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Dereeper A, Allouch N, Guerlais V, Garnier M, Ma L, De Jonckheere JF, Joseph SJ, Ali IKM, Talarmin A, Marcelino I. Naegleria genus pangenome reveals new structural and functional insights into the versatility of these free-living amoebae. Front Microbiol 2023; 13:1056418. [PMID: 36817109 PMCID: PMC9928731 DOI: 10.3389/fmicb.2022.1056418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/21/2022] [Indexed: 02/04/2023] Open
Abstract
Introduction Free-living amoebae of the Naegleria genus belong to the major protist clade Heterolobosea and are ubiquitously distributed in soil and freshwater habitats. Of the 47 Naegleria species described, N. fowleri is the only one being pathogenic to humans, causing a rare but fulminant primary amoebic meningoencephalitis. Some Naegleria genome sequences are publicly available, but the genetic basis for Naegleria diversity and ability to thrive in diverse environments (including human brain) remains unclear. Methods Herein, we constructed a high-quality Naegleria genus pangenome to obtain a comprehensive catalog of genes encoded by these amoebae. For this, we first sequenced, assembled, and annotated six new Naegleria genomes. Results and Discussion Genome architecture analyses revealed that Naegleria may use genome plasticity features such as ploidy/aneuploidy to modulate their behavior in different environments. When comparing 14 near-to-complete genome sequences, our results estimated the theoretical Naegleria pangenome as a closed genome, with 13,943 genes, including 3,563 core and 10,380 accessory genes. The functional annotations revealed that a large fraction of Naegleria genes show significant sequence similarity with those already described in other kingdoms, namely Animalia and Plantae. Comparative analyses highlighted a remarkable genomic heterogeneity, even for closely related strains and demonstrate that Naegleria harbors extensive genome variability, reflected in different metabolic repertoires. If Naegleria core genome was enriched in conserved genes essential for metabolic, regulatory and survival processes, the accessory genome revealed the presence of genes involved in stress response, macromolecule modifications, cell signaling and immune response. Commonly reported N. fowleri virulence-associated genes were present in both core and accessory genomes, suggesting that N. fowleri's ability to infect human brain could be related to its unique species-specific genes (mostly of unknown function) and/or to differential gene expression. The construction of Naegleria first pangenome allowed us to move away from a single reference genome (that does not necessarily represent each species as a whole) and to identify essential and dispensable genes in Naegleria evolution, diversity and biology, paving the way for further genomic and post-genomic studies.
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Affiliation(s)
- Alexis Dereeper
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Nina Allouch
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Vincent Guerlais
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Maëlle Garnier
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Laurence Ma
- Institut Pasteur de Paris, Biomics, Paris, France
| | | | - Sandeep J. Joseph
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States
| | - Ibne Karim M. Ali
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States
| | - Antoine Talarmin
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Isabel Marcelino
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France,*Correspondence: Isabel Marcelino,
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Hammond M, Zoltner M, Garrigan J, Butterfield E, Varga V, Lukeš J, Field MC. The distinctive flagellar proteome of Euglena gracilis illuminates the complexities of protistan flagella adaptation. THE NEW PHYTOLOGIST 2021; 232:1323-1336. [PMID: 34292600 DOI: 10.1111/nph.17638] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
The eukaryotic flagellum/cilium is a prominent organelle with conserved structure and diverse functions. Euglena gracilis, a photosynthetic and highly adaptable protist, employs its flagella for both locomotion and environmental sensing. Using proteomics of isolated E. gracilis flagella we identify nearly 1700 protein groups, which challenges previous estimates of the protein complexity of motile eukaryotic flagella. We not only identified several unexpected similarities shared with mammalian flagella, including an entire glycolytic pathway and proteasome, but also document a vast array of flagella-based signal transduction components that coordinate gravitaxis and phototactic motility. By contrast, the pellicle was found to consist of > 900 protein groups, containing additional structural and signalling components. Our data identify significant adaptations within the E. gracilis flagellum, many of which are clearly linked to the highly flexible lifestyle.
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Affiliation(s)
- Michael Hammond
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), 370 05, Czech Republic
| | - Martin Zoltner
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, Vestec, 252 50, Czech Republic
| | - Jack Garrigan
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Erin Butterfield
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Vladimir Varga
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, 142 20, Czech Republic
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), 370 05, Czech Republic
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), 370 05, Czech Republic
| | - Mark C Field
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), 370 05, Czech Republic
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
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Photoreaction of photoactivated adenylate cyclase from cyanobacterium Microcoleus chthonoplastes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2021; 221:112252. [PMID: 34265548 DOI: 10.1016/j.jphotobiol.2021.112252] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 05/19/2021] [Accepted: 06/28/2021] [Indexed: 11/21/2022]
Abstract
The photochemical reaction of photoactivated adenylate cyclase from cyanobacterium Microcoleus chthonoplastes PCC 7420 (mPAC), which consists of a Per-Arnt-Sim (PAS), a light‑oxygene-voltage (LOV), and an adenylate cyclase (AC) domain, was investigated mainly using the time-resolved transient grating method. An absorption spectral change associated with an adduct formation between its chromophore (flavin mononucleotide) and a cysteine residue was observed with a time constant of 0.66 μs. After this reaction, a significant diffusion coefficient (D)-change was observed with a time constant of 38 ms. The determined D-value was concentration-dependent indicating a rapid equilibrium between the dimer and tetramer. Combining the results of size exclusion chromatography and CD spectroscopy, we concluded that the photoinduced D-change was mainly attributed to the equilibrium shift from the dimer rich to the tetramer rich states upon light exposure. Since the reaction rate does not depend on concentration, the rate determining step of the tetramer formation is not the collision of proteins by diffusion, but a conformation change. The roles of the PAS and AC domains as well as the N- and C-terminal flanking helices of the LOV domain (A'α- and Jα-helices) were investigated using various truncated mutants. The PAS domain was found to be a strong dimerization site and is related to efficient signal transduction. It was found that simultaneous existence of the A'α- and Jα-helices in mPAC is important for the light-induced conformation change to lead the conformation change which induces the tetramer formation. The results suggest that the angle changes of the coiled-coil structures in the A'α and Jα-helices are essential for this conformation change. The reaction scheme of mPAC is proposed.
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Häder DP, Iseki M. Photomovement in Euglena. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 979:207-235. [DOI: 10.1007/978-3-319-54910-1_11] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Hemmersbach R, Simon A, Waßer K, Hauslage J, Christianen PC, Albers PW, Lebert M, Richter P, Alt W, Anken R. Impact of a high magnetic field on the orientation of gravitactic unicellular organisms--a critical consideration about the application of magnetic fields to mimic functional weightlessness. ASTROBIOLOGY 2014; 14:205-15. [PMID: 24621307 PMCID: PMC3952527 DOI: 10.1089/ast.2013.1085] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 01/16/2014] [Indexed: 06/03/2023]
Abstract
The gravity-dependent behavior of Paramecium biaurelia and Euglena gracilis have previously been studied on ground and in real microgravity. To validate whether high magnetic field exposure indeed provides a ground-based facility to mimic functional weightlessness, as has been suggested earlier, both cell types were observed during exposure in a strong homogeneous magnetic field (up to 30 T) and a strong magnetic field gradient. While swimming, Paramecium cells were aligned along the magnetic field lines; orientation of Euglena was perpendicular, demonstrating that the magnetic field determines the orientation and thus prevents the organisms from the random swimming known to occur in real microgravity. Exposing Astasia longa, a flagellate that is closely related to Euglena but lacks chloroplasts and the photoreceptor, as well as the chloroplast-free mutant E. gracilis 1F, to a high magnetic field revealed no reorientation to the perpendicular direction as in the case of wild-type E. gracilis, indicating the existence of an anisotropic structure (chloroplasts) that determines the direction of passive orientation. Immobilized Euglena and Paramecium cells could not be levitated even in the highest available magnetic field gradient as sedimentation persisted with little impact of the field on the sedimentation velocities. We conclude that magnetic fields are not suited as a microgravity simulation for gravitactic unicellular organisms due to the strong effect of the magnetic field itself, which masks the effects known from experiments in real microgravity.
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Affiliation(s)
- Ruth Hemmersbach
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Anja Simon
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Kai Waßer
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Jens Hauslage
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Peter C.M. Christianen
- High Field Magnet Laboratory, Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Peter W. Albers
- High Field Magnet Laboratory, Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Michael Lebert
- Department of Biology, Friedrich-Alexander-University, Erlangen, Germany
| | - Peter Richter
- Department of Biology, Friedrich-Alexander-University, Erlangen, Germany
| | - Wolfgang Alt
- Theoretical Biology, University of Bonn, Bonn, Germany
| | - Ralf Anken
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
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Ozasa K, Lee J, Song S, Hara M, Maeda M. Two-dimensional optical feedback control of Euglena confined in closed-type microfluidic channels. LAB ON A CHIP 2011; 11:1933-1940. [PMID: 21491041 DOI: 10.1039/c0lc00719f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We examined two-dimensional (2D) optical feedback control of phototaxis flagellate Euglena cells confined in closed-type microfluidic channels (microaquariums), and demonstrated that the 2D optical feedback enables the control of the density and position of Euglena cells in microaquariums externally, flexibly, and dynamically. Using three types of feedback algorithms, the density of Euglena cells in a specified area can be controlled arbitrarily and dynamically, and more than 70% of the cells can be concentrated into a specified area. Separation of photo-sensitive/insensitive Euglena cells was also demonstrated. Moreover, Euglena-based neuro-computing has been achieved, where 16 imaginary neurons were defined as Euglena-activity levels in 16 individual areas in microaquariums. The study proves that 2D optical feedback control of photoreactive flagellate microbes is promising for microbial biology studies as well as applications such as microbe-based particle transportation in microfluidic channels or separation of photo-sensitive/insensitive microbes.
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Affiliation(s)
- Kazunari Ozasa
- RIKEN Advanced Science Institute, Hirosawa, Wako, Saitama, Japan.
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Daiker V, Häder DP, Richter PR, Lebert M. The involvement of a protein kinase in phototaxis and gravitaxis of Euglena gracilis. PLANTA 2011; 233:1055-1062. [PMID: 21286747 DOI: 10.1007/s00425-011-1364-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 01/14/2011] [Indexed: 05/30/2023]
Abstract
The unicellular flagellate Euglena gracilis shows positive phototaxis at low-light intensities (<10 W/m(2)) and a negative one at higher irradiances (>10 W/m(2)). Phototaxis is based on blue light-activated adenylyl cyclases, which produce cAMP upon irradiation. In the absence of light the cells swim upward in the water column (negative gravitaxis). The results of sounding rocket campaigns and of a large number of ground experiments led to the following model of signal perception and transduction in gravitaxis of E. gracilis: The body of the cell is heavier than the surrounding medium, sediments and thereby exerts a force onto the lower membrane. Upon deviation from a vertical swimming path mechano-sensitive ion channels are activated. Calcium is gated inwards which leads to an increase in the intracellular calcium concentration and causes a change of the membrane potential. After influx, calcium activates one of several calmodulins found in Euglena, which in turn activates an adenylyl cyclase (different from the one involved in phototaxis) to produce cAMP from ATP. One further element in the sensory transduction chain of both phototaxis and gravitaxis is a specific protein kinase A. We found five different protein kinases A in E. gracilis. The blockage of only one of these (PK.4, accession No. EU935859) by means of RNAi inhibited both phototaxis and gravitaxis, while inhibition of the other four affected neither phototaxis nor gravitaxis. It is assumed that cAMP directly activates this protein kinase A which may in turn phosphorylate a protein involved in the flagellar beating mechanism.
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Affiliation(s)
- Viktor Daiker
- Department of Biology, Cell Biology Division, Friedrich-Alexander University, Staudtstr. 5, 91058 Erlangen, Germany
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Ntefidou M, Lüdtke T, Ahmad M, Häder DP. Heterologous expression of photoactivated adenylyl cyclase (PAC) genes from the flagellate Euglena gracilis in insect cells. Photochem Photobiol 2007; 82:1601-5. [PMID: 16939367 DOI: 10.1562/2006-04-06-ra-867] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The unicellular, green flagellate wild-type Euglena gracilis (strain Z) possesses two genes of the photoactivated adenylyl cyclase (PAC) family. The corresponding gene products were found to be responsible for step-up (but not step-down) photophobic responses as well as both positive and negative phototaxis. The proteins consist of two PACalpha (Mr 105 kDa) and two PACbeta (90 kDa) subunits. In an effort to produce sufficient amounts of PAC proteins, several routes of over-expression have been tried including homologous expression in Euglena and heterologous expression in Escherichia coli. All these approaches were hampered by low yield or formation of inclusion bodies. Therefore we decided to attempt a heterologous expression in an insect cell line. PACalpha and PACbeta were separately cloned in the transfer vector pBacPAK9 with a His tag attached. The transfer vector was subsequently cotransfected via baculovirus into the insect cells and amplified. For the expression both recombinant viruses (containing PACbeta and PACbeta, respectively) were cotransfected simultaneously into insect cells. The expressed proteins were analyzed in Western blots using PACalpha and PACbeta antibodies. Most of the proteins were found to be in soluble form in high yield. The recombinant PAC proteins were purified via their attached His tag on an anti-His resin. Adenylyl cyclase activity was quantified after blue-light excitation using a cAMP enzyme immunoassay kit.
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Affiliation(s)
- Maria Ntefidou
- Friedrich-Alexander Universität, Institut für Biologie, Erlangen, Germany
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Ntefidou M, Lüdtke T, Ahmad M, Häder DP. Heterologous Expression of Photoactivated Adenylyl Cyclase (PAC) Genes from the Flagellate Euglena gracilis in Insect Cells. Photochem Photobiol 2006. [DOI: 10.1111/j.1751-1097.2006.tb09818.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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