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Roy PK, Paul A, Lalchhuanawmi S, Babu NK, Singh S. Pyridoxal kinase gene deletion leads to impaired growth, deranged redox metabolism and cell cycle arrest in Leishmania donovani. Biochimie 2024; 222:72-86. [PMID: 38403043 DOI: 10.1016/j.biochi.2024.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 02/19/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024]
Abstract
Pyridoxal kinase (PdxK) is a vitamin B6 salvage pathway enzyme which produces pyridoxal phosphate. We have investigated the impact of PdxK deletion in Leishmania donovani on parasite survivability, infectivity and cellular metabolism. LdPdxK mutants were generated by gene replacement strategy. All mutants showed significant reduction in growth in comparison to wild type. For PdxK mediated biochemical perturbations, only heterozygous mutants and complementation mutants were used as the growth of null mutants were compromised. Heterozygous mutant showed reduction invitro infectivity and higher cytosolic and mitochondrial ROS levels. Glutathione levels decreased significantly in heterozygous mutant indicating its involvement in cellular oxidative metabolism. Pyridoxal kinase gene deletion resulted in reduced ATP levels in parasites and arrest at G0/G1 phase of cell cycle. All these perturbations were rescued by PdxK gene complementation. This is the first report to confirm that LdPdxK plays an indispensable role in cell survival, pathogenicity, redox metabolism and cell cycle progression of L. donovani parasites. These results provide substantial evidence supporting PdxK as a therapeutic target for the development of specific antileishmanial drug candidates.
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Affiliation(s)
- Pradyot Kumar Roy
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, 160062, Punjab, India
| | - Anindita Paul
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, 160062, Punjab, India
| | - Sandra Lalchhuanawmi
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, 160062, Punjab, India
| | - Neerupudi Kishore Babu
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, 160062, Punjab, India
| | - Sushma Singh
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, 160062, Punjab, India.
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Dobbelaere J, Su TY, Erdi B, Schleiffer A, Dammermann A. A phylogenetic profiling approach identifies novel ciliogenesis genes in Drosophila and C. elegans. EMBO J 2023; 42:e113616. [PMID: 37317646 PMCID: PMC10425847 DOI: 10.15252/embj.2023113616] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/22/2023] [Accepted: 06/01/2023] [Indexed: 06/16/2023] Open
Abstract
Cilia are cellular projections that perform sensory and motile functions in eukaryotic cells. A defining feature of cilia is that they are evolutionarily ancient, yet not universally conserved. In this study, we have used the resulting presence and absence pattern in the genomes of diverse eukaryotes to identify a set of 386 human genes associated with cilium assembly or motility. Comprehensive tissue-specific RNAi in Drosophila and mutant analysis in C. elegans revealed signature ciliary defects for 70-80% of novel genes, a percentage similar to that for known genes within the cluster. Further characterization identified different phenotypic classes, including a set of genes related to the cartwheel component Bld10/CEP135 and two highly conserved regulators of cilium biogenesis. We propose this dataset defines the core set of genes required for cilium assembly and motility across eukaryotes and presents a valuable resource for future studies of cilium biology and associated disorders.
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Affiliation(s)
- Jeroen Dobbelaere
- Max Perutz LabsUniversity of Vienna, Vienna Biocenter (VBC)ViennaAustria
| | - Tiffany Y Su
- Max Perutz LabsUniversity of Vienna, Vienna Biocenter (VBC)ViennaAustria
- Vienna BioCenter PhD ProgramDoctoral School of the University of Vienna and Medical University of ViennaViennaAustria
| | - Balazs Erdi
- Max Perutz LabsUniversity of Vienna, Vienna Biocenter (VBC)ViennaAustria
| | - Alexander Schleiffer
- Research Institute of Molecular Pathology, Vienna Biocenter (VBC)ViennaAustria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna Biocenter (VBC)ViennaAustria
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Cooper C, Thompson RCA, Clode PL. Investigating parasites in three dimensions: trends in volume microscopy. Trends Parasitol 2023; 39:668-681. [PMID: 37302958 DOI: 10.1016/j.pt.2023.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/17/2023] [Accepted: 05/17/2023] [Indexed: 06/13/2023]
Abstract
To best understand parasite, host, and vector morphologies, host-parasite interactions, and to develop new drug and vaccine targets, structural data should, ideally, be obtained and visualised in three dimensions (3D). Recently, there has been a significant uptake of available 3D volume microscopy techniques that allow collection of data across centimetre (cm) to Angstrom (Å) scales by utilising light, X-ray, electron, and ion sources. Here, we present and discuss microscopy tools available for the collection of 3D structural data, focussing on electron microscopy-based techniques. We highlight their strengths and limitations, such that parasitologists can identify techniques best suited to answer their research questions. Additionally, we review the importance of volume microscopy to the advancement of the field of parasitology.
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Affiliation(s)
- Crystal Cooper
- Centre for Microscopy, Characterisation, and Analysis, University of Western Australia, Stirling Hwy, Crawley, WA 6009, Australia.
| | - R C Andrew Thompson
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia
| | - Peta L Clode
- Centre for Microscopy, Characterisation, and Analysis, University of Western Australia, Stirling Hwy, Crawley, WA 6009, Australia; School of Biological Sciences, University of Western Australia, Stirling Hwy, Crawley, WA 6009, Australia
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Becker C, Adam A, Dommisch H, Stach T, Schaefer AS. In vitro induction of Entamoeba gingivalis cyst-like structures from trophozoites in response to antibiotic treatment. Front Cell Infect Microbiol 2023; 13:1201394. [PMID: 37469604 PMCID: PMC10352839 DOI: 10.3389/fcimb.2023.1201394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 06/16/2023] [Indexed: 07/21/2023] Open
Abstract
Background Entamoeba gingivalis (E. gingivalis) is an anaerobic protozoan that is strongly associated with inflamed periodontal pockets. It is able to invade the mucosal epithelium of the human host, where it can feed on epithelial cells and elicit a severe innate immune response. Unlike other Entamoeba species, it is considered that E. gingivalis cannot form cysts, because it is a non-infectious protozoan. The lack of encystation capability would make it susceptible to periodontal treatment. However, it is not clear how the human host becomes infected with E. gingivalis trophozoites. We investigated the ability of E. gingivalis to encapsulate in response to an unfavorable environment in vitro. Methods Different strains of E. gingivalis, isolated from inflamed periodontal pocket samples, were cultured for 8 days in the presence or absence of the antimicrobials amoxycillin and metronidazole. To reveal cyst formation, we investigated the morphology and ultrastructure of the amoeba by light, fluorescence, transmission and scanning electron microscopy. We also used the fluorescent dye calcofluor white M2R to demonstrate chitin present in the cyst wall. Results We observed exocysts and an intra-cystic space separating the encapsulated trophozoite from the environment. Remarkably, cysts showed a smooth surface, polygonal edges and smaller size compared to free-living trophozoites. In addition, encapsulated trophozoites that detached from the cyst wall had a dense cytoplasma without phagocytic vesicles. The cyst walls consisted of chitin as in other Entamoba species. The encapsulated trophozoids were mononuclear after antibioticinduced encapsulation. Discussion We conclude that E. gingivalis cyst formation has significant implications for dissemination and infection and may explain why established treatment approaches often fail to halt periodontal tissue destruction during periodontitis and peri-implantitis.
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Affiliation(s)
- Christin Becker
- Molecular Genetics of Oral Inflammatory Diseases Group, Institute for Dental and Craniofacial Sciences, Department of Periodontology, Oral Medicine and Oral Surgery, Charité – University Medicine Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Aysegül Adam
- Molecular Genetics of Oral Inflammatory Diseases Group, Institute for Dental and Craniofacial Sciences, Department of Periodontology, Oral Medicine and Oral Surgery, Charité – University Medicine Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Henrik Dommisch
- Molecular Genetics of Oral Inflammatory Diseases Group, Institute for Dental and Craniofacial Sciences, Department of Periodontology, Oral Medicine and Oral Surgery, Charité – University Medicine Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Thomas Stach
- Department of Molecular Parasitology, Institute of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Arne S. Schaefer
- Molecular Genetics of Oral Inflammatory Diseases Group, Institute for Dental and Craniofacial Sciences, Department of Periodontology, Oral Medicine and Oral Surgery, Charité – University Medicine Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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Teh-Poot CF, Dzul-Huchim VM, Mercado JM, Villanueva-Lizama LE, Bottazzi ME, Jones KM, Tsai FTF, Cruz-Chan JV. A short-term method to evaluate anti-leishmania drugs by inhibition of stage differentiation in Leishmania mexicana using flow cytometry. Exp Parasitol 2023; 249:108519. [PMID: 37004860 PMCID: PMC10231665 DOI: 10.1016/j.exppara.2023.108519] [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: 08/09/2022] [Revised: 03/17/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
Leishmaniasis is a vector-borne neglected tropical disease caused by the Leishmania spp. Parasite. The disease is transmitted to humans and animals by the bite of infected female sandflies during the ingestion of bloodmeal. Because current drug treatments induce toxicity and parasite resistance, there is an urgent need to evaluate new drugs. Most therapeutics target the differentiation of promastigotes to amastigotes, which is necessary to maintain Leishmania infection. However, in vitro assays are laborious, time-consuming, and depend on the experience of the technician. In this study, we aimed to establish a short-term method to assess the differentiation status of Leishmania mexicana (L. mexicana) using flow cytometry. Here, we showed that flow cytometry provides a rapid means to quantify parasite differentiation in cell culture as reliably as light microscopy. Interestingly, we found using flow cytometry that miltefosine reduced promastigote-to-amastigote differentiation of L. mexicana. We conclude that flow cytometry provides a means to rapidly assay the efficacy of small molecules or natural compounds as potential anti-leishmanials.
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Affiliation(s)
- Christian Florian Teh-Poot
- Laboratorio de Parasitología, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Mexico
| | - Victor Manuel Dzul-Huchim
- Laboratorio de Parasitología, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Mexico
| | - Jonathan M Mercado
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Liliana Estefanía Villanueva-Lizama
- Laboratorio de Parasitología, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Mexico; Texas Children's Hospital Center for Vaccine Development, Houston, TX, USA; Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Maria Elena Bottazzi
- Texas Children's Hospital Center for Vaccine Development, Houston, TX, USA; Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Biochemistry and Molecular Biology, and Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Kathryn M Jones
- Texas Children's Hospital Center for Vaccine Development, Houston, TX, USA; Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Biochemistry and Molecular Biology, and Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Francis T F Tsai
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA; Department of Biochemistry and Molecular Biology, and Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Julio Vladimir Cruz-Chan
- Laboratorio de Parasitología, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Mexico; Texas Children's Hospital Center for Vaccine Development, Houston, TX, USA; Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA.
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Recent advances on the piezoelectric, electrochemical, and optical biosensors for the detection of protozoan pathogens. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Chakrabarti A, Kaushik M, Khan J, Soota D, Ponnusamy K, Saini S, Manvati S, Singhal J, Ranganathan A, Pati S, Dhar PK, Singh S. tREPs-A New Class of Functional tRNA-Encoded Peptides. ACS OMEGA 2022; 7:18361-18373. [PMID: 35694484 PMCID: PMC9178612 DOI: 10.1021/acsomega.2c00661] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
We asked if transfer RNA (tRNA) ever got an opportunity of translating its own sequence during evolution, what would have been the function of such tRNA-encoded peptides (tREPs)? If not, could one artificially synthesize tREPs to study the corresponding functional outcomes? Here, we report a novel, first-in-the-class, chemically synthesized tREP-18 molecule originating from the Escherichia coli tRNA sequence showing potent antileishmanial property. As a first step, E. coli tRNAs were computationally translated into peptide sequence equivalents and a database of full-length hypothetical tREPs was created. The tREP sequences were sent into sequence, structure, and energy filters to narrow down potential peptides for experimental validation. Based on the functional predictions, tREPs were screened against antiparasitic targets, leading to the identification of tREP-18 as a potential antiparasitic peptide. The in vitro assay of chemically synthesized tREP-18 on the Ag83 strain of Leishmania donovani showed its potent antileishmanial property (IC50 value of 22.13 nM). The atomic force microscopy and scanning electron microscopy images indicated significant alteration in the cytoskeletal architecture of tREP-18-treated parasites. Also, tREP-18 seems to destabilize the mitochondrial membrane potential of parasites, disrupting their cellular integrity and leading to parasitic death. The cellular assays of the tREP-18 peptide on the BS12 strain, a clinical isolate of post-kala azar dermal leishmaniasis, demonstrated its significant efficacy at an IC50 value of 15 nM. The tREP-18 peptide showed a toxic effect on the amastigote stage of the parasite, showing macrophage pathogen clearance at a concentration of 22.5 nM. This study provides the proof of the concept of making a new class of functional peptides from tRNA sequences. It also opens a huge untapped tRNA-peptide space toward novel discoveries and applications. In the future, it would be interesting to perform tREP edits and redesign tREPs toward specific applications.
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Affiliation(s)
- Amrita Chakrabarti
- Department of Life Sciences, Shiv Nadar University, Greater Noida 201314, Uttar Pradesh, India
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India
| | - Monika Kaushik
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Juveria Khan
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Deepanshu Soota
- National Centre for Biological Sciences, Bangalore 560065, India
| | | | - Sunil Saini
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India
| | - Siddharth Manvati
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Jhalak Singhal
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India
| | - Anand Ranganathan
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India
| | - Soumya Pati
- Department of Life Sciences, Shiv Nadar University, Greater Noida 201314, Uttar Pradesh, India
| | - Pawan Kumar Dhar
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
- Special Centre for Systems Medicine, Jawaharlal Nehru University, New Delhi 110067, India
| | - Shailja Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India
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Firdaus MER, Muh F, Park JH, Lee SK, Na SH, Park WS, Ha KS, Han JH, Han ET. In-depth biological analysis of alteration in Plasmodium knowlesi-infected red blood cells using a noninvasive optical imaging technique. Parasit Vectors 2022; 15:68. [PMID: 35236400 PMCID: PMC8889714 DOI: 10.1186/s13071-022-05182-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 01/28/2022] [Indexed: 12/13/2022] Open
Abstract
Background Imaging techniques are commonly used to understand disease mechanisms and their biological features in the microenvironment of the cell. Many studies have added to our understanding of the biology of the malaria parasite Plasmodium knowlesi from functional in vitro and imaging analysis using serial block-face scanning electron microscopy (SEM). However, sample fixation and metal coating during SEM analysis can alter the parasite membrane. Methods In this study, we used noninvasive diffraction optical tomography (DOT), also known as holotomography, to explore the morphological, biochemical, and mechanical alterations of each stage of P. knowlesi-infected red blood cells (RBCs). Each stage of the parasite was synchronized using Nycodenz and magnetic-activated cell sorting (MACS) for P. knowlesi and P. falciparum, respectively. Holotomography was applied to measure individual three-dimensional refractive index tomograms without metal coating, fixation, or additional dye agent. Results Distinct profiles were found on the surface area and hemoglobin content of the two parasites. The surface area of P. knowlesi-infected RBCs showed significant expansion, while P. falciparum-infected RBCs did not show any changes compared to uninfected RBCs. In terms of hemoglobin consumption, P. falciparum tended to consume hemoglobin more than P. knowlesi. The observed profile of P. knowlesi-infected RBCs generally showed similar results to other studies, proving that this technique is unbiased. Conclusions The observed profile of the surface area and hemoglobin content of malaria infected-RBCs can potentially be used as a diagnostic parameter to distinguish P. knowlesi and P. falciparum infection. In addition, we showed that holotomography could be used to study each Plasmodium species in greater depth, supporting strategies for the development of diagnostic and treatment strategies for malaria. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05182-1.
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Affiliation(s)
- Moh Egy Rahman Firdaus
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Fauzi Muh
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Ji-Hoon Park
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | | | - Sung-Hun Na
- Department of Obstetrics and Gynecology, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Won-Sun Park
- Department of Physiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, 24341, Republic of Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, 24341, Republic of Korea.
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Kumar V, Ghosh S, Roy K, Pal C, Singh S. Deletion of Glutamine Synthetase Gene Disrupts the Survivability and Infectivity of Leishmania donovani. Front Cell Infect Microbiol 2021; 11:622266. [PMID: 33732662 PMCID: PMC7959746 DOI: 10.3389/fcimb.2021.622266] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 01/25/2021] [Indexed: 12/24/2022] Open
Abstract
Glutamine synthetase (GS) is one of the most important metabolic enzymes which catalyzes ligation of glutamate and ammonia to form glutamine. Previous studies from our lab had revealed significant differences in parasite and host GS enzyme which warranted us to further work on its relevance in parasite. To analyze glutamine synthetase function in Leishmania, we generated GS overexpressors and knockout mutants and evaluated their ability to grow in vitro in monocyte differentiated macrophage and in vivo by infections in BALB/c mice. GS knocked out strain showed significant growth retardation with delayed cell cycle progression and morphological alteration. Null mutants exhibited attenuated infectivity both in in vitro and in vivo experiments and the effect was reverted back when infected with GS complemented parasites. This indicated that the alterations in phenotype observed were indeed due to GS knockout. GS knockout also made the parasite increasingly sensitive to Miltefosine. Detailed investigation of mode of parasite death upon Miltefosine treatment by dual staining with Annexin-V conjugated FITC and propidium iodide, pointed towards apoptotic or necrotic mode of cell death. This is the first report to confirm that GS is essential for the survivability and infectivity of Leishmania donovani, and can be exploited as a potential drug-target.
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Affiliation(s)
- Vinay Kumar
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Mohali, India
| | - Sanhita Ghosh
- Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, India
| | - Kamalika Roy
- Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, India
| | - Chiranjib Pal
- Cellular Immunology and Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, India
| | - Sushma Singh
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Mohali, India
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Paik D, Pramanik PK, Chakraborti T. Curative efficacy of purified serine protease inhibitor PTF3 from potato tuber in experimental visceral leishmaniasis. Int Immunopharmacol 2020; 85:106623. [PMID: 32504996 DOI: 10.1016/j.intimp.2020.106623] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/04/2020] [Accepted: 05/18/2020] [Indexed: 10/24/2022]
Abstract
To overcome the drug toxicity and frequent resistance of parasites against the conventional drugs for the healing of human visceral leishmaniasis, innovative plant derived antileishmanial components are very imperative. Fuelled by the complications of clinically available antileishmanial drugs, a novel potato serine protease inhibitor was identified with its efficacy on experimental visceral leishmaniasis (VL). The serine protease inhibitors from potato tuber extract (PTEx) bearing molecular mass of 39 kDa (PTF1), 23 kDa (PTF2) and 17 kDa (PTF3) were purified and identified. Among them, PTF3 was selected as the most active inhibitor (IC50 143.5 ± 2.4 µg/ml) regarding its antileishmanial property. Again, intracellular amastigote load was reduced upto 83.1 ± 1.7% in pre-treated parasite and 88.5 ± 0.5% in in vivo model with effective dose of PTF3. Protective immune response by PTF3 was noted with increased production of antimicrobial substances and up-regulation of pro-inflammatory cytokines. Therapeutic potency of PTF3 is also followed by 80% survival in infected hamster. The peptide mass fingerprint (MALDI-TOF) results showed similarity of PTF3 with serine protease inhibitors database. Altogether, these results strongly propose the effectiveness of PTF3 as potent immunomodulatory therapeutics for controlling VL.
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Affiliation(s)
- Dibyendu Paik
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India
| | - Pijush Kanti Pramanik
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India
| | - Tapati Chakraborti
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India.
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Damianou A, Burge RJ, Catta-Preta CMC, Geoghegan V, Nievas YR, Newling K, Brown E, Burchmore R, Rodenko B, Mottram JC. Essential roles for deubiquitination in Leishmania life cycle progression. PLoS Pathog 2020; 16:e1008455. [PMID: 32544189 PMCID: PMC7319358 DOI: 10.1371/journal.ppat.1008455] [Citation(s) in RCA: 28] [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: 02/29/2020] [Revised: 06/26/2020] [Accepted: 05/07/2020] [Indexed: 12/22/2022] Open
Abstract
The parasitic protozoan Leishmania requires proteasomal, autophagic and lysosomal proteolytic pathways to enact the extensive cellular remodelling that occurs during its life cycle. The proteasome is essential for parasite proliferation, yet little is known about the requirement for ubiquitination/deubiquitination processes in growth and differentiation. Activity-based protein profiling of L. mexicana C12, C19 and C65 deubiquitinating cysteine peptidases (DUBs) revealed DUB activity remains relatively constant during differentiation of procyclic promastigote to amastigote. However, when life cycle phenotyping (bar-seq) was performed on a pool including 15 barcoded DUB null mutants created in promastigotes using CRISPR-Cas9, significant loss of fitness was observed during differentiation and intracellular infection. DUBs 4, 7, and 13 are required for successful transformation from metacyclic promastigote to amastigote and DUBs 3, 5, 6, 8, 10, 11 and 14 are required for normal amastigote proliferation in mice. DUBs 1, 2, 12 and 16 are essential for promastigote viability and the essential role of DUB2 in establishing infection was demonstrated using DiCre inducible gene deletion in vitro and in vivo. DUB2 is found in the nucleus and interacts with nuclear proteins associated with transcription/chromatin dynamics, mRNA splicing and mRNA capping. DUB2 has broad linkage specificity, cleaving all the di-ubiquitin chains except for Lys27 and Met1. Our study demonstrates the crucial role that DUBs play in differentiation and intracellular survival of Leishmania and that amastigotes are exquisitely sensitive to disruption of ubiquitination homeostasis.
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Affiliation(s)
- Andreas Damianou
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Rebecca J. Burge
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| | | | - Vincent Geoghegan
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| | - Y. Romina Nievas
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| | - Katherine Newling
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| | - Elaine Brown
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| | - Richard Burchmore
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Boris Rodenko
- UbiQ Bio BV, Amsterdam Science Park, The Netherlands
| | - Jeremy C. Mottram
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
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12
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Edwards BFL, Wheeler RJ, Barker AR, Moreira-Leite FF, Gull K, Sunter JD. Direction of flagellum beat propagation is controlled by proximal/distal outer dynein arm asymmetry. Proc Natl Acad Sci U S A 2018; 115:E7341-E7350. [PMID: 30030284 PMCID: PMC6077732 DOI: 10.1073/pnas.1805827115] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The 9 + 2 axoneme structure of the motile flagellum/cilium is an iconic, apparently symmetrical cellular structure. Recently, asymmetries along the length of motile flagella have been identified in a number of organisms, typically in the inner and outer dynein arms. Flagellum-beat waveforms are adapted for different functions. They may start either near the flagellar tip or near its base and may be symmetrical or asymmetrical. We hypothesized that proximal/distal asymmetry in the molecular composition of the axoneme may control the site of waveform initiation and the direction of waveform propagation. The unicellular eukaryotic pathogens Trypanosoma brucei and Leishmania mexicana often switch between tip-to-base and base-to-tip waveforms, making them ideal for analysis of this phenomenon. We show here that the proximal and distal portions of the flagellum contain distinct outer dynein arm docking-complex heterodimers. This proximal/distal asymmetry is produced and maintained through growth by a concentration gradient of the proximal docking complex, generated by intraflagellar transport. Furthermore, this asymmetry is involved in regulating whether a tip-to-base or base-to-tip beat occurs, which is linked to a calcium-dependent switch. Our data show that the mechanism for generating proximal/distal flagellar asymmetry can control waveform initiation and propagation direction.
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Affiliation(s)
| | - Richard John Wheeler
- Sir William Dunn School of Pathology, University of Oxford, OX1 3RE Oxford, United Kingdom;
| | - Amy Rachel Barker
- Sir William Dunn School of Pathology, University of Oxford, OX1 3RE Oxford, United Kingdom
| | | | - Keith Gull
- Sir William Dunn School of Pathology, University of Oxford, OX1 3RE Oxford, United Kingdom
| | - Jack Daniel Sunter
- Department of Biological and Medical Sciences, Oxford Brookes University, OX3 0BP Oxford, United Kingdom
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13
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New advances in scanning microscopy and its application to study parasitic protozoa. Exp Parasitol 2018; 190:10-33. [PMID: 29702111 DOI: 10.1016/j.exppara.2018.04.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 04/10/2018] [Accepted: 04/23/2018] [Indexed: 12/31/2022]
Abstract
Scanning electron microscopy has been used to observe and study parasitic protozoa for at least 40 years. However, field emission electron sources, as well as improvements in lenses and detectors, brought the resolution power of scanning electron microscopes (SEM) to a new level. Parallel to the refinement of instruments, protocols for preservation of the ultrastructure, immunolabeling, exposure of cytoskeleton and inner structures of parasites and host cells were developed. This review is focused on protozoan parasites of medical and veterinary relevance, e.g., Toxoplasma gondii, Tritrichomonas foetus, Giardia intestinalis, and Trypanosoma cruzi, compilating the main achievements in describing the fine ultrastructure of their surface, cytoskeleton and interaction with host cells. Two new resources, namely, Helium Ion Microscopy (HIM) and Slice and View, using either Focused Ion Beam (FIB) abrasion or Microtome Serial Sectioning (MSS) within the microscope chamber, combined to backscattered electron imaging of fixed (chemically or by quick freezing followed by freeze substitution and resin embedded samples is bringing an exponential amount of valuable information. In HIM there is no need of conductive coating and the depth of field is much higher than in any field emission SEM. As for FIB- and MSS-SEM, high resolution 3-D models of areas and volumes larger than any other technique allows can be obtained. The main results achieved with all these technological tools and some protocols for sample preparation are included in this review. In addition, we included some results obtained with environmental/low vacuum scanning microscopy and cryo-scanning electron microscopy, both promising, but not yet largely employed SEM modalities.
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14
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Umaer K, Bush PJ, Bangs JD. Rab11 mediates selective recycling and endocytic trafficking in Trypanosoma brucei. Traffic 2018; 19:406-420. [PMID: 29582527 DOI: 10.1111/tra.12565] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/15/2018] [Accepted: 03/15/2018] [Indexed: 01/21/2023]
Abstract
Trypanosoma brucei possesses a streamlined secretory system that guarantees efficient delivery to the cell surface of the critical glycosyl-phosphatidylinositol (GPI)-anchored virulence factors, variant surface glycoprotein (VSG) and transferrin receptor (TfR). Both are thought to be constitutively endocytosed and returned to the flagellar pocket via TbRab11+ recycling endosomes. We use conditional knockdown with established reporters to investigate the role of TbRab11 in specific endomembrane trafficking pathways in bloodstream trypanosomes. TbRab11 is essential. Ablation has a modest negative effect on general endocytosis, but does not affect turnover, steady state levels or surface localization of TfR. Nor are biosynthetic delivery to the cell surface and recycling of VSG affected. TbRab11 depletion also causes increased shedding of VSG into the media by formation of nanotubes and extracellular vesicles. In contrast to GPI-anchored cargo, TbRab11 depletion reduces recycling of the transmembrane invariant surface protein, ISG65, leading to increased lysosomal turnover. Thus, TbRab11 plays a critical role in recycling of transmembrane, but not GPI-anchored surface proteins. We proposed a two-step model for VSG turnover involving release of VSG-containing vesicles followed by GPI hydrolysis. Collectively, our results indicate a critical role of TbRab11 in the homeostatic maintenance of the secretory/endocytic system of bloodstream T. brucei.
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Affiliation(s)
- Khan Umaer
- Department of Microbiology & Immunology, School of Medicine and Biomedical Sciences, University at Buffalo (SUNY), Buffalo, New York
| | - Peter J Bush
- South Campus Instrument Center, School of Dental Medicine, University at Buffalo (SUNY), Buffalo, New York
| | - James D Bangs
- Department of Microbiology & Immunology, School of Medicine and Biomedical Sciences, University at Buffalo (SUNY), Buffalo, New York
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15
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Morriswood B, Engstler M. Let's get fISSical: fast in silico synchronization as a new tool for cell division cycle analysis. Parasitology 2018; 145:196-209. [PMID: 28166845 PMCID: PMC5964468 DOI: 10.1017/s0031182017000038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/23/2016] [Accepted: 01/05/2017] [Indexed: 12/23/2022]
Abstract
Cell cycle progression is a question of fundamental biological interest. The coordinated duplication and segregation of all cellular structures and organelles is however an extremely complex process, and one which remains only partially understood even in the most intensively researched model organisms. Trypanosomes are in an unusual position in this respect - they are both outstanding model systems for fundamental questions in eukaryotic cell biology, and pathogens that are the causative agents of three of the neglected tropical diseases. As a failure to successfully complete cell division will be deleterious or lethal, analysis of the cell division cycle is of relevance both to basic biology and drug design efforts. Cell division cycle analysis is however experimentally challenging, as the analysis of phenotypes associated with it remains hypothesis-driven and therefore biased. Current methods of analysis are extremely labour-intensive, and cell synchronization remains difficult and unreliable. Consequently, there exists a need - both in basic and applied trypanosome biology - for a global, unbiased, standardized and high-throughput analysis of cell division cycle progression. In this review, the requirements - both practical and computational - for such a system are considered and compared with existing techniques for cell cycle analysis.
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Affiliation(s)
- Brooke Morriswood
- Department of Cell & Developmental Biology,University of Würzburg,Biocentre, Am Hubland, 97074 Würzburg,Germany
| | - Markus Engstler
- Department of Cell & Developmental Biology,University of Würzburg,Biocentre, Am Hubland, 97074 Würzburg,Germany
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16
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Banerjee M, Parai D, Dhar P, Roy M, Barik R, Chattopadhyay S, Mukherjee SK. Andrographolide induces oxidative stress-dependent cell death in unicellular protozoan parasite Trypanosoma brucei. Acta Trop 2017; 176:58-67. [PMID: 28739368 DOI: 10.1016/j.actatropica.2017.07.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 07/13/2017] [Accepted: 07/20/2017] [Indexed: 11/16/2022]
Abstract
African sleeping sickness is a parasitic disease in humans and livestock caused by Trypanosoma brucei throughout sub-Saharan Africa. Absence of appropriate vaccines and prevalence of drug resistance proclaim that a new way of therapeutic interventions is essential against African trypanosomiasis. In the present study, we have looked into the effect of andrographolide (andro), a diterpenoid lactone from Andrographis paiculata on Trypanosoma brucei PRA 380. Although andro has been recognized as a promosing anti-cancer drug, its usefulness against Trypanosoma spp remained unexplored. Andro showed promising anti-trypanosomal activity with an IC50 value of 8.3μM assessed through SYBR Green cell viability assay and also showed no cytotoxicity towards normal murine macrophages. Cell cycle analysis revealed that andro could induce sub-G0/G1 phase arrest. Flow cytometric analysis also revealed that incubation with andro caused exposure of phosphatidyl serine to the outer leaflet of plasma membrane in T. brucei PCF. This event was preceded by andro-induced depolarization of mitochondrial membrane potential (Δym) and elevation of cytosolic calcium. Andro also caused elevation of intracellular reactive oxygen species (ROS) as well as lipid peroxidation level, and depletion in reduced thiol levels. Taken together, these data indicate that andro has promising antitrypanosomal activity mediated by promoting oxidative stress and depolarizing the mitochondrial membrane potential and thereby triggering an apoptosis-like programmed cell death. Therefore, this study merits further investigation to the therapeutic possibility of using andro for the treatment of African trypanosomiasis.
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Affiliation(s)
- Malabika Banerjee
- Department of Microbiology, University of Kalyani, Kalyani 741235, WB, India; TCG Life Science Ltd., Bengal Intelligent Park, Tower-B, Block-EP & GP, Sector-5, Salt Lake, Kolkata, 700091, India
| | - Debaprasad Parai
- Department of Microbiology, University of Kalyani, Kalyani 741235, WB, India
| | - Pranab Dhar
- TCG Life Science Ltd., Bengal Intelligent Park, Tower-B, Block-EP & GP, Sector-5, Salt Lake, Kolkata, 700091, India
| | - Manab Roy
- TCG Life Science Ltd., Bengal Intelligent Park, Tower-B, Block-EP & GP, Sector-5, Salt Lake, Kolkata, 700091, India
| | - Rajib Barik
- TCG Life Science Ltd., Bengal Intelligent Park, Tower-B, Block-EP & GP, Sector-5, Salt Lake, Kolkata, 700091, India
| | - Subrata Chattopadhyay
- TCG Life Science Ltd., Bengal Intelligent Park, Tower-B, Block-EP & GP, Sector-5, Salt Lake, Kolkata, 700091, India
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17
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Tiengwe C, Bush PJ, Bangs JD. Controlling transferrin receptor trafficking with GPI-valence in bloodstream stage African trypanosomes. PLoS Pathog 2017; 13:e1006366. [PMID: 28459879 PMCID: PMC5426795 DOI: 10.1371/journal.ppat.1006366] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/11/2017] [Accepted: 04/19/2017] [Indexed: 01/10/2023] Open
Abstract
Bloodstream-form African trypanosomes encode two structurally related glycosylphosphatidylinositol (GPI)-anchored proteins that are critical virulence factors, variant surface glycoprotein (VSG) for antigenic variation and transferrin receptor (TfR) for iron acquisition. Both are transcribed from the active telomeric expression site. VSG is a GPI2 homodimer; TfR is a GPI1 heterodimer of GPI-anchored ESAG6 and ESAG7. GPI-valence correlates with secretory progression and fate in bloodstream trypanosomes: VSG (GPI2) is a surface protein; truncated VSG (GPI0) is degraded in the lysosome; and native TfR (GPI1) localizes in the flagellar pocket. Tf:Fe starvation results in up-regulation and redistribution of TfR to the plasma membrane suggesting a saturable mechanism for flagellar pocket retention. However, because such surface TfR is non-functional for ligand binding we proposed that it represents GPI2 ESAG6 homodimers that are unable to bind transferrin-thereby mimicking native VSG. We now exploit a novel RNAi system for simultaneous lethal silencing of all native TfR subunits and exclusive in-situ expression of RNAi-resistant TfR variants with valences of GPI0-2. Our results conform to the valence model: GPI0 ESAG7 homodimers traffick to the lysosome and GPI2 ESAG6 homodimers to the cell surface. However, when expressed alone ESAG6 is up-regulated ~7-fold, leaving the issue of saturable retention in the flagellar pocket in question. Therefore, we created an RNAi-resistant GPI2 TfR heterodimer by fusing the C-terminal domain of ESAG6 to ESAG7. Co-expression with ESAG6 generates a functional heterodimeric GPI2 TfR that restores Tf uptake and cell viability, and localizes to the cell surface, without overexpression. These results resolve the longstanding issue of TfR trafficking under over-expression and confirm GPI valence as a critical determinant of intracellular sorting in trypanosomes.
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Affiliation(s)
- Calvin Tiengwe
- Department of Microbiology & Immunology, School of Medicine and Biomedical Sciences, University at Buffalo (SUNY), Buffalo, New York, United States of America
| | - Peter J. Bush
- South Campus Instrument Center, School of Dental Medicine, University at Buffalo (SUNY), Buffalo, New York, United States of America
| | - James D. Bangs
- Department of Microbiology & Immunology, School of Medicine and Biomedical Sciences, University at Buffalo (SUNY), Buffalo, New York, United States of America
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18
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Titze B, Genoud C. Volume scanning electron microscopy for imaging biological ultrastructure. Biol Cell 2016; 108:307-323. [DOI: 10.1111/boc.201600024] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 07/13/2016] [Accepted: 07/14/2016] [Indexed: 12/01/2022]
Affiliation(s)
- Benjamin Titze
- Friedrich Miescher Institute for Biomedical Research; Basel Switzerland
| | - Christel Genoud
- Friedrich Miescher Institute for Biomedical Research; Basel Switzerland
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19
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Wheeler RJ, Sunter JD, Gull K. Flagellar pocket restructuring through the Leishmania life cycle involves a discrete flagellum attachment zone. J Cell Sci 2016; 129:854-67. [PMID: 26746239 PMCID: PMC4760377 DOI: 10.1242/jcs.183152] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/29/2015] [Indexed: 01/10/2023] Open
Abstract
Leishmania promastigote parasites have a flagellum, which protrudes from the flagellar pocket at the cell anterior, yet, surprisingly, have homologs of many flagellum attachment zone (FAZ) proteins – proteins used in the related Trypanosoma species to laterally attach the flagellum to the cell body from the flagellar pocket to the cell posterior. Here, we use seven Leishmania mexicana cell lines that expressed eYFP fusions of FAZ protein homologs to show that the Leishmania flagellar pocket includes a FAZ structure. Electron tomography revealed a precisely defined 3D organisation for both the flagellar pocket and FAZ, with striking similarities to those of Trypanosoma brucei. Expression of two T. brucei FAZ proteins in L. mexicana showed that T. brucei FAZ proteins can assemble into the Leishmania FAZ structure. Leishmania therefore have a previously unrecognised FAZ structure, which we show undergoes major structural reorganisation in the transition from the promastigote (sandfly vector) to amastigote (in mammalian macrophages). Morphogenesis of the Leishmania flagellar pocket, a structure important for pathogenicity, is therefore intimately associated with a FAZ; a finding with implications for understanding shape changes involving component modules during evolution. Summary:Leishmania parasites have a highly structured flagellar pocket, including a structure homologous to the Trypanosoma brucei flagellum attachment zone, which undergoes structural adaptations in different life cycle stages.
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Affiliation(s)
- Richard J Wheeler
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, Dresden 01307, Germany Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
| | - Jack D Sunter
- Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
| | - Keith Gull
- Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
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Basal body multipotency and axonemal remodelling are two pathways to a 9+0 flagellum. Nat Commun 2015; 6:8964. [PMID: 26667778 PMCID: PMC4682162 DOI: 10.1038/ncomms9964] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 10/21/2015] [Indexed: 02/07/2023] Open
Abstract
Eukaryotic cilia/flagella exhibit two characteristic ultrastructures reflecting two main functions; a 9+2 axoneme for motility and a 9+0 axoneme for sensation and signalling. Whether, and if so how, they interconvert is unclear. Here we analyse flagellum length, structure and molecular composition changes in the unicellular eukaryotic parasite Leishmania during the transformation of a life cycle stage with a 9+2 axoneme (the promastigote) to one with a 9+0 axoneme (the amastigote). We show 9+0 axonemes can be generated by two pathways: by de novo formation and by restructuring of existing 9+2 axonemes associated with decreased intraflagellar transport. Furthermore, pro-basal bodies formed under conditions conducive for 9+2 axoneme formation can form a 9+0 axoneme de novo. We conclude that pro-centrioles/pro-basal bodies are multipotent and not committed to form either a 9+2 or 9+0 axoneme. In an alternative pathway structures can also be removed from existing 9+2 axonemes to convert them to 9+0. Whether basal bodies are pre-committed to form 9+2 motile or 9+0 sensory axonemes and whether interconversion occurs between the two types of axonemes is not clear. Here, the authors used the unicellular eukaryote Leishmania as a model system to demonstrate that 9+0 axonemes can be formed de novo or by restructuring of 9+2 axonemes.
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21
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Mukhopadhyay AG, Dey CS. Two-headed outer- and inner-arm dyneins of Leishmania sp bear conserved IQ-like motifs. Biochem Biophys Rep 2015; 4:283-290. [PMID: 29124215 PMCID: PMC5669419 DOI: 10.1016/j.bbrep.2015.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 10/01/2015] [Accepted: 10/06/2015] [Indexed: 11/25/2022] Open
Abstract
Dyneins are high molecular weight microtubule based motor proteins responsible for beating of the flagellum. The flagellum is important for the viability of trypanosomes like Leishmania. However, very little is known about dynein and its role in flagellar motility in such trypanosomatid species. Here, we have identified genes in five species of Leishmania that code for outer-arm dynein (OAD) heavy chains α and β, and inner-arm dynein (IAD) heavy chains 1α and 1β using BLAST and MSA. Our sequence analysis indicates that unlike the three-headed outer-arm dyneins of Chlamydomonas and Tetrahymena, the outer-arm dyneins of the genus Leishmania are two-headed, lacking the γ chain like that of metazoans. N-terminal sequence analysis revealed a conserved IQ-like calmodulin binding motif in the outer-arm α and inner-arm 1α dynein heavy chain in the five species of Leishmania similar to Chlamydomonas reinhardtii outer-arm γ. It was predicted that both motifs were incapable of binding calmodulin. Phosphorylation site prediction revealed conserved serine and threonine residues in outer-arm dynein α and inner-arm 1α as putative phosphorylation sites exclusive to Leishmania but not in Trypanosoma brucei suggesting that regulation of dynein activity might be via phosphorylation of these IQ-like motifs in Leishmania sp. Identified outer and inner-arm dynein heavy chain genes in five Leishmania species. Outer-arm dyneins of the genus Leishmania are two-headed like metazoans. Conserved IQ-like motif present in outer-arm α and inner-arm 1α in Leishmania sp. Conserved serine and threonine residues in dynein arms exclusive to Leishmania sp. Possible regulation of dynein activity via phosphorylation of these IQ-like motifs.
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