, Alveolata, and Amoebozoa supergroups, highlighting their often-underappreciated diversity and complexity. Billions of people and animals across the world are at risk from these pathogens, for which vaccines and/or optimal treatments are often not available. Exploiting the divergent cell division machinery in these parasites may provide new avenues for the treatment of protozoal disease.
Collapse
Affiliation(s)
- Tansy C Hammarton
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| |
Collapse
|
12
|
Double-stranded RNA reduces growth rates of the gut parasite Crithidia mellificae. Parasitol Res 2019; 118:715-721. [DOI: 10.1007/s00436-018-6176-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 12/11/2018] [Indexed: 10/27/2022]
|
13
|
Mensa-Wilmot K, Hoffman B, Wiedeman J, Sullenberger C, Sharma A. Kinetoplast Division Factors in a Trypanosome. Trends Parasitol 2019; 35:119-128. [PMID: 30638954 DOI: 10.1016/j.pt.2018.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/06/2018] [Accepted: 11/11/2018] [Indexed: 02/08/2023]
Abstract
Inheritance of the single mitochondrial nucleoid (kinetoplast) in the trypanosome requires numerous proteins, many of whose precise roles are unclear. By considering kinetoplast DNA (kDNA) as a template for cleavage into two equal-size networks, we predicted sets of mutant kinetoplasts associated with defects in each of the five steps in the kinetoplast cycle. Comparison of these kinetoplasts with those obtained after gene knockdowns enabled assignment of proteins to five classes - kDNA synthesis, site of scission selection, scission, separation, and partitioning. These studies highlight how analysis of mutant kinetoplast phenotypes may be used to predict functional categories of proteins involved in the biogenesis of kinetoplasts.
Collapse
Affiliation(s)
- Kojo Mensa-Wilmot
- Department of Cellular Biology, 724 Biological Sciences Building, University of Georgia, Athens, Georgia 30602, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, USA.
| | - Benjamin Hoffman
- Department of Cellular Biology, 724 Biological Sciences Building, University of Georgia, Athens, Georgia 30602, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, USA
| | - Justin Wiedeman
- Department of Cellular Biology, 724 Biological Sciences Building, University of Georgia, Athens, Georgia 30602, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, USA
| | - Catherine Sullenberger
- Department of Cellular Biology, 724 Biological Sciences Building, University of Georgia, Athens, Georgia 30602, USA
| | - Amrita Sharma
- Department of Cellular Biology, 724 Biological Sciences Building, University of Georgia, Athens, Georgia 30602, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, USA
| |
Collapse
|
14
|
Rapid, Selection-Free, High-Efficiency Genome Editing in Protozoan Parasites Using CRISPR-Cas9 Ribonucleoproteins. mBio 2017; 8:mBio.01788-17. [PMID: 29114029 PMCID: PMC5676044 DOI: 10.1128/mbio.01788-17] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Trypanosomatids (order Kinetoplastida), including the human pathogens Trypanosoma cruzi (agent of Chagas disease), Trypanosoma brucei, (African sleeping sickness), and Leishmania (leishmaniasis), affect millions of people and animals globally. T. cruzi is considered one of the least studied and most poorly understood tropical disease-causing parasites, in part because of the relative lack of facile genetic engineering tools. This situation has improved recently through the application of clustered regularly interspaced short palindromic repeats–CRISPR-associated protein 9 (CRISPR-Cas9) technology, but a number of limitations remain, including the toxicity of continuous Cas9 expression and the long drug marker selection times. In this study, we show that the delivery of ribonucleoprotein (RNP) complexes composed of recombinant Cas9 from Staphylococcus aureus (SaCas9), but not from the more routinely used Streptococcus pyogenes Cas9 (SpCas9), and in vitro-transcribed single guide RNAs (sgRNAs) results in rapid gene edits in T. cruzi and other kinetoplastids at frequencies approaching 100%. The highly efficient genome editing via SaCas9/sgRNA RNPs was obtained for both reporter and endogenous genes and observed in multiple parasite life cycle stages in various strains of T. cruzi, as well as in T. brucei and Leishmania major. RNP complex delivery was also used to successfully tag proteins at endogenous loci and to assess the biological functions of essential genes. Thus, the use of SaCas9 RNP complexes for gene editing in kinetoplastids provides a simple, rapid, and cloning- and selection-free method to assess gene function in these important human pathogens. Protozoan parasites remain some of the highest-impact human and animal pathogens, with very limited treatment and prevention options. The development of improved therapeutics and vaccines depends on a better understanding of the unique biology of these organisms, and understanding their biology, in turn, requires the ability to track and manipulate the products of genes. In this work, we describe new methods that are available to essentially any laboratory and applicable to any parasite isolate for easily and rapidly editing the genomes of kinetoplastid parasites. We demonstrate that these methods provide the means to quickly assess function, including that of the products of essential genes and potential targets of drugs, and to tag gene products at their endogenous loci. This is all achieved without gene cloning or drug selection. We expect this advance to enable investigations, especially in Trypanosoma cruzi and Leishmania spp., that have eluded investigators for decades.
Collapse
|
15
|
Proximity Interactions among Basal Body Components in Trypanosoma brucei Identify Novel Regulators of Basal Body Biogenesis and Inheritance. mBio 2017; 8:mBio.02120-16. [PMID: 28049148 PMCID: PMC5210500 DOI: 10.1128/mbio.02120-16] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The basal body shares similar architecture with centrioles in animals and is involved in nucleating flagellar axonemal microtubules in flagellated eukaryotes. The early-branching Trypanosoma brucei possesses a motile flagellum nucleated from the basal body that consists of a mature basal body and an adjacent pro-basal body. Little is known about the basal body proteome and its roles in basal body biogenesis and flagellar axoneme assembly in T. brucei. Here, we report the identification of 14 conserved centriole/basal body protein homologs and 25 trypanosome-specific basal body proteins. These proteins localize to distinct subdomains of the basal body, and several of them form a ring-like structure surrounding the basal body barrel. Functional characterization of representative basal body proteins revealed distinct roles in basal body duplication/separation and flagellar axoneme assembly. Overall, this work identified novel proteins required for basal body duplication and separation and uncovered new functions of conserved basal body proteins in basal body duplication and separation, highlighting an unusual mechanism of basal body biogenesis and inheritance in this early divergent eukaryote. The basal body in the early-branching protozoan Trypanosoma brucei nucleates flagellum assembly and also regulates organelle segregation, cell morphogenesis, and cell division. However, the molecular composition and the assembly process of the basal body remain poorly understood. Here, we identify 14 conserved basal body proteins and 25 trypanosome-specific basal body proteins via bioinformatics, localization-based screening, and proximity-dependent biotin identification. We further localized these proteins to distinct subdomains of the basal body by using fluorescence microscopy and superresolution microscopy, discovered novel regulators of basal body duplication and separation, and uncovered new functions of conserved basal body proteins in basal body duplication and separation. This work lays the foundation for dissecting the mechanisms underlying basal body biogenesis and inheritance in T. brucei.
Collapse
|
16
|
Leandro de Jesus TC, Calderano SG, Vitorino FNDL, Llanos RP, Lopes MDC, de Araújo CB, Thiemann OH, Reis MDS, Elias MC, Chagas da Cunha JP. Quantitative Proteomic Analysis of Replicative and Nonreplicative Forms Reveals Important Insights into Chromatin Biology of Trypanosoma cruzi. Mol Cell Proteomics 2016; 16:23-38. [PMID: 27852749 DOI: 10.1074/mcp.m116.061200] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 10/02/2016] [Indexed: 01/02/2023] Open
Abstract
Chromatin associated proteins are key regulators of many important processes in the cell. Trypanosoma cruzi, a protozoa flagellate that causes Chagas disease, alternates between replicative and nonreplicative forms accompanied by a shift on global transcription levels and by changes in its chromatin architecture. Here, we investigated the T. cruzi chromatin proteome using three different protocols and compared it between replicative (epimastigote) and nonreplicative (trypomastigote) forms by high-resolution mass spectrometry. More than 2000 proteins were identified and quantified both in chromatin and nonchromatin extracts. Besides histones and other known nuclear proteins, trypanosomes chromatin also contains metabolic (mainly from carbohydrate pathway), cytoskeleton and many other proteins with unknown functions. Strikingly, the two parasite forms differ greatly regarding their chromatin-associated factors composition and amount. Although the nucleosome content is the same for both life forms (as seen by MNase digestion), the remaining proteins were much less detected in nonreplicative forms, suggesting that they have a naked chromatin. Proteins associated to DNA proliferation, such as PCNA, RPA, and DNA topoisomerases were exclusively found in the chromatin of replicative stages. On the other hand, the nonreplicative stages have an enrichment of a histone H2B variant. Furthermore, almost 20% of replicative stages chromatin-associated proteins are expressed in nonreplicative forms, but located at nonchromatin space. We identified different classes of proteins including phosphatases and a Ran-binding protein, that may shuttle between chromatin and nonchromatin space during differentiation. Seven proteins, including those with unknown functions, were selected for further validation. We confirmed their location in chromatin and their differential expression, using Western blotting assays and chromatin immunoprecipitation (ChIP). Our results indicate that the replicative state in trypanosomes involves an increase of chromatin associated proteins content. We discuss in details, the qualitative and quantitative implication of this chromatin set in trypanosome chromatin biology. Because trypanosomes are early-branching organisms, this data can boost our understanding of chromatin-associated processes in other cell types.
Collapse
Affiliation(s)
- Teresa Cristina Leandro de Jesus
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil.,§Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo - USP, São Carlos, SP, 13563-120, Brazil
| | - Simone Guedes Calderano
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil.,¶Laboratório de Parasitologia, Instituto Butantan, São Paulo, 05503-900, Brazil
| | - Francisca Nathalia de Luna Vitorino
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Ricardo Pariona Llanos
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Mariana de Camargo Lopes
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Christiane Bezerra de Araújo
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Otavio Henrique Thiemann
- §Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo - USP, São Carlos, SP, 13563-120, Brazil
| | - Marcelo da Silva Reis
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Maria Carolina Elias
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Julia Pinheiro Chagas da Cunha
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil;
| |
Collapse
|
17
|
Hu H, Zhou Q, Li Z. SAS-4 Protein in Trypanosoma brucei Controls Life Cycle Transitions by Modulating the Length of the Flagellum Attachment Zone Filament. J Biol Chem 2015; 290:30453-63. [PMID: 26504079 DOI: 10.1074/jbc.m115.694109] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Indexed: 01/05/2023] Open
Abstract
The evolutionarily conserved centriole/basal body protein SAS-4 regulates centriole duplication in metazoa and basal body duplication in flagellated and ciliated organisms. Here, we report that the SAS-4 homolog in the flagellated protozoan Trypanosoma brucei, TbSAS-4, plays an unusual role in controlling life cycle transitions by regulating the length of the flagellum attachment zone (FAZ) filament, a specialized cytoskeletal structure required for flagellum adhesion and cell morphogenesis. TbSAS-4 is concentrated at the distal tip of the FAZ filament, and depletion of TbSAS-4 in the trypomastigote form disrupts the elongation of the new FAZ filament, generating cells with a shorter FAZ associated with a longer unattached flagellum and repositioned kinetoplast and basal body, reminiscent of epimastigote-like morphology. Further, we show that TbSAS-4 associates with six additional FAZ tip proteins, and depletion of TbSAS-4 disrupts the enrichment of these FAZ tip proteins at the new FAZ tip, suggesting a role of TbSAS-4 in maintaining the integrity of this FAZ tip protein complex. Together, these results uncover a novel function of TbSAS-4 in regulating the length of the FAZ filament to control basal body positioning and life cycle transitions in T. brucei.
Collapse
Affiliation(s)
- Huiqing Hu
- From the Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, Texas 77030
| | - Qing Zhou
- From the Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, Texas 77030
| | - Ziyin Li
- From the Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, Texas 77030
| |
Collapse
|
18
|
Abstract
Replication of Trypanosoma cruzi, the etiological agent of Chagas disease, displays peculiar features, such as absence of chromosome condensation and closed mitosis. Although previous proteome and subproteome analyses of T. cruzi have been carried out, the nuclear subproteome of this protozoan has not been described. Here, we report, for the first time to the best of our knowledge, the isolation and proteome analysis of T. cruzi nuclear fraction. For that, T. cruzi epimastigote cells were lysed and subjected to cell fractionation using two steps of sucrose density gradient centrifugation. The purity of the nuclear fraction was confirmed by phase contrast and fluorescence microscopy. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) allowed the identification of 864 proteins. Among those, 272 proteins were annotated as putative uncharacterized, and 275 had not been previously reported on global T. cruzi proteome analysis. Additionally, to support our enrichment method, bioinformatics analysis in DAVID was carried out. It grouped the nuclear proteins in 65 gene clusters, wherein the clusters with the highest enrichment scores harbor members with chromatin organization and DNA binding functions.
Collapse
|
19
|
McAllaster MR, Ikeda KN, Lozano-Núñez A, Anrather D, Unterwurzacher V, Gossenreiter T, Perry JA, Crickley R, Mercadante CJ, Vaughan S, de Graffenried CL. Proteomic identification of novel cytoskeletal proteins associated with TbPLK, an essential regulator of cell morphogenesis in Trypanosoma brucei. Mol Biol Cell 2015; 26:3013-29. [PMID: 26133384 PMCID: PMC4551316 DOI: 10.1091/mbc.e15-04-0219] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/16/2015] [Accepted: 06/24/2015] [Indexed: 01/06/2023] Open
Abstract
Trypanosoma brucei is the causative agent of African sleeping sickness, a devastating disease endemic to sub-Saharan Africa with few effective treatment options. The parasite is highly polarized, including a single flagellum that is nucleated at the posterior of the cell and adhered along the cell surface. These features are essential and must be transmitted to the daughter cells during division. Recently we identified the T. brucei homologue of polo-like kinase (TbPLK) as an essential morphogenic regulator. In the present work, we conduct proteomic screens to identify potential TbPLK binding partners and substrates to better understand the molecular mechanisms of kinase function. These screens identify a cohort of proteins, most of which are completely uncharacterized, which localize to key cytoskeletal organelles involved in establishing cell morphology, including the flagella connector, flagellum attachment zone, and bilobe structure. Depletion of these proteins causes substantial changes in cell division, including mispositioning of the kinetoplast, loss of flagellar connection, and prevention of cytokinesis. The proteins identified in these screens provide the foundation for establishing the molecular networks through which TbPLK directs cell morphogenesis in T. brucei.
Collapse
Affiliation(s)
- Michael R McAllaster
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912
| | - Kyojiro N Ikeda
- Max F. Perutz Laboratories, Department of Medical Biochemistry, Medical University of Vienna, 1030 Vienna, Austria
| | - Ana Lozano-Núñez
- Max F. Perutz Laboratories, Center for Molecular Biology, University of Vienna, 1030 Vienna, Austria
| | - Dorothea Anrather
- Max F. Perutz Laboratories, Mass Spectrometry Facility, University of Vienna, 1030 Vienna, Austria
| | - Verena Unterwurzacher
- Max F. Perutz Laboratories, Mass Spectrometry Facility, University of Vienna, 1030 Vienna, Austria
| | - Thomas Gossenreiter
- Max F. Perutz Laboratories, Mass Spectrometry Facility, University of Vienna, 1030 Vienna, Austria
| | - Jenna A Perry
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912
| | - Robbie Crickley
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
| | - Courtney J Mercadante
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912
| | - Sue Vaughan
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
| | | |
Collapse
|
20
|
Zhou Q, Hu H, He CY, Li Z. Assembly and maintenance of the flagellum attachment zone filament in Trypanosoma brucei. J Cell Sci 2015; 128:2361-72. [PMID: 25972344 DOI: 10.1242/jcs.168377] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/06/2015] [Indexed: 11/20/2022] Open
Abstract
Adhesion of motile flagella to the cell body in Trypanosoma brucei requires a filamentous cytoskeletal structure termed the flagellum attachment zone (FAZ). Despite its essentiality, the complete molecular composition of the FAZ filament and its roles in FAZ filament assembly remain poorly understood. By localization-based screening, we here identified a new FAZ protein, which we called FAZ2. Knockdown of FAZ2 disrupted the FAZ filament, destabilized multiple FAZ filament proteins and caused a cytokinesis defect. We also showed that FAZ2 depletion destabilized another new FAZ filament protein and several flagellum and cytoskeleton proteins. Furthermore, we identified CC2D and KMP11 as FAZ2 partners through affinity purification, and showed that they are each required for maintaining a stable complex. Finally, we demonstrated that FAZ filament proteins are incorporated into the FAZ filament from the proximal region, in contrast to the flagellum components, which are incorporated from the distal tip. In summary, we identified three new FAZ filament proteins and a FAZ filament protein complex, and our results suggest that assembly of the FAZ filament occurs at the proximal region and is essential to maintain the stability of FAZ filament proteins.
Collapse
Affiliation(s)
- Qing Zhou
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, TX 77030, USA
| | - Huiqing Hu
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, TX 77030, USA
| | - Cynthia Y He
- Department of Biological Sciences, National University of Singapore, 117543, Singapore
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, TX 77030, USA
| |
Collapse
|
21
|
Finkelsztein EJ, Diaz-Soto JC, Vargas-Zambrano JC, Suesca E, Guzmán F, López MC, Thomas MC, Forero-Shelton M, Cuellar A, Puerta CJ, González JM. Altering the motility of Trypanosoma cruzi with rabbit polyclonal anti-peptide antibodies reduces infection to susceptible mammalian cells. Exp Parasitol 2015; 150:36-43. [PMID: 25633439 DOI: 10.1016/j.exppara.2015.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Revised: 11/10/2014] [Accepted: 01/11/2015] [Indexed: 10/24/2022]
Abstract
Trypanosoma cruzi's trypomastigotes are highly active and their incessant motility seems to be important for mammalian host cell infection. The kinetoplastid membrane protein-11 (KMP-11) is a protein expressed in all parasite stages, which induces a cellular and humoral immune response in the infected host, and is hypothesized to participate in the parasite's motility. An N-terminal peptide from KMP-11, termed K1 or TcTLE, induced polyclonal antibodies that inhibit parasitic invasion of Vero cells. The goal of this study was to evaluate the motility and infectivity of T. cruzi when exposed to polyclonal anti-TcTLE antibodies. Rabbits were immunized with TcTLE peptide along with FIS peptide as an immunomodulator. ELISA assay results showed that post-immunization sera contained high titers of polyclonal anti-TcTLE antibodies, which were also reactive against the native KMP-11 protein and live parasites as detected by immunofluorescence and flow cytometry assays. Trypomastigotes of T. cruzi were incubated with pre- or post-immunization sera, and infectivity to human astrocytes was assessed by Giemsa staining/light microscope and flow cytometry using carboxyfluorescein diacetate succinimidyl ester (CFSE) labeled parasites. T. cruzi infection in astrocytes decreased approximately by 30% upon incubation with post-immunization sera compared with pre-immunization sera. Furthermore, trypomastigotes were recorded by video microscopy and the parasite's flagellar speed was calculated by tracking the flagella. Trypomastigotes exposed to post-immunization sera had qualitative alterations in motility and significantly slower flagella (45.5 µm/s), compared with those exposed to pre-immunization sera (69.2 µm/s). In summary, polyclonal anti-TcTLE serum significantly reduced the parasite's flagellar speed and cell infectivity. These findings support that KMP-11 could be important for parasite motility, and that by targeting its N-terminal peptide infectivity can be reduced.
Collapse
Affiliation(s)
- Eli J Finkelsztein
- Grupo de Ciencias Básicas, Facultad de Medicina, Universidad de Los Andes, Bogotá, DC, Colombia
| | - Juan C Diaz-Soto
- Grupo de Ciencias Básicas, Facultad de Medicina, Universidad de Los Andes, Bogotá, DC, Colombia
| | - Juan C Vargas-Zambrano
- Grupo de Ciencias Básicas, Facultad de Medicina, Universidad de Los Andes, Bogotá, DC, Colombia
| | - Elizabeth Suesca
- Grupo de Biofísica, Departamento de Física, Universidad de los Andes, Bogotá, DC, Colombia
| | - Fanny Guzmán
- Núcleo de Biotecnología Curauma, Pontificia Universidad Católica Valparaíso, Valparaíso, Chile
| | - Manuel C López
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas (IPBLN-CSIC) P.T. de Ciencias de la Salud, Granada, Spain
| | - M Carmen Thomas
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas (IPBLN-CSIC) P.T. de Ciencias de la Salud, Granada, Spain
| | - Manu Forero-Shelton
- Grupo de Biofísica, Departamento de Física, Universidad de los Andes, Bogotá, DC, Colombia
| | - Adriana Cuellar
- Grupo de Inmunobiología y Biología Celular, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, DC, Colombia
| | - Concepción J Puerta
- Laboratorio de Parasitología Molecular, Departamento de microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, DC, Colombia
| | - John M González
- Grupo de Ciencias Básicas, Facultad de Medicina, Universidad de Los Andes, Bogotá, DC, Colombia.
| |
Collapse
|
22
|
Sahoo DK, Dey N, Maiti IB. pSiM24 is a novel versatile gene expression vector for transient assays as well as stable expression of foreign genes in plants. PLoS One 2014; 9:e98988. [PMID: 24897541 PMCID: PMC4045853 DOI: 10.1371/journal.pone.0098988] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 05/08/2014] [Indexed: 01/03/2023] Open
Abstract
We have constructed a small and highly efficient binary Ti vector pSiM24 for plant transformation with maximum efficacy. In the pSiM24 vector, the size of the backbone of the early binary vector pKYLXM24 (GenBank Accession No. HM036220; a derivative of pKYLX71) was reduced from 12.8 kb to 7.1 kb. The binary vector pSiM24 is composed of the following genetic elements: left and right T-DNA borders, a modified full-length transcript promoter (M24) of Mirabilis mosaic virus with duplicated enhancer domains, three multiple cloning sites, a 3'rbcsE9 terminator, replication functions for Escherichia coli (ColE1) and Agrobacterium tumefaciens (pRK2-OriV) and the replicase trfA gene, selectable marker genes for kanamycin resistance (nptII) and ampicillin resistance (bla). The pSiM24 plasmid offers a wide selection of cloning sites, high copy numbers in E. coli and a high cloning capacity for easily manipulating different genetic elements. It has been fully tested in transferring transgenes such as green fluorescent protein (GFP) and β-glucuronidase (GUS) both transiently (agro-infiltration, protoplast electroporation and biolistic) and stably in plant systems (Arabidopsis and tobacco) using both agrobacterium-mediated transformation and biolistic procedures. Not only reporter genes, several other introduced genes were also effectively expressed using pSiM24 expression vector. Hence, the pSiM24 vector would be useful for various plant biotechnological applications. In addition, the pSiM24 plasmid can act as a platform for other applications, such as gene expression studies and different promoter expressional analyses.
Collapse
Affiliation(s)
- Dipak Kumar Sahoo
- KTRDC, College of Agriculture, Food and Environment, University of Kentucky, Lexington, Kentucky, United States of America
| | - Nrisingha Dey
- Department of Gene Function and Regulation, Institute of Life Sciences, Bhubaneswar, Odisha, India
| | - Indu Bhushan Maiti
- KTRDC, College of Agriculture, Food and Environment, University of Kentucky, Lexington, Kentucky, United States of America
| |
Collapse
|
23
|
Zhou Q, Hu H, Li Z. New insights into the molecular mechanisms of mitosis and cytokinesis in trypanosomes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 308:127-66. [PMID: 24411171 DOI: 10.1016/b978-0-12-800097-7.00004-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Trypanosoma brucei, a unicellular eukaryote and the causative agent of human sleeping sickness, possesses multiple single-copy organelles that all need to be duplicated and segregated during cell division. Trypanosomes undergo a closed mitosis in which the mitotic spindle is anchored on the nuclear envelope and connects the kinetochores made of novel protein components. Cytokinesis in trypanosomes is initiated from the anterior tip of the new flagellum attachment zone, and proceeds along the longitudinal axis without the involvement of the actomyosin contractile ring, the well-recognized cytokinesis machinery conserved from yeast to humans. Trypanosome appears to employ both evolutionarily conserved and trypanosome-specific proteins to regulate its cell cycle, and has evolved certain cell cycle regulatory pathways that are either distinct between its life cycle stages or different from its human host. Understanding the mechanisms of mitosis and cytokinesis in trypanosomes not only would shed novel light on the evolution of cell cycle control, but also could provide new drug targets for chemotherapy.
Collapse
Affiliation(s)
- Qing Zhou
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, Texas, USA
| | - Huiqing Hu
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, Texas, USA
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, Texas, USA.
| |
Collapse
|
24
|
Hu H, Yu Z, Liu Y, Wang T, Wei Y, Li Z. The Aurora B kinase in Trypanosoma brucei undergoes post-translational modifications and is targeted to various subcellular locations through binding to TbCPC1. Mol Microbiol 2013; 91:256-74. [PMID: 24224936 DOI: 10.1111/mmi.12458] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2013] [Indexed: 11/30/2022]
Abstract
The chromosomal passenger complex (CPC) in animals, consisting of Aurora B kinase and three evolutionarily conserved proteins, plays crucial roles in mitosis and cytokinesis. However, Trypanosoma brucei expresses an unusual CPC consisting of an Aurora-like kinase, TbAUK1, and two kinetoplastid-specific proteins, TbCPC1 and TbCPC2. Despite their essential functions, little is known about the regulation of TbAUK1 and the roles of TbCPC1 and TbCPC2. Here, we investigate the effect of post-translational modification on the activity and spatiotemporal control of TbAUK1, and demonstrate that phosphorylation of two conserved threonine residues in the activation loop of the kinase domain contributes to TbAUK1 activation and function. TbAUK1 is SUMOylated in vivo, and mutation of the SUMO-conjugation site compromises TbAUK1 function. Degradation of TbAUK1 requires two destruction boxes and is mediated by the anaphase-promoting complex/cyclosome (APC/C), whereas degradation of TbCPC1 and TbCPC2 is not dependent on the predicted destruction boxes and is APC/C-independent. Moreover, we determine the domains in CPC subunits that mediate the pairwise interactions, and show that disruption of the interaction impairs the localization of TbAUK1 and TbCPC2 but not TbCPC1. Our results demonstrate the requirement of post-translational modifications for TbAUK1 function and a crucial role of TbCPC1 in mediating TbAUK1 localization.
Collapse
Affiliation(s)
- Huiqing Hu
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, TX, 77030, USA
| | | | | | | | | | | |
Collapse
|
25
|
Distinct roles of a mitogen-activated protein kinase in cytokinesis between different life cycle forms of Trypanosoma brucei. EUKARYOTIC CELL 2013; 13:110-8. [PMID: 24213350 DOI: 10.1128/ec.00258-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mitogen-activated protein kinase (MAPK) modules are evolutionarily conserved signaling cascades that function in response to the environment and play crucial roles in intracellular signal transduction in eukaryotes. The involvement of a MAP kinase in regulating cytokinesis in yeast, animals, and plants has been reported, but the requirement for a MAP kinase for cytokinesis in the early-branching protozoa is not documented. Here, we show that a MAP kinase homolog (TbMAPK6) from Trypanosoma brucei plays distinct roles in cytokinesis in two life cycle forms of T. brucei. TbMAPK6 is distributed throughout the cytosol in the procyclic form but is localized in both the cytosol and the nucleus in the bloodstream form. RNA interference (RNAi) of TbMAPK6 results in moderate growth inhibition in the procyclic form but severe growth defects and rapid cell death in the bloodstream form. Moreover, TbMAPK6 appears to be implicated in furrow ingression and cytokinesis completion in the procyclic form but is essential for cytokinesis initiation in the bloodstream form. Despite the distinct defects in cytokinesis in the two forms, RNAi of TbMAPK6 also caused defective basal body duplication/segregation in a small cell population in both life cycle forms. Altogether, our results demonstrate the involvement of the TbMAPK6-mediated pathway in regulating cytokinesis in trypanosomes and suggest distinct roles of TbMAPK6 in cytokinesis between different life cycle stages of T. brucei.
Collapse
|
26
|
Diniz MC, Pacheco ACL, Farias KM, de Oliveira DM. The eukaryotic flagellum makes the day: novel and unforeseen roles uncovered after post-genomics and proteomics data. Curr Protein Pept Sci 2013; 13:524-46. [PMID: 22708495 PMCID: PMC3499766 DOI: 10.2174/138920312803582951] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 05/22/2012] [Accepted: 05/23/2012] [Indexed: 12/21/2022]
Abstract
This review will summarize and discuss the current biological understanding of the motile eukaryotic flagellum,
as posed out by recent advances enabled by post-genomics and proteomics approaches. The organelle, which is crucial
for motility, survival, differentiation, reproduction, division and feeding, among other activities, of many eukaryotes,
is a great example of a natural nanomachine assembled mostly by proteins (around 350-650 of them) that have been conserved
throughout eukaryotic evolution. Flagellar proteins are discussed in terms of their arrangement on to the axoneme,
the canonical “9+2” microtubule pattern, and also motor and sensorial elements that have been detected by recent proteomic
analyses in organisms such as Chlamydomonas reinhardtii, sea urchin, and trypanosomatids. Such findings can be
remarkably matched up to important discoveries in vertebrate and mammalian types as diverse as sperm cells, ciliated
kidney epithelia, respiratory and oviductal cilia, and neuro-epithelia, among others. Here we will focus on some exciting
work regarding eukaryotic flagellar proteins, particularly using the flagellar proteome of C. reinhardtii as a reference map
for exploring motility in function, dysfunction and pathogenic flagellates. The reference map for the eukaryotic flagellar
proteome consists of 652 proteins that include known structural and intraflagellar transport (IFT) proteins, less well-characterized
signal transduction proteins and flagellar associated proteins (FAPs), besides almost two hundred unannotated
conserved proteins, which lately have been the subject of intense investigation and of our present examination.
Collapse
Affiliation(s)
- Michely C Diniz
- Programa de Pós-Graduação em Biotecnologia-RENORBIO-Rede Nordeste de Biotecnologia, Universidade Estadual do Ceará-UECE, Av. Paranjana, 1700, Campus do Itaperi, Fortaleza, CE 60740-000 Brasil
| | | | | | | |
Collapse
|
27
|
Zhang X, Shen Y, Ding G, Tian Y, Liu Z, Li B, Wang Y, Jiang C. TFPP: an SVM-based tool for recognizing flagellar proteins in Trypanosoma brucei. PLoS One 2013; 8:e54032. [PMID: 23349782 PMCID: PMC3547966 DOI: 10.1371/journal.pone.0054032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/07/2012] [Indexed: 11/18/2022] Open
Abstract
Trypanosoma brucei is a unicellular flagellated eukaryotic parasite that causes African trypanosomiasis in human and domestic animals with devastating health and economic consequences. Recent studies have revealed the important roles of the single flagellum of T. brucei in many aspects, especially that the flagellar motility is required for the viability of the bloodstream form T. brucei, suggesting that impairment of the flagellar function may provide a promising cure for African sleeping sickness. Knowing the flagellum proteome is crucial to study the molecular mechanism of the flagellar functions. Here we present a novel computational method for identifying flagellar proteins in T. brucei, called trypanosome flagellar protein predictor (TFPP). TFPP was developed based on a list of selected discriminating features derived from protein sequences, and could predict flagellar proteins with ∼92% specificity at a ∼84% sensitivity rate. Applied to the whole T. brucei proteome, TFPP reveals 811 more flagellar proteins with high confidence, suggesting that the flagellar proteome covers ∼10% of the whole proteome. Comparison of the expression profiles of the whole T. brucei proteome at three typical life cycle stages found that ∼45% of the flagellar proteins were significantly changed in expression levels between the three life cycle stages, indicating life cycle stage-specific regulation of flagellar functions in T. brucei. Overall, our study demonstrated that TFPP is highly effective in identifying flagellar proteins and could provide opportunities to study the trypanosome flagellar proteome systematically. Furthermore, the web server for TFPP can be freely accessed at http:/wukong.tongji.edu.cn/tfpp.
Collapse
Affiliation(s)
- Xiaobai Zhang
- Department of Bioinformatics, the School of Life Sciences and Technology, Tongji University, Shanghai, China
- * E-mail: (XZ); (CJ)
| | - Yuefeng Shen
- Department of Bioinformatics, the School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Guitao Ding
- Department of Bioinformatics, the School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yi Tian
- Department of Bioinformatics, the School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhenping Liu
- Department of Bioinformatics, the School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Bing Li
- Department of Bioinformatics, the School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yun Wang
- Department of Bioinformatics, the School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Cizhong Jiang
- Department of Bioinformatics, the School of Life Sciences and Technology, Tongji University, Shanghai, China
- * E-mail: (XZ); (CJ)
| |
Collapse
|
28
|
Diaz-Soto JC, Lasso P, Guzmán F, Forero-Shelton M, Thomas MDC, López MC, Guhl F, Cuellar A, Puerta CJ, González JM. Rabbit serum against K1 peptide, an immunogenic epitope of the Trypanosoma cruzi KMP-11, decreases parasite invasion to cells. Acta Trop 2012; 123:224-9. [PMID: 22687575 DOI: 10.1016/j.actatropica.2012.05.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/22/2012] [Accepted: 05/23/2012] [Indexed: 11/17/2022]
Abstract
KMP-11 is a highly conserved protein of Trypanosoma cruzi implicated in parasite's motility. Here we show that K1, a peptide derived from KMP-11, induced polyclonal antibodies capable of decreasing T. cruzi infection in vitro. Rabbit sera rose against K1 peptide showed recognition of the recombinant protein by ELISA and Western blot and also of the native protein in both epimastigotes and trypomastigotes as evaluated by immunofluorescence test and flow cytometry. Invasion assays showed a significant reduction of trypomastigotes infection of eukaryotic cells when parasites were pre-incubated with anti-K1 rabbit serum. Computational modeling predicted that the K1 sequence conserved its α-helical configuration into the protein, and some of the amino acid residues appear accessible for recognition by antibodies in vivo. Taken together, these results support the idea that the K1 peptide induces antibodies than can have a potential role in protective immunity in Chagas disease.
Collapse
Affiliation(s)
- Juan Camilo Diaz-Soto
- Grupo de Ciencias Básicas Médicas, Facultad de Medicina, Universidad de los Andes, Bogotá, D.C., Colombia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
The cell division cycle is tightly regulated by the activation and inactivation of a series of proteins that control the replication and segregation of organelles to the daughter cells. During the past decade, we have witnessed significant advances in our understanding of the cell cycle in Trypanosoma brucei and how the cycle is regulated by various regulatory proteins. However, many other regulators, especially those unique to trypanosomes, remain to be identified, and we are just beginning to delineate the signaling pathways that drive the transitions through different cell cycle stages, such as the G(1)/S transition, G(2)/M transition, and mitosis-cytokinesis transition. Trypanosomes appear to employ both evolutionarily conserved and trypanosome-specific molecules to regulate the various stages of its cell cycle, including DNA replication initiation, spindle assembly, chromosome segregation, and cytokinesis initiation and completion. Strikingly, trypanosomes lack some crucial regulators that are well conserved across evolution, such as Cdc6 and Cdt1, which are involved in DNA replication licensing, the spindle motor kinesin-5, which is required for spindle assembly, the central spindlin complex, which has been implicated in cytokinesis initiation, and the actomyosin contractile ring, which is located at the cleavage furrow. Conversely, trypanosomes possess certain regulators, such as cyclins, cyclin-dependent kinases, and mitotic centromere-associated kinesins, that are greatly expanded and likely play diverse cellular functions. Overall, trypanosomes apparently have integrated unique regulators into the evolutionarily conserved pathways to compensate for the absence of those conserved molecules and, additionally, have evolved certain cell cycle regulatory pathways that are either different from its human host or distinct between its own life cycle forms.
Collapse
|
30
|
Hu H, Hu L, Yu Z, Chasse AE, Chu F, Li Z. An orphan kinesin in trypanosomes cooperates with a kinetoplastid-specific kinesin to maintain cell morphology by regulating subpellicular microtubules. J Cell Sci 2012; 125:4126-36. [PMID: 22623724 DOI: 10.1242/jcs.106534] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microtubules are a vital part of the cytoskeleton of eukaryotic cells and are involved in various cellular processes. The cytoskeleton of Trypanosoma brucei is characterized by an array of subpellicular microtubules and is essential for maintenance of cell shape and polarity, but little is known about the regulation of the assembly and organization of the subpellicular microtubule corset. Here, we report that the orphan kinesin TbKIN-D regulates the organization of subpellicular microtubules and is required for maintaining cell morphology. TbKIN-D possesses in vitro ATPase activity, associates with cytoskeletal microtubules and is distributed throughout the cytoskeleton at all cell cycle stages. RNAi of TbKIN-D disrupts the organization of the subpellicular microtubule corset and distorts cell morphology, resulting in round cells with an elongated posterior filled with newly assembled microtubules. Depletion of TbKIN-D also abolishes the segregation of organelles and cytoskeletal structures, suggesting that cellular morphogenesis is essential for proper organelle segregation. Moreover, TbKIN-D deficiency impairs the attachment of the new flagellum without compromising the formation of the flagellum attachment zone. Finally, we identified TbKIN-C, a kinetoplastid-specific kinesin known to regulate subpellicular microtubules and cell morphogenesis in T. brucei, as a partner of TbKIN-D. Further, we demonstrate that interaction between TbKIN-C and TbKIN-D requires the coiled-coil motifs in the C-termini of both proteins. Altogether, our results suggest that TbKIN-D cooperates with TbKIN-C to maintain cell morphology by regulating the organization of the subpellicular microtubule corset.
Collapse
Affiliation(s)
- Huiqing Hu
- Department of Microbiology and Molecular Genetics, University of Texas Medical School, Houston, TX 77030, USA
| | | | | | | | | | | |
Collapse
|
31
|
Yu Z, Liu Y, Li Z. Structure-function relationship of the Polo-like kinase in Trypanosoma brucei. J Cell Sci 2012; 125:1519-30. [PMID: 22275435 PMCID: PMC3336379 DOI: 10.1242/jcs.094243] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2011] [Indexed: 12/19/2022] Open
Abstract
Polo-like kinases (Plks) play multiple roles in mitosis and cytokinesis in eukaryotes and are characterized by the C-terminal Polo-box domain (PBD), which is implicated in binding to Plk substrates, targeting Plk and regulating Plk activity. The Plk homolog in Trypanosoma brucei (TbPLK) possesses a similar architecture, but it lacks the crucial residues involved in substrate binding and regulates cytokinesis but not mitosis. Little is known about the regulation of TbPLK and the role of the PBD in TbPLK localization and function. Here, we addressed the requirement of the kinase activity and the PBD for TbPLK localization and function through coupling RNAi of endogenous TbPLK with ectopic expression of TbPLK mutants. We demonstrate that the kinase activity and phosphorylation of two threonine residues, Thr198 and Thr202, in the activation loop (T-loop) of the kinase domain are essential for TbPLK function but not for TbPLK localization. Deletion of the PBD abolishes TbPLK localization, but the PBD itself is not correctly targeted, indicating that TbPLK localization requires both the PBD and the kinase domain. Surprisingly, the kinase domain of TbPLK, but not the PBD, binds to its substrates TbCentrin2 and p110, suggesting that TbPLK might interact with its substrate through different mechanisms. Finally, the PBD interacts with the kinase domain of TbPLK and inhibits its activity, and this inhibition is relieved when Thr198 is phosphorylated. Together, these results suggest an essential role of T-loop phosphorylation in TbPLK activation and crucial roles of the PBD in regulating TbPLK activity and localization.
Collapse
Affiliation(s)
- Zhonglian Yu
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| | - Yi Liu
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| |
Collapse
|
32
|
Hu L, Hu H, Li Z. A kinetoplastid-specific kinesin is required for cytokinesis and for maintenance of cell morphology in Trypanosoma brucei. Mol Microbiol 2012; 83:565-78. [PMID: 22168367 DOI: 10.1111/j.1365-2958.2011.07951.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Kinesins are motor-based transport proteins that play diverse roles in various cellular processes. The trypanosome genome lacks the homologues of many conserved mitotic kinesins, but encodes a number of trypanosome-specific kinesins with unknown function. Here, we report the biochemical and functional characterization of TbKIN-C, a trypanosome-specific kinesin, which was initially identified through an RNAi screen for cytokinesis genes in T. brucei. TbKIN-C possesses in vitro ATPase activity and associates with cytoskeletal tubulin microtubules in vivo. It is distributed throughout the cytoskeleton with a focal enrichment at the posterior end of the cell during early cell cycle stages. RNAi of TbKIN-C resulted in distorted cell shape with an elongated posterior filled with tyrosinated tubulin microtubules. Silencing of TbKIN-C impaired the segregation of organelles and cytoskeletal structures and led to detachment of the new flagellum and a small portion of the cytoplasm. We also show that RNAi of TbKIN-C compromised cytokinesis and abolished the trans-localization of TbCPC1, a subunit of the chromosomal passenger complex, from the central spindle to the initiation site of cytokinesis. Our results suggest an essential role of TbKIN-C in maintaining cell morphology, likely through regulating microtubule dynamics at the posterior end of the cell.
Collapse
Affiliation(s)
- Liu Hu
- Department of Microbiology & Molecular Genetics, University of Texas Medical School at Houston, TX 77030, USA
| | | | | |
Collapse
|
33
|
Zhou Q, Liu B, Sun Y, He CY. A coiled-coil- and C2-domain-containing protein is required for FAZ assembly and cell morphology in Trypanosoma brucei. J Cell Sci 2011; 124:3848-58. [PMID: 22114307 DOI: 10.1242/jcs.087676] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Trypanosoma brucei, a flagellated protozoan parasite causing human sleeping sickness, relies on a subpellicular microtubule array for maintenance of cell morphology. The flagellum is attached to the cell body through a poorly understood flagellum attachment zone (FAZ), and regulates cell morphogenesis using an unknown mechanism. Here we identified a new FAZ component, CC2D, which contains coiled-coil motifs followed by a C-terminal C2 domain. T. brucei CC2D is present on the FAZ filament, FAZ-juxtaposed ER membrane and the basal bodies. Depletion of CC2D inhibits the assembly of a new FAZ filament, forming a FAZ stub with a relatively fixed size at the base of a detached, but otherwise normal, flagellum. Inhibition of new FAZ formation perturbs subpellicular microtubule organization and generates short daughter cells. The cell length shows a strong linear correlation with FAZ length, in both control cells and in cells with inhibited FAZ assembly. Together, our data support a direct function of FAZ assembly in determining new daughter cell length by regulating subpellicular microtubule synthesis.
Collapse
Affiliation(s)
- Qing Zhou
- Department of Biological Sciences, National University of Singapore, Singapore 117543
| | | | | | | |
Collapse
|
34
|
Dang HQ, Li Z. The Cdc45·Mcm2-7·GINS protein complex in trypanosomes regulates DNA replication and interacts with two Orc1-like proteins in the origin recognition complex. J Biol Chem 2011; 286:32424-35. [PMID: 21799014 DOI: 10.1074/jbc.m111.240143] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Accurate DNA replication requires a complex interplay of many regulatory proteins at replication origins. The CMG (Cdc45·Mcm2-7·GINS) complex, which is composed of Cdc45, Mcm2-7, and the GINS (Go-Ichi-Ni-San) complex consisting of Sld5 and Psf1 to Psf3, is recruited by Cdc6 and Cdt1 onto origins bound by the heterohexameric origin recognition complex (ORC) and functions as a replicative helicase. Trypanosoma brucei, an early branched microbial eukaryote, appears to express an archaea-like ORC consisting of a single Orc1/Cdc6-like protein. However, unlike archaea, trypanosomes possess components of the eukaryote-like CMG complex, but whether they form an active helicase complex, associate with the ORC, and regulate DNA replication remains unknown. Here, we demonstrated that the CMG complex is formed in vivo in trypanosomes and that Mcm2-7 helicase activity is activated by the association with Cdc45 and the GINS complex in vitro. Mcm2-7 and GINS proteins are confined to the nucleus throughout the cell cycle, whereas Cdc45 is exported out of the nucleus after DNA replication, indicating that nuclear exclusion of Cdc45 constitutes one mechanism for preventing DNA re-replication in trypanosomes. With the exception of Mcm4, Mcm6, and Psf1, knockdown of individual CMG genes inhibits DNA replication and cell proliferation. Finally, we identified a novel Orc1-like protein, Orc1b, as an additional component of the ORC and showed that both Orc1b and Orc1/Cdc6 associate with Mcm2-7 via interactions with Mcm3. All together, we identified the Cdc45·Mcm2-7·GINS complex as the replicative helicase that interacts with two Orc1-like proteins in the unusual origin recognition complex in trypanosomes.
Collapse
Affiliation(s)
- Hung Quang Dang
- Department of Microbiology and Molecular Genetics, University of Texas Medical School, Houston, Texas 77030, USA
| | | |
Collapse
|
35
|
TbPRMT6 is a type I protein arginine methyltransferase that contributes to cytokinesis in Trypanosoma brucei. EUKARYOTIC CELL 2010; 9:866-77. [PMID: 20418380 DOI: 10.1128/ec.00018-10] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Arginine methylation is a widespread posttranslational modification of proteins catalyzed by a family of protein arginine methyltransferases (PRMTs). In Saccharomyces cerevisiae and mammals, this modification affects multiple cellular processes, such as chromatin remodeling leading to transcriptional regulation, RNA processing, DNA repair, and cell signaling. The protozoan parasite Trypanosoma brucei possesses five putative PRMTs in its genome. This is a large number of PRMTs relative to other unicellular eukaryotes, suggesting an important role for arginine methylation in trypanosomes. Here, we present the in vitro and in vivo characterization of a T. brucei enzyme homologous to human PRMT6, which we term TbPRMT6. Like human PRMT6, TbPRMT6 is a type I PRMT, catalyzing the production of monomethylarginine and asymmetric dimethylarginine residues. In in vitro methylation assays, TbPRMT6 utilizes bovine histones as a substrate, but it does not methylate several T. brucei glycine/arginine-rich proteins. As such, it exhibits a relatively narrow substrate specificity compared to other T. brucei PRMTs. Knockdown of TbPRMT6 in both procyclic form and bloodstream form T. brucei leads to a modest but reproducible effect on parasite growth in culture. Moreover, upon TbPRMT6 depletion, both PF and BF exhibit aberrant morphologies indicating defects in cell division, and these defects differ in the two life cycle stages. Mass spectrometry of TbPRMT6-associated proteins reveals histones, components of the nuclear pore complex, and flagellar proteins that may represent TbPRMT6 substrates contributing to the observed growth and morphological defects.
Collapse
|
36
|
Liao S, Wang T, Fan K, Tu X. The small ubiquitin-like modifier (SUMO) is essential in cell cycle regulation in Trypanosoma brucei. Exp Cell Res 2010; 316:704-15. [PMID: 20045687 DOI: 10.1016/j.yexcr.2009.12.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 12/17/2009] [Accepted: 12/18/2009] [Indexed: 01/18/2023]
Abstract
SUMO, a reversible post-translational protein modifier, plays important roles in many processes of higher eukaryotic cell life. Although SUMO has been identified in many eukaryotes, SUMO and SUMO system are still unknown in some eukaryotic unicellular organisms, such as Trypanosoma brucei (T. brucei). In this study, only one SUMO homologue (TbSUMO) was identified in T. brucei. Expression of TbSUMO was knocked down by using RNA interference technique in procyclic-form T. brucei. The growth of TbSUMO-deficient cells was significantly inhibited. TbSUMO-deficient cells were arrested in G2/M phase accompanied with an obvious increase of 0N1K cells (zoids), and failed in chromosome segregation. These results indicate that TbSUMO is essential in cell cycle regulation, with one important role in mitosis. Meanwhile, the enrichment of zoids suggests the inhibition of mitosis does not prevent the cell division in procyclic-form T. brucei. HA-tagged TbSUMO was overexpressed in T. brucei and was shown to be localized to the nucleus through the whole cell cycle, further revealing its distinguished functions in nucleus. All these accumulated data imply that a SUMO system essential for regulating cell cycle progression might exist in the procyclic-form T. brucei.
Collapse
Affiliation(s)
- Shanhui Liao
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, PR China
| | | | | | | |
Collapse
|
37
|
|
38
|
Demonchy R, Blisnick T, Deprez C, Toutirais G, Loussert C, Marande W, Grellier P, Bastin P, Kohl L. Kinesin 9 family members perform separate functions in the trypanosome flagellum. ACTA ACUST UNITED AC 2009; 187:615-22. [PMID: 19948486 PMCID: PMC2806587 DOI: 10.1083/jcb.200903139] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
KIF9B localizes to the axoneme and basal body and is needed for flagella assembly, whereas KIF9A localizes only to the axoneme and controls flagella motility without affecting their structure. Numerous eukaryote genome projects have uncovered a variety of kinesins of unknown function. The kinesin 9 family is limited to flagellated species. Our phylogenetic experiments revealed two subfamilies: KIF9A (including Chlamydomonasreinhardtii KLP1) and KIF9B (including human KIF6). The function of KIF9A and KIF9B was investigated in the protist Trypanosoma brucei that possesses a single motile flagellum. KIF9A and KIF9B are strongly associated with the cytoskeleton and are required for motility. KIF9A is localized exclusively in the axoneme, and its depletion leads to altered motility without visible structural modifications. KIF9B is found in both the axoneme and the basal body, and is essential for the assembly of the paraflagellar rod (PFR), a large extra-axonemal structure. In the absence of KIF9B, cells grow abnormal flagella with excessively large blocks of PFR-like material that alternate with regions where only the axoneme is present. The functional diversity of the kinesin 9 family illustrates the capacity for adaptation of organisms to suit specific cytoskeletal requirements.
Collapse
Affiliation(s)
- Raphaël Demonchy
- Adaptation Processes of Protozoa to their Environment, Centre National de la Recherche Scientifique FRE3206, 75231 Paris, France
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Smith TK, Vasileva N, Gluenz E, Terry S, Portman N, Kramer S, Carrington M, Michaeli S, Gull K, Rudenko G. Blocking variant surface glycoprotein synthesis in Trypanosoma brucei triggers a general arrest in translation initiation. PLoS One 2009; 4:e7532. [PMID: 19855834 PMCID: PMC2762041 DOI: 10.1371/journal.pone.0007532] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Accepted: 09/22/2009] [Indexed: 01/22/2023] Open
Abstract
Background The African trypanosome Trypanosoma brucei is covered with a dense layer of Variant Surface Glycoprotein (VSG), which protects it from lysis by host complement via the alternative pathway in the mammalian bloodstream. Blocking VSG synthesis by the induction of VSG RNAi triggers an unusually precise precytokinesis cell-cycle arrest. Methodology/Principal Findings Here, we characterise the cells arrested after the induction of VSG RNAi. We were able to rescue the VSG221 RNAi induced cell-cycle arrest through expression of a second different VSG (VSG117 which is not recognised by the VSG221 RNAi) from the VSG221 expression site. Metabolic labeling of the arrested cells showed that blocking VSG synthesis triggered a global translation arrest, with total protein synthesis reduced to less than 1–4% normal levels within 24 hours of induction of VSG RNAi. Analysis by electron microscopy showed that the translation arrest was coupled with rapid disassociation of ribosomes from the endoplasmic reticulum. Polysome analysis showed a drastic decrease in polysomes in the arrested cells. No major changes were found in levels of transcription, total RNA transcript levels or global amino acid concentrations in the arrested cells. Conclusions The cell-cycle arrest phenotype triggered by the induction of VSG221 RNAi is not caused by siRNA toxicity, as this arrest can be alleviated if a second different VSG is inserted downstream of the active VSG221 expression site promoter. Analysis of polysomes in the stalled cells showed that the translation arrest is mediated at the level of translation initiation rather than elongation. The cell-cycle arrest induced in the presence of a VSG synthesis block is reversible, suggesting that VSG synthesis and/or trafficking to the cell surface could be monitored during the cell-cycle as part of a specific cell-cycle checkpoint.
Collapse
Affiliation(s)
- Terry K. Smith
- Centre for Biomolecular Sciences, University of St. Andrews, Fife, Scotland, United Kingdom
| | - Nadina Vasileva
- The Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
| | - Eva Gluenz
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Stephen Terry
- The Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
| | - Neil Portman
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Susanne Kramer
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | | | - Keith Gull
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Gloria Rudenko
- The Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom
- * E-mail:
| |
Collapse
|
40
|
El Fadili K, Drummelsmith J, Roy G, Jardim A, Ouellette M. Down regulation of KMP-11 in Leishmania infantum axenic antimony resistant amastigotes as revealed by a proteomic screen. Exp Parasitol 2009; 123:51-7. [PMID: 19500579 DOI: 10.1016/j.exppara.2009.05.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 05/25/2009] [Accepted: 05/26/2009] [Indexed: 12/01/2022]
Abstract
The therapeutic mainstay against the protozoan parasite Leishmania is still based on the antiquated pentavalent antimonials, but resistance is increasing in several parts of the world. Resistance is now partly understood in laboratory promastigote isolates, but the mechanism leading to drug resistance in amastigote isolates is lagging behind. Here we describe a comparative proteomic analysis of a genetically related pair of antimonial-sensitive and -resistant Leishmania infantum axenic amastigote strains. The proteomics screen has highlighted a number of proteins differentially expressed in the resistant parasite. The expression of the protein argininosuccinate synthetase (ARGG) was increased in the drug resistant mutant while a decrease in the expression of the kinetoplastid membrane protein (KMP-11) correlated with the drug resistance phenotype. This proteomic screen highlighted several novel proteins that are putatively involved in resistance to antimonials.
Collapse
Affiliation(s)
- Karima El Fadili
- Centre de Recherche en Infectiologie du Centre de Recherche du CHUQ and Division de Microbiologie, Faculté de Médecine, Université Laval, Que., Canada G1V 4G2
| | | | | | | | | |
Collapse
|
41
|
Portman N, Lacomble S, Thomas B, McKean PG, Gull K. Combining RNA interference mutants and comparative proteomics to identify protein components and dependences in a eukaryotic flagellum. J Biol Chem 2009; 284:5610-9. [PMID: 19074134 PMCID: PMC2645819 DOI: 10.1074/jbc.m808859200] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Indexed: 01/23/2023] Open
Abstract
Eukaryotic flagella from organisms such as Trypanosoma brucei can be isolated and their protein components identified by mass spectrometry. Here we used a comparative approach utilizing two-dimensional difference gel electrophoresis and isobaric tags for relative and absolute quantitation to reveal protein components of flagellar structures via ablation by inducible RNA interference mutation. By this approach we identified 20 novel components of the paraflagellar rod (PFR). Using epitope tagging we validated a subset of these as being present within the PFR by immunofluorescence. Bioinformatic analysis of the PFR cohort reveals a likely calcium/calmodulin regulatory/signaling linkage between some components. We extended the RNA interference mutant/comparative proteomic analysis to individual novel components of our PFR proteome, showing that the approach has the power to reveal dependences between subgroups within the cohort.
Collapse
MESH Headings
- Animals
- Cells, Cultured
- Chromatography, Liquid
- DNA, Protozoan/genetics
- DNA, Protozoan/metabolism
- Electrophoresis, Gel, Two-Dimensional
- Flagella/genetics
- Flagella/metabolism
- Fluorescent Antibody Technique
- Proteomics
- Protozoan Proteins/antagonists & inhibitors
- Protozoan Proteins/genetics
- Protozoan Proteins/metabolism
- RNA Interference
- RNA, Protozoan/genetics
- RNA, Protozoan/metabolism
- RNA, Small Interfering/pharmacology
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Trypanosoma brucei brucei/genetics
- Trypanosoma brucei brucei/metabolism
Collapse
Affiliation(s)
- Neil Portman
- Sir William Dunn School of Pathology and Oxford Centre for Integrative Systems Biology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom
| | | | | | | | | |
Collapse
|