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Calmodulin in Paramecium: Focus on Genomic Data. Microorganisms 2022; 10:microorganisms10101915. [PMID: 36296191 PMCID: PMC9608856 DOI: 10.3390/microorganisms10101915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/14/2022] [Accepted: 09/22/2022] [Indexed: 11/26/2022] Open
Abstract
Calcium (Ca2+) is a universal second messenger that plays a key role in cellular signaling. However, Ca2+ signals are transduced with the help of Ca2+-binding proteins, which serve as sensors, transducers, and elicitors. Among the collection of these Ca2+-binding proteins, calmodulin (CaM) emerged as the prototypical model in eukaryotic cells. This is a small protein that binds four Ca2+ ions and whose functions are multiple, controlling many essential aspects of cell physiology. CaM is universally distributed in eukaryotes, from multicellular organisms, such as human and land plants, to unicellular microorganisms, such as yeasts and ciliates. Here, we review most of the information gathered on CaM in Paramecium, a group of ciliates. We condense the information here by mentioning that mature Paramecium CaM is a 148 amino acid-long protein codified by a single gene, as in other eukaryotic microorganisms. In these ciliates, the protein is notoriously localized and regulates cilia function and can stimulate the activity of some enzymes. When Paramecium CaM is mutated, cells show flawed locomotion and/or exocytosis. We further widen this and additional information in the text, focusing on genomic data.
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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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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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Orrego PR, Serrano-Rodríguez M, Cortez M, Araya JE. In Silico Characterization of Calcineurin from Pathogenic Obligate Intracellular Trypanosomatids: Potential New Biological Roles. Biomolecules 2021; 11:biom11091322. [PMID: 34572535 PMCID: PMC8470620 DOI: 10.3390/biom11091322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/16/2021] [Accepted: 08/09/2021] [Indexed: 12/28/2022] Open
Abstract
Calcineurin (CaN) is present in all eukaryotic cells, including intracellular trypanosomatid parasites such as Trypanosoma cruzi (Tc) and Leishmania spp. (Lspp). In this study, we performed an in silico analysis of the CaN subunits, comparing them with the human (Hs) and looking their structure, post-translational mechanisms, subcellular distribution, interactors, and secretion potential. The differences in the structure of the domains suggest the existence of regulatory mechanisms and differential activity between these protozoa. Regulatory subunits are partially conserved, showing differences in their Ca2+-binding domains and myristoylation potential compared with human CaN. The subcellular distribution reveals that the catalytic subunits TcCaNA1, TcCaNA2, LsppCaNA1, LsppCaNA1_var, and LsppCaNA2 associate preferentially with the plasma membrane compared with the cytoplasmic location of HsCaNAα. For regulatory subunits, HsCaNB-1 and LsppCaNB associate preferentially with the nucleus and cytoplasm, and TcCaNB with chloroplast and cytoplasm. Calpain cleavage sites on CaNA suggest differential processing. CaNA and CaNB of these trypanosomatids have the potential to be secreted and could play a role in remote communication. Therefore, this background can be used to develop new drugs for protozoan pathogens that cause neglected disease.
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Affiliation(s)
- Patricio R. Orrego
- Departamento Biomédico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta 1270300, Chile
- Correspondence: (P.R.O.); (J.E.A.); Tel.: +56-55-2637664 (J.E.A.)
| | - Mayela Serrano-Rodríguez
- Departamento de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta 1270300, Chile;
| | - Mauro Cortez
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508-000, Brazil;
| | - Jorge E. Araya
- Departamento de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta 1270300, Chile;
- Center for Biotechnology and Bioengineering, CeBIB, Universidad de Antofagasta, Antofagasta 1270300, Chile
- Correspondence: (P.R.O.); (J.E.A.); Tel.: +56-55-2637664 (J.E.A.)
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Hinrichsen R, Hawsawi O. A possible role for reactive oxygen species in the regulation of an ultradian rhythm in Paramecium. BIOL RHYTHM RES 2019. [DOI: 10.1080/09291016.2018.1512293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Robert Hinrichsen
- Department of Biology, Indiana University of Pennsylvania, Indiana, PA, USA
| | - Ohuod Hawsawi
- Department of Biology, Indiana University of Pennsylvania, Indiana, PA, USA
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He J, Huang F, Zhang J, Chen H, Chen Q, Zhang J, Li J, Zheng Z, Chen D, Chen J. DNA prime-protein boost vaccine encoding HLA-A2, HLA-A24 and HLA-DR1 restricted epitopes of CaNA2 against visceral leishmaniasis. Immunology 2018; 156:94-108. [PMID: 30285279 DOI: 10.1111/imm.13007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 09/09/2018] [Accepted: 09/26/2018] [Indexed: 12/21/2022] Open
Abstract
Visceral leishmaniasis is a tropical and neglected disease with an estimated 200 000-400 000 cases and 60 000 deaths worldwide each year. Currently, no clinically valid vaccine is available for this disease. In this study, we formulated DNA and protein vaccines encoding HLA-A2, HLA-A24 and HLA-DR1 restricted epitopes of CaNA2 against visceral leishmaniasis. We predicted the secondary and tertiary structures, surface properties, subcellular localization, potential binding sites and HLA-A2, HLA-A24 and HLA-DR1 restricted epitopes of CaNA2. The best candidate CpG ODN (2395, M362, D-SL03 or 685) was screened out as a DNA vaccine adjuvant. We also prepared Kmp-11 and Kmp-11/CaNA2 DNA and protein vaccines, respectively, for comparison. BALB/c mice were immunized with a DNA prime-protein boost immunization strategy and challenged with a newly isolated Leishmania strain from an individual with visceral leishmaniasis. The IgG antibody titers showed that our vaccine had strong immunogenicity with a long duration, especially cellular immunity. The spleen parasite burden of each group demonstrated that the CaNA2 vaccine had a certain immune protective effect on visceral leishmaniasis in BALB/c mice, and the amastigote reduction rate reached 76%. Preliminary safety tests confirmed the safety of the vaccine. Our work demonstrates that the HLA-A2, HLA-A24 and HLA-DR1 restricted epitope CaNA2 DNA prime-protein boost vaccine may be a safe and effective epitope vaccine candidate against visceral leishmaniasis.
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Affiliation(s)
- Jinlei He
- Department of Parasitology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Fan Huang
- Surgical Department, Chengdu Shuangliu Hospital of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Jianhui Zhang
- Department of Parasitology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Han Chen
- Department of Parasitology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Qiwei Chen
- Department of Parasitology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Junrong Zhang
- Department of Parasitology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Jiao Li
- Department of Parasitology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Zhiwan Zheng
- Department of Parasitology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Dali Chen
- Department of Parasitology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Jianping Chen
- Department of Parasitology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China.,Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Sichuan University, Chengdu, Sichuan, China
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The remembrance of the things past: Conserved signalling pathways link protozoa to mammalian nervous system. Cell Calcium 2018; 73:25-39. [DOI: 10.1016/j.ceca.2018.04.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/01/2018] [Accepted: 04/01/2018] [Indexed: 12/13/2022]
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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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Fowler CA, Núñez Hernandez MF, O'Donnell SE, Yu L, Shea MA. Backbone and side-chain resonance assignments of (Ca 2+) 4-calmodulin bound to beta calcineurin A CaMBD peptide. BIOMOLECULAR NMR ASSIGNMENTS 2017; 11:275-280. [PMID: 28815458 PMCID: PMC5693717 DOI: 10.1007/s12104-017-9762-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/09/2017] [Indexed: 06/07/2023]
Abstract
Calcineurin (CaN) is a heterodimeric and highly conserved serine/threonine phosphatase (PP2B) that plays a critical role in coupling calcium signals to physiological processes including embryonic cardiac development, NF-AT-regulated gene expression in immune responses, and apoptosis. The catalytic subunit (CaNA) has three isoforms (α, β, and γ,) in humans and seven isoforms in Paramecium. In all eukaryotes, the EF-hand protein calmodulin (CaM) regulates CaN activity in a calcium-dependent manner. The N- and C-domains of CaM (CaMN and CaMC) recognize a CaM-binding domain (CaMBD) within an intrinsically disordered region of CaNA that precedes the auto-inhibitory domain (AID) of CaNA. Here we present nearly complete 1H, 13C, and 15N resonance assignments of (Ca2+)4-CaM bound to a peptide containing the CaMBD sequence in the beta isoform of CaNA (βCaNA-CaMBDp). Its secondary structure elements predicted from the assigned chemical shifts were in good agreement with those observed in the high-resolution structures of (Ca2+)4-CaM bound to CaMBDs of multiple enzymes. Based on the reported literature, the CaMBD of the α isoform of CaNA can bind to CaM in two opposing orientations which may influence the regulatory function of CaM. Because a high resolution structure of (Ca2+)4-CaM bound to βCaNA-CaMBDp has not been reported, our studies serve as a starting point for determining the solution structure of this complex. This will demonstrate the preferred orientation of (Ca2+)4-CaM on the CaMBD as well as the orientations of CaMN and CaMC relative to each other and to the AID of βCaNA.
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Affiliation(s)
- C Andrew Fowler
- NMR Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa, IA, 52242-1109, USA
| | - Maria F Núñez Hernandez
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa, IA, 52242-1109, USA
| | - Susan E O'Donnell
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa, IA, 52242-1109, USA
| | - Liping Yu
- NMR Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa, IA, 52242-1109, USA
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa, IA, 52242-1109, USA
| | - Madeline A Shea
- Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa, IA, 52242-1109, USA.
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Plattner H. Evolutionary Cell Biology of Proteins from Protists to Humans and Plants. J Eukaryot Microbiol 2017; 65:255-289. [PMID: 28719054 DOI: 10.1111/jeu.12449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/04/2017] [Accepted: 07/07/2017] [Indexed: 01/10/2023]
Abstract
During evolution, the cell as a fine-tuned machine had to undergo permanent adjustments to match changes in its environment, while "closed for repair work" was not possible. Evolution from protists (protozoa and unicellular algae) to multicellular organisms may have occurred in basically two lineages, Unikonta and Bikonta, culminating in mammals and angiosperms (flowering plants), respectively. Unicellular models for unikont evolution are myxamoebae (Dictyostelium) and increasingly also choanoflagellates, whereas for bikonts, ciliates are preferred models. Information accumulating from combined molecular database search and experimental verification allows new insights into evolutionary diversification and maintenance of genes/proteins from protozoa on, eventually with orthologs in bacteria. However, proteins have rarely been followed up systematically for maintenance or change of function or intracellular localization, acquirement of new domains, partial deletion (e.g. of subunits), and refunctionalization, etc. These aspects are discussed in this review, envisaging "evolutionary cell biology." Protozoan heritage is found for most important cellular structures and functions up to humans and flowering plants. Examples discussed include refunctionalization of voltage-dependent Ca2+ channels in cilia and replacement by other types during evolution. Altogether components serving Ca2+ signaling are very flexible throughout evolution, calmodulin being a most conservative example, in contrast to calcineurin whose catalytic subunit is lost in plants, whereas both subunits are maintained up to mammals for complex functions (immune defense and learning). Domain structure of R-type SNAREs differs in mono- and bikonta, as do Ca2+ -dependent protein kinases. Unprecedented selective expansion of the subunit a which connects multimeric base piece and head parts (V0, V1) of H+ -ATPase/pump may well reflect the intriguing vesicle trafficking system in ciliates, specifically in Paramecium. One of the most flexible proteins is centrin when its intracellular localization and function throughout evolution is traced. There are many more examples documenting evolutionary flexibility of translation products depending on requirements and potential for implantation within the actual cellular context at different levels of evolution. From estimates of gene and protein numbers per organism, it appears that much of the basic inventory of protozoan precursors could be transmitted to highest eukaryotic levels, with some losses and also with important additional "inventions."
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, P. O. Box M625, Konstanz, 78457, Germany
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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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Nicolao MC, Cumino AC. Biochemical and molecular characterization of the calcineurin in Echinococcus granulosus larval stages. Acta Trop 2015; 146:141-51. [PMID: 25818323 DOI: 10.1016/j.actatropica.2015.03.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 03/06/2015] [Accepted: 03/10/2015] [Indexed: 01/26/2023]
Abstract
Calcineurin (CaN) is a Ca(2+)-calmodulin activated serine-threonine protein phosphatase that couples the local or global calcium signals, thus controlling important cellular functions in physiological and developmental processes. The aim of this study was to characterize CaN in Echinococcus granulosus (Eg-CaN), a human cestode parasite of clinical importance, both functionally and molecularly. We found that the catalytic subunit isoforms have predicted sequences of 613 and 557 amino acids and are substantially similar to those of the human counterpart, except for the C-terminal end. We also found that the regulatory subunit consists of 169 amino acids which are 87% identical to the human ortholog. We cloned a cDNA encoding for one of the two catalytic subunit isoforms of CaN (Eg-can-A1) as well as the only copy of the Eg-can-B gene, both constitutively transcribed in all Echinococcus larval stages and responsible for generating a functionally active heterodimer. Eg-CaN native enzyme has phosphatase activity, which is enhanced by Ca(2+)/Ni(2+) and reduced by cyclosporine A and Ca(2+) chelators. Participation of Eg-CaN in exocytosis was demonstrated using the FM4-64 probe and Eg-CaN-A was immunolocalized in the cytoplasm of tegumental cells, suckers and excretory bladder of protoscoleces. We also showed that the Eg-can-B transcripts were down-regulated in response to low Ca(2+) intracellular level, in agreement with decreased enzyme activity. Confocal microscopy revealed a striking pattern of Eg-CaN-A in discrete fluorescent spots in the protoscolex posterior bladder and vesicularized protoscoleces beginning the vesicular differentiation. In contrast, Eg-CaN-A was undetectable during the pre-microcyst closing stage while a high DDX-like RNA helicase expression was evidenced. Finally, we identified and analyzed the expression of CaN-related endogenous regulators.
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Affiliation(s)
- María Celeste Nicolao
- Laboratorio de Zoonosis Parasitarias, Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata (UNMdP), Funes 3350, Nivel Cero, 7600 Mar del Plata, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Andrea C Cumino
- Laboratorio de Zoonosis Parasitarias, Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata (UNMdP), Funes 3350, Nivel Cero, 7600 Mar del Plata, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata (UNMdP), Funes 3350, Nivel 2, 7600 Mar del Plata, Argentina.
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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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Echevarria ML, Wolfe GV, Strom SL, Taylor AR. Connecting alveolate cell biology with trophic ecology in the marine plankton using the ciliateFavellaas a model. FEMS Microbiol Ecol 2014; 90:18-38. [DOI: 10.1111/1574-6941.12382] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/11/2014] [Accepted: 07/13/2014] [Indexed: 11/30/2022] Open
Affiliation(s)
- Michael L. Echevarria
- Department of Biology and Marine Biology; University of North Carolina Wilmington; Wilmington NC USA
| | - Gordon V. Wolfe
- Department Biological Sciences; California State University of Chico; Chico CA USA
| | - Suzanne L. Strom
- Shannon Point Marine Center; Western Washington University; Anacortes WA USA
| | - Alison R. Taylor
- Department of Biology and Marine Biology; University of North Carolina Wilmington; Wilmington NC USA
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Abstract
Calcium ions are ubiquitous intracellular messengers. An increase in the cytosolic Ca(2+) concentration activates many proteins, including calmodulin and the Ca(2+)/calmodulin-dependent protein phosphatase calcineurin. The phosphatase is conserved from yeast to humans (except in plants), and many target proteins of calcineurin have been identified. The most prominent and best-investigated targets, however, are the transcription factors NFAT (nuclear factor of activated T cells) in mammals and Crz1 (calcineurin-responsive zinc finger 1) in yeast. In recent years, many orthologues of Crz1 have been identified and characterized in various species of fungi, amoebae, and other lower eukaryotes. It has been shown that the functions of calcineurin-Crz1 signaling, ranging from ion homeostasis through cell wall biogenesis to the building of filamentous structures, are conserved in the different organisms. Furthermore, frequency-modulated gene expression through Crz1 has been discovered as a striking new mechanism by which cells can coordinate their response to a signal. In this review, I focus on the latest findings concerning calcineurin-Crz1 signaling in fungi, amoebae and other lower eukaryotes. I discuss the potential of Crz1 and its orthologues as putative drug targets, and I also discuss possible parallels with calcineurin-NFAT signaling in mammals.
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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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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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Hinrichsen R, Belsky D, Jones L, Mialki R. The frequency of the spontaneous behavioral response inParamecium tetraureliais simultaneously modulated by both ultradian and circadian rhythms. BIOL RHYTHM RES 2013. [DOI: 10.1080/09291016.2012.692254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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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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Plattner H, Sehring IM, Mohamed IK, Miranda K, De Souza W, Billington R, Genazzani A, Ladenburger EM. Calcium signaling in closely related protozoan groups (Alveolata): non-parasitic ciliates (Paramecium, Tetrahymena) vs. parasitic Apicomplexa (Plasmodium, Toxoplasma). Cell Calcium 2012; 51:351-82. [PMID: 22387010 DOI: 10.1016/j.ceca.2012.01.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 01/10/2012] [Accepted: 01/12/2012] [Indexed: 12/20/2022]
Abstract
The importance of Ca2+-signaling for many subcellular processes is well established in higher eukaryotes, whereas information about protozoa is restricted. Recent genome analyses have stimulated such work also with Alveolates, such as ciliates (Paramecium, Tetrahymena) and their pathogenic close relatives, the Apicomplexa (Plasmodium, Toxoplasma). Here we compare Ca2+ signaling in the two closely related groups. Acidic Ca2+ stores have been characterized in detail in Apicomplexa, but hardly in ciliates. Two-pore channels engaged in Ca2+-release from acidic stores in higher eukaryotes have not been stingently characterized in either group. Both groups are endowed with plasma membrane- and endoplasmic reticulum-type Ca2+-ATPases (PMCA, SERCA), respectively. Only recently was it possible to identify in Paramecium a number of homologs of ryanodine and inositol 1,3,4-trisphosphate receptors (RyR, IP3R) and to localize them to widely different organelles participating in vesicle trafficking. For Apicomplexa, physiological experiments suggest the presence of related channels although their identity remains elusive. In Paramecium, IP3Rs are constitutively active in the contractile vacuole complex; RyR-related channels in alveolar sacs are activated during exocytosis stimulation, whereas in the parasites the homologous structure (inner membrane complex) may no longer function as a Ca2+ store. Scrutinized comparison of the two closely related protozoan phyla may stimulate further work and elucidate adaptation to parasitic life. See also "Conclusions" section.
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Affiliation(s)
- H Plattner
- Department of Biology, University of Konstanz, P.O. Box 5560, 78457 Konstanz, Germany.
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Norcantharidin inhibits the expression of extracellular matrix and TGF-β1 in HK-2 cells induced by high glucose independent of calcineurin signal pathway. J Transl Med 2011; 91:1706-16. [PMID: 21931301 DOI: 10.1038/labinvest.2011.119] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Norcantharidin (NCTD) was shown in our previous studies to attenuate renal tubulointerstitial fibrosis in rat models with diabetic nephropathy (DN). The aim of this study was to determine the effects of NCTD on the expression of extracellular matrix (ECM) and TGF-β1 in HK-2 cells stimulated by high glucose and on calcineurin (CaN)/NFAT pathway. Whether or not the antifibrotic effect of NCTD on renal interstitium was dependent on its inhibition of CaN pathway was also investigated. Experimental concentrations of NCTD were verified by cytotoxic test and MTT assay. HK-2 cells were transfected with CaN small interference RNA (siRNA). The mRNA and protein expressions of FN, ColIV, TGF-β1, and CaN in HK-2 cells were detected by real-time PCR and western blot. The CaN/NFAT pathway was examined by indirect immunofluorescence and western blot. Our study revealed that NCTD concentrations over 5 mg/l had overt cytotoxicity on HK-2 cells. Meanwhile, both 2.5 and 5 mg/l NCTD inhibited HK-2 cell proliferation (P < 0.05). NCTD inhibited the upregulation of FN, ColIV, and TGF-β1 of HK-2 cells stimulated by high glucose (P < 0.05), and also significantly downregulated the expression of CaN mRNA and protein in HK-2 cells (P < 0.05). In addition, not only was the nuclear translocation of NFATc inhibited, but its protein level in the nucleus was also reduced. Following CaN siRNA transfection, CaN mRNA and protein expression were significantly decreased. In contrast, the protein levels of FN, ColIV, and TGF-β1 increased in HK-2 cells stimulated by high glucose (P < 0.05). However, NCTD treatment downregulated their expression. These results indicated that NCTD could decrease the expression of ECM and TGF-β1 in HK-2 cells stimulated by high glucose, downregulate CaN expression, and block the CaN/NFAT signaling pathway. However, the effect of NCTD on inhibition of the expression of ECM and TGF-β1 was not associated with its inhibition of the CaN/NFAT pathway.
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O'Donnell SE, Yu L, Fowler CA, Shea MA. Recognition of β-calcineurin by the domains of calmodulin: thermodynamic and structural evidence for distinct roles. Proteins 2010; 79:765-86. [PMID: 21287611 DOI: 10.1002/prot.22917] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 10/04/2010] [Accepted: 10/07/2010] [Indexed: 11/08/2022]
Abstract
Calcineurin (CaN, PP2B, PPP3), a heterodimeric Ca(2+)-calmodulin-dependent Ser/Thr phosphatase, regulates swimming in Paramecia, stress responses in yeast, and T-cell activation and cardiac hypertrophy in humans. Calcium binding to CaN(B) (the regulatory subunit) triggers conformational change in CaN(A) (the catalytic subunit). Two isoforms of CaN(A) (α, β) are both abundant in brain and heart and activated by calcium-saturated calmodulin (CaM). The individual contribution of each domain of CaM to regulation of calcineurin is not known. Hydrodynamic analyses of (Ca(2+))₄-CaM(1-148) bound to βCaNp, a peptide representing its CaM-binding domain, indicated a 1:1 stoichiometry. βCaNp binding to CaM increased the affinity of calcium for the N- and C-domains equally, thus preserving intrinsic domain differences, and the preference of calcium for sites III and IV. The equilibrium constants for individual calcium-saturated CaM domains dissociating from βCaNp were ∼1 μM. A limiting K(d) ≤ 1 nM was measured directly for full-length CaM, while thermodynamic linkage analysis indicated that it was approximately 1 pM. βCaNp binding to ¹⁵N-(Ca(2+))₄-CaM(1-148) monitored by ¹⁵N/¹HN HSQC NMR showed that association perturbed the N-domain of CaM more than its C-domain. NMR resonance assignments of CaM and βCaNp, and interpretation of intermolecular NOEs observed in the ¹³C-edited and ¹²C-¹⁴N-filtered 3D NOESY spectrum indicated anti-parallel binding. The sole aromatic residue (Phe) located near the βCaNp C-terminus was in close contact with several residues of the N-domain of CaM outside the hydrophobic cleft. These structural and thermodynamic properties would permit the domains of CaM to have distinct physiological roles in regulating activation of βCaN.
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Affiliation(s)
- Susan E O'Donnell
- Department of Biochemistry, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa 52242-1109, USA
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