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Mthethwa-Hlongwa NP, Amoah ID, Gomez A, Davison S, Reddy P, Bux F, Kumari S. Profiling pathogenic protozoan and their functional pathways in wastewater using 18S rRNA and shotgun metagenomics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169602. [PMID: 38154626 DOI: 10.1016/j.scitotenv.2023.169602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 12/20/2023] [Accepted: 12/20/2023] [Indexed: 12/30/2023]
Abstract
Despite extensive research, little is known about the composition of eukaryotic protists in environmental samples. This is due to low parasite concentrations, the complexity of parasite diversity, and a lack of suitable reference databases and standardized protocols. To bridge this knowledge gap, this study used 18S rRNA short amplicon and shotgun metagenomic sequencing approaches to profile protozoan microbial communities as well as their functional pathways in treated and untreated wastewater samples collected from different regions of South Africa. Results demonstrated that protozoan diversity (Shannon index P-value = 0.03) and taxonomic composition (PERMANOVA, P-value = 0.02) was mainly driven by the type of wastewater samples (treated & untreated) and geographic location. However, these WWTPs were also found to contain a core community of protozoan parasites. The untreated wastewater samples revealed a predominant presence of free-living, parasitic, and potentially pathogenic protists typically found in humans and animals, ranging from Alveolata (27 %) phylum (Apicomplexa and Ciliophora) to Excavata (3.88 %) (Discoba and Parasalia) and Amoebozoa (2.84 %) (Entamoeba and Acanthamoeba). Shotgun metagenomics analyses in a subset of the untreated wastewater samples confirmed the presence of public health-importance protozoa, including Cryptosporidium species (3.48 %), Entamoeba hystolitica (6.58 %), Blastocystis hominis (2.91 %), Naegleria gruberi (2.37 %), Toxoplasma gondii (1.98 %), Cyclospora cayetanensis (1.30 %), and Giardia intestinalis (0.31 %). Virulent gene families linked to pathogenic protozoa, such as serine/threonine protein phosphatase and mucin-desulfating sulfatase were identified. Additionally, enriched pathways included thiamine diphosphate biosynthesis III, heme biosynthesis, Methylerythritol 4-Phosphate Pathway, methyl erythritol phosphate (MEP), and pentose phosphate pathways. These findings suggest that protozoan pathogens may possess metabolic and growth potential within WWTPs, posing a severe risk of transmission to humans and animals if inadequately disinfected before release. This study provides a baseline for the future investigation of diverse protozoal communities in wastewater, which are of public health importance.
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Affiliation(s)
- Nonsikelelo P Mthethwa-Hlongwa
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban 4000, South Africa; Department Community Health Studies, Faculty of Health Sciences, Durban University of Technology, Durban 4000, South Africa
| | - Isaac D Amoah
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban 4000, South Africa; Department of Environmental Science, The University of Arizona, Shantz Building Rm 4291177 E 4th St., Tucson, AZ 85721, USA
| | - Andres Gomez
- Department of Animal Science, University of Minnesota, St. Paul, MN, USA
| | - Sam Davison
- Department of Animal Science, University of Minnesota, St. Paul, MN, USA
| | - Poovendhree Reddy
- Department Community Health Studies, Faculty of Health Sciences, Durban University of Technology, Durban 4000, South Africa
| | - Faizal Bux
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban 4000, South Africa
| | - Sheena Kumari
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban 4000, South Africa.
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2
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Plattner H. Ciliate Research. From Myth to Trendsetting Science. J Eukaryot Microbiol 2022; 69:e12926. [PMID: 35608570 DOI: 10.1111/jeu.12926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/18/2022] [Accepted: 05/18/2022] [Indexed: 11/28/2022]
Abstract
This special issue of the Journal of Eukaryotic Microbiology (JEM) summarizes achievements obtained by generations of researchers with ciliates in widely different disciplines. In fact, ciliates range among the first cells seen under the microscope centuries ago. Their beauty made them an object of scientia amabilis and their manifold reactions made them attractive for college experiments and finally challenged causal analyses at the cellular level. Some of this work was honored by a Nobel Prize. Some observations yielded a baseline for additional novel discoveries, occasionally facilitated by specific properties of some ciliates. This also offers some advantage in the exploration of closely related parasites (malaria). Articles contributed here by colleagues from all over the world encompass a broad spectrum of ciliate life, from genetics to evolution, from molecular cell biology to ecology, from intercellular signaling to epigenetics etc. This introductory chapter, largely based on my personal perception, aims at integrating work presented in this special issue of JEM into a broader historical context up to current research.
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3
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Plattner H. Membrane Traffic and Ca 2+ -Signals in Ciliates. J Eukaryot Microbiol 2022; 69:e12895. [PMID: 35156735 DOI: 10.1111/jeu.12895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/01/2022] [Accepted: 02/01/2022] [Indexed: 11/30/2022]
Abstract
A Paramecium cell has as many types of membrane interactions as mammalian cells, as established with monoclonal antibodies by R. Allen and A. Fok. Since then, we have identified key-players, such as SNARE-proteins, Ca2+ -regulating proteins, including Ca2+ -channels, Ca2+ -pumps, Ca2+ -binding proteins of different affinity etc. at the molecular level, probed their function and localized them at the light and electron microscopy level. SNARE-proteins, in conjunction with a synaptotagmin-like Ca2+ -sensor protein, mediate membrane fusion. This interaction is additionally regulated by monomeric GTPases whose spectrum in Tetrahymena and Paramecium has been established by A. Turkewitz. As known from mammalian cells, GTPases are activated on membranes in conjunction with lumenal acidification by an H+ -ATPase. For these complex molecules we found in Paramecium an unsurpassed number of 17 a-subunit paralogs which connect the polymeric head and basis part, V1 and V0. (This multitude may reflect different local functional requirements.) Together with plasmalemmal Ca2+ -influx-channels, locally enriched intracellular InsP3 -type (InsP3 R, mainly in osmoregulatory system) and ryanodine receptor-like Ca2+ -release channels (ryanodine receptor-like proteins, RyR-LP), this complexity mediates Ca2+ signals for most flexible local membrane-to-membrane interactions. As we found, the latter channel types miss a substantial portion of the N-terminal part. Caffeine and 4-chloro-meta-cresol (the agent used to probe mutations of RyRs in man during surgery in malignant insomnia patients) initiate trichocyst exocytosis by activating Ca2+ -release channels type CRC-IV in the peripheral part of alveolar sacs. This is superimposed by Ca2+ -influx, i.e. a mechanism called "store-operated Ca2+ -entry" (SOCE). For the majority of key players, we have mapped paralogs throughout the Paramecium cell, with features in common or at variance in the different organelles participating in vesicle trafficking. Local values of free Ca2+ -concentration, [Ca2+ ]i , and their change, e.g. upon exocytosis stimulation, have been registered by flurochromes and chelator effects. In parallel we have registered release of Ca2+ from alveolar sacs by quenched-flow analysis combined with cryofixation and x-ray microanalysis.
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4
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Cole E, Gaertig J. Anterior-posterior pattern formation in ciliates. J Eukaryot Microbiol 2022; 69:e12890. [PMID: 35075744 PMCID: PMC9309198 DOI: 10.1111/jeu.12890] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/06/2022] [Accepted: 01/17/2022] [Indexed: 11/29/2022]
Abstract
As single cells, ciliates build, duplicate, and even regenerate complex cortical patterns by largely unknown mechanisms that precisely position organelles along two cell‐wide axes: anterior–posterior and circumferential (left–right). We review our current understanding of intracellular patterning along the anterior–posterior axis in ciliates, with emphasis on how the new pattern emerges during cell division. We focus on the recent progress at the molecular level that has been driven by the discovery of genes whose mutations cause organelle positioning defects in the model ciliate Tetrahymena thermophila. These investigations have revealed a network of highly conserved kinases that are confined to either anterior or posterior domains in the cell cortex. These pattern‐regulating kinases create zones of cortical inhibition that by exclusion determine the precise placement of organelles. We discuss observations and models derived from classical microsurgical experiments in large ciliates (including Stentor) and interpret them in light of recent molecular findings in Tetrahymena. In particular, we address the involvement of intracellular gradients as vehicles for positioning organelles along the anterior‐posterior axis.
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Affiliation(s)
- Eric Cole
- Biology Department, St. Olaf College, Northfield, MN, USA
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
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5
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Pereira PHS, Borges-Pereira L, Garcia CRS. Evidences of G Coupled-Protein Receptor (GPCR) Signaling in the human Malaria Parasite Plasmodium falciparum for Sensing its Microenvironment and the Role of Purinergic Signaling in Malaria Parasites. Curr Top Med Chem 2021; 21:171-180. [PMID: 32851963 DOI: 10.2174/1568026620666200826122716] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/15/2020] [Accepted: 07/20/2020] [Indexed: 11/22/2022]
Abstract
The nucleotides were discovered in the early 19th century and a few years later, the role of such molecules in energy metabolism and cell survival was postulated. In 1972, a pioneer work by Burnstock and colleagues suggested that ATP could also work as a neurotransmitter, which was known as the "purinergic hypothesis". The idea of ATP working as a signaling molecule faced initial resistance until the discovery of the receptors for ATP and other nucleotides, called purinergic receptors. Among the purinergic receptors, the P2Y family is of great importance because it comprises of G proteincoupled receptors (GPCRs). GPCRs are widespread among different organisms. These receptors work in the cells' ability to sense the external environment, which involves: to sense a dangerous situation or detect a pheromone through smell; the taste of food that should not be eaten; response to hormones that alter metabolism according to the body's need; or even transform light into an electrical stimulus to generate vision. Advances in understanding the mechanism of action of GPCRs shed light on increasingly promising treatments for diseases that have hitherto remained incurable, or the possibility of abolishing side effects from therapies widely used today.
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Affiliation(s)
- Pedro H S Pereira
- Department of Clinical and Toxicological Analyses, University of Sao Paulo, Sao Paulo, Brazil
| | - Lucas Borges-Pereira
- Department of Clinical and Toxicological Analyses, University of Sao Paulo, Sao Paulo, Brazil
| | - Célia R S Garcia
- Department of Clinical and Toxicological Analyses, University of Sao Paulo, Sao Paulo, Brazil
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6
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Hamilton E, Cicuta P. Changes in geometrical aspects of a simple model of cilia synchronization control the dynamical state, a possible mechanism for switching of swimming gaits in microswimmers. PLoS One 2021; 16:e0249060. [PMID: 33831025 PMCID: PMC8031381 DOI: 10.1371/journal.pone.0249060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 03/10/2021] [Indexed: 12/23/2022] Open
Abstract
Active oscillators, with purely hydrodynamic coupling, are useful simple models to understand various aspects of motile cilia synchronization. Motile cilia are used by microorganisms to swim and to control the flow fields in their surroundings; the patterns observed in cilia carpets can be remarkably complex, and can be changed over time by the organism. It is often not known to what extent the coupling between cilia is due to just hydrodynamic forces, and neither is it known if it is biological or physical triggers that can change the dynamical collective state. Here we treat this question from a very simplified point of view. We describe three possible mechanisms that enable a switch in the dynamical state, in a simple scenario of a chain of oscillators. We find that shape-change provides the most consistent strategy to control collective dynamics, but also imposing small changes in frequency produces some unique stable states. Demonstrating these effects in the abstract minimal model proves that these could be possible explanations for gait switching seen in ciliated micro organisms like Paramecium and others. Microorganisms with many cilia could in principle be taking advantage of hydrodynamic coupling, to switch their swimming gait through either a shape change that manifests in decreased coupling between groups of cilia, or alterations to the beat style of a small subset of the cilia.
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Affiliation(s)
- Evelyn Hamilton
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Pietro Cicuta
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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7
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Ghartey-Kwansah G, Yin Q, Li Z, Gumpper K, Sun Y, Yang R, Wang D, Jones O, Zhou X, Wang L, Bryant J, Ma J, Boampong JN, Xu X. Calcium-dependent Protein Kinases in Malaria Parasite Development and Infection. Cell Transplant 2021; 29:963689719884888. [PMID: 32180432 PMCID: PMC7444236 DOI: 10.1177/0963689719884888] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Apicomplexan parasites have challenged researchers for nearly a century. A major challenge to developing efficient treatments and vaccines is the parasite's ability to change its cellular and molecular makeup to develop intracellular and extracellular niches in its hosts. Ca2+ signaling is an important messenger for the egress of the malaria parasite from the infected erythrocyte, gametogenesis, ookinete motility in the mosquito, and sporozoite invasion of mammalian hepatocytes. Calcium-dependent protein kinases (CDPKs) have crucial functions in calcium signaling at various stages of the parasite's life cycle; this therefore makes them attractive drug targets against malaria. Here, we summarize the functions of the various CDPK isoforms in relation to the malaria life cycle by emphasizing the molecular mechanism of developmental progression within host tissues. We also discuss the current development of anti-malarial drugs, such as how specific bumped kinase inhibitors (BKIs) for parasite CDPKs have been shown to reduce infection in Toxoplasma gondii, Cryptosporidium parvum, and Plasmodium falciparum. Our suggested combinations of BKIs, artemisinin derivatives with peroxide bridge, and inhibitors on the Ca(2+)-ATPase PfATP6 as a potential target should be inspected further as a treatment against malaria.
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Affiliation(s)
- George Ghartey-Kwansah
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China.,Department of Biomedical Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana.,Authors contributed equally to this article
| | - Qinan Yin
- Clinical Center of National Institutes of Health, Bethesda, MD, USA.,Authors contributed equally to this article
| | - Zhongguang Li
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China.,Ohio State University School of Medicine, Columbus, OH, USA.,Authors contributed equally to this article
| | - Kristyn Gumpper
- Ohio State University School of Medicine, Columbus, OH, USA.,Authors contributed equally to this article
| | - Yuting Sun
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China
| | - Rong Yang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China
| | - Dan Wang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China
| | - Odell Jones
- University of Pennsylvania School of Medicine, Animal Center, Philadelphia, PA, USA
| | - Xin Zhou
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China.,Ohio State University School of Medicine, Columbus, OH, USA
| | - Liyang Wang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China.,Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Joseph Bryant
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jianjie Ma
- Ohio State University School of Medicine, Columbus, OH, USA
| | - Johnson Nyarko Boampong
- Department of Biomedical Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Xuehong Xu
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China, Shaanxi Normal University College of Life Sciences, Xi'an, China
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8
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Scarpelli PH, Pecenin MF, Garcia CRS. Intracellular Ca 2+ Signaling in Protozoan Parasites: An Overview with a Focus on Mitochondria. Int J Mol Sci 2021; 22:ijms22010469. [PMID: 33466510 PMCID: PMC7796463 DOI: 10.3390/ijms22010469] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/07/2020] [Accepted: 12/29/2020] [Indexed: 02/06/2023] Open
Abstract
Ca2+ signaling has been involved in controling critical cellular functions such as activation of proteases, cell death, and cell cycle control. The endoplasmatic reticulum plays a significant role in Ca2+ storage inside the cell, but mitochondria have long been recognized as a fundamental Ca2+ pool. Protozoan parasites such as Plasmodium falciparum, Toxoplasma gondii, and Trypanosoma cruzi display a Ca2+ signaling toolkit with similarities to higher eukaryotes, including the participation of mitochondria in Ca2+-dependent signaling events. This review summarizes the most recent knowledge in mitochondrial Ca2+ signaling in protozoan parasites, focusing on the mechanism involved in mitochondrial Ca2+ uptake by pathogenic protists.
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9
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Abstract
Studying Ca2+ dynamics in protozoan parasites is not an easy task. Loading of parasites with commonly used Ca2+ fluorescent dyes (such as Fuo4-AM) remains as the major protocol to measure the Ca2+ oscillations inside the cell. In this chapter, we describe an alternative method to study Ca2+ signaling in Plasmodium falciparum parasite. This method employs the construction of transgenic parasites (through standard molecular biology techniques), selection of the transfected population, and use of those parasites in spectrofluorometric Ca2+ assays.
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Goodenough U, Roth R, Kariyawasam T, He A, Lee JH. Epiplasts: Membrane Skeletons and Epiplastin Proteins in Euglenids, Glaucophytes, Cryptophytes, Ciliates, Dinoflagellates, and Apicomplexans. mBio 2018; 9:e02020-18. [PMID: 30377285 PMCID: PMC6212826 DOI: 10.1128/mbio.02020-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 01/03/2023] Open
Abstract
Animals and amoebae assemble actin/spectrin-based plasma membrane skeletons, forming what is often called the cell cortex, whereas euglenids and alveolates (ciliates, dinoflagellates, and apicomplexans) have been shown to assemble a thin, viscoelastic, actin/spectrin-free membrane skeleton, here called the epiplast. Epiplasts include a class of proteins, here called the epiplastins, with a head/medial/tail domain organization, whose medial domains have been characterized in previous studies by their low-complexity amino acid composition. We have identified two additional features of the medial domains: a strong enrichment of acid/base amino acid dyads and a predicted β-strand/random coil secondary structure. These features have served to identify members in two additional unicellular eukaryotic radiations-the glaucophytes and cryptophytes-as well as additional members in the alveolates and euglenids. We have analyzed the amino acid composition and domain structure of 219 epiplastin sequences and have used quick-freeze deep-etch electron microscopy to visualize the epiplasts of glaucophytes and cryptophytes. We define epiplastins as proteins encoded in organisms that assemble epiplasts, but epiplastin-like proteins, of unknown function, are also encoded in Insecta, Basidiomycetes, and Caulobacter genomes. We discuss the diverse cellular traits that are supported by epiplasts and propose evolutionary scenarios that are consonant with their distribution in extant eukaryotes.IMPORTANCE Membrane skeletons associate with the inner surface of the plasma membrane to provide support for the fragile lipid bilayer and an elastic framework for the cell itself. Several radiations, including animals, organize such skeletons using actin/spectrin proteins, but four major radiations of eukaryotic unicellular organisms, including disease-causing parasites such as Plasmodium, have been known to construct an alternative and essential skeleton (the epiplast) using a class of proteins that we term epiplastins. We have identified epiplastins in two additional radiations and present images of their epiplasts using electron microscopy. We analyze the sequences and secondary structure of 219 epiplastins and present an in-depth overview and analysis of their known and posited roles in cellular organization and parasite infection. An understanding of epiplast assembly may suggest therapeutic approaches to combat infectious agents such as Plasmodium as well as approaches to the engineering of useful viscoelastic biofilms.
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Affiliation(s)
- Ursula Goodenough
- Department of Biology, Washington University, St. Louis, Missouri, USA
| | - Robyn Roth
- Center for Cellular Imaging, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Thamali Kariyawasam
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amelia He
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jae-Hyeok Lee
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
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11
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Chen F, Zhang L, Lin Z, Cheng ZMM. Identification of a novel fused gene family implicates convergent evolution in eukaryotic calcium signaling. BMC Genomics 2018; 19:306. [PMID: 29703146 PMCID: PMC5924475 DOI: 10.1186/s12864-018-4685-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 04/16/2018] [Indexed: 12/31/2022] Open
Abstract
Background Both calcium signals and protein phosphorylation responses are universal signals in eukaryotic cell signaling. Currently three pathways have been characterized in different eukaryotes converting the Ca2+ signals to the protein phosphorylation responses. All these pathways have based mostly on studies in plants and animals. Results Based on the exploration of genomes and transcriptomes from all the six eukaryotic supergroups, we report here in Metakinetoplastina protists a novel gene family. This family, with a proposed name SCAMK, comprises SnRK3 fused calmodulin-like III kinase genes and was likely evolved through the insertion of a calmodulin-like3 gene into an SnRK3 gene by unequal crossover of homologous chromosomes in meiosis cell. Its origin dated back to the time intersection at least 450 million-year-ago when Excavata parasites, Vertebrata hosts, and Insecta vectors evolved. We also analyzed SCAMK’s unique expression pattern and structure, and proposed it as one of the leading calcium signal conversion pathways in Excavata parasite. These characters made SCAMK gene as a potential drug target for treating human African trypanosomiasis. Conclusions This report identified a novel gene fusion and dated its precise fusion time in Metakinetoplastina protists. This potential fourth eukaryotic calcium signal conversion pathway complements our current knowledge that convergent evolution occurs in eukaryotic calcium signaling. Electronic supplementary material The online version of this article (10.1186/s12864-018-4685-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fei Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; Center for Genomics and Biotechnology; Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology; Ministry of Education Key Laboratory of Genetics, Breeding and Multiple Utilization of Corps; Fujian Agriculture and Forestry University, Fuzhou, 350002, China.,College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.,Department of Plant Sciences, University of Tennessee, Knoxville, 37996, USA
| | - Liangsheng Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops; Center for Genomics and Biotechnology; Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology; Ministry of Education Key Laboratory of Genetics, Breeding and Multiple Utilization of Corps; Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhenguo Lin
- Department of Biology, Saint Louis University, St. Louis, 63103-2010, USA
| | - Zong-Ming Max Cheng
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China. .,Department of Plant Sciences, University of Tennessee, Knoxville, 37996, USA.
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12
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Plattner H, Verkhratsky A. Inseparable tandem: evolution chooses ATP and Ca2+ to control life, death and cellular signalling. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0419. [PMID: 27377729 DOI: 10.1098/rstb.2015.0419] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2016] [Indexed: 01/01/2023] Open
Abstract
From the very dawn of biological evolution, ATP was selected as a multipurpose energy-storing molecule. Metabolism of ATP required intracellular free Ca(2+) to be set at exceedingly low concentrations, which in turn provided the background for the role of Ca(2+) as a universal signalling molecule. The early-eukaryote life forms also evolved functional compartmentalization and vesicle trafficking, which used Ca(2+) as a universal signalling ion; similarly, Ca(2+) is needed for regulation of ciliary and flagellar beat, amoeboid movement, intracellular transport, as well as of numerous metabolic processes. Thus, during evolution, exploitation of atmospheric oxygen and increasingly efficient ATP production via oxidative phosphorylation by bacterial endosymbionts were a first step for the emergence of complex eukaryotic cells. Simultaneously, Ca(2+) started to be exploited for short-range signalling, despite restrictions by the preset phosphate-based energy metabolism, when both phosphates and Ca(2+) interfere with each other because of the low solubility of calcium phosphates. The need to keep cytosolic Ca(2+) low forced cells to restrict Ca(2+) signals in space and time and to develop energetically favourable Ca(2+) signalling and Ca(2+) microdomains. These steps in tandem dominated further evolution. The ATP molecule (often released by Ca(2+)-regulated exocytosis) rapidly grew to be the universal chemical messenger for intercellular communication; ATP effects are mediated by an extended family of purinoceptors often linked to Ca(2+) signalling. Similar to atmospheric oxygen, Ca(2+) must have been reverted from a deleterious agent to a most useful (intra- and extracellular) signalling molecule. Invention of intracellular trafficking further increased the role for Ca(2+) homeostasis that became critical for regulation of cell survival and cell death. Several mutually interdependent effects of Ca(2+) and ATP have been exploited in evolution, thus turning an originally unholy alliance into a fascinating success story.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'.
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Alexei Verkhratsky
- Faculty of Biological Sciences, University of Manchester, Manchester M13 9PT, UK Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia
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13
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Suárez-Cortés P, Gambara G, Favia A, Palombi F, Alano P, Filippini A. Ned-19 inhibition of parasite growth and multiplication suggests a role for NAADP mediated signalling in the asexual development of Plasmodium falciparum. Malar J 2017; 16:366. [PMID: 28899381 PMCID: PMC5596470 DOI: 10.1186/s12936-017-2013-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 09/04/2017] [Indexed: 11/26/2022] Open
Abstract
Background Although malaria is a preventable and curable human disease, millions of people risk to be infected by the Plasmodium parasites and to develop this illness. Therefore, there is an urgent need to identify new anti-malarial drugs. Ca2+ signalling regulates different processes in the life cycle of Plasmodium falciparum, representing a suitable target for the development of new drugs. Results This study investigated for the first time the effect of a highly specific inhibitor of nicotinic acid adenine dinucleotide phosphate (NAADP)-induced Ca2+ release (Ned-19) on P. falciparum, revealing the inhibitory effect of this compound on the blood stage development of this parasite. Ned-19 inhibits both the transition of the parasite from the early to the late trophozoite stage and the ability of the late trophozoite to develop to the multinucleated schizont stage. In addition, Ned-19 affects spontaneous intracellular Ca2+ oscillations in ring and trophozoite stage parasites, suggesting that the observed inhibitory effects may be associated to regulation of intracellular Ca2+ levels. Conclusions This study highlights the inhibitory effect of Ned-19 on progression of the asexual life cycle of P. falciparum. The observation that Ned-19 inhibits spontaneous Ca2+ oscillations suggests a potential role of NAADP in regulating Ca2+ signalling of P. falciparum. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-2013-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pablo Suárez-Cortés
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Viale Regina Elena n. 299, 00161, Rome, Italy.,Department of Vector Biology, Max-Planck Institute for Infection Biology, Charitéplatz 1, 10117, Berlin, Germany
| | - Guido Gambara
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Annarita Favia
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy.,Nucleic Acids Laboratory, Institute of Molecular Biology and Pathology, National Research Council (IBPM-CNR), Department of Biology and Biotechnologies, Sapienza University, Rome, Italy
| | - Fioretta Palombi
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Pietro Alano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Viale Regina Elena n. 299, 00161, Rome, Italy.
| | - Antonio Filippini
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy.
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14
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Garcia CRS, Alves E, Pereira PHS, Bartlett PJ, Thomas AP, Mikoshiba K, Plattner H, Sibley LD. InsP3 Signaling in Apicomplexan Parasites. Curr Top Med Chem 2017; 17:2158-2165. [PMID: 28137231 PMCID: PMC5490149 DOI: 10.2174/1568026617666170130121042] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/20/2016] [Accepted: 10/30/2016] [Indexed: 11/22/2022]
Abstract
Background:
Phosphoinositides (PIs) and their derivatives are essential cellular components that form the building blocks for cell membranes and regulate numerous cell functions. Specifically, the ability to generate myo-inositol 1,4,5-trisphosphate (InsP3) via phospholipase C (PLC) dependent hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) to InsP3 and diacylglycerol (DAG) initiates intracellular calcium signaling events representing a fundamental signaling mechanism dependent on PIs. InsP3 produced by PI turnover as a second messenger causes intracellular calcium release, especially from endoplasmic reticulum, by binding to the InsP3 receptor (InsP3R). Various PIs and the enzymes, such as phosphatidylinositol synthase and phosphatidylinositol 4-kinase, necessary for their turnover have been characterized in Apicomplexa, a large phylum of mostly commensal organisms that also includes several clinically relevant parasites. However, InsP3Rs have not been identified in genomes of apicomplexans, despite evidence that these parasites produce InsP3 that mediates intracellular Ca2+ signaling. Conclusion: Evidence to supporting IP3-dependent signaling cascades in apicomplexans suggests that they may harbor a primitive or non-canonical InsP3R. Understanding these pathways may be informative about early branching eukaryotes, where such signaling pathways also diverge from animal systems, thus identifying potential novel and essential targets for therapeutic intervention.
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Affiliation(s)
- Celia R S Garcia
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo. Sao Paulo 05508-090, Brazil
| | - Eduardo Alves
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo. Sao Paulo 05508-000, Brazil
| | - Pedro H S Pereira
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo. Sao Paulo 05508-090, Brazil,Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo. Sao Paulo 05508-000, Brazil
| | - Paula J Bartlett
- New Jersey Medical School, Rutgers, The State University of New Jersey, New Jersey, USA
| | - Andrew P Thomas
- New Jersey Medical School, Rutgers, The State University of New Jersey, New Jersey, USA
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Wako, Saitama, Japan
| | - Helmut Plattner
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - L David Sibley
- Department of Molecular Microbiology, Washington University Sch. Med., Saint Louis, USA
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15
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Beckmann L, Edel KH, Batistič O, Kudla J. A calcium sensor - protein kinase signaling module diversified in plants and is retained in all lineages of Bikonta species. Sci Rep 2016; 6:31645. [PMID: 27538881 PMCID: PMC4990929 DOI: 10.1038/srep31645] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 07/21/2016] [Indexed: 01/09/2023] Open
Abstract
Calcium (Ca2+) signaling is a universal mechanism of signal transduction and involves Ca2+ signal formation and decoding of information by Ca2+ binding proteins. Calcineurin B-like proteins (CBLs), which upon Ca2+ binding activate CBL-interacting protein kinases (CIPKs) regulate a multitude of physiological processes in plants. Here, we combine phylogenomics and functional analyses to investigate the occurrence and structural conservation of CBL and CIPK proteins in 26 species representing all major clades of eukaryotes. We demonstrate the presence of at least singular CBL-CIPK pairs in representatives of Archaeplastida, Chromalveolates and Excavates and their general absence in Opisthokonta and Amoebozoa. This denotes CBL-CIPK complexes as evolutionary ancient Ca2+ signaling modules that likely evolved in the ancestor of all Bikonta. Furthermore, we functionally characterize the CBLs and CIPK from the parabasalid human pathogen Trichomonas vaginalis. Our results reveal strict evolutionary conservation of functionally important structural features, preservation of biochemical properties and a remarkable cross-kingdom protein-protein interaction potential between CBLs and CIPKs from Arabidopsis thaliana and T. vaginalis. Together our findings suggest an ancient evolutionary origin of a functional CBL-CIPK signaling module close to the root of eukaryotic evolution and provide insights into the initial evolution of signaling networks and Ca2+ signaling specificity.
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Affiliation(s)
- Linda Beckmann
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, 48149 Münster, Germany
| | - Kai H Edel
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, 48149 Münster, Germany
| | - Oliver Batistič
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, 48149 Münster, Germany
| | - Jörg Kudla
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, 48149 Münster, Germany.,College of Science, King Saud University, Riyadh 11451, Kingdom of Saudi Arabia
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16
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Xiao B, Kuang Z, Zhan Y, Chen D, Gao Y, Li M, Luo S, Hao W. A Novel Polyclonal Antiserum against Toxoplasma gondii Sodium Hydrogen Exchanger 1. THE KOREAN JOURNAL OF PARASITOLOGY 2016; 54:21-9. [PMID: 26951975 PMCID: PMC4792324 DOI: 10.3347/kjp.2016.54.1.21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/21/2015] [Accepted: 12/29/2015] [Indexed: 11/23/2022]
Abstract
The sodium hydrogen exchanger 1 (NHE1), which functions in maintaining the ratio of Na+ and H+ ions, is widely distributed in cell plasma membranes. It plays a prominent role in pH balancing, cell proliferation, differentiation, adhesion, and migration. However, its exact subcellular location and biological functions in Toxoplasma gondii are largely unclear. In this study, we cloned the C-terminal sequence of T. gondii NHE1 (TgNHE1) incorporating the C-terminal peptide of NHE1 (C-NHE1) into the pGEX4T-1 expression plasmid. The peptide sequence was predicted to have good antigenicity based on the information obtained from an immune epitope database. After induction of heterologous gene expression with isopropyl-b-D-thiogalactoside, the recombinant C-NHE1 protein successfully expressed in a soluble form was purified by glutathione sepharose beads as an immunogen for production of a rabbit polyclonal antiserum. The specificity of this antiserum was confirmed by western blotting and immunofluorescence. The antiserum could reduce T. gondii invasion into host cells, indicated by the decreased TgNHE1 expression in T. gondii parasites that were pre-incubated with antiserum in the process of cell entry. Furthermore, the antiserum reduced the virulence of T. gondii parasites to host cells in vitro, possibly by blocking the release of Ca2+. In this regard, this antiserum has potential to be a valuable tool for further studies of TgNHE1.
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Affiliation(s)
- Bin Xiao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Zhenzhan Kuang
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Yanli Zhan
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Daxiang Chen
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Yang Gao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Ming Li
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Shuhong Luo
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Wenbo Hao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
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17
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Presence of an isoform of H+-pyrophosphatase located in the alveolar sacs of a scuticociliate parasite of turbot: physiological consequences. Parasitology 2016; 143:576-87. [DOI: 10.1017/s0031182015001997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
SUMMARYH+-pyrophosphatases (H+-PPases) are integral membrane proteins that couple pyrophosphate energy to an electrochemical gradient across biological membranes and promote the acidification of cellular compartments. Eukaryotic organisms, essentially plants and protozoan parasites, contain various types of H+-PPases associated with vacuoles, plasma membrane and acidic Ca+2storage organelles called acidocalcisomes. We used Lysotracker Red DND-99 staining to identify two acidic cellular compartments in trophozoites of the marine scuticociliate parasitePhilasterides dicentrarchi: the phagocytic vacuoles and the alveolar sacs. The membranes of these compartments also contain H+-PPase, which may promote acidification of these cell structures. We also demonstrated for the first time that theP. dicentrarchiH+-PPase has two isoforms: H+-PPase 1 and 2. Isoform 2, which is probably generated by splicing, is located in the membranes of the alveolar sacs and has an amino acid motif recognized by the H+-PPase-specific antibody PABHK. The amino acid sequences of different isolates of this ciliate are highly conserved. Gene and protein expression in this isoform are significantly regulated by variations in salinity, indicating a possible physiological role of this enzyme and the alveolar sacs in osmoregulation and salt tolerance inP. dicentrarchi.
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18
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Lu Y, Wohlrab S, Groth M, Glöckner G, Guillou L, John U. Transcriptomic profiling of Alexandrium fundyense
during physical interaction with or exposure to chemical signals from the parasite Amoebophrya. Mol Ecol 2016; 25:1294-307. [DOI: 10.1111/mec.13566] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 01/08/2016] [Accepted: 01/26/2016] [Indexed: 01/02/2023]
Affiliation(s)
- Yameng Lu
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung; Bremerhaven Germany
| | - Sylke Wohlrab
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung; Bremerhaven Germany
| | - Marco Groth
- Leibniz-Institute for Age Research; Fritz Lipmann Institute Jena; Jena Germany
| | - Gernot Glöckner
- Biochemistry I; Medical Faculty; University of Cologne and Institute for Freshwater Ecology and Inland Fisheries (IGB); Berlin Germany
| | - Laure Guillou
- Laboratoire Adaptation et Diversité en Milieu Marin; CNRS; UMR 7144, Place Georges Teissier, CS90074 29688 Roscoff Cedex France
- Université Pierre et Marie Curie-Paris 6; Sorbonne Universités; UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, CS90074 29688 Roscoff Cedex France
| | - Uwe John
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung; Bremerhaven Germany
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19
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Mallo N, Lamas J, DeFelipe AP, Sueiro RA, Fontenla F, Leiro JM. Enzymes Involved in Pyrophosphate and Calcium Metabolism as Targets for Anti-scuticociliate Chemotherapy. J Eukaryot Microbiol 2016; 63:505-15. [DOI: 10.1111/jeu.12294] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 12/18/2015] [Accepted: 01/05/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Natalia Mallo
- Departamento de Microbiología y Parasitología; Instituto de Investigación y Análisis Alimentarios; Universidad de Santiago de Compostela; Santiago de Compostela Spain
| | - Jesús Lamas
- Departamento de Biología Celular y Ecología; Facultad de Biología; Instituto de Acuicultura; Universidad de Santiago de Compostela; Santiago de Compostela Spain
| | - Ana-Paula DeFelipe
- Departamento de Microbiología y Parasitología; Instituto de Investigación y Análisis Alimentarios; Universidad de Santiago de Compostela; Santiago de Compostela Spain
| | - Rosa-Ana Sueiro
- Departamento de Microbiología y Parasitología; Instituto de Investigación y Análisis Alimentarios; Universidad de Santiago de Compostela; Santiago de Compostela Spain
- Departamento de Biología Celular y Ecología; Facultad de Biología; Instituto de Acuicultura; Universidad de Santiago de Compostela; Santiago de Compostela Spain
| | - Francisco Fontenla
- Departamento de Biología Celular y Ecología; Facultad de Biología; Instituto de Acuicultura; Universidad de Santiago de Compostela; Santiago de Compostela Spain
| | - José-Manuel Leiro
- Departamento de Microbiología y Parasitología; Instituto de Investigación y Análisis Alimentarios; Universidad de Santiago de Compostela; Santiago de Compostela Spain
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20
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Diversity of extracellular proteins during the transition from the ‘proto-apicomplexan’ alveolates to the apicomplexan obligate parasites. Parasitology 2015; 143:1-17. [DOI: 10.1017/s0031182015001213] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
SUMMARYThe recent completion of high-coverage draft genome sequences for several alveolate protozoans – namely, the chromerids, Chromera velia and Vitrella brassicaformis; the perkinsid Perkinsus marinus; the apicomplexan, Gregarina niphandrodes, as well as high coverage transcriptome sequence information for several colpodellids, allows for new genome-scale comparisons across a rich landscape of apicomplexans and other alveolates. Genome annotations can now be used to help interpret fine ultrastructure and cell biology, and guide new studies to describe a variety of alveolate life strategies, such as symbiosis or free living, predation, and obligate intracellular parasitism, as well to provide foundations to dissect the evolutionary transitions between these niches. This review focuses on the attempt to identify extracellular proteins which might mediate the physical interface of cell–cell interactions within the above life strategies, aided by annotation of the repertoires of predicted surface and secreted proteins encoded within alveolate genomes. In particular, we discuss what descriptions of the predicted extracellular proteomes reveal regarding a hypothetical last common ancestor of a pre-apicomplexan alveolate – guided by ultrastructure, life strategies and phylogenetic relationships – in an attempt to understand the evolution of obligate parasitism in apicomplexans.
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21
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Plattner H. Signalling in ciliates: long- and short-range signals and molecular determinants for cellular dynamics. Biol Rev Camb Philos Soc 2015; 92:60-107. [PMID: 26487631 DOI: 10.1111/brv.12218] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 07/28/2015] [Accepted: 08/21/2015] [Indexed: 12/30/2022]
Abstract
In ciliates, unicellular representatives of the bikont branch of evolution, inter- and intracellular signalling pathways have been analysed mainly in Paramecium tetraurelia, Paramecium multimicronucleatum and Tetrahymena thermophila and in part also in Euplotes raikovi. Electrophysiology of ciliary activity in Paramecium spp. is a most successful example. Established signalling mechanisms include plasmalemmal ion channels, recently established intracellular Ca2+ -release channels, as well as signalling by cyclic nucleotides and Ca2+ . Ca2+ -binding proteins (calmodulin, centrin) and Ca2+ -activated enzymes (kinases, phosphatases) are involved. Many organelles are endowed with specific molecules cooperating in signalling for intracellular transport and targeted delivery. Among them are recently specified soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), monomeric GTPases, H+ -ATPase/pump, actin, etc. Little specification is available for some key signal transducers including mechanosensitive Ca2+ -channels, exocyst complexes and Ca2+ -sensor proteins for vesicle-vesicle/membrane interactions. The existence of heterotrimeric G-proteins and of G-protein-coupled receptors is still under considerable debate. Serine/threonine kinases dominate by far over tyrosine kinases (some predicted by phosphoproteomic analyses). Besides short-range signalling, long-range signalling also exists, e.g. as firmly installed microtubular transport rails within epigenetically determined patterns, thus facilitating targeted vesicle delivery. By envisaging widely different phenomena of signalling and subcellular dynamics, it will be shown (i) that important pathways of signalling and cellular dynamics are established already in ciliates, (ii) that some mechanisms diverge from higher eukaryotes and (iii) that considerable uncertainties still exist about some essential aspects of signalling.
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, PO Box M625, 78457, Konstanz, Germany
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22
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Abstract
Toxoplasmosis is the clinical and pathological consequence of acute infection with the obligate intracellular apicomplexan parasite Toxoplasma gondii. Symptoms result from tissue destruction that accompanies lytic parasite growth. This review updates current understanding of the host cell invasion, parasite replication, and eventual egress that constitute the lytic cycle, as well as the ways T. gondii manipulates host cells to ensure its survival. Since the publication of a previous iteration of this review 15 years ago, important advances have been made in our molecular understanding of parasite growth and mechanisms of host cell egress, and knowledge of the parasite's manipulation of the host has rapidly progressed. Here we cover molecular advances and current conceptual frameworks that include each of these topics, with an eye to what may be known 15 years from now.
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Affiliation(s)
- Ira J Blader
- Department of Microbiology and Immunology, University at Buffalo, Buffalo, New York 14127;
| | - Bradley I Coleman
- Department of Biology, Boston College, Chestnut Hill, Massachusetts 02467; , ,
| | - Chun-Ti Chen
- Department of Biology, Boston College, Chestnut Hill, Massachusetts 02467; , ,
| | - Marc-Jan Gubbels
- Department of Biology, Boston College, Chestnut Hill, Massachusetts 02467; , ,
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23
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Plattner H. Molecular aspects of calcium signalling at the crossroads of unikont and bikont eukaryote evolution – The ciliated protozoan Paramecium in focus. Cell Calcium 2015; 57:174-85. [DOI: 10.1016/j.ceca.2014.12.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 12/01/2014] [Accepted: 12/02/2014] [Indexed: 12/19/2022]
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Plattner H, Verkhratsky A. The ancient roots of calcium signalling evolutionary tree. Cell Calcium 2015; 57:123-32. [DOI: 10.1016/j.ceca.2014.12.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 12/05/2014] [Indexed: 12/26/2022]
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25
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Evolution of acidic Ca2+ stores and their resident Ca2+-permeable channels. Cell Calcium 2015; 57:222-30. [DOI: 10.1016/j.ceca.2014.12.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/05/2014] [Accepted: 12/09/2014] [Indexed: 11/18/2022]
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26
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Kumar U, Saier MH. Comparative Genomic Analysis of Integral Membrane Transport Proteins in Ciliates. J Eukaryot Microbiol 2014; 62:167-87. [DOI: 10.1111/jeu.12156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 04/23/2014] [Accepted: 04/28/2014] [Indexed: 11/25/2022]
Affiliation(s)
- Ujjwal Kumar
- Division of Biological Sciences; University of California at San Diego; La Jolla California
| | - Milton H. Saier
- Division of Biological Sciences; University of California at San Diego; La Jolla California
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27
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Plattner H. Calcium signalling in the ciliated protozoan model, Paramecium: strict signal localisation by epigenetically controlled positioning of different Ca²⁺-channels. Cell Calcium 2014; 57:203-13. [PMID: 25277862 DOI: 10.1016/j.ceca.2014.09.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 09/01/2014] [Indexed: 11/17/2022]
Abstract
The Paramecium tetraurelia cell is highly organised, with regularly spaced elements pertinent to Ca(2+) signalling under epigenetic control. Vesicles serving as stationary Ca(2+) stores or undergoing trafficking contain Ca(2+)-release channels (PtCRCs) which, according to sequence and domain comparison, are related either to inositol 1,4,5-trisphosphate (InsP3) receptors (IP3R) or to ryanodine receptor-like proteins (RyR-LP) or to both, with intermediate characteristics or deviation from conventional domain structure. Six groups of such PtCRCs have been found. The ryanodine-InsP3-receptor homology (RIH) domain is not always recognisable, in contrast to the channel domain with six trans-membrane domains and the pore between transmembrane domain 5 and 6. Two CRC subtypes tested more closely, PtCRC-II and PtCRC-IV, with and without an InsP3-binding domain, reacted to InsP3 and to caffeine, respectively, and hence represent IP3Rs and RyR-LPs. IP3Rs occur in the contractile vacuole complex where they allow for stochastic constitutive Ca(2+) reflux into the cytosol. RyR-LPs are localised to cortical Ca(2+) stores; they are engaged in dense core-secretory vesicle exocytosis by Ca(2+) release, superimposed by Ca(2+)-influx via non-ciliary Ca(2+)-channels. One or two different types of PtCRCs also occur in other vesicles undergoing trafficking. Since the PtCRCs described combine different features they are considered derivatives of primitive precursors. The highly regular, epigenetically controlled design of a Paramecium cell allows it to make Ca(2+) available very locally, in a most efficient way, along predetermined trafficking pathways, including regulation of exocytosis, endocytosis, phagocytosis and recycling phenomena. The activity of cilia is also regulated by Ca(2+), yet independently from any CRCs, by de- and hyperpolarisation of the cell membrane potential.
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, P.O. Box M625, 78457 Konstanz, Germany.
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28
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Briguglio JS, Turkewitz AP. Tetrahymena thermophila: a divergent perspective on membrane traffic. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2014; 322:500-16. [PMID: 24634411 DOI: 10.1002/jez.b.22564] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 01/13/2014] [Accepted: 01/22/2014] [Indexed: 12/12/2022]
Abstract
Tetrahymena thermophila, a member of the Ciliates, represents a class of organisms distantly related from commonly used model organisms in cell biology, and thus offers an opportunity to explore potentially novel mechanisms and their evolution. Ciliates, like all eukaryotes, possess a complex network of organelles that facilitate both macromolecular uptake and secretion. The underlying endocytic and exocytic pathways are key mediators of a cell's interaction with its environment, and may therefore show niche-specific adaptations. Our laboratory has taken a variety of approaches to identify key molecular determinants for membrane trafficking pathways in Tetrahymena. Studies of Rab GTPases, dynamins, and sortilin-family receptors substantiate the widespread conservation of some features but also uncover surprising roles for lineage-restricted innovation.
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Affiliation(s)
- Joseph S Briguglio
- The Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois
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29
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Simon M, Plattner H. Unicellular Eukaryotes as Models in Cell and Molecular Biology. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 309:141-98. [DOI: 10.1016/b978-0-12-800255-1.00003-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Araujo N, Afonso R, Bringela A, Cancela M, Cristiano M, Leite R. Peroxides with antiplasmodial activity inhibit proliferation of Perkinsus olseni, the causative agent of Perkinsosis in bivalves. Parasitol Int 2013; 62:575-82. [DOI: 10.1016/j.parint.2013.06.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 06/15/2013] [Accepted: 06/17/2013] [Indexed: 11/25/2022]
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Abstract
Ca(2+)-signaling pathways and intracellular Ca(2+) channels are present in protozoa. Ancient origin of inositol 1,4,5-trisphosphate receptors (IP3Rs) and other intracellular channels predates the divergence of animals and fungi as evidenced by their presence in the choanoflagellate Monosiga brevicollis, the closest known relative to metazoans. The first protozoan IP3R cloned, from the ciliate Paramecium, displays strong sequence similarity to the rat type 3 IP3R. This ciliate has a large number of IP3- and ryanodine(Ry)-like receptors in six subfamilies suggesting the evolutionary adaptation to local requirements for an expanding diversification of vesicle trafficking. IP3Rs have also been functionally characterized in trypanosomatids, where they are essential for growth, differentiation, and establishment of infection. The presence of the mitochondrial calcium uniporter (MCU) in a number of protozoa indicates that mitochondrial regulation of Ca(2+) signaling is also an early appearance in evolution, and contributed to the discovery of the molecular nature of this channel in mammalian cells. There is only sequence evidence for the occurrence of two-pore channels (TPCs), transient receptor potential Ca(2+) channels (TRPCs) and intracellular mechanosensitive Ca(2+)-channels in Paramecium and in parasitic protozoa.
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Plattner H. Calcium regulation in the protozoan model, Paramecium tetraurelia. J Eukaryot Microbiol 2013; 61:95-114. [PMID: 24001309 DOI: 10.1111/jeu.12070] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 06/21/2013] [Accepted: 06/28/2013] [Indexed: 01/24/2023]
Abstract
Early in eukaryotic evolution, the cell has evolved a considerable inventory of proteins engaged in the regulation of intracellular Ca(2+) concentrations, not only to avoid toxic effects but beyond that to exploit the signaling capacity of Ca(2+) by small changes in local concentration. Among protozoa, the ciliate Paramecium may now be one of the best analyzed models. Ciliary activity and exo-/endocytosis are governed by Ca(2+) , the latter by Ca(2+) mobilization from alveolar sacs and a superimposed store-operated Ca(2+) -influx. Paramecium cells possess plasma membrane- and endoplasmic reticulum-resident Ca(2+) -ATPases/pumps (PMCA, SERCA), a variety of Ca(2+) influx channels, including mechanosensitive and voltage-dependent channels in the plasma membrane, furthermore a plethora of Ca(2+) -release channels (CRC) of the inositol 1,4,5-trisphosphate and ryanodine receptor type in different compartments, notably the contractile vacuole complex and the alveolar sacs, as well as in vesicles participating in vesicular trafficking. Additional types of CRC probably also occur but they have not been identified at a molecular level as yet, as is the equivalent of synaptotagmin as a Ca(2+) sensor for exocytosis. Among established targets and sensors of Ca(2+) in Paramecium are calmodulin, calcineurin, as well as Ca(2+) /calmodulin-dependent protein kinases, all with multiple functions. Thus, basic elements of Ca(2+) signaling are available for Paramecium.
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, P.O. Box 5544, 78457, Konstanz, Germany
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Plattner H. The contractile vacuole complex of protists--new cues to function and biogenesis. Crit Rev Microbiol 2013; 41:218-27. [PMID: 23919298 DOI: 10.3109/1040841x.2013.821650] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The contractile vacuole complex (CVC) of freshwater protists sequesters the excess of water and ions (Ca(2+)) for exocytosis cycles at the pore. Sequestration is based on a chemiosmotic proton gradient produced by a V-type H(+)-ATPase. So far, many pieces of information available have not been combined to a comprehensive view on CVC biogenesis and function. One main function now appears as follows. Ca(2+)-release channels, type inositol 1,4,5-trisphosphate receptors (InsP3R), may serve for fine-tuning of local cytosolic Ca(2+) concentration and mediate numerous membrane-to-membrane interactions within the tubular spongiome meshwork. Such activity is suggested by the occurrence of organelle-specific soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) and Ras-related in brain (Rab) proteins, which may regulate functional requirements. For tubulation, F-Bin-amphiphysin-Rvs (F-BAR) proteins are available. In addition, there is indirect evidence for the occurrence of H(+)/Ca(2+) exchangers (to sequester Ca(2+)) and mechanosensitive Ca(2+)-channels (for signaling the filling sate). The periodic activity of the CVC may be regulated by the mechanosensitive Ca(2+)-channels. Such channels are known to colocalize with and to be functionally supported by stomatins, which were recently detected in the CVC. A Kif18-related kinesin motor protein might control the length of radial arms. Two additional InsP3-related channels and several SNAREs are associated with the pore. De novo organelle biogenesis occurs under epigenetic control during mitotic activity and may involve the assembly of γ-tubulin, centrin, calmodulin and a never in mitosis A-type (NIMA) kinase - components also engaged in mitotic processes.
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz , Konstanz , Germany
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Abstract
Early in evolution, Ca(2+) emerged as the most important second messenger for regulating widely different cellular functions. In eukaryotic cells Ca(2+) signals originate from several sources, i.e. influx from the outside medium, release from internal stores or from both. In mammalian cells, Ca(2+)-release channels represented by inositol 1,4,5-trisphosphate receptors and ryanodine receptors (InsP3R and RyR, respectively) are the most important. In unicellular organisms and plants, these channels are characterised with much less precision. In the ciliated protozoan, Paramecium tetraurelia, 34 molecularly distinct Ca(2+)-release channels that can be grouped in six subfamilies, based on criteria such as domain structure, pore, selectivity filter and activation mechanism have been identified. Some of these channels are genuine InsP3Rs and some are related to RyRs. Others show some--but not all--features that are characteristic for one or the other type of release channel. Localisation and gene silencing experiments revealed widely different--yet distinct--localisation, activation and functional engagement of the different Ca(2+)-release channels. Here, we shall discuss early evolutionary routes of Ca(2+)-release machinery in protozoa and demonstrate that detailed domain analyses and scrutinised functional analyses are instrumental for in-depth evolutionary mapping of Ca(2+)-release channels in unicellular organisms.
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Affiliation(s)
- Helmut Plattner
- Faculty of Biology, University of Konstanz, 78457 Konstanz, Germany.
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The Plasmodium berghei Ca(2+)/H(+) exchanger, PbCAX, is essential for tolerance to environmental Ca(2+) during sexual development. PLoS Pathog 2013; 9:e1003191. [PMID: 23468629 PMCID: PMC3585132 DOI: 10.1371/journal.ppat.1003191] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 12/28/2012] [Indexed: 12/15/2022] Open
Abstract
Ca(2+) contributes to a myriad of important cellular processes in all organisms, including the apicomplexans, Plasmodium and Toxoplasma. Due to its varied and essential roles, free Ca(2+) is tightly regulated by complex mechanisms. These mechanisms are therefore of interest as putative drug targets. One pathway in Ca(2+) homeostatic control in apicomplexans uses a Ca(2+)/H(+) exchanger (a member of the cation exchanger family, CAX). The P. falciparum CAX (PfCAX) has recently been characterised in asexual blood stage parasites. To determine the physiological importance of apicomplexan CAXs, tagging and knock-out strategies were undertaken in the genetically tractable T. gondii and P. berghei parasites. In addition, a yeast heterologous expression system was used to study the function of apicomplexan CAXs. Tagging of T. gondii and P. berghei CAXs (TgCAX and PbCAX) under control of their endogenous promoters could not demonstrate measureable expression of either CAX in tachyzoites and asexual blood stages, respectively. These results were consistent with the ability of parasites to tolerate knock-outs of the genes for TgCAX and PbCAX at these developmental stages. In contrast, PbCAX expression was detectable during sexual stages of development in female gametocytes/gametes, zygotes and ookinetes, where it was dispersed in membranous networks within the cytosol (with minimal mitochondrial localisation). Furthermore, genetically disrupted parasites failed to develop further from "round" form zygotes, suggesting that PbCAX is essential for ookinete development and differentiation. This impeded phenotype could be rescued by removal of extracellular Ca(2+). Therefore, PbCAX provides a mechanism for free living parasites to multiply within the ionic microenvironment of the mosquito midgut. Ca(2+) homeostasis mediated by PbCAX is critical and suggests plasmodial CAXs may be targeted in approaches designed to block parasite transmission.
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Identification, localization, and functional implications of the microdomain-forming stomatin family in the ciliated protozoan Paramecium tetraurelia. EUKARYOTIC CELL 2013; 12:529-44. [PMID: 23376944 DOI: 10.1128/ec.00324-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The SPFH protein superfamily is assumed to occur universally in eukaryotes, but information from protozoa is scarce. In the Paramecium genome, we found only Stomatins, 20 paralogs grouped in 8 families, STO1 to STO8. According to cDNA analysis, all are expressed, and molecular modeling shows the typical SPFH domain structure for all subgroups. For further analysis we used family-specific sequences for fluorescence and immunogold labeling, gene silencing, and functional tests. With all family members tested, we found a patchy localization at/near the cell surface and on vesicles. The Sto1p and Sto4p families are also associated with the contractile vacuole complex. Sto4p also makes puncta on some food vacuoles and is abundant on vesicles recycling from the release site of spent food vacuoles to the site of nascent food vacuole formation. Silencing of the STO1 family reduces mechanosensitivity (ciliary reversal upon touching an obstacle), thus suggesting relevance for positioning of mechanosensitive channels in the plasmalemma. Silencing of STO4 members increases pulsation frequency of the contractile vacuole complex and reduces phagocytotic activity of Paramecium cells. In summary, Sto1p and Sto4p members seem to be involved in positioning specific superficial and intracellular microdomain-based membrane components whose functions may depend on mechanosensation (extracellular stimuli and internal osmotic pressure).
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Contractile Vacuole Complex—Its Expanding Protein Inventory. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 306:371-416. [DOI: 10.1016/b978-0-12-407694-5.00009-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Schönemann B, Bledowski A, Sehring IM, Plattner H. A set of SNARE proteins in the contractile vacuole complex of Paramecium regulates cellular calcium tolerance and also contributes to organelle biogenesis. Cell Calcium 2012; 53:204-16. [PMID: 23280185 DOI: 10.1016/j.ceca.2012.11.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/15/2012] [Accepted: 11/29/2012] [Indexed: 02/07/2023]
Abstract
The contractile vacuole complex (CVC) of freshwater protists serves the extrusion of water and ions, including Ca(2+). No vesicle trafficking based on SNAREs has been detected so far in any CVC. SNAREs (soluble NSF [N-ethylmaleimide sensitive factor] attachment protein receptors) are required for membrane-to-membrane interaction, i.e. docking and fusion also in Paramecium. We have identified three v-/R- and three t/Q-SNAREs selectively in the CVC. Posttranscriptional silencing of Syb2, Syb6 or Syx2 slows down the pumping cycle; silencing of the latter two also causes vacuole swelling. Increase in extracellular Ca(2+) after Syb2, Syb6 or Syx2 silencing causes further swelling of the contractile vacuole and deceleration of its pulsation. Silencing of Syx14 or Syx15 entails lethality in the Ca(2+) stress test. Thus, the effects of silencing strictly depend on the type of the silenced SNARE and on the concentration of Ca(2+) in the medium. This shows the importance of organelle-resident SNARE functions (which may encompass the vesicular delivery of other organelle-resident proteins) for Ca(2+) tolerance. A similar principle may be applicable also to the CVC in widely different unicellular organisms. In addition, in Paramecium, silencing particularly of Syx6 causes aberrant positioning of the CVC during de novo biogenesis before cytokinesis.
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Grønlien HK, Bruskeland GE, Jansen AK, Sand O. Electrophysiological Properties of the Microstome and Macrostome Morph of the Polymorphic Ciliate Tetrahymena vorax. J Eukaryot Microbiol 2012. [DOI: 10.1111/jeu.12006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Heidi K. Grønlien
- Department of Molecular Biosciences; University of Oslo; Blindern N-0316 Oslo Norway
- Faculty of Health and Social Studies; Østfold University College; N-1757 Halden Norway
| | - Guttorm E. Bruskeland
- Department of Molecular Biosciences; University of Oslo; Blindern N-0316 Oslo Norway
| | - Anne K. Jansen
- Department of Molecular Biosciences; University of Oslo; Blindern N-0316 Oslo Norway
| | - Olav Sand
- Department of Molecular Biosciences; University of Oslo; Blindern N-0316 Oslo Norway
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Evolution of apicomplexan secretory organelles. Int J Parasitol 2012; 42:1071-81. [PMID: 23068912 DOI: 10.1016/j.ijpara.2012.09.009] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 09/16/2012] [Accepted: 09/17/2012] [Indexed: 12/26/2022]
Abstract
The alveolate superphylum includes many free-living and parasitic organisms, which are united by the presence of alveolar sacs lying proximal to the plasma membrane, providing cell structure. All species comprising the apicomplexan group of alveolates are parasites and have adapted to the unique requirements of the parasitic lifestyle. Here the evolution of apicomplexan secretory organelles that are involved in the critical process of egress from one cell and invasion of another is explored. The variations within the Apicomplexa and how these relate to species-specific biology will be discussed. In addition, recent studies have identified specific calcium-sensitive molecules that coordinate the various events and regulate the release of these secretory organelles within apicomplexan parasites. Some aspects of this machinery are conserved outside the Apicomplexa, and are beginning to elucidate the conserved nature of the machinery. Briefly, the relationship of this secretion machinery within the Apicomplexa will be discussed, compared with free-living and predatory alveolates, and how these might have evolved from a common ancestor.
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