1
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Sakoshita K, Aratani S, Kameda N, Takebe R, Tominaga T, Ishida M, Hori M. Anoctamin-like protein 1 regulates repolarization in Paramecium behavioral responses. J Eukaryot Microbiol 2024; 71:e13030. [PMID: 38757880 DOI: 10.1111/jeu.13030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 04/06/2024] [Accepted: 04/06/2024] [Indexed: 05/18/2024]
Abstract
Paramecium exhibits responsive behavior to environmental changes, moving either closer to or further away from stimuli. Electrophysiological experiments have revealed that these behavioral responses are controlled by membrane potentials. Anoctamin, a Ca2+-activated Cl- channel, is involved in the regulation of membrane potential in mammals. However, it remains uncertain whether Cl- channels like anoctamin regulate Paramecium behavior. Herein, replacement of external Cl- ions with acetate ion and application of Cl- channel blocker niflumic acid (NFA, 0.1 μM) increased spontaneous avoiding reactions (sARs). Hence, we hypothesized that anoctamin is involved in the stabilization of membrane potential fluctuation. Paramecium cells in which the anoctamin-like protein 1 gene was knocked down displayed frequent sARs in the culture medium without external stimulation. Treatment of anoctamin-like protein 1-knockdown cells with the Ca2+ chelator BAPTA or Ca-channel blocker nicardipine reversed the increase in sARs. Electrophysiological experiments revealed extension of membrane depolarization when positive currents were applied to anoctamin-like protein 1-knockdown cells. We concluded that anoctamin-like protein 1 works as a Cl-channel and stabilizes the membrane potential oscillation, reducing sARs.
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Affiliation(s)
- Kana Sakoshita
- Faculty of Science, Yamaguchi University, Yamaguchi, Japan
| | | | - Nana Kameda
- Faculty of Science, Yamaguchi University, Yamaguchi, Japan
| | - Ryo Takebe
- Faculty of Science, Yamaguchi University, Yamaguchi, Japan
| | - Takashi Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Sanuki, Kagawa, Japan
| | - Masaki Ishida
- School of Science Education, Nara University of Education, Nara, Japan
| | - Manabu Hori
- Faculty of Science, Yamaguchi University, Yamaguchi, Japan
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2
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Sterling P, Laughlin S. Why an animal needs a brain. Anim Cogn 2023; 26:1751-1762. [PMID: 38041700 DOI: 10.1007/s10071-023-01825-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2023] [Indexed: 12/03/2023]
Abstract
In Principles of Neural Design (2015, MIT Press), inspired by Charles Darwin, Sterling and Laughlin undertook the unfashionable task of distilling principles from facts in the technique-driven, data-saturated domain of neuroscience. Their starting point for deriving the organizing principles of brains are two brainless single-celled organisms, Escherichia coli and Paramecium, and the 302-neuron brain of the nematode Caenorhabditis elegans. The book is an exemplar in how to connect the dots between simpler and (much) more complex organisms in a particular area. Here, they have generously agreed to republish an abridged version of Chapter 2 (Why an Animal Needs a Brain), in which many of their principles are first described.
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Affiliation(s)
- Peter Sterling
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA.
| | - Simon Laughlin
- Department of Zoology, University of Cambridge, Cambridge, England
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3
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Hori M, Tominaga T, Ishida M, Kawano M. RNA interference reveals the escape response mechanism of Paramecium to mechanical stimulation. Biophys Physicobiol 2023; 20:e200025. [PMID: 37867561 PMCID: PMC10587447 DOI: 10.2142/biophysico.bppb-v20.0025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/29/2023] [Indexed: 10/24/2023] Open
Abstract
In Paramecium, a mechanical stimulus applied to the posterior portion of the cell causes a transient increase in membrane permeability to potassium ions, transiently rendering the membrane in a hyperpolarized state. Hyperpolarization causes a transient increase in Cyclic adenosine monophosphate (cAMP) concentration in the cilia, resulting in a transient fast-forward swimming of the cell. Schultz and coworkers (1992) reported that a unique adenylate cyclase (AC)-coupled potassium channel is involved in the reaction underlying this response, which is known as the "escape response." However, the AC responsible for this reaction remains to be identified. Moreover, the molecular linkage between mechanoreception and AC activation has not been elucidated adequately. Currently, we can perform an efficient and simple gene-knockdown technique in Paramecium using RNA interference (RNAi). Paramecium is one of the several model organisms for which whole-genome sequences have been elucidated. The RNAi technique can be applied to whole genome sequences derived from the Paramecium database (ParameciumDB) to investigate the types of proteins that elicit specific biological responses and compare them with those of other model organisms. In this review, we describe the applications of the RNAi technique in elucidating the molecular mechanism underlying the escape response and identifying the AC involved in this reaction. The findings of this study highlight the advantages of the RNAi technique and ParameciumDB.
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Affiliation(s)
- Manabu Hori
- Department of Biology, Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan
| | - Takashi Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Sanuki, Kagawa 769-2193, Japan
| | - Masaki Ishida
- School of Science Education, Nara University of Education, Nara 630-8528, Japan
| | - Mutsumi Kawano
- Department of Biology, Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan
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4
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Escoubet N, Brette R, Pontani LL, Prevost AM. Interaction of the mechanosensitive microswimmer Paramecium with obstacles. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221645. [PMID: 37234495 PMCID: PMC10206458 DOI: 10.1098/rsos.221645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023]
Abstract
In this work, we report investigations of the swimming behaviour of Paramecium tetraurelia, a unicellular microorganism, in micro-engineered pools that are decorated with thousands of cylindrical pillars. Two types of contact interactions are measured, either passive scattering of Paramecium along the obstacle or avoiding reactions (ARs), characterized by an initial backward swimming upon contact, followed by a reorientation before resuming forward motion. We find that ARs are only mechanically triggered approximately 10% of the time. In addition, we observe that only a third of all ARs triggered by contact are instantaneous while two-thirds are delayed by approximately 150 ms. These measurements are consistent with a simple electrophysiological model of mechanotransduction composed of a strong transient current followed by a persistent one upon prolonged contact. This is in apparent contrast with previous electrophysiological measurements where immobilized cells were stimulated with thin probes, which showed instantaneous behavioural responses and no persistent current. Our findings highlight the importance of ecologically relevant approaches to unravel the motility of mechanosensitive microorganisms in complex environments.
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Affiliation(s)
- Nicolas Escoubet
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Jean Perrin, 4 place Jussieu, Paris 75005, France
| | - Romain Brette
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, Paris 75012, France
| | - Lea-Laetitia Pontani
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Jean Perrin, 4 place Jussieu, Paris 75005, France
| | - Alexis Michel Prevost
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Jean Perrin, 4 place Jussieu, Paris 75005, France
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5
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Van Houten J. A Review for the Special Issue on Paramecium as a Modern Model Organism. Microorganisms 2023; 11:microorganisms11040937. [PMID: 37110360 PMCID: PMC10143506 DOI: 10.3390/microorganisms11040937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/28/2023] [Accepted: 03/29/2023] [Indexed: 04/07/2023] Open
Abstract
This review provides background and perspective for the articles contributing to the Special Issue of MDPI Micro-organisms on Paramecium as a Modern Model Organism. The six articles cover a variety of topics, each taking advantage of an important aspect of Paramecium biology: peripheral surface proteins that are developmentally regulated, endosymbiont algae and bacteria, ion channel regulation by calmodulin, regulation of cell mating reactivity and senescence, and the introns that dwell in the large genome. Each article highlights a significant aspect of Paramecium and its versatility.
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Affiliation(s)
- Judith Van Houten
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
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6
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Elices I, Kulkarni A, Escoubet N, Pontani LL, Prevost AM, Brette R. An electrophysiological and kinematic model of Paramecium, the "swimming neuron". PLoS Comput Biol 2023; 19:e1010899. [PMID: 36758112 PMCID: PMC9946239 DOI: 10.1371/journal.pcbi.1010899] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 02/22/2023] [Accepted: 01/26/2023] [Indexed: 02/11/2023] Open
Abstract
Paramecium is a large unicellular organism that swims in fresh water using cilia. When stimulated by various means (mechanically, chemically, optically, thermally), it often swims backward then turns and swims forward again in a new direction: this is called the avoiding reaction. This reaction is triggered by a calcium-based action potential. For this reason, several authors have called Paramecium the "swimming neuron". Here we present an empirically constrained model of its action potential based on electrophysiology experiments on live immobilized paramecia, together with simultaneous measurement of ciliary beating using particle image velocimetry. Using these measurements and additional behavioral measurements of free swimming, we extend the electrophysiological model by coupling calcium concentration to kinematic parameters, turning it into a swimming model. In this way, we obtain a model of autonomously behaving Paramecium. Finally, we demonstrate how the modeled organism interacts with an environment, can follow gradients and display collective behavior. This work provides a modeling basis for investigating the physiological basis of autonomous behavior of Paramecium in ecological environments.
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Affiliation(s)
- Irene Elices
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Anirudh Kulkarni
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- Department of Bioengineering and Centre for Neurotechnology, Imperial College London, South Kensington Campus, London, United Kingdom
| | - Nicolas Escoubet
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratoire Jean Perrin (LJP), Paris
| | - Léa-Laetitia Pontani
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratoire Jean Perrin (LJP), Paris
| | - Alexis Michel Prevost
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratoire Jean Perrin (LJP), Paris
| | - Romain Brette
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- * E-mail:
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7
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Valentine M, Yano J, Lodh S, Nabi A, Deng B, Van Houten J. Methods for Paramecium tetraurelia ciliary membrane protein identification and function. Methods Cell Biol 2023; 175:177-219. [PMID: 36967141 DOI: 10.1016/bs.mcb.2022.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In this chapter we provide some tools to study the ciliary proteins that make it possible for Paramecium cells to swim by beating their cilia. These proteins include many ion channels, accessory proteins, peripheral proteins, structural proteins, rootlets of cilia, and enzymes. Some of these proteins are also found in the soma membrane, but their distinct and critical functions are in the cilia. Paramecium has 4000 or more cilia per cell, giving it an advantage for biochemical studies over cells that have one primarily cilium per cell. Nonetheless, a challenge for studies of many ciliary proteins in Paramecium is their low abundance. We discuss here several strategies to overcome this challenge and other challenges such as working with very large channel proteins. We also include for completeness other techniques that are critical to the study of swimming behavior, such as genetic crosses, recording of swimming patterns, electrical recordings, expression of very large channel proteins, RNA Interference, among others.
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Affiliation(s)
- Megan Valentine
- State University of New York, Plattsburgh, NY, United States
| | - Junji Yano
- University of Vermont, Burlington, VT, United States
| | - Sukanya Lodh
- Marquette University, Milwaukee, WI, United States
| | | | - Bin Deng
- Vermont Biomedical Research Network, University of Vermont, Burlington, VT, United States
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8
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Paeger A, Fillafer C, Schneider MF. Evidence for a transition in the cortical membranes of Paramecium. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184073. [PMID: 36243036 DOI: 10.1016/j.bbamem.2022.184073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/02/2022] [Accepted: 10/07/2022] [Indexed: 11/06/2022]
Abstract
Ever since the pioneering studies in the 1960s and 70s, the importance of order transitions for cell membrane functions has remained a matter of debate. Recently, it has been proposed that the nonlinear stimulus-response curve of excitable cells, which manifests in all-or-none pulses (action potentials (AP)), is due to a transition in the cell membrane. Indeed, evidence for transitions has accumulated in plant cells and neurons, but studies with other excitable cells are expedient in order to show if this finding is of a general nature. Herein, we investigated intact, motile specimens of the "swimming neuron" Paramecium. The cellular membranes were labelled with the solvatochromic fluorophores LAURDAN or Di-4-ANEPPDHQ. Subsequently, a cell was trapped in a microfluidic channel and investigated by fluorescence spectroscopy. The generalized polarization (GP) of the fluorescence emission from cell cortical membranes (probably plasma and alveolar membranes) was extracted by an edge-finding algorithm. The thermo-optical state diagram, i.e. the dependence of GP on temperature, exhibited clear indications for a reversible transition. This transition had a width of ~10-15 °C and a midpoint that was located ~4 °C below the growth temperature. The state diagrams with LAURDAN and Di-4-ANEPPDHQ had widely identical characteristics. These results suggested that the cortical membranes of Paramecium reside in an order transition regime under physiological growth conditions. Based on these findings, membrane potential fluctuations, spontaneous depolarizing spikes, and thermal excitation of Paramecium was interpreted.
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Affiliation(s)
- Anne Paeger
- Medical and Biological Physics, Department of Physics, Technical University Dortmund, Otto-Hahn-Str. 4, 44227 Dortmund, Germany.
| | - Christian Fillafer
- Medical and Biological Physics, Department of Physics, Technical University Dortmund, Otto-Hahn-Str. 4, 44227 Dortmund, Germany.
| | - Matthias F Schneider
- Medical and Biological Physics, Department of Physics, Technical University Dortmund, Otto-Hahn-Str. 4, 44227 Dortmund, Germany.
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9
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Cheng K. Oscillators and servomechanisms in orientation and navigation, and sometimes in cognition. Proc Biol Sci 2022; 289:20220237. [PMID: 35538783 PMCID: PMC9091845 DOI: 10.1098/rspb.2022.0237] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Navigational mechanisms have been characterized as servomechanisms. A navigational servomechanism specifies a goal state to strive for. Discrepancies between the perceived current state and the goal state specify error. Servomechanisms adjust the course of travel to reduce the error. I now add that navigational servomechanisms work with oscillators, periodic movements of effectors that drive locomotion. I illustrate this concept selectively over a vast range of scales of travel from micrometres in bacteria to thousands of kilometres in sea turtles. The servomechanisms differ in sophistication, with some interrupting forward motion occasionally or changing travel speed in kineses and others adjusting the direction of travel in taxes. I suggest that in other realms of life as well, especially in cognition, servomechanisms work with oscillators.
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Affiliation(s)
- Ken Cheng
- School of Natural Sciences, Macquarie University, Sydney, North Ryde, NSW 2109, Australia
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10
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Bouhouche K, Valentine MS, Le Borgne P, Lemullois M, Yano J, Lodh S, Nabi A, Tassin AM, Van Houten JL. Paramecium, a Model to Study Ciliary Beating and Ciliogenesis: Insights From Cutting-Edge Approaches. Front Cell Dev Biol 2022; 10:847908. [PMID: 35359441 PMCID: PMC8964087 DOI: 10.3389/fcell.2022.847908] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 02/14/2022] [Indexed: 12/30/2022] Open
Abstract
Cilia are ubiquitous and highly conserved extensions that endow the cell with motility and sensory functions. They were present in the first eukaryotes and conserved throughout evolution (Carvalho-Santos et al., 2011). Paramecium has around 4,000 motile cilia on its surface arranged in longitudinal rows, beating in waves to ensure movement and feeding. As with cilia in other model organisms, direction and speed of Paramecium ciliary beating is under bioelectric control of ciliary ion channels. In multiciliated cells of metazoans as well as paramecia, the cilia become physically entrained to beat in metachronal waves. This ciliated organism, Paramecium, is an attractive model for multidisciplinary approaches to dissect the location, structure and function of ciliary ion channels and other proteins involved in ciliary beating. Swimming behavior also can be a read-out of the role of cilia in sensory signal transduction. A cilium emanates from a BB, structurally equivalent to the centriole anchored at the cell surface, and elongates an axoneme composed of microtubule doublets enclosed in a ciliary membrane contiguous with the plasma membrane. The connection between the BB and the axoneme constitutes the transition zone, which serves as a diffusion barrier between the intracellular space and the cilium, defining the ciliary compartment. Human pathologies affecting cilia structure or function, are called ciliopathies, which are caused by gene mutations. For that reason, the molecular mechanisms and structural aspects of cilia assembly and function are actively studied using a variety of model systems, ranging from unicellular organisms to metazoa. In this review, we will highlight the use of Paramecium as a model to decipher ciliary beating mechanisms as well as high resolution insights into BB structure and anchoring. We will show that study of cilia in Paramecium promotes our understanding of cilia formation and function. In addition, we demonstrate that Paramecium could be a useful tool to validate candidate genes for ciliopathies.
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Affiliation(s)
- K. Bouhouche
- CEA, CNRS, Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | | | - P. Le Borgne
- CEA, CNRS, Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - M. Lemullois
- CEA, CNRS, Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - J. Yano
- Department of Biology, University of Vermont, Burlington, VT, United States
| | - S. Lodh
- Biological Sciences, Marquette University, Milwaukee, WI, United States
| | - A. Nabi
- Luminex, Austin, TX, United States
| | - A. M. Tassin
- CEA, CNRS, Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
- *Correspondence: A. M. Tassin, ; J. L. Van Houten,
| | - J. L. Van Houten
- Department of Biology, University of Vermont, Burlington, VT, United States
- *Correspondence: A. M. Tassin, ; J. L. Van Houten,
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11
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Valentine MS, Van Houten J. Ion Channels of Cilia: Paramecium as a Model. J Eukaryot Microbiol 2022; 69:e12884. [PMID: 34995386 DOI: 10.1111/jeu.12884] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 12/27/2021] [Indexed: 11/29/2022]
Abstract
Holotrichous ciliates, like Paramecium, swim through their aqueous environment by beating their many cilia. They can alter swimming speed and direction, which seems to have mesmerized early microscopists of the 1600's. We know from extensive and elegant physiological studies and generation of mutants that these cells can be considered little swimming neurons because their ciliary beating is under bioelectric control of ion channels in the cilia. This chapter will focus on the ionic control of swimming behavior by ciliary ion channels, primarily in the holotrichous ciliate Paramecium. Voltage gated and calcium activated channels for calcium, magnesium, sodium, and potassium are regulated in a closely orchestrated manner that allows cilia to bend and propel the cell forward or backward. Sensory input that generates receptor potentials feeds into the control of this channel activity and allows the cell to turn or speed up. This in turn helps the cell to avoid predators or toxic conditions. While the focus is on P. tetraurelia and P. caudatum, the principles of ciliary ion channel activity and control are easily extendable to other ciliates and protists. The high conservation of channel and ion pump structures also extends the lessons from Paramecium to higher organisms.
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Affiliation(s)
- Megan S Valentine
- SUNY Plattsburgh, Department of Biological Sciences, 101 Broad Street, Plattsburgh, NY, USA, 518-564-3174
| | - Judith Van Houten
- University of Vermont, Department of Biology, University of Vermont, 109 Carrigan Drive, Burlington, 802-434-4006
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12
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Marumo A, Yamagishi M, Yajima J. Three-dimensional tracking of the ciliate Tetrahymena reveals the mechanism of ciliary stroke-driven helical swimming. Commun Biol 2021; 4:1209. [PMID: 34675362 PMCID: PMC8531007 DOI: 10.1038/s42003-021-02756-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 10/06/2021] [Indexed: 11/09/2022] Open
Abstract
Helical swimming in free-space is a common behavior among microorganisms, such as ciliates that are covered with thousands hair-like motile cilia, and is thought to be essential for cells to orient directly to an external stimulus. However, a direct quantification of their three-dimensional (3D) helical trajectories has not been reported, in part due to difficulty in tracking 3D swimming behavior of ciliates, especially Tetrahymena with a small, transparent cell body. Here, we conducted 3D tracking of fluorescent microbeads within a cell to directly visualize the helical swimming exhibited by Tetrahymena. Our technique showed that Tetrahymena swims along a right-handed helical path with right-handed rolling of its cell body. Using the Tetrahymena cell permeabilized with detergent treatment, we also observed that influx of Ca2+ into cilia changed the 3D-trajectory patterns of Tetrahymena swimming, indicating that the beating pattern of cilia is the determining factor in its swimming behavior.
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Affiliation(s)
- Akisato Marumo
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan
| | - Masahiko Yamagishi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan
| | - Junichiro Yajima
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan. .,Komaba Institute for Science, The University of Tokyo, 3-8-1, Komaba, Meguro-ku, Tokyo, 153-8902, Japan. .,Research Center for Complex Systems Biology, The University of Tokyo, 3-8-1, Komaba, Meguro-ku, Tokyo, 153-8902, Japan.
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13
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Yano J, Wells R, Lam YW, Van Houten JL. Ciliary Ca2+ pumps regulate intraciliary Ca2+ from the action potential and may co-localize with ciliary voltage-gated Ca2+ channels. J Exp Biol 2021; 224:261763. [PMID: 33944932 DOI: 10.1242/jeb.232074] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 03/02/2021] [Indexed: 11/20/2022]
Abstract
Calcium ions (Ca2+) entering cilia through the ciliary voltage-gated calcium channels (CaV) during the action potential causes reversal of the ciliary power stroke and backward swimming in Paramecium tetraurelia. How calcium is returned to the resting level is not yet clear. Our focus is on calcium pumps as a possible mechanism. There are 23 P. tetraurelia genes for calcium pumps that are members of the family of plasma membrane Ca2+ ATPases (PMCAs). They have domains homologous to those found in mammalian PMCAs. Of the 13 pump proteins previously identified in cilia, ptPMCA2a and ptPMCA2b are most abundant in the cilia. We used RNAi to examine which PMCA might be involved in regulating intraciliary Ca2+ after the action potential. RNAi for only ptPMCA2a and ptPMCA2b causes cells to significantly prolong their backward swimming, which indicates that Ca2+ extrusion in the cilia is impaired when these PMCAs are depleted. We used immunoprecipitations (IP) to find that ptPMCA2a and ptPMCA2b are co-immunoprecipitated with the CaV channel α1 subunits that are found only in the cilia. We used iodixanol (OptiPrep) density gradients to show that ptPMCA2a and ptPMCA2b and CaV1c are found in the same density fractions. These results suggest that ptPMCA2a and ptPMCA2b are located in the proximity of ciliary CaV channels.
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Affiliation(s)
- Junji Yano
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | - Russell Wells
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | - Ying-Wai Lam
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
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14
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Brette R. Integrative Neuroscience of Paramecium, a "Swimming Neuron". eNeuro 2021; 8:ENEURO.0018-21.2021. [PMID: 33952615 PMCID: PMC8208649 DOI: 10.1523/eneuro.0018-21.2021] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 11/28/2022] Open
Abstract
Paramecium is a unicellular organism that swims in fresh water by beating thousands of cilia. When it is stimulated (mechanically, chemically, optically, thermally…), it often swims backward then turns and swims forward again. This "avoiding reaction" is triggered by a calcium-based action potential. For this reason, some authors have called Paramecium a "swimming neuron." This review summarizes current knowledge about the physiological basis of behavior of Paramecium.
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Affiliation(s)
- Romain Brette
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Institut de la Vision, Paris 75012, France
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15
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Wang Z, Beneke T, Gluenz E, Wheeler RJ. The single flagellum of Leishmania has a fixed polarisation of its asymmetric beat. J Cell Sci 2020; 133:133/20/jcs246637. [PMID: 33093230 PMCID: PMC7595685 DOI: 10.1242/jcs.246637] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 09/17/2020] [Indexed: 12/20/2022] Open
Abstract
Eukaryotic flagella undertake different beat types as necessary for different functions; for example, the Leishmania parasite flagellum undergoes a symmetric tip-to-base beat for forward swimming and an asymmetric base-to-tip beat to rotate the cell. In multi-ciliated tissues or organisms, the asymmetric beats are coordinated, leading to movement of the cell, organism or surrounding fluid. This coordination involves a polarisation of power stroke direction. Here, we asked whether the asymmetric beat of the single Leishmania flagellum also has a fixed polarisation. We developed high frame rate dual-colour fluorescence microscopy to visualise flagellar-associated structures in live swimming cells. This showed that the asymmetric Leishmania beat is polarised, with power strokes only occurring in one direction relative to the asymmetric flagellar machinery. Polarisation of bending was retained in deletion mutants whose flagella cannot beat but have a static bend. Furthermore, deletion mutants for proteins required for asymmetric extra-axonemal and rootlet-like flagellum-associated structures also retained normal polarisation. Leishmania beat polarisation therefore likely arises from either the nine-fold rotational symmetry of the axoneme structure or is due to differences between the outer doublet decorations. Highlighted Article: By using high speed, high-resolution fluorescence microscopy of swimming Leishmania cells, we showed that the asymmetric flagellar beat always wafts in the same direction and investigate which structures are involved.
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Affiliation(s)
- Ziyin Wang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Tom Beneke
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Eva Gluenz
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Richard John Wheeler
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Kulkarni A, Elices I, Escoubet N, Pontani LL, Prevost AM, Brette R. A simple device to immobilize protists for electrophysiology and microinjection. J Exp Biol 2020; 223:jeb219253. [PMID: 32409484 DOI: 10.1242/jeb.219253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 05/05/2020] [Indexed: 11/20/2022]
Abstract
We present a simple device to mechanically immobilize motile cells such as ciliates. It can be used in particular for intracellular electrophysiology and microinjection. A transparent filter with holes smaller than the specimen is stretched over an outlet. A flow is induced by either a peristaltic pump or a depressurized tank, mechanically entraining cells to the bottom, where they are immobilized against the filter. The cells start swimming again as soon as the flow is stopped. We demonstrate the device by recording action potentials in Paramecium and injecting a fluorescent dye into the cytosol.
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Affiliation(s)
- Anirudh Kulkarni
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
| | - Irene Elices
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
| | - Nicolas Escoubet
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratoire Jean Perrin (LJP), F-75005, Paris, France
| | - Léa-Laetitia Pontani
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratoire Jean Perrin (LJP), F-75005, Paris, France
| | - Alexis Michel Prevost
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Laboratoire Jean Perrin (LJP), F-75005, Paris, France
| | - Romain Brette
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
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17
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Kawano M, Tominaga T, Ishida M, Hori M. Roles of Adenylate Cyclases in Ciliary Responses of Paramecium to Mechanical Stimulation. J Eukaryot Microbiol 2020; 67:532-540. [PMID: 32379929 DOI: 10.1111/jeu.12800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 04/14/2020] [Accepted: 04/26/2020] [Indexed: 11/28/2022]
Abstract
Paramecium shows rapid forward swimming due to increased beat frequency of cilia in normal (forward swimming) direction in response to various kinds of stimuli applied to the cell surface that cause K+ -outflow accompanied by a membrane hyperpolarization. Some adenylate cyclases are known to be functional K+ channels in the membrane. Using gene-specific knockdown methods, we examined nine paralogues of adenylate cyclases in P. tetraurelia to ascertain whether and how they are involved in the mechanical stimulus-induced hyperpolarization-coupled acceleration of forward swimming. Results demonstrated that knockdown of the adenylate cyclase 1 (ac1)-gene and 2 (ac2)-gene inhibited the acceleration of forward swimming in response to mechanical stimulation of the cell, whereas that spared the acceleration response to external application of 8-Br-cAMP and dilution of extracellular [K+ ] induced hyperpolarization. Electrophysiological examination of the knockdown cells revealed that the hyperpolarization-activated inward K+ current is smaller than that of a normal cell. Our results suggest that AC1 and AC2 are involved in the mechanical stimulus-induced acceleration of ciliary beat in Paramecium.
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Affiliation(s)
- Mutsumi Kawano
- Faculty of Science, Yamaguchi University, Yamaguchi, 753-8512, Japan
| | - Takashi Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Kagawa, 769-2193, Japan
| | - Masaki Ishida
- School of Science Education, Nara University of Education, Nara, 630-8528, Japan
| | - Manabu Hori
- Faculty of Science, Yamaguchi University, Yamaguchi, 753-8512, Japan
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Valentine MS, Yano J, Van Houten J. A Novel Role for Polycystin-2 (Pkd2) in P. tetraurelia as a Probable Mg 2+ Channel Necessary for Mg 2+-Induced Behavior. Genes (Basel) 2019; 10:genes10060455. [PMID: 31207979 PMCID: PMC6627415 DOI: 10.3390/genes10060455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/05/2019] [Accepted: 06/11/2019] [Indexed: 01/26/2023] Open
Abstract
A human ciliopathy gene codes for Polycystin-2 (Pkd2), a non-selective cation channel. Here, the Pkd2 channel was explored in the ciliate Paramecium tetraurelia using combinations of RNA interference, over-expression, and epitope-tagging, in a search for function and novel interacting partners. Upon depletion of Pkd2, cells exhibited a phenotype similar to eccentric (XntA1), a Paramecium mutant lacking the inward Ca2+-dependent Mg2+ conductance. Further investigation showed both Pkd2 and XntA localize to the cilia and cell membrane, but do not require one another for trafficking. The XntA-myc protein co-immunoprecipitates Pkd2-FLAG, but not vice versa, suggesting two populations of Pkd2-FLAG, one of which interacts with XntA. Electrophysiology data showed that depletion and over-expression of Pkd2 led to smaller and larger depolarizations in Mg2+ solutions, respectively. Over-expression of Pkd2-FLAG in the XntA1 mutant caused slower swimming, supporting an increase in Mg2+ permeability, in agreement with the electrophysiology data. We propose that Pkd2 in P. tetraurelia collaborates with XntA for Mg2+-induced behavior. Our data suggest Pkd2 is sufficient and necessary for Mg2+ conductance and membrane permeability to Mg2+, and that Pkd2 is potentially a Mg2+-permeable channel.
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Affiliation(s)
- Megan S Valentine
- State University of New York at Plattsburgh, 101 Broad Street, Plattsburgh, NY 12901, USA.
| | - Junji Yano
- University of Vermont, Department of Biology, 120 Marsh Life Science, 109 Carrigan Drive, Burlington, VT 05405, USA.
| | - Judith Van Houten
- University of Vermont, Department of Biology, 120 Marsh Life Science, 109 Carrigan Drive, Burlington, VT 05405, USA.
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Abstract
Imagine that in 1678 you are Christiaan Huygens or Antonie van Leeuwenhoek seeing paramecia swim gracefully across the field of view of your new microscope. These unicellular, free-living, and swimming cells might have remained a curiosity if not for the ability of H.S. Jennings (Behavior of the lower organisms. Indiana University Press, Bloomington, 1906) and T.M. Sonneborn (Proc Natl Acad Sci USA 23:378-385, 1937) to recognize them for their behavior and genetics, both Mendelian and non-Mendelian. Following many years of painstaking work by Sonneborn and other researchers, Paramecium now serves as a modern model organism that has made specific contributions to cell and molecular biology and development. We will review the continuing usefulness and contributions of Paramecium species in this chapter.Even without a microscope, Paramecium species is visible to the naked eye because of their size (50-300 μ long). Paramecia are holotrichous ciliates, that is, unicellular organisms in the phylum Ciliophora that are covered with cilia. It was the beating of these cilia that propelled them across the slides of the first microscopes and continue to fascinate us today. Over time, Paramecium became a favorite model organism for a large variety of studies. Denis Lyn has called Paramecium the "white rat" of the Ciliophora for their manipulability and amenity to research. We will touch upon the use of Paramecium species to examine swimming behavior, ciliary structure and function, ion channel function, basal body duplication and patterning, non-Mendelian cortical inheritance, programmed DNA rearrangements, regulated secretion and exocytosis, and cell trafficking. In particular, we will focus on the use of P. tetraurelia and P. caudatum.
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20
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Wan KY, Goldstein RE. Time Irreversibility and Criticality in the Motility of a Flagellate Microorganism. PHYSICAL REVIEW LETTERS 2018; 121:058103. [PMID: 30118294 PMCID: PMC7616082 DOI: 10.1103/physrevlett.121.058103] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 03/27/2018] [Indexed: 06/08/2023]
Abstract
Active living organisms exhibit behavioral variability, partitioning between fast and slow dynamics. Such variability may be key to generating rapid responses in a heterogeneous, unpredictable environment wherein cellular activity effects continual exchanges of energy fluxes. We demonstrate a novel, noninvasive strategy for revealing nonequilibrium control of swimming-specifically, in an octoflagellate microalga. These organisms exhibit surprising features of flagellar excitability and mechanosensitivity, which characterize a novel, time-irreversible "run-stop-shock" motility comprising forward runs, knee-jerk shocks with dramatic beat reversal, and long stops during which cells are quiescent yet continue to exhibit submicron flagellar vibrations. Entropy production, associated with flux cycles arising in a reaction graph representation of the gait-switching dynamics, provides a direct measure of detailed balance violation in this primitive alga.
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Affiliation(s)
- Kirsty Y. Wan
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Cambridge CB3 0WA, United Kingdom
- Living Systems Institute, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Raymond E. Goldstein
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Cambridge CB3 0WA, United Kingdom
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21
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Phenomena of synchronized response in biosystems and the possible mechanism. Biochem Biophys Res Commun 2018; 496:661-666. [DOI: 10.1016/j.bbrc.2018.01.118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 01/14/2018] [Accepted: 01/18/2018] [Indexed: 11/18/2022]
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Kunita I, Yamaguchi T, Tero A, Akiyama M, Kuroda S, Nakagaki T. A ciliate memorizes the geometry of a swimming arena. J R Soc Interface 2017; 13:rsif.2016.0155. [PMID: 27226383 DOI: 10.1098/rsif.2016.0155] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 04/20/2016] [Indexed: 11/12/2022] Open
Abstract
Previous studies on adaptive behaviour in single-celled organisms have given hints to the origin of their memorizing capacity. Here we report evidence that a protozoan ciliate Tetrahymena has the capacity to learn the shape and size of its swimming space. Cells confined in a small water droplet for a short period were found to recapitulate circular swimming trajectories upon release. The diameter of the circular trajectories and their duration reflected the size of the droplet and the period of confinement. We suggest a possible mechanism for this adaptive behaviour based on a Ca(2+) channel. In our model, repeated collisions with the walls of a confining droplet result in a slow rise in intracellular calcium that leads to a long-term increase in the reversal frequency of the ciliary beat.
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Affiliation(s)
- Itsuki Kunita
- Research Institute for Electronic Science, Hokkaido University, N20W10, Kita-Ward Sapporo 001-0020, Japan
| | - Tatsuya Yamaguchi
- Graduate School of Mathematics, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Atsushi Tero
- Graduate School of Mathematics, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan Institute of Mathematics for Industry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Masakazu Akiyama
- Research Institute for Electronic Science, Hokkaido University, N20W10, Kita-Ward Sapporo 001-0020, Japan
| | - Shigeru Kuroda
- Research Institute for Electronic Science, Hokkaido University, N20W10, Kita-Ward Sapporo 001-0020, Japan
| | - Toshiyuki Nakagaki
- Research Institute for Electronic Science, Hokkaido University, N20W10, Kita-Ward Sapporo 001-0020, Japan
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Lodh S, Yano J, Valentine MS, Van Houten JL. Voltage-gated calcium channels of Paramecium cilia. ACTA ACUST UNITED AC 2017; 219:3028-3038. [PMID: 27707864 DOI: 10.1242/jeb.141234] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/19/2016] [Indexed: 01/08/2023]
Abstract
Paramecium cells swim by beating their cilia, and make turns by transiently reversing their power stroke. Reversal is caused by Ca2+ entering the cilium through voltage-gated Ca2+ (CaV) channels that are found exclusively in the cilia. As ciliary Ca2+ levels return to normal, the cell pivots and swims forward in a new direction. Thus, the activation of the CaV channels causes cells to make a turn in their swimming paths. For 45 years, the physiological characteristics of the Paramecium ciliary CaV channels have been known, but the proteins were not identified until recently, when the P. tetraurelia ciliary membrane proteome was determined. Three CaVα1 subunits that were identified among the proteins were cloned and confirmed to be expressed in the cilia. We demonstrate using RNA interference that these channels function as the ciliary CaV channels that are responsible for the reversal of ciliary beating. Furthermore, we show that Pawn (pw) mutants of Paramecium that cannot swim backward for lack of CaV channel activity do not express any of the three CaV1 channels in their ciliary membrane, until they are rescued from the mutant phenotype by expression of the wild-type PW gene. These results reinforce the correlation of the three CaV channels with backward swimming through ciliary reversal. The PwB protein, found in endoplasmic reticulum fractions, co-immunoprecipitates with the CaV1c channel and perhaps functions in trafficking. The PwA protein does not appear to have an interaction with the channel proteins but affects their appearance in the cilia.
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Affiliation(s)
- Sukanya Lodh
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | - Junji Yano
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | - Megan S Valentine
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
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Wakazono Y, Sakurai T, Terakawa S. Suppression of ciliary movements by a hypertonic stress in the newt olfactory receptor neuron. Am J Physiol Cell Physiol 2017; 313:C371-C379. [PMID: 28684540 DOI: 10.1152/ajpcell.00243.2016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 06/26/2017] [Accepted: 06/26/2017] [Indexed: 11/22/2022]
Abstract
Olfactory receptor neurons isolated from the newt maintain a high activity of the ciliary beat. A cilium of neuron is so unique that only little is known about regulatory factors for its beat frequency. We examined the olfactory receptor neuron immersed in various extracellular media under the video-enhanced differential interference contrast microscope. The activation of voltage-gated Ca2+ channels by K+ depolarization or by application of Ca2+ to membrane-permeabilized olfactory cells did not affect the ciliary movement, suggesting that Ca2+ influx through the cell membrane has no direct effect on the movement. However, when an extracellular medium contained NaCl or sucrose at concentrations only 30% higher than normal levels, ciliary movement was greatly and reversibly suppressed. In contrast, a hypotonic solution of such a solute did not change the ciliary movement. The hypertonic solutions had no effect when applied to permeabilized cells. Suction of the cell membrane with a patch pipette easily suppressed the ciliary movement in an isotonic medium. Application of positive pressure inside the cell through the same patch pipette eliminated the suppressive effect. From these findings, we concluded that the hypertonic stress suppressed the ciliary movement not by disabling the motor proteins, microtubules, or their associates in the cilia, but rather by modifying the chemical environment for the motor proteins. The ciliary motility of the olfactory receptor cell is directly sensitive to the external environment, namely, the air or water on the nasal epithelium, depending on lifestyle of the animal.
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Affiliation(s)
- Yoshihiko Wakazono
- Medical Photonics Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan.,Department of Physiology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan; and
| | - Takashi Sakurai
- Medical Photonics Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Susumu Terakawa
- Medical Photonics Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan; .,Faculty of Health Science, Tokoha University, Shizuoka, Japan
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Behavioral Effects of a Chemorepellent Receptor Knockout Mutation in Tetrahymena thermophila. mSphere 2017; 2:mSphere00182-17. [PMID: 28685161 PMCID: PMC5497023 DOI: 10.1128/msphere.00182-17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 05/25/2017] [Indexed: 12/19/2022] Open
Abstract
Although many single-cell eukaryotes have served as classical model systems for chemosensory studies for decades, the major emphasis has been on chemoattraction and no chemorepellent receptor gene has been identified in any unicellular eukaryote. This is the first description of a gene that codes for a chemorepellent receptor in any protozoan. Integration of both depolarizing chemorepellent pathways and hyperpolarizing chemoattractant pathways is as important to chemoresponses of motile unicells as excitatory and inhibitory neurotransmitter pathways are to neurons. Therefore, both chemoattractant and chemorepellent pathways should be represented in a useful unicellular model system. Tetrahymena cells provide such a model system because simple behavioral bioassays, gene knockouts, biochemical analysis, and other approaches can be used with these eukaryotic model cells. This work can contribute to the basic understanding of unicellular sensory responses and provide insights into the evolution of chemoreceptors and possible chemorepellent approaches for preventing infections by some pathogenic protozoa. A conditioned supernatant from Tetrahymena thermophila contains a powerful chemorepellent for wild-type cells, and a gene called G37 is required for this response. This is the first genomic identification of a chemorepellent receptor in any eukaryotic unicellular organism. This conditioned supernatant factor (CSF) is small (<1 kDa), and its repellent effect is resistant to boiling, protease treatment, and nuclease digestion. External BAPTA eliminated the CSF response, suggesting that Ca2+ entry is required for the classical avoiding reactions (AR) used for chemorepulsion. A macronuclear G37 gene knockout (G37-KO) mutant is both nonresponsive to the CSF and overresponsive to other repellents such as quinine, lysozyme, GTP, and high potassium concentrations. All of these mutant phenotypes were reversed by overexpression of the wild-type G37 gene in a G37 overexpression mutant. Overexpression of G37 in the wild type caused increased responsiveness to the CSF and underresponsiveness to high K+ concentrations. Behavioral adaptation (by prolonged exposure to the CSF) caused decreases in responsiveness to all of the stimuli used in the wild type and the overexpression mutant but not in the G37-KO mutant. We propose that the constant presence of the CSF causes a decreased basal excitability of the wild type due to chemosensory adaptation through G37 and that all of the G37-KO phenotypes are due to an inability to detect the CSF. Therefore, the G37 protein may be the CSF receptor. The physiological role of these G37-mediated responses may be to both moderate basal excitability and detect the CSF as an indicator of high cell density growth. IMPORTANCE Although many single-cell eukaryotes have served as classical model systems for chemosensory studies for decades, the major emphasis has been on chemoattraction and no chemorepellent receptor gene has been identified in any unicellular eukaryote. This is the first description of a gene that codes for a chemorepellent receptor in any protozoan. Integration of both depolarizing chemorepellent pathways and hyperpolarizing chemoattractant pathways is as important to chemoresponses of motile unicells as excitatory and inhibitory neurotransmitter pathways are to neurons. Therefore, both chemoattractant and chemorepellent pathways should be represented in a useful unicellular model system. Tetrahymena cells provide such a model system because simple behavioral bioassays, gene knockouts, biochemical analysis, and other approaches can be used with these eukaryotic model cells. This work can contribute to the basic understanding of unicellular sensory responses and provide insights into the evolution of chemoreceptors and possible chemorepellent approaches for preventing infections by some pathogenic protozoa.
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Carrisoza-Gaytán R, Wang L, Schreck C, Kleyman TR, Wang WH, Satlin LM. The mechanosensitive BKα/β1 channel localizes to cilia of principal cells in rabbit cortical collecting duct (CCD). Am J Physiol Renal Physiol 2016; 312:F143-F156. [PMID: 27806944 DOI: 10.1152/ajprenal.00256.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 10/12/2016] [Accepted: 10/26/2016] [Indexed: 11/22/2022] Open
Abstract
Within the CCD of the distal nephron of the rabbit, the BK (maxi K) channel mediates Ca2+- and/or stretch-dependent flow-induced K+ secretion (FIKS) and contributes to K+ adaptation in response to dietary K+ loading. An unresolved question is whether BK channels in intercalated cells (ICs) and/or principal cells (PCs) in the CCD mediate these K+ secretory processes. In support of a role for ICs in FIKS is the higher density of immunoreactive apical BKα (pore-forming subunit) and functional BK channel activity than detected in PCs, and an increase in IC BKα expression in response to a high-K+ diet. PCs possess a single apical cilium which has been proposed to serve as a mechanosensor; direct manipulation of cilia leads to increases in cell Ca2+ concentration, albeit of nonciliary origin. Immunoperfusion of isolated and fixed CCDs isolated from control K+-fed rabbits with channel subunit-specific antibodies revealed colocalization of immunodetectable BKα- and β1-subunits in cilia as well as on the apical membrane of cilia-expressing PCs. Ciliary BK channels were more easily detected in rabbits fed a low-K+ vs. high-K+ diet. Single-channel recordings of cilia revealed K+ channels with conductance and kinetics typical of the BK channel. The observations that 1) FIKS was preserved but 2) the high-amplitude Ca2+ peak elicited by flow was reduced in microperfused CCDs subject to pharmacological deciliation suggest that cilia BK channels do not contribute to K+ secretion in this segment, but that cilia serve as modulators of cell signaling.
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Affiliation(s)
| | - Lijun Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Carlos Schreck
- Servicio de Nefrologia-Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
| | - Thomas R Kleyman
- Departments of Medicine, Cell Biology, and Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Lisa M Satlin
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, New York;
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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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28
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Yano J, Valentine MS, Van Houten JL. Novel Insights into the Development and Function of Cilia Using the Advantages of the Paramecium Cell and Its Many Cilia. Cells 2015; 4:297-314. [PMID: 26230712 PMCID: PMC4588038 DOI: 10.3390/cells4030297] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/16/2015] [Accepted: 07/24/2015] [Indexed: 12/26/2022] Open
Abstract
Paramecium species, especially P. tetraurelia and caudatum, are model organisms for modern research into the form and function of cilia. In this review, we focus on the ciliary ion channels and other transmembrane proteins that control the beat frequency and wave form of the cilium by controlling the signaling within the cilium. We put these discussions in the context of the advantages that Paramecium brings to the understanding of ciliary motility: mutants for genetic dissections of swimming behavior, electrophysiology, structural analysis, abundant cilia for biochemistry and modern proteomics, genomics and molecular biology. We review the connection between behavior and physiology, which allows the cells to broadcast the function of their ciliary channels in real time. We build a case for the important insights and advantages that this model organism continues to bring to the study of cilia.
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Affiliation(s)
- Junji Yano
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | - Megan S Valentine
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
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29
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Amaroli A, Ravera S, Parker S, Panfoli I, Benedicenti A, Benedicenti S. Effect of 808 nm Diode Laser on Swimming Behavior, Food Vacuole Formation and Endogenous ATP Production of Paramecium primaurelia (Protozoa). Photochem Photobiol 2015; 91:1150-5. [PMID: 26118482 DOI: 10.1111/php.12486] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/18/2015] [Indexed: 12/19/2022]
Abstract
Photobiomodulation (PBM) has been used in clinical practice for more than 40 years. To clarify the mechanisms of action of PBM at cellular and organism levels, we investigated its effect on Paramecium primaurelia (Protozoa) irradiated by an 808 nm infrared diode laser with a flat-top handpiece (1 W in CW). Our results led to the conclusion that: (1) the 808 nm laser stimulates the P. primaurelia without a thermal effect, (2) the laser effect is demonstrated by an increase in swimming speed and in food vacuole formation, (3) the laser treatment affects endogenous adenosine triphosphate (ATP) production in a positive way, (4) the effects of irradiation dose suggest an optimum exposure time of 50 s (64 J cm(-2) of fluence) to stimulate the Paramecium cells; irradiation of 25 s shows no effect or only mild effects and irradiation up to 100 s does not increase the effect observed with 50 s of treatment, (5) the increment of endogenous ATP concentration highlights the positive photobiomodulating effect of the 808 nm laser and the optimal irradiation conditions by the flat-top handpiece.
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Affiliation(s)
- Andrea Amaroli
- Department of Earth, Environmental and Life Sciences, Protistology Laboratory, University of Genoa, Genoa, Italy
| | - Silvia Ravera
- Department of Pharmacy, Biochemistry Laboratory, University of Genoa, Genoa, Italy
| | - Steven Parker
- Department of Surgical Sciences and Integrated Diagnostic, University of Genoa, Genoa, Italy
| | - Isabella Panfoli
- Department of Pharmacy, Biochemistry Laboratory, University of Genoa, Genoa, Italy
| | - Alberico Benedicenti
- Department of Surgical Sciences and Integrated Diagnostic, University of Genoa, Genoa, Italy
| | - Stefano Benedicenti
- Department of Surgical Sciences and Integrated Diagnostic, University of Genoa, Genoa, Italy
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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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Aubusson-Fleury A, Cohen J, Lemullois M. Ciliary heterogeneity within a single cell: the Paramecium model. Methods Cell Biol 2015; 127:457-85. [PMID: 25837404 DOI: 10.1016/bs.mcb.2014.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Paramecium is a single cell able to divide in its morphologically differentiated stage that has many cilia anchored at its cell surface. Many thousands of cilia are thus assembled in a short period of time during division to duplicate the cell pattern while the cell continues swimming. Most, but not all, of these sensory cilia are motile and involved in two main functions: prey capture and cell locomotion. These cilia display heterogeneity, both in their length and their biochemical properties. Thanks to these properties, as well as to the availability of many postgenomic tools and the possibility to follow the regrowth of cilia after deciliation, Paramecium offers a nice opportunity to study the assembly of the cilia, as well as the genesis of their diversity within a single cell. In this paper, after a brief survey of Paramecium morphology and cilia properties, we describe the tools and the protocols currently used for immunofluorescence, transmission electron microscopy, and ultrastructural immunocytochemistry to analyze cilia, with special recommendations to overcome the problem raised by cilium diversity.
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Affiliation(s)
- Anne Aubusson-Fleury
- Centre de Génétique Moléculaire, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Bat 26 Allée de la terrasse, 91 198 Gif sur Yvette Cedex, France
| | - Jean Cohen
- Centre de Génétique Moléculaire, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Bat 26 Allée de la terrasse, 91 198 Gif sur Yvette Cedex, France
| | - Michel Lemullois
- Centre de Génétique Moléculaire, Institute for Integrative Biology of the Cell (I2BC), Université Paris Saclay, CEA, CNRS, Université Paris Sud, Bat 26 Allée de la terrasse, 91 198 Gif sur Yvette Cedex, France
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Abstract
Cilia are highly conserved for their structure and also for their sensory functions. They serve as antennae for extracellular information. Whether the cilia are motile or not, they respond to environmental mechanical and chemical stimuli and signal to the cell body. The information from extracellular stimuli is commonly converted to electrical signals through the repertoire of ion-conducting channels in the ciliary membrane resulting in changes in concentrations of ions, especially Ca2+, in the cilia. These changes, in turn, affect motility and signaling pathways in the cilia and cell body to carry on the signal transduction. We review here the activities of ion channels in cilia from protists to vertebrates.
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Affiliation(s)
- Steven J Kleene
- Department of Molecular and Cellular Physiology University of Cincinnati Cincinnati, OH 45267-0576 USA 1-513-558-6099 (phone) 1-513-558-5738 (fax)
| | - Judith L Van Houten
- Department of Biology University of Vermont Burlington, VT 05405, USA 1-802-656-0452 (phone) 1-802-656-2914 (FAX)
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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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Wan GJ, Jiang SL, Zhao ZC, Xu JJ, Tao XR, Sword GA, Gao YB, Pan WD, Chen FJ. Bio-effects of near-zero magnetic fields on the growth, development and reproduction of small brown planthopper, Laodelphax striatellus and brown planthopper, Nilaparvata lugens. JOURNAL OF INSECT PHYSIOLOGY 2014; 68:7-15. [PMID: 24995837 DOI: 10.1016/j.jinsphys.2014.06.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 06/04/2014] [Accepted: 06/18/2014] [Indexed: 06/03/2023]
Abstract
Magnetic fields markedly affect the growth and development of many species of organisms potentially due to cryptochrome and endogenous presence of magnetic materials. Sensitivity to magnetic fields can also be involved in geomagnetic orientation by some long-distance migratory insects. In this study, near-zero magnetic fields (NZMF) in relation to normal geomagnetic fields (GMF) were setup using the Hypomagnetic Field Space System (HMFs) to investigate the effects of magnetic fields on the growth, development and reproduction of two species of migratory planthopper, the small brown planthopper (abbr. SBPH), Laodelphax striatellus, and the brown planthopper (abbr. BPH), Nilaparvata lugens. Exposure of both L. striatellus and N. lugens to NZMF delayed egg and nymphal developmental durations and decreased adult weight and female fecundity. The 1st-5th instars of SBPH and BPH showed different responses to NZMF. The 4th instar was significantly affected by NZMF, especially for BPH males, in which NZMF exposure reduced the difference in development duration between females and males. Compared with GMF, the vitellogenin transcript levels of newly molted female adults and the number of eggs per female were significantly reduced in both planthopper species, indicating a negative effect on fertility under NZMF. Our findings provided experimental evidence that NZMF negatively affected the growth and development of SBPH and BPH, with particularly strong effects on reproduction.
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Affiliation(s)
- Gui-jun Wan
- Laboratory of Insect-Information Ecology, Department of Entomology, Nanjing Agricultural University, Nanjing 210095, China
| | - Shou-lin Jiang
- Laboratory of Insect-Information Ecology, Department of Entomology, Nanjing Agricultural University, Nanjing 210095, China
| | - Zong-chao Zhao
- Laboratory of Insect-Information Ecology, Department of Entomology, Nanjing Agricultural University, Nanjing 210095, China
| | - Jing-jing Xu
- Beijing Key Laboratory of Bioelectromagetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiao-rong Tao
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Gregory A Sword
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Yue-bo Gao
- Institute of Plant Protection, Jilin Academy of Agricultural Sciences, Changchun 130124, China
| | - Wei-dong Pan
- Beijing Key Laboratory of Bioelectromagetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China.
| | - Fa-jun Chen
- Laboratory of Insect-Information Ecology, Department of Entomology, Nanjing Agricultural University, Nanjing 210095, China.
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Kunita I, Kuroda S, Ohki K, Nakagaki T. Attempts to retreat from a dead-ended long capillary by backward swimming in Paramecium. Front Microbiol 2014; 5:270. [PMID: 24966852 PMCID: PMC4052044 DOI: 10.3389/fmicb.2014.00270] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 05/16/2014] [Indexed: 11/13/2022] Open
Abstract
We have observed how the ciliate Paramecium attempts to retreat from the dead-end of a long capillary that is too narrow for turning. After many trial-and-error episodes of short-term backward swimming (SBS), which is the conventional avoidance behavior exhibited in free swimming when an obstacle is faced, long-term backward swimming (LBS) that lasted five to ten times longer was developed. LBS may have a beneficial effect for complete withdrawal from the capillary space, although in our experiment it was impossible for the organism to do so due to the capillary length. In order to identify a physically possible mechanism for LBS, we propose model equations for the membrane potential of Hodgkin-Huxley type, which describe the control of ciliary movement. The physiological implications and physical mechanism of the development of LBS are discussed.
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Affiliation(s)
- Itsuki Kunita
- Physical Ethology Laboratory, Research Institute for Electronic Science, Hokkaido University Sapporo, Hokkaido, Japan
| | - Shigeru Kuroda
- Physical Ethology Laboratory, Research Institute for Electronic Science, Hokkaido University Sapporo, Hokkaido, Japan
| | - Kaito Ohki
- Department of Complex and Intelligent Systems, Faculty of Systems Information Science, Future University Hakodate Hakodate, Japan
| | - Toshiyuki Nakagaki
- Physical Ethology Laboratory, Research Institute for Electronic Science, Hokkaido University Sapporo, Hokkaido, Japan ; JST, CREST Tokyo, Japan
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Teng J, Loukin S, Anishkin A, Kung C. The force-from-lipid (FFL) principle of mechanosensitivity, at large and in elements. Pflugers Arch 2014; 467:27-37. [PMID: 24888690 DOI: 10.1007/s00424-014-1530-2] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 04/29/2014] [Accepted: 05/05/2014] [Indexed: 12/27/2022]
Abstract
Focus on touch and hearing distracts attention from numerous subconscious force sensors, such as the vital control of blood pressure and systemic osmolarity, and sensors in nonanimals. Multifarious manifestations should not obscure invariant and fundamental physicochemical principles. We advocate that force from lipid (FFL) is one such principle. It is based on the fact that the self-assembled bilayer necessitates inherent forces that are large and anisotropic, even at life's origin. Functional response of membrane proteins is governed by bilayer force changes. Added stress can redirect these forces, leading to geometric changes of embedded proteins such as ion channels. The FFL principle was first demonstrated when purified bacterial mechanosensitive channel of large conductance (MscL) remained mechanosensitive (MS) after reconstituting into bilayers. This key experiment has recently been unequivocally replicated with two vertebrate MS K2p channels. Even the canonical Kv and the Drosophila canonical transient receptor potentials (TRPCs) have now been shown to be MS in biophysical and in physiological contexts, supporting the universality of the FFL paradigm. We also review the deterministic role of mechanical force during stem cell differentiation as well as the cell-cell and cell-matrix tethers that provide force communications. In both the ear hair cell and the worm's touch neuron, deleting the cadherin or microtubule tethers reduces but does not eliminate MS channel activities. We found no evidence to distinguish whether these tethers directly pull on the channel protein or a surrounding lipid platform. Regardless of the implementation, pulling tether tenses up the bilayer. Membrane tenting is directly visible at the apexes of the stereocilia.
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Affiliation(s)
- Jinfeng Teng
- Laboratory of Molecular Biology, University of Wisconsin, Madison, WI, 53706, USA
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Maier I, Calenberg M. Effect of Extracellular Ca2+and Ca2+-Antagonists on the Movement and Chemoorientation of Male Gametes ofEctocarpus siliculosus(Phaeophyceae). ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1994.tb00820.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Stock C, Ludwig FT, Hanley PJ, Schwab A. Roles of ion transport in control of cell motility. Compr Physiol 2013; 3:59-119. [PMID: 23720281 DOI: 10.1002/cphy.c110056] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell motility is an essential feature of life. It is essential for reproduction, propagation, embryonic development, and healing processes such as wound closure and a successful immune defense. If out of control, cell motility can become life-threatening as, for example, in metastasis or autoimmune diseases. Regardless of whether ciliary/flagellar or amoeboid movement, controlled motility always requires a concerted action of ion channels and transporters, cytoskeletal elements, and signaling cascades. Ion transport across the plasma membrane contributes to cell motility by affecting the membrane potential and voltage-sensitive ion channels, by inducing local volume changes with the help of aquaporins and by modulating cytosolic Ca(2+) and H(+) concentrations. Voltage-sensitive ion channels serve as voltage detectors in electric fields thus enabling galvanotaxis; local swelling facilitates the outgrowth of protrusions at the leading edge while local shrinkage accompanies the retraction of the cell rear; the cytosolic Ca(2+) concentration exerts its main effect on cytoskeletal dynamics via motor proteins such as myosin or dynein; and both, the intracellular and the extracellular H(+) concentration modulate cell migration and adhesion by tuning the activity of enzymes and signaling molecules in the cytosol as well as the activation state of adhesion molecules at the cell surface. In addition to the actual process of ion transport, both, channels and transporters contribute to cell migration by being part of focal adhesion complexes and/or physically interacting with components of the cytoskeleton. The present article provides an overview of how the numerous ion-transport mechanisms contribute to the various modes of cell motility.
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Affiliation(s)
- Christian Stock
- Institute of Physiology II, University of Münster, Münster, Germany.
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Abstract
Microorganisms and specifically motile bacteria have been recently added to the list of micro-actuators typically considered for the implementation of microsystems and microrobots. Such trend has been motivated by the fact these microorganisms are self-powered actuators with overall sizes at the lower end of the micrometer range and which have proven to be extremely effective in low Reynolds number hydrodynamic regime of usually less than 10(-2). Furthermore, the various sensors or taxes in bacteria influencing their movements can also be exploited to perform tasks that were previously considered only for futuristic artificial microrobots. Bacterial implementations and related issues are not only reviewed, but this paper also proposes many techniques and approaches that can be considered as building blocks for the implementations of more sophisticated microsystems and microrobots.
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Schwab A, Fabian A, Hanley PJ, Stock C. Role of ion channels and transporters in cell migration. Physiol Rev 2013; 92:1865-913. [PMID: 23073633 DOI: 10.1152/physrev.00018.2011] [Citation(s) in RCA: 315] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cell motility is central to tissue homeostasis in health and disease, and there is hardly any cell in the body that is not motile at a given point in its life cycle. Important physiological processes intimately related to the ability of the respective cells to migrate include embryogenesis, immune defense, angiogenesis, and wound healing. On the other side, migration is associated with life-threatening pathologies such as tumor metastases and atherosclerosis. Research from the last ≈ 15 years revealed that ion channels and transporters are indispensable components of the cellular migration apparatus. After presenting general principles by which transport proteins affect cell migration, we will discuss systematically the role of channels and transporters involved in cell migration.
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Ramoino P, Candiani S, Pittaluga AM, Usai C, Gallus L, Ferrando S, Milanese M, Faimali M, Bonanno G. Pharmacological characterization of N-methyl-d-aspartic acid (NMDA)-like receptors in the single-celled organism Paramecium primaurelia. J Exp Biol 2013; 217:463-71. [DOI: 10.1242/jeb.093914] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Summary
Paramecium primaurelia is a unicellular eukaryote that moves in freshwater by ciliary beating and responds to environmental stimuli by altering motile behaviour. The movements of the cilia are controlled by the electrical changes of the cell membrane: when the intraciliary Ca2+ concentration associated with plasma membrane depolarization increases, the ciliary beating reverses its direction, and consequently the swimming direction changes. The ciliary reversal duration is correlated with the amount of Ca2+ influx. Here we evaluated the effects due to the activation or blockade of NMDA receptors on swimming behaviour in Paramecium. Paramecia normally swim forward drawing almost linear tracks. We observed that the simultaneous administration of NMDA and glycine induced a partial ciliary reversal (PaCR) leading to a continuous spiral-like swim. Furthermore, the duration of continuous ciliary reversal (CCR), triggered by high external KCl concentrations, was longer in NMDA/glycine treated cells. NMDA action required the presence of Ca2+, as the normal forward swimming was restored when the ion was omitted from the extracellular milieu. The PaCR and the enhancement of CCR duration significantly decreased when the antagonists of the glutamate site D-AP5 or CGS19755, the NMDA channel blocker MK-801, or the glycine site antagonist DCKA were added. The action of NMDA/glycine was also abolished by Zn2+ or ifenprodil, the GluN2A and the GluN2B NMDA-containing subunit blockers, respectively. Searches of the Paramecium genome database currently available indicate that the NMDA-like receptor with ligand binding characteristics of an NMDA receptor-like complex, purified from rat brain synaptic membranes and found in some metazoan genome, is also present in Paramecium. These results provide evidence that functional NMDA receptors similar to those typical of mammalian neuronal cells are present in the single-celled organism Paramecium and thus suggest that the glutamatergic NMDA system is a phylogenetically old behaviour-controlling mechanism.
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Proteomic analysis of the cilia membrane of Paramecium tetraurelia. J Proteomics 2012; 78:113-22. [PMID: 23146917 DOI: 10.1016/j.jprot.2012.09.040] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 08/21/2012] [Accepted: 09/30/2012] [Indexed: 02/01/2023]
Abstract
Channels, pumps, receptors, cyclases and other membrane proteins modulate the motility and sensory function of cilia, but these proteins are generally under-represented in proteomic analyses of cilia. Studies of these ciliary membrane proteins would benefit from a protocol to greatly enrich for integral and lipidated membrane proteins. We used LC-MS/MS to compare the proteomes of unfractionated cilia (C), the ciliary membrane (CM) and the ciliary membrane in the detergent phase (DP) of Triton X-114 phase separation. 55% of the proteins in DP were membrane proteins (i.e. predicted transmembrane or membrane-associated through lipid modifications) and 31% were transmembrane. This is to be compared to 23% membrane proteins with 9% transmembrane in CM and 9% membrane proteins with 3% transmembrane in C. 78% of the transmembrane proteins in the DP were found uniquely in DP, and not in C or CM. There were ion channels, cyclases, plasma membrane pumps, Ca(2+) dependent protein kinases, and Rab GTPases involved in the signal transduction in DP that were not identified in the other C and CM preparations. Of 267 proteins unique to the DP, 147 were novel, i.e. not found in other proteomic and genomic studies of cilia.
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Valentine MS, Rajendran A, Yano J, Weeraratne SD, Beisson J, Cohen J, Koll F, Van Houten J. Paramecium BBS genes are key to presence of channels in Cilia. Cilia 2012; 1:16. [PMID: 23351336 PMCID: PMC3556005 DOI: 10.1186/2046-2530-1-16] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 06/14/2012] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED BACKGROUND Changes in genes coding for ciliary proteins contribute to complex human syndromes called ciliopathies, such as Bardet-Biedl Syndrome (BBS). We used the model organism Paramecium to focus on ciliary ion channels that affect the beat form and sensory function of motile cilia and evaluate the effects of perturbing BBS proteins on these channels. METHODS We used immunoprecipitations and mass spectrometry to explore whether Paramecium proteins interact as in mammalian cells. We used RNA interference (RNAi) and swimming behavior assays to examine the effects of BBS depletion on ciliary ion channels that control ciliary beating. Combining RNA interference and epitope tagging, we examined the effects of BBS depletion of BBS 7, 8 and 9 on the location of three channels and a chemoreceptor in cilia. RESULTS We found 10 orthologs of 8 BBS genes in P. tetraurelia. BBS1, 2, 4, 5, 7, 8 and 9 co-immunoprecipitate. While RNAi reduction of BBS 7 and 9 gene products caused loss and shortening of cilia, RNAi for all BBS genes except BBS2 affected patterns of ciliary motility that are governed by ciliary ion channels. Swimming behavior assays pointed to loss of ciliary K+ channel function. Combining RNAi and epitope tagged ciliary proteins we demonstrated that a calcium activated K+ channel was no longer located in the cilia upon depletion of BBS 7, 8 or 9, consistent with the cells' swimming behavior. The TRPP channel PKD2 was also lost from the cilia. In contrast, the ciliary voltage gated calcium channel was unaffected by BBS depletion, consistent with behavioral assays. The ciliary location of a chemoreceptor for folate was similarly unperturbed by the depletion of BBS 7, 8 or 9. CONCLUSIONS The co-immunoprecipitation of BBS 1,2,4,5,7,8, and 9 suggests a complex of BBS proteins. RNAi for BBS 7, 8 or 9 gene products causes the selective loss of K+ and PKD2 channels from the cilia while the critical voltage gated calcium channel and a peripheral receptor protein remain undisturbed. These channels govern ciliary beating and sensory function. Importantly, in P. tetraurelia we can combine studies of ciliopathy protein function with behavior and location and control of ciliary channels.
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Affiliation(s)
- Megan Smith Valentine
- Department of Biology, University of Vermont, 109 Carrigan Drive, Burlington, VT, 05405, USA
| | - Anbazhagan Rajendran
- Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, 02215, USA
| | - Junji Yano
- Department of Biology, University of Vermont, 109 Carrigan Drive, Burlington, VT, 05405, USA
| | | | - Janine Beisson
- Center for Molecular Genetics, National Center for Scientific Research, Génétique Moléculaire, CNRS, Gif-sur-Yvette, 91198, France
- Université Paris-Sud, Orsay, 91405, France
| | - Jean Cohen
- Center for Molecular Genetics, National Center for Scientific Research, Génétique Moléculaire, CNRS, Gif-sur-Yvette, 91198, France
- Université Paris-Sud, Orsay, 91405, France
| | - France Koll
- Center for Molecular Genetics, National Center for Scientific Research, Génétique Moléculaire, CNRS, Gif-sur-Yvette, 91198, France
- Université Paris-Sud, Orsay, 91405, France
| | - Judith Van Houten
- Department of Biology, University of Vermont, 109 Carrigan Drive, Burlington, VT, 05405, USA
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Outer dynein arm light chain 1 is essential for controlling the ciliary response to cyclic AMP in Paramecium tetraurelia. EUKARYOTIC CELL 2012; 11:645-53. [PMID: 22427431 DOI: 10.1128/ec.05279-11] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The individual role of the outer dynein arm light chains in the molecular mechanisms of ciliary movements in response to second messengers, such as Ca(2+) and cyclic nucleotides, is unclear. We examined the role of the gene termed the outer dynein arm light chain 1 (LC1) gene of Paramecium tetraurelia (ODAL1), a homologue of the outer dynein arm LC1 gene of Chlamydomonas reinhardtii, in ciliary movements by RNA interference (RNAi) using a feeding method. The ODAL1-silenced (ODAL1-RNAi) cells swam slowly, and their swimming velocity did not increase in response to membrane-hyperpolarizing stimuli. Ciliary movements on the cortical sheets of ODAL1-RNAi cells revealed that the ciliary beat frequency was significantly lower than that of control cells in the presence of ≥ 1 mM Mg(2+)-ATP. In addition, the ciliary orientation of ODAL1-RNAi cells did not change in response to cyclic AMP (cAMP). A 29-kDa protein phosphorylated in a cAMP-dependent manner in the control cells disappeared in the axoneme of ODAL1-RNAi cells. These results indicate that ODAL1 is essential for controlling the ciliary response by cAMP-dependent phosphorylation.
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Lampert TJ, Coleman KD, Hennessey TM. A knockout mutation of a constitutive GPCR in Tetrahymena decreases both G-protein activity and chemoattraction. PLoS One 2011; 6:e28022. [PMID: 22140501 PMCID: PMC3226668 DOI: 10.1371/journal.pone.0028022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 10/30/2011] [Indexed: 11/18/2022] Open
Abstract
Although G-protein coupled receptors (GPCRs) are a common element in many chemosensory transduction pathways in eukaryotic cells, no GPCR or regulated G-protein activity has yet been shown in any ciliate. To study the possible role for a GPCR in the chemoresponses of the ciliate Tetrahymena, we have generated a number of macronuclear gene knockouts of putative GPCRs found in the Tetrahymena Genome database. One of these knockout mutants, called G6, is a complete knockout of a gene that we call GPCR6 (TTHERM_00925490). Based on sequence comparisons, the Gpcr6p protein belongs to the Rhodopsin Family of GPCRs. Notably, Gpcr6p shares highest amino acid sequence homologies to GPCRs from Paramecium and several plants. One of the phenotypes of the G6 mutant is a decreased responsiveness to the depolarizing ions Ba2+ and K+, suggesting a decrease in basal excitability (decrease in Ca2+ channel activity). The other major phenotype of G6 is a loss of chemoattraction to lysophosphatidic acid (LPA) and proteose peptone (PP), two known chemoattractants in Tetrahymena. Using microsomal [35S]GTPγS binding assays, we found that wild-type (CU427) have a prominent basal G-protein activity. This activity is decreased to the same level by pertussis toxin (a G-protein inhibitor), addition of chemoattractants, or the G6 mutant. Since the basal G-protein activity is decreased by the GPCR6 knockout, it is likely that this gene codes for a constitutively active GPCR in Tetrahymena. We propose that chemoattractants like LPA and PP cause attraction in Tetrahymena by decreasing the basal G-protein stimulating activity of Gpcr6p. This leads to decreased excitability in wild-type and longer runs of smooth forward swimming (less interrupted by direction changes) towards the attractant. Therefore, these attractants may work as inverse agonists through the constitutively active Gpcr6p coupled to a pertussis-sensitive G-protein.
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Affiliation(s)
- Thomas J Lampert
- Department of Biological Sciences, University at Buffalo, Amherst, New York, United States of America
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Riedel-Kruse IH, Hilfinger A, Howard J, Jülicher F. How molecular motors shape the flagellar beat. HFSP JOURNAL 2011; 1:192-208. [PMID: 19404446 DOI: 10.2976/1.2773861] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Accepted: 07/04/2007] [Indexed: 11/19/2022]
Abstract
Cilia and eukaryotic flagella are slender cellular appendages whose regular beating propels cells and microorganisms through aqueous media. The beat is an oscillating pattern of propagating bends generated by dynein motor proteins. A key open question is how the activity of the motors is coordinated in space and time. To elucidate the nature of this coordination we inferred the mechanical properties of the motors by analyzing the shape of beating sperm: Steadily beating bull sperm were imaged and their shapes were measured with high precision using a Fourier averaging technique. Comparing our experimental data with wave forms calculated for different scenarios of motor coordination we found that only the scenario of interdoublet sliding regulating motor activity gives rise to satisfactory fits. We propose that the microscopic origin of such "sliding control" is the load dependent detachment rate of motors. Agreement between observed and calculated wave forms was obtained only if significant sliding between microtubules occurred at the base. This suggests a novel mechanism by which changes in basal compliance could reverse the direction of beat propagation. We conclude that the flagellar beat patterns are determined by an interplay of the basal properties of the axoneme and the mechanical feedback of dynein motors.
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Savić T, Janać B, Todorović D, Prolić Z. The embryonic and post-embryonic development in two Drosophila species exposed to the static magnetic field of 60 mT. Electromagn Biol Med 2011; 30:108-14. [DOI: 10.3109/15368378.2011.566780] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Chemoattraction to lysophosphatidic acid does not require a change in membrane potential inTetrahymena thermophila. Cell Biol Int 2011; 35:519-28. [DOI: 10.1042/cbi20100320] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Grønlien HK, Rønnevig AK, Hagen B, Sand O. Chemo-accumulation without changes in membrane potential in the microstome form of the ciliate Tetrahymena vorax. ACTA ACUST UNITED AC 2011; 213:3980-7. [PMID: 21075939 DOI: 10.1242/jeb.042903] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The swimming behaviour of ciliates is mainly determined by membrane potential and transmembrane fluxes. In a chemical gradient, swimming ciliates may approach or move away from the source. Based on experiments on Paramecium, it is generally assumed that chemical attractants and repellents affect the swimming behaviour of ciliates by specific changes in the membrane potential. We have examined whether there is a causal relationship between membrane potential and chemo-accumulation in the microstome form of the polymorphic ciliate Tetrahymena vorax. Effects of chemo-attractants on the membrane potential of Tetrahymena have not been previously reported. Microstome T. vorax cells aggregated close to a point source of l-cysteine and the complex meat hydrolysate proteose peptone. Chemo-accumulated cells displayed a significantly higher turning frequency than control cells at a similar cell density. A concentration of 20 mmol l(-1) l-cysteine did not evoke any detectable change in the membrane potential whereas 1% proteose peptone depolarised the cells by ∼12 mV. This is contrary to the current model, which predicts agents that induce a moderate depolarisation to be repellents. A solution of 1% proteose peptone contains 21 mmol(-1) Na(+). A solution of 21 mmol(-1) NaCl without organic compounds also caused ∼12 mV depolarisation but had no aggregating effect on the cells. Collectively, the electrophysiological and behavioural data indicate that chemo-accumulation in the microstome form of T. vorax is not governed obligatorily by the membrane potential. We thus suggest that the simple membrane potential model for chemokinesis in Paramecium may not be valid for T. vorax.
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Affiliation(s)
- Heidi K Grønlien
- Department of Molecular Biosciences, Physiology Program, University of Oslo, PO Box 1041 Blindern, NO-0316 Oslo, Norway.
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