1
|
Gray S, Fort C, Wheeler RJ. Intraflagellar transport speed is sensitive to genetic and mechanical perturbations to flagellar beating. J Cell Biol 2024; 223:e202401154. [PMID: 38829962 PMCID: PMC11148470 DOI: 10.1083/jcb.202401154] [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] [Received: 01/31/2024] [Revised: 05/01/2024] [Accepted: 05/13/2024] [Indexed: 06/05/2024] Open
Abstract
Two sets of motor proteins underpin motile cilia/flagella function. The axoneme-associated inner and outer dynein arms drive sliding of adjacent axoneme microtubule doublets to periodically bend the flagellum for beating, while intraflagellar transport (IFT) kinesins and dyneins carry IFT trains bidirectionally along the axoneme. Despite assembling motile cilia and flagella, IFT train speeds have only previously been quantified in immobilized flagella-mechanical immobilization or genetic paralysis. This has limited investigation of the interaction between IFT and flagellar beating. Here, in uniflagellate Leishmania parasites, we use high-frequency, dual-color fluorescence microscopy to visualize IFT train movement in beating flagella. We discovered that adhesion of flagella to a microscope slide is detrimental, reducing IFT train speed and increasing train stalling. In flagella free to move, IFT train speed is not strongly dependent on flagella beat type; however, permanent disruption of flagella beating by deletion of genes necessary for formation or regulation of beating showed an inverse correlation of beat frequency and IFT train speed.
Collapse
Affiliation(s)
- Sophie Gray
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, UK
| | - Cecile Fort
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, UK
| | - Richard John Wheeler
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, UK
| |
Collapse
|
2
|
Bondoc-Naumovitz KG, Laeverenz-Schlogelhofer H, Poon RN, Boggon AK, Bentley SA, Cortese D, Wan KY. Methods and Measures for Investigating Microscale Motility. Integr Comp Biol 2023; 63:1485-1508. [PMID: 37336589 PMCID: PMC10755196 DOI: 10.1093/icb/icad075] [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] [Received: 02/28/2023] [Revised: 05/31/2023] [Accepted: 06/06/2023] [Indexed: 06/21/2023] Open
Abstract
Motility is an essential factor for an organism's survival and diversification. With the advent of novel single-cell technologies, analytical frameworks, and theoretical methods, we can begin to probe the complex lives of microscopic motile organisms and answer the intertwining biological and physical questions of how these diverse lifeforms navigate their surroundings. Herein, we summarize the main mechanisms of microscale motility and give an overview of different experimental, analytical, and mathematical methods used to study them across different scales encompassing the molecular-, individual-, to population-level. We identify transferable techniques, pressing challenges, and future directions in the field. This review can serve as a starting point for researchers who are interested in exploring and quantifying the movements of organisms in the microscale world.
Collapse
Affiliation(s)
| | | | - Rebecca N Poon
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Alexander K Boggon
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Samuel A Bentley
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Dario Cortese
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| | - Kirsty Y Wan
- Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD, Exeter, UK
| |
Collapse
|
3
|
Oshima D, Yoshida M, Saga K, Ito N, Tsuji M, Isu A, Watanabe N, Wakabayashi KI, Yoshimura K. Mechanoresponses mediated by the TRP11 channel in cilia of Chlamydomonas reinhardtii. iScience 2023; 26:107926. [PMID: 37790279 PMCID: PMC10543168 DOI: 10.1016/j.isci.2023.107926] [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: 07/19/2023] [Revised: 08/15/2023] [Accepted: 09/12/2023] [Indexed: 10/05/2023] Open
Abstract
Cilia are organelles involved in motility and sensory transduction, but how these two functions coexist has not been elucidated in depth. Here, the involvement of the ciliary transient receptor potential (TRP) channel TRP11 in mechanoresponses is studied in Chlamydomonas reinhardtii using a TRP11-knockout mutant. The mutant has defects in the conversion of the bending mode of the cilium from forward to reverse when tapped with a glass rod, the detachment of cilia when shear is applied, the increase in ciliary beat frequency upon application of mechanical agitation by vortex mixing, and the initiation of gliding while both cilia are attached in opposite directions to a glass surface. These observations indicate that TRP11 can perceive mechanical stimuli with distinct intensities and durations and induce various types of ciliary responses.
Collapse
Affiliation(s)
- Daichi Oshima
- Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan
| | - Megumi Yoshida
- Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan
| | - Kosuke Saga
- Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan
| | - Neo Ito
- Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan
| | - Miyu Tsuji
- Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan
| | - Atsuko Isu
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Nobuo Watanabe
- Department of Bio-Science and Engineering, College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan
| | - Ken-ichi Wakabayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- Department of Industrial Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Kenjiro Yoshimura
- Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama 337-8570, Japan
| |
Collapse
|
4
|
Pivato M, Grenzi M, Costa A, Ballottari M. Compartment-specific Ca 2+ imaging in the green alga Chlamydomonas reinhardtii reveals high light-induced chloroplast Ca 2+ signatures. THE NEW PHYTOLOGIST 2023; 240:258-271. [PMID: 37488718 DOI: 10.1111/nph.19142] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 06/26/2023] [Indexed: 07/26/2023]
Abstract
To investigate the role of intracellular Ca2+ signaling in the perception and response mechanisms to light in unicellular microalgae, the genetically encoded ratiometric Ca2+ indicator Yellow Cameleon (YC3.6) was expressed in the model organism for green algae Chlamydomonas reinhardtii, targeted to cytosol, chloroplast, and mitochondria. Through in vivo single-cell confocal microscopy imaging, light-induced Ca2+ signaling was investigated in different conditions and different genotypes, including the photoreceptors mutants phot and acry. A genetically encoded H2 O2 sensor was also adopted to investigate the possible role of H2 O2 formation in light-dependent Ca2+ signaling. Light-dependent Ca2+ response was observed in Chlamydomonas reinhardtii cells only in the chloroplast as an organelle-autonomous response, influenced by light intensity and photosynthetic electron transport. The absence of blue and red-light photoreceptor aCRY strongly reduced the light-dependent chloroplast Ca2+ response, while the absence of the blue photoreceptor PHOT had no significant effects. A correlation between high light-induced chloroplast H2 O2 gradients and Ca2+ transients was drawn, supported by H2 O2 -induced chloroplast Ca2+ transients in the dark. In conclusion, different triggers are involved in the light-induced chloroplast Ca2+ signaling as saturation of the photosynthetic electron transport, H2 O2 formation, and aCRY-dependent light perception.
Collapse
Affiliation(s)
- Matteo Pivato
- Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Matteo Grenzi
- Department of Biosciences, University of Milan, Via Giovanni Celoria 26, 20133, Milan, Italy
| | - Alex Costa
- Department of Biosciences, University of Milan, Via Giovanni Celoria 26, 20133, Milan, Italy
- Institute of Biophysics, National Research Council of Italy (CNR), Milan, 20133, Italy
| | - Matteo Ballottari
- Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| |
Collapse
|
5
|
Ishikawa H, Moore J, Diener DR, Delling M, Marshall WF. Testing the ion-current model for flagellar length sensing and IFT regulation. eLife 2023; 12:e82901. [PMID: 36637158 PMCID: PMC9891718 DOI: 10.7554/elife.82901] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 01/12/2023] [Indexed: 01/14/2023] Open
Abstract
Eukaryotic cilia and flagella are microtubule-based organelles whose relatively simple shape makes them ideal for investigating the fundamental question of organelle size regulation. Most of the flagellar materials are transported from the cell body via an active transport process called intraflagellar transport (IFT). The rate of IFT entry into flagella, known as IFT injection, has been shown to negatively correlate with flagellar length. However, it remains unknown how the cell measures the length of its flagella and controls IFT injection. One of the most-discussed theoretical models for length sensing to control IFT is the ion-current model, which posits that there is a uniform distribution of Ca2+ channels along the flagellum and that the Ca2+ current from the flagellum into the cell body increases linearly with flagellar length. In this model, the cell uses the Ca2+ current to negatively regulate IFT injection. The recent discovery that IFT entry into flagella is regulated by the phosphorylation of kinesin through a calcium-dependent protein kinase has provided further impetus for the ion-current model. To test this model, we measured and manipulated the levels of Ca2+ inside of Chlamydomonas flagella and quantified IFT injection. Although the concentration of Ca2+ inside of flagella was weakly correlated with the length of flagella, we found that IFT injection was reduced in calcium-deficient flagella, rather than increased as the model predicted, and that variation in IFT injection was uncorrelated with the occurrence of flagellar Ca2+ spikes. Thus, Ca2+ does not appear to function as a negative regulator of IFT injection, hence it cannot form the basis of a stable length control system.
Collapse
Affiliation(s)
- Hiroaki Ishikawa
- Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
| | - Jeremy Moore
- Kenyon College, Gambier, and Summer Research Training Program at University of California San FranciscoSan FranciscoUnited States
| | - Dennis R Diener
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Markus Delling
- Department of Physiology, University of California, San FranciscoSan FranciscoUnited States
| | - Wallace F Marshall
- Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
| |
Collapse
|
6
|
Catalan RE, Fragkopoulos AA, von Trott N, Kelterborn S, Baidukova O, Hegemann P, Bäumchen O. Light-regulated adsorption and desorption of Chlamydomonas cells at surfaces. SOFT MATTER 2023; 19:306-314. [PMID: 36520090 DOI: 10.1039/d2sm01039a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Microbial colonization of surfaces represents the first step towards biofilm formation, which is a recurring phenomenon in nature with beneficial and detrimental implications in technological and medical settings. Consequently, there is interest in elucidating the fundamental aspects of the initial stages of biofilm formation of microorganisms on solid surfaces. While most of the research is oriented to understand bacterial surface colonization, the fundamental principles of surface colonization of motile, photosynthetic microbes remain largely unexplored so far. Recent single-cell studies showed that the flagellar adhesion of Chlamydomonas reinhardtii is switched on in blue light and switched off under red light [Kreis et al., Nat. Phys., 2018, 14, 45-49]. Here, we study this light-switchable surface association on the population level and measure the kinetics of adsorption and desorption of suspensions of motile C. reinhardtii cells on glass surfaces using bright-field optical microscopy. We observe that both processes exhibit a response lag relative to the time at which the blue- and red-light conditions are set and model this feature using time-delayed Langmuir-type kinetics. We find that cell adsorption occurs significantly faster than desorption, which we attribute to the protein-mediated molecular adhesion mechanism of the cells. Adsorption experiments using phototactically blind C. reinhardtii mutants demonstrate that phototaxis does not affect the cell adsorption kinetics. Hence, this framework can be used as an assay for characterizing the dynamics of the surface colonization of microbial species exhibiting light-regulated surface adhesion under precisely controlled environmental conditions.
Collapse
Affiliation(s)
- Rodrigo E Catalan
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
- Experimental Physics V, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
| | - Alexandros A Fragkopoulos
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
- Experimental Physics V, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
| | - Nicolas von Trott
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
| | - Simon Kelterborn
- Institute of Biology, Experimental Biophysics, Humboldt-Universität, Invalidenstraße 42, 10115 Berlin, Germany
- Institute of Translational Physiology, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Olga Baidukova
- Institute of Biology, Experimental Biophysics, Humboldt-Universität, Invalidenstraße 42, 10115 Berlin, Germany
| | - Peter Hegemann
- Institute of Biology, Experimental Biophysics, Humboldt-Universität, Invalidenstraße 42, 10115 Berlin, Germany
| | - Oliver Bäumchen
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
- Experimental Physics V, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
| |
Collapse
|
7
|
Sanchez GM, Incedal TC, Prada J, O'Callaghan P, Dyachok O, Echeverry S, Dumral Ö, Nguyen PM, Xie B, Barg S, Kreuger J, Dandekar T, Idevall-Hagren O. The β-cell primary cilium is an autonomous Ca2+ compartment for paracrine GABA signaling. J Cell Biol 2023; 222:213674. [PMID: 36350286 DOI: 10.1083/jcb.202108101] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 04/11/2022] [Accepted: 10/12/2022] [Indexed: 11/11/2022] Open
Abstract
The primary cilium is an organelle present in most adult mammalian cells that is considered as an antenna for sensing the local microenvironment. Here, we use intact mouse pancreatic islets of Langerhans to investigate signaling properties of the primary cilium in insulin-secreting β-cells. We find that GABAB1 receptors are strongly enriched at the base of the cilium, but are mobilized to more distal locations upon agonist binding. Using cilia-targeted Ca2+ indicators, we find that activation of GABAB1 receptors induces selective Ca2+ influx into primary cilia through a mechanism that requires voltage-dependent Ca2+ channel activation. Islet β-cells utilize cytosolic Ca2+ increases as the main trigger for insulin secretion, yet we find that increases in cytosolic Ca2+ fail to propagate into the cilium, and that this isolation is largely due to enhanced Ca2+ extrusion in the cilium. Our work reveals local GABA action on primary cilia that involves Ca2+ influx and depends on restricted Ca2+ diffusion between the cilium and cytosol.
Collapse
Affiliation(s)
| | | | - Juan Prada
- Department of Bioinformatics, University of Würzburg, Würzburg, Germany
| | - Paul O'Callaghan
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Oleg Dyachok
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | | | - Özge Dumral
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Phuoc My Nguyen
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Beichen Xie
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Sebastian Barg
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Johan Kreuger
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Thomas Dandekar
- Department of Bioinformatics, University of Würzburg, Würzburg, Germany
| | | |
Collapse
|
8
|
Mitra A, Peterman EJG. Intraflagellar transport: Derailing causes turnarounds. Curr Biol 2022; 32:R967-R969. [PMID: 36167049 DOI: 10.1016/j.cub.2022.07.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In intraflagellar transport, protein complexes travel along cilia from base to tip without stopping and change direction only at the tip. A new study shows that this directional change does not depend on any tip-associated machinery.
Collapse
Affiliation(s)
- Aniruddha Mitra
- Department of Physics and Astronomy, and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Erwin J G Peterman
- Department of Physics and Astronomy, and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| |
Collapse
|
9
|
Conversion of anterograde into retrograde trains is an intrinsic property of intraflagellar transport. Curr Biol 2022; 32:4071-4078.e4. [PMID: 35926510 PMCID: PMC9521741 DOI: 10.1016/j.cub.2022.07.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 06/06/2022] [Accepted: 07/14/2022] [Indexed: 12/30/2022]
Abstract
Cilia or eukaryotic flagella are microtubule-based organelles found across the eukaryotic tree of life. Their very high aspect ratio and crowded interior are unfavorable to diffusive transport of most components required for their assembly and maintenance. Instead, a system of intraflagellar transport (IFT) trains moves cargo rapidly up and down the cilium (Figure 1A).1-3 Anterograde IFT, from the cell body to the ciliary tip, is driven by kinesin-II motors, whereas retrograde IFT is powered by cytoplasmic dynein-1b motors.4 Both motors are associated with long chains of IFT protein complexes, known as IFT trains, and their cargoes.5-8 The conversion from anterograde to retrograde motility at the ciliary tip involves (1) the dissociation of kinesin motors from trains,9 (2) a fundamental restructuring of the train from the anterograde to the retrograde architecture,8,10,11 (3) the unloading and reloading of cargo,2 and (4) the activation of the dynein motors.8,12 A prominent hypothesis is that there is dedicated calcium-dependent protein-based machinery at the ciliary tip to mediate these processes.4,13 However, the mechanisms of IFT turnaround have remained elusive. In this study, we use mechanical and chemical methods to block IFT at intermediate positions along the cilia of the green algae Chlamydomonas reinhardtii, in normal and calcium-depleted conditions. We show that IFT turnaround, kinesin dissociation, and dynein-1b activation can consistently be induced at arbitrary distances from the ciliary tip, with no stationary tip machinery being required. Instead, we demonstrate that the anterograde-to-retrograde conversion is a calcium-independent intrinsic ability of IFT.
Collapse
|
10
|
Pivato M, Ballottari M. Chlamydomonas reinhardtii cellular compartments and their contribution to intracellular calcium signalling. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5312-5335. [PMID: 34077536 PMCID: PMC8318260 DOI: 10.1093/jxb/erab212] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 05/11/2021] [Indexed: 05/12/2023]
Abstract
Calcium (Ca2+)-dependent signalling plays a well-characterized role in the response to different environmental stimuli, in both plant and animal cells. In the model organism for green algae, Chlamydomonas reinhardtii, Ca2+ signals were reported to have a crucial role in different physiological processes, such as stress responses, photosynthesis, and flagella functions. Recent reports identified the underlying components of the Ca2+ signalling machinery at the level of specific subcellular compartments and reported in vivo imaging of cytosolic Ca2+ concentration in response to environmental stimuli. The characterization of these Ca2+-related mechanisms and proteins in C. reinhardtii is providing knowledge on how microalgae can perceive and respond to environmental stimuli, but also on how this Ca2+ signalling machinery has evolved. Here, we review current knowledge on the cellular mechanisms underlying the generation, shaping, and decoding of Ca2+ signals in C. reinhardtii, providing an overview of the known and possible molecular players involved in the Ca2+ signalling of its different subcellular compartments. The advanced toolkits recently developed to measure time-resolved Ca2+ signalling in living C. reinhardtii cells are also discussed, suggesting how they can improve the study of the role of Ca2+ signals in the cellular response of microalgae to environmental stimuli.
Collapse
Affiliation(s)
- Matteo Pivato
- Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Matteo Ballottari
- Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134 Verona, Italy
| |
Collapse
|
11
|
Dave N, Cetiner U, Arroyo D, Fonbuena J, Tiwari M, Barrera P, Lander N, Anishkin A, Sukharev S, Jimenez V. A novel mechanosensitive channel controls osmoregulation, differentiation, and infectivity in Trypanosoma cruzi. eLife 2021; 10:67449. [PMID: 34212856 PMCID: PMC8282336 DOI: 10.7554/elife.67449] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/01/2021] [Indexed: 12/19/2022] Open
Abstract
The causative agent of Chagas disease undergoes drastic morphological and biochemical modifications as it passes between hosts and transitions from extracellular to intracellular stages. The osmotic and mechanical aspects of these cellular transformations are not understood. Here we identify and characterize a novel mechanosensitive channel in Trypanosoma cruzi (TcMscS) belonging to the superfamily of small-conductance mechanosensitive channels (MscS). TcMscS is activated by membrane tension and forms a large pore permeable to anions, cations, and small osmolytes. The channel changes its location from the contractile vacuole complex in epimastigotes to the plasma membrane as the parasites develop into intracellular amastigotes. TcMscS knockout parasites show significant fitness defects, including increased cell volume, calcium dysregulation, impaired differentiation, and a dramatic decrease in infectivity. Our work provides mechanistic insights into components supporting pathogen adaptation inside the host, thus opening the exploration of mechanosensation as a prerequisite for protozoan infectivity.
Collapse
Affiliation(s)
- Noopur Dave
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, United States
| | - Ugur Cetiner
- Department of Biology, University of Maryland, College Park, United States
| | - Daniel Arroyo
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, United States
| | - Joshua Fonbuena
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, United States
| | - Megna Tiwari
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, United States
| | - Patricia Barrera
- Departmento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Histologia y Embriologia IHEM-CONICET, Facultad de Medicina, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Noelia Lander
- Department of Biological Sciences, University of Cincinnati, Cincinnati, United States
| | - Andriy Anishkin
- Department of Biology, University of Maryland, College Park, United States
| | - Sergei Sukharev
- Department of Biology, University of Maryland, College Park, United States
| | - Veronica Jimenez
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, United States
| |
Collapse
|
12
|
Bauer D, Ishikawa H, Wemmer KA, Hendel NL, Kondev J, Marshall WF. Analysis of biological noise in the flagellar length control system. iScience 2021; 24:102354. [PMID: 33898946 PMCID: PMC8059064 DOI: 10.1016/j.isci.2021.102354] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 02/06/2023] Open
Abstract
Any proposed mechanism for organelle size control should be able to account not only for average size but also for the variation in size. We analyzed cell-to-cell variation and within-cell variation of length for the two flagella in Chlamydomonas, finding that cell-to-cell variation is dominated by cell size, whereas within-cell variation results from dynamic fluctuations. Fluctuation analysis suggests tubulin assembly is not directly coupled with intraflagellar transport (IFT) and that the observed length fluctuations reflect tubulin assembly and disassembly events involving large numbers of tubulin dimers. Length variation is increased in long-flagella mutants, an effect consistent with theoretical models for flagellar length regulation. Cells with unequal flagellar lengths show impaired swimming but improved gliding, raising the possibility that cells have evolved mechanisms to tune biological noise in flagellar length. Analysis of noise at the level of organelle size provides a way to probe the mechanisms determining cell geometry.
Collapse
Affiliation(s)
- David Bauer
- Department of Biochemistry & Biophysics, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
| | - Hiroaki Ishikawa
- Department of Biochemistry & Biophysics, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
| | - Kimberly A. Wemmer
- Department of Biochemistry & Biophysics, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
| | - Nathan L. Hendel
- Department of Biochemistry & Biophysics, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
| | - Jane Kondev
- Department of Physics, Brandeis University, Abelson-Bass-Yalem Building, 97-301, Waltham, MA, USA
| | - Wallace F. Marshall
- Department of Biochemistry & Biophysics, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
- Center for Cellular Construction, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
| |
Collapse
|
13
|
Liu P, Lou X, Wingfield JL, Lin J, Nicastro D, Lechtreck K. Chlamydomonas PKD2 organizes mastigonemes, hair-like glycoprotein polymers on cilia. J Cell Biol 2021; 219:151720. [PMID: 32348466 PMCID: PMC7265326 DOI: 10.1083/jcb.202001122] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/10/2020] [Accepted: 03/16/2020] [Indexed: 12/20/2022] Open
Abstract
Mutations in the channel protein PKD2 cause autosomal dominant polycystic kidney disease, but the function of PKD2 in cilia remains unclear. Here, we show that PKD2 targets and anchors mastigonemes, filamentous polymers of the glycoprotein MST1, to the extracellular surface of Chlamydomonas cilia. PKD2–mastigoneme complexes physically connect to the axonemal doublets 4 and 8, positioning them perpendicular to the plane of ciliary beating. pkd2 mutant cilia lack mastigonemes, and mutant cells swim with reduced velocity, indicating a motility-related function of the PKD2–mastigoneme complex. Association with both the axoneme and extracellular structures supports a mechanosensory role of Chlamydomonas PKD2. We propose that PKD2–mastigoneme arrays, on opposing sides of the cilium, could perceive forces during ciliary beating and transfer these signals to locally regulate the response of the axoneme.
Collapse
Affiliation(s)
- Peiwei Liu
- Department of Cellular Biology, University of Georgia, Athens, GA
| | - Xiaochu Lou
- Departments of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | | | - Jianfeng Lin
- Departments of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Daniela Nicastro
- Departments of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA
| |
Collapse
|
14
|
Fort C, Collingridge P, Brownlee C, Wheeler G. Ca 2+ elevations disrupt interactions between intraflagellar transport and the flagella membrane in Chlamydomonas. J Cell Sci 2021; 134:jcs.253492. [PMID: 33495279 DOI: 10.1242/jcs.253492] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 01/05/2021] [Indexed: 01/29/2023] Open
Abstract
The movement of ciliary membrane proteins is directed by transient interactions with intraflagellar transport (IFT) trains. The green alga Chlamydomonas has adapted this process for gliding motility, using retrograde IFT motors to move adhesive glycoproteins in the flagella membrane. Ca2+ signalling contributes directly to the gliding process, although uncertainty remains over the mechanism through which it acts. Here, we show that flagella Ca2+ elevations initiate the movement of paused retrograde IFT trains, which accumulate at the distal end of adherent flagella, but do not influence other IFT processes. On highly adherent surfaces, flagella exhibit high-frequency Ca2+ elevations that prevent the accumulation of paused retrograde IFT trains. Flagella Ca2+ elevations disrupt the IFT-dependent movement of microspheres along the flagella membrane, suggesting that Ca2+ acts by directly disrupting an interaction between retrograde IFT trains and flagella membrane glycoproteins. By regulating the extent to which glycoproteins on the flagella surface interact with IFT motor proteins on the axoneme, this signalling mechanism allows precise control of traction force and gliding motility in adherent flagella.
Collapse
Affiliation(s)
- Cecile Fort
- Marine Biological Association, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
| | - Peter Collingridge
- Marine Biological Association, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
| | - Colin Brownlee
- Marine Biological Association, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK.,School of Ocean and Earth Science, University of Southampton, Southampton SO14 3ZH, UK
| | - Glen Wheeler
- Marine Biological Association, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
| |
Collapse
|
15
|
Xu N, Oltmanns A, Zhao L, Girot A, Karimi M, Hoepfner L, Kelterborn S, Scholz M, Beißel J, Hegemann P, Bäumchen O, Liu LN, Huang K, Hippler M. Altered N-glycan composition impacts flagella-mediated adhesion in Chlamydomonas reinhardtii. eLife 2020; 9:58805. [PMID: 33300874 PMCID: PMC7759384 DOI: 10.7554/elife.58805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 12/09/2020] [Indexed: 01/22/2023] Open
Abstract
For the unicellular alga Chlamydomonas reinhardtii, the presence of N-glycosylated proteins on the surface of two flagella is crucial for both cell-cell interaction during mating and flagellar surface adhesion. However, it is not known whether only the presence or also the composition of N-glycans attached to respective proteins is important for these processes. To this end, we tested several C. reinhardtii insertional mutants and a CRISPR/Cas9 knockout mutant of xylosyltransferase 1A, all possessing altered N-glycan compositions. Taking advantage of atomic force microscopy and micropipette force measurements, our data revealed that reduction in N-glycan complexity impedes the adhesion force required for binding the flagella to surfaces. This results in impaired polystyrene bead binding and transport but not gliding of cells on solid surfaces. Notably, assembly, intraflagellar transport, and protein import into flagella are not affected by altered N-glycosylation. Thus, we conclude that proper N-glycosylation of flagellar proteins is crucial for adhering C. reinhardtii cells onto surfaces, indicating that N-glycans mediate surface adhesion via direct surface contact.
Collapse
Affiliation(s)
- Nannan Xu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Anne Oltmanns
- Institute for Plant Biology and Biotechnology, University of Münster, Münster, Germany
| | - Longsheng Zhao
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom.,State Key Laboratory of Microbial Technology, and Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Antoine Girot
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Göttingen, Germany
| | - Marzieh Karimi
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Göttingen, Germany
| | - Lara Hoepfner
- Institute for Plant Biology and Biotechnology, University of Münster, Münster, Germany
| | - Simon Kelterborn
- Institute of Biology, Experimental Biophysics, Humboldt University of Berlin, Berlin, Germany
| | - Martin Scholz
- Institute for Plant Biology and Biotechnology, University of Münster, Münster, Germany
| | - Julia Beißel
- Institute for Plant Biology and Biotechnology, University of Münster, Münster, Germany
| | - Peter Hegemann
- Institute of Biology, Experimental Biophysics, Humboldt University of Berlin, Berlin, Germany
| | - Oliver Bäumchen
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Göttingen, Germany.,Experimental Physics V, University of Bayreuth, Bayreuth, Germany
| | - Lu-Ning Liu
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom.,College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
| | - Kaiyao Huang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Michael Hippler
- Institute for Plant Biology and Biotechnology, University of Münster, Münster, Germany.,Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| |
Collapse
|
16
|
Gigante ED, Caspary T. Signaling in the primary cilium through the lens of the Hedgehog pathway. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 9:e377. [PMID: 32084300 DOI: 10.1002/wdev.377] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/22/2020] [Accepted: 01/25/2020] [Indexed: 12/14/2022]
Abstract
Cilia are microtubule-based, cell-surface projections whose machinery is evolutionarily conserved. In vertebrates, cilia are observed on almost every cell type and are either motile or immotile. Immotile sensory, or primary cilia, are responsive to extracellular ligands and signals. Cilia can be thought of as compartments, functionally distinct from the cell that provides an environment for signaling cascades. Hedgehog is a critical developmental signaling pathway which is functionally linked to primary cilia in vertebrates. The major components of the vertebrate Hedgehog signaling pathway dynamically localize to the ciliary compartment and ciliary membrane. Critically, G-protein coupled receptor (GPCR) Smoothened, the obligate transducer of the pathway, is enriched and activated in the cilium. While Smoothened is the most intensely studied ciliary receptor, many GPCRs localize within cilia. Understanding the link between Smoothened and cilia defines common features, and distinctions, of GPCR signaling within the primary cilium. This article is categorized under: Signaling Pathways > Global Signaling Mechanisms Signaling Pathways > Cell Fate Signaling.
Collapse
Affiliation(s)
- Eduardo D Gigante
- Graduate Program in Neuroscience, Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| |
Collapse
|
17
|
Reza AM, Tavakoli J, Zhou Y, Qin J, Tang Y. Synthetic fluorescent probes to apprehend calcium signalling in lipid droplet accumulation in microalgae—an updated review. Sci China Chem 2020. [DOI: 10.1007/s11426-019-9664-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
18
|
Mijalkovic J, Girard J, van Krugten J, van Loo J, Zhang Z, Loseva E, Oswald F, Peterman EJG. Cutting off ciliary protein import: intraflagellar transport after dendritic femtosecond-laser ablation. Mol Biol Cell 2020; 31:324-334. [PMID: 31940255 PMCID: PMC7183794 DOI: 10.1091/mbc.e18-06-0399] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Primary cilia, organelles protruding from the surface of eukaryotic cells, act as cellular antennae to detect and transmit signals from the extracellular environment. They are built and maintained by continuous cycles of intraflagellar transport (IFT), where ciliary proteins are transported between the ciliary base and tip. These proteins originate from the cell body because cilia lack protein synthesis machinery. How input from the cell body affects IFT and ciliary function is not well understood. Here, we use femtosecond-laser ablation to perturb the dendritic input of proteins to chemosensory cilia in living Caenorhabditis elegans. Using fluorescence microscopy, we visualize and quantify the real-time response of ciliary proteins to dendritic ablation. We find that the response occurs in three distinct stages. First, IFT dynein is activated within seconds, redistributing IFT components toward the ciliary base; second, the ciliary axoneme shortens and motors slow down; and third, motors leave the cilium. Depletion of ATP by adding azide also results in IFT slowdown and IFT components leaving the cilium, but not in activation of retrograde IFT. These results indicate that laser ablation triggers a specific mechanism important for IFT regulation that allows the cilium to rapidly adapt to changes in the outside environment.
Collapse
Affiliation(s)
- Jona Mijalkovic
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Jules Girard
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Jaap van Krugten
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Jasmijn van Loo
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Zhiqing Zhang
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Elizaveta Loseva
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Felix Oswald
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Erwin J G Peterman
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| |
Collapse
|
19
|
Sasaki K, Shiba K, Nakamura A, Kawano N, Satouh Y, Yamaguchi H, Morikawa M, Shibata D, Yanase R, Jokura K, Nomura M, Miyado M, Takada S, Ueno H, Nonaka S, Baba T, Ikawa M, Kikkawa M, Miyado K, Inaba K. Calaxin is required for cilia-driven determination of vertebrate laterality. Commun Biol 2019; 2:226. [PMID: 31240264 PMCID: PMC6586612 DOI: 10.1038/s42003-019-0462-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 05/14/2019] [Indexed: 12/24/2022] Open
Abstract
Calaxin is a Ca2+-binding dynein-associated protein that regulates flagellar and ciliary movement. In ascidians, calaxin plays essential roles in chemotaxis of sperm. However, nothing has been known for the function of calaxin in vertebrates. Here we show that the mice with a null mutation in Efcab1, which encodes calaxin, display typical phenotypes of primary ciliary dyskinesia, including hydrocephalus, situs inversus, and abnormal motility of trachea cilia and sperm flagella. Strikingly, both males and females are viable and fertile, indicating that calaxin is not essential for fertilization in mice. The 9 + 2 axonemal structures of epithelial multicilia and sperm flagella are normal, but the formation of 9 + 0 nodal cilia is significantly disrupted. Knockout of calaxin in zebrafish also causes situs inversus due to the irregular ciliary beating of Kupffer's vesicle cilia, although the 9 + 2 axonemal structure appears to remain normal.
Collapse
Affiliation(s)
- Keita Sasaki
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, 415-0025 Japan
| | - Kogiku Shiba
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, 415-0025 Japan
| | - Akihiro Nakamura
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, 415-0025 Japan
- Department of Reproductive Biology, National Center for Child Health and Development, Tokyo, 157-8535 Japan
| | - Natsuko Kawano
- Department of Life Science, School of Agriculture, Meiji University, Kanagawa, 214-8574 Japan
| | - Yuhkoh Satouh
- Research Institute for Microbial Diseases, Osaka University, Osaka, 565-0871 Japan
| | - Hiroshi Yamaguchi
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033 Japan
| | - Motohiro Morikawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033 Japan
| | - Daisuke Shibata
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, 415-0025 Japan
| | - Ryuji Yanase
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, 415-0025 Japan
| | - Kei Jokura
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, 415-0025 Japan
| | - Mami Nomura
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, 415-0025 Japan
| | - Mami Miyado
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, 157-8535 Japan
| | - Shuji Takada
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, Tokyo, 157-8535 Japan
| | - Hironori Ueno
- Molecular Function & Life Sciences, Aichi University of Education, Aichi, 448-8542 Japan
| | - Shigenori Nonaka
- Spatiotemporal Regulations Group, Exploratory Research Center on Life and Living Systems (ExCELLS), Okazaki, 444-8585 Japan
- Laboratory for Spatiotemporal Regulations, National Institute for Basic Biology, Okazaki, 444-8585 Japan
| | - Tadashi Baba
- Faculty of Life and Environmental Sciences, and Life Science Center for Survival Dynamics Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, 305-8577 Japan
| | - Masahito Ikawa
- Research Institute for Microbial Diseases, Osaka University, Osaka, 565-0871 Japan
| | - Masahide Kikkawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033 Japan
| | - Kenji Miyado
- Department of Reproductive Biology, National Center for Child Health and Development, Tokyo, 157-8535 Japan
| | - Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, 415-0025 Japan
| |
Collapse
|
20
|
Lin CH, Lane HY. The Role of N-Methyl-D-Aspartate Receptor Neurotransmission and Precision Medicine in Behavioral and Psychological Symptoms of Dementia. Front Pharmacol 2019; 10:540. [PMID: 31191302 PMCID: PMC6539199 DOI: 10.3389/fphar.2019.00540] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 04/29/2019] [Indexed: 12/16/2022] Open
Abstract
While the world’s population is aging, the prevalence of dementia and the associated behavioral and psychological symptoms of dementia (BPSD) rises rapidly. BPSD are associated with worsening of cognitive function and poorer prognosis. No pharmacological treatment has been approved to be beneficial for BPSD to date. Dysfunction of the N-methyl-D-aspartate receptor (NMDAR)-related neurotransmission leads to cognitive impairment and behavioral changes, both of which are core symptoms of BPSD. Memantine, an NMDAR partial antagonist, is used to treat moderate to severe Alzheimer’s disease (AD). On the other hand, a D-amino acid oxidase inhibitor improved early-phase AD. Whether to enhance or to attenuate the NMDAR may depend on the phases of dementia. It will be valuable to develop biomarkers indicating the activity of NMDAR, particularly in BPSD. In addition, recent reports suggest that gender difference exists in the treatment of dementia. Selecting subpopulations of patients with BPSD who are prone to improvement with treatment would be important. We reviewed literatures regarding the treatment of BPSD, focusing on the NMDAR-related modulation and precision medicine. Future studies examining the NMDAR modulators with the aid of potential biomarkers to tailor the treatment for individualized patients with BPSD are warranted.
Collapse
Affiliation(s)
- Chieh-Hsin Lin
- Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.,School of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
| | - Hsien-Yuan Lane
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan.,Department of Psychiatry and Brain Disease Research Center, China Medical University Hospital, Taichung, Taiwan.,Department of Psychology, College of Medical and Health Sciences, Asia University, Taichung, Taiwan
| |
Collapse
|
21
|
Alternative Mechanisms for Fast Na +/Ca 2+ Signaling in Eukaryotes via a Novel Class of Single-Domain Voltage-Gated Channels. Curr Biol 2019; 29:1503-1511.e6. [PMID: 31006567 PMCID: PMC6509283 DOI: 10.1016/j.cub.2019.03.041] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/11/2019] [Accepted: 03/20/2019] [Indexed: 01/16/2023]
Abstract
Rapid Na+/Ca2+-based action potentials govern essential cellular functions in eukaryotes, from the motile responses of unicellular protists, such as Paramecium [1, 2], to complex animal neuromuscular activity [3]. A key innovation underpinning this fundamental signaling process has been the evolution of four-domain voltage-gated Na+/Ca2+ channels (4D-Cavs/Navs). These channels are widely distributed across eukaryote diversity [4], albeit several eukaryotes, including land plants and fungi, have lost voltage-sensitive 4D-Cav/Navs [5, 6, 7]. Because these lineages appear to lack rapid Na+/Ca2+-based action potentials, 4D-Cav/Navs are generally considered necessary for fast Na+/Ca2+-based signaling [7]. However, the cellular mechanisms underpinning the membrane physiology of many eukaryotes remain unexamined. Eukaryotic phytoplankton critically influence our climate as major primary producers. Several taxa, including the globally abundant diatoms, exhibit membrane excitability [8, 9, 10]. We previously demonstrated that certain diatom genomes encode 4D-Cav/Navs [4] but also proteins of unknown function, resembling prokaryote single-domain, voltage-gated Na+ channels (BacNavs) [4]. Here, we show that single-domain channels are actually broadly distributed across major eukaryote phytoplankton lineages and represent three novel classes of single-domain channels, which we refer collectively to as EukCats. Functional characterization of diatom EukCatAs indicates that they are voltage-gated Na+- and Ca2+-permeable channels, with rapid kinetics resembling metazoan 4D-Cavs/Navs. In Phaeodactylum tricornutum, which lacks 4D-Cav/Navs, EukCatAs underpin voltage-activated Ca2+ signaling important for membrane excitability, and mutants exhibit impaired motility. EukCatAs therefore provide alternative mechanisms for rapid Na+/Ca2+ signaling in eukaryotes and may functionally replace 4D-Cavs/Navs in pennate diatoms. Marine phytoplankton thus possess unique signaling mechanisms that may be key to environmental sensing in the oceans. Novel class of single-domain, voltage-gated channels (EukCatAs) identified in diatoms EukCatAs are fast voltage-gated Na+- and Ca2+-permeable channels EukCatAs underpin voltage-activated Ca2+ signaling and membrane excitability EukCatAs may have functionally replaced 4D-Cav/Nav channels in pennate diatoms
Collapse
|
22
|
Picariello T, Brown JM, Hou Y, Swank G, Cochran DA, King OD, Lechtreck K, Pazour GJ, Witman GB. A global analysis of IFT-A function reveals specialization for transport of membrane-associated proteins into cilia. J Cell Sci 2019; 132:jcs220749. [PMID: 30659111 PMCID: PMC6382014 DOI: 10.1242/jcs.220749] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 01/02/2019] [Indexed: 12/28/2022] Open
Abstract
Intraflagellar transport (IFT), which is essential for the formation and function of cilia in most organisms, is the trafficking of IFT trains (i.e. assemblies of IFT particles) that carry cargo within the cilium. Defects in IFT cause several human diseases. IFT trains contain the complexes IFT-A and IFT-B. To dissect the functions of these complexes, we studied a Chlamydomonas mutant that is null for the IFT-A protein IFT140. The mutation had no effect on IFT-B but destabilized IFT-A, preventing flagella assembly. Therefore, IFT-A assembly requires IFT140. Truncated IFT140, which lacks the N-terminal WD repeats of the protein, partially rescued IFT and supported formation of half-length flagella that contained normal levels of IFT-B but greatly reduced amounts of IFT-A. The axonemes of these flagella had normal ultrastructure and, as investigated by SDS-PAGE, normal composition. However, composition of the flagellar 'membrane+matrix' was abnormal. Analysis of the latter fraction by mass spectrometry revealed decreases in small GTPases, lipid-anchored proteins and cell signaling proteins. Thus, IFT-A is specialized for the import of membrane-associated proteins. Abnormal levels of the latter are likely to account for the multiple phenotypes of patients with defects in IFT140.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Tyler Picariello
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Jason M Brown
- Department of Biology, Salem State University, Salem, MA 01970, USA
| | - Yuqing Hou
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Gregory Swank
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Deborah A Cochran
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Oliver D King
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - George B Witman
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| |
Collapse
|
23
|
Liu Y, Claydon R, Polin M, Brumley DR. Transitions in synchronization states of model cilia through basal-connection coupling. J R Soc Interface 2018; 15:rsif.2018.0450. [PMID: 30305422 DOI: 10.1098/rsif.2018.0450] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 09/11/2018] [Indexed: 12/20/2022] Open
Abstract
Despite evidence for a hydrodynamic origin of flagellar synchronization between different eukaryotic cells, recent experiments have shown that in single multi-flagellated organisms, coordination hinges instead on direct basal body connections. The mechanism by which these connections lead to coordination, however, is currently not understood. Here, we focus on the model biflagellate Chlamydomonas reinhardtii, and propose a minimal model for the synchronization of its two flagella as a result of both hydrodynamic and direct mechanical coupling. A spectrum of different types of coordination can be selected, depending on small changes in the stiffness of intracellular couplings. These include prolonged in-phase and anti-phase synchronization, as well as a range of multi-stable states induced by spontaneous symmetry breaking of the system. Linking synchrony to intracellular stiffness could lead to the use of flagellar dynamics as a probe for the mechanical state of the cell.
Collapse
Affiliation(s)
- Yujie Liu
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Rory Claydon
- Physics Department, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Marco Polin
- Physics Department, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK .,Centre for Mechanochemical Cell Biology, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Douglas R Brumley
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria 3010, Australia
| |
Collapse
|
24
|
Kamiya R, Shiba K, Inaba K, Kato-Minoura T. Release of Sticky Glycoproteins from Chlamydomonas Flagella During Microsphere Translocation on the Surface Membrane. Zoolog Sci 2018; 35:299-305. [DOI: 10.2108/zs180025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Ritsu Kamiya
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Kogiku Shiba
- Shimoda Marine Research Center, University of Tsukuba, Shimoda 5-10-1, Shizuoka 415-0025, Japan
| | - Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, Shimoda 5-10-1, Shizuoka 415-0025, Japan
| | - Takako Kato-Minoura
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| |
Collapse
|
25
|
Rea G, Antonacci A, Lambreva MD, Mattoo AK. Features of cues and processes during chloroplast-mediated retrograde signaling in the alga Chlamydomonas. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 272:193-206. [PMID: 29807591 DOI: 10.1016/j.plantsci.2018.04.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/04/2018] [Accepted: 04/23/2018] [Indexed: 06/08/2023]
Abstract
Retrograde signaling is an intracellular communication process defined by cues generated in chloroplast and mitochondria which traverse membranes to their destination in the nucleus in order to regulate nuclear gene expression and protein synthesis. The coding and decoding of such organellar message(s) involve gene medleys and metabolic components about which more is known in higher plants than the unicellular organisms such as algae. Chlamydomonas reinhardtii is an oxygenic microalgal model for genetic and physiological studies. It harbors a single chloroplast and is amenable for generating mutants. The focus of this review is on studies that delineate retrograde signaling in Chlamydomonas vis a vis higher plants. Thus, communication networks between chloroplast and nucleus involving photosynthesis- and ROS-generated signals, functional tetrapyrrole biosynthesis intermediates, and Ca2+-signaling that modulate nuclear gene expression in this alga are discussed. Conceptually, different signaling components converge to regulate either the same or functionally-overlapping gene products.
Collapse
Affiliation(s)
- Giuseppina Rea
- Institute of Crystallography, National Research Council of Italy, Via Salaria Km 29, 3 00015 Monterotondo Scalo, Rome, Italy
| | - Amina Antonacci
- Institute of Crystallography, National Research Council of Italy, Via Salaria Km 29, 3 00015 Monterotondo Scalo, Rome, Italy
| | - Maya D Lambreva
- Institute of Crystallography, National Research Council of Italy, Via Salaria Km 29, 3 00015 Monterotondo Scalo, Rome, Italy
| | - Autar K Mattoo
- The Henry A Wallace Agricultural Research Centre, U.S. Department of Agriculture, Sustainable Agricultural Systems Laboratory, Beltsville, MD 20705, USA.
| |
Collapse
|
26
|
Morthorst SK, Christensen ST, Pedersen LB. Regulation of ciliary membrane protein trafficking and signalling by kinesin motor proteins. FEBS J 2018; 285:4535-4564. [PMID: 29894023 DOI: 10.1111/febs.14583] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/09/2018] [Accepted: 06/11/2018] [Indexed: 12/14/2022]
Abstract
Primary cilia are antenna-like sensory organelles that regulate a substantial number of cellular signalling pathways in vertebrates, both during embryonic development as well as in adulthood, and mutations in genes coding for ciliary proteins are causative of an expanding group of pleiotropic diseases known as ciliopathies. Cilia consist of a microtubule-based axoneme core, which is subtended by a basal body and covered by a bilayer lipid membrane of unique protein and lipid composition. Cilia are dynamic organelles, and the ability of cells to regulate ciliary protein and lipid content in response to specific cellular and environmental cues is crucial for balancing ciliary signalling output. Here we discuss mechanisms involved in regulation of ciliary membrane protein trafficking and signalling, with main focus on kinesin-2 and kinesin-3 family members.
Collapse
|
27
|
Chien A, Shih SM, Bower R, Tritschler D, Porter ME, Yildiz A. Dynamics of the IFT machinery at the ciliary tip. eLife 2017; 6:28606. [PMID: 28930071 PMCID: PMC5662288 DOI: 10.7554/elife.28606] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 09/12/2017] [Indexed: 12/15/2022] Open
Abstract
Intraflagellar transport (IFT) is essential for the elongation and maintenance of eukaryotic cilia and flagella. Due to the traffic jam of multiple trains at the ciliary tip, how IFT trains are remodeled in these turnaround zones cannot be determined by conventional imaging. Using PhotoGate, we visualized the full range of movement of single IFT trains and motors in Chlamydomonas flagella. Anterograde trains split apart and IFT complexes mix with each other at the tip to assemble retrograde trains. Dynein-1b is carried to the tip by kinesin-II as inactive cargo on anterograde trains. Unlike dynein-1b, kinesin-II detaches from IFT trains at the tip and diffuses in flagella. As the flagellum grows longer, diffusion delays return of kinesin-II to the basal body, depleting kinesin-II available for anterograde transport. Our results suggest that dissociation of kinesin-II from IFT trains serves as a negative feedback mechanism that facilitates flagellar length control in Chlamydomonas.
Collapse
Affiliation(s)
- Alexander Chien
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, United States
| | - Sheng Min Shih
- Physics Department, University of California, Berkeley, Berkeley, United States
| | - Raqual Bower
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States
| | - Douglas Tritschler
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States
| | - Mary E Porter
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States
| | - Ahmet Yildiz
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, United States.,Physics Department, University of California, Berkeley, Berkeley, United States.,Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| |
Collapse
|
28
|
Prevo B, Scholey JM, Peterman EJG. Intraflagellar transport: mechanisms of motor action, cooperation, and cargo delivery. FEBS J 2017; 284:2905-2931. [PMID: 28342295 PMCID: PMC5603355 DOI: 10.1111/febs.14068] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/20/2017] [Accepted: 03/23/2017] [Indexed: 02/06/2023]
Abstract
Intraflagellar transport (IFT) is a form of motor-dependent cargo transport that is essential for the assembly, maintenance, and length control of cilia, which play critical roles in motility, sensory reception, and signal transduction in virtually all eukaryotic cells. During IFT, anterograde kinesin-2 and retrograde IFT dynein motors drive the bidirectional transport of IFT trains that deliver cargo, for example, axoneme precursors such as tubulins as well as molecules of the signal transduction machinery, to their site of assembly within the cilium. Following its discovery in Chlamydomonas, IFT has emerged as a powerful model system for studying general principles of motor-dependent cargo transport and we now appreciate the diversity that exists in the mechanism of IFT within cilia of different cell types. The absence of heterotrimeric kinesin-2 function, for example, causes a complete loss of both IFT and cilia in Chlamydomonas, but following its loss in Caenorhabditis elegans, where its primary function is loading the IFT machinery into cilia, homodimeric kinesin-2-driven IFT persists and assembles a full-length cilium. Generally, heterotrimeric kinesin-2 and IFT dynein motors are thought to play widespread roles as core IFT motors, whereas homodimeric kinesin-2 motors are accessory motors that mediate different functions in a broad range of cilia, in some cases contributing to axoneme assembly or the delivery of signaling molecules but in many other cases their ciliary functions, if any, remain unknown. In this review, we focus on mechanisms of motor action, motor cooperation, and motor-dependent cargo delivery during IFT.
Collapse
Affiliation(s)
- Bram Prevo
- Department of Cellular & Molecular Medicine, University of California San Diego, CA, USA
- Ludwig Institute for Cancer Research, San Diego, CA, USA
| | - Jonathan M Scholey
- Department of Molecular & Cell Biology, University of California Davis, CA, USA
| | - Erwin J G Peterman
- Department of Physics and Astronomy and LaserLaB Amsterdam, Vrije Universiteit, Amsterdam, The Netherlands
| |
Collapse
|
29
|
Lechtreck KF, Van De Weghe JC, Harris JA, Liu P. Protein transport in growing and steady-state cilia. Traffic 2017; 18:277-286. [PMID: 28248449 DOI: 10.1111/tra.12474] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 02/22/2017] [Accepted: 02/22/2017] [Indexed: 12/18/2022]
Abstract
Cilia and eukaryotic flagella are threadlike cell extensions with motile and sensory functions. Their assembly requires intraflagellar transport (IFT), a bidirectional motor-driven transport of protein carriers along the axonemal microtubules. IFT moves ample amounts of structural proteins including tubulin into growing cilia likely explaining its critical role for assembly. IFT continues in non-growing cilia contributing to a variety of processes ranging from axonemal maintenance and the export of non-ciliary proteins to cell locomotion and ciliary signaling. Here, we discuss recent data on cues regulating the type, amount and timing of cargo transported by IFT. A regulation of IFT-cargo interactions is critical to establish, maintain and adjust ciliary length, protein composition and function.
Collapse
Affiliation(s)
- Karl F Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, Georgia
| | | | | | - Peiwei Liu
- Department of Cellular Biology, University of Georgia, Athens, Georgia
| |
Collapse
|
30
|
Abstract
Anton van Leeuwenhoek's startling microscopic observations in the 1600s first stimulated fascination with the way that cells use cilia to generate currents and to swim in a fluid environment. Research in recent decades has yielded deep knowledge about the mechanical and biochemical nature of these organelles but only opened a greater fascination about how such beautifully intricate and multifunctional structures arose during evolution. Answers to this evolutionary puzzle are not only sought to satisfy basic curiosity, but also, as stated so eloquently by Dobzhansky (Am Zool 4: 443 [1964]), because "nothing in biology makes sense except in the light of evolution." Here I attempt to summarize current knowledge of what ciliary organelles of the last eukaryotic common ancestor (LECA) were like, explore the ways in which cilia have evolved since that time, and speculate on the selective processes that might have generated these organelles during early eukaryotic evolution.
Collapse
Affiliation(s)
- David R Mitchell
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| |
Collapse
|
31
|
Calcium-Dependent Signalling Processes in Chlamydomonas. CHLAMYDOMONAS: MOLECULAR GENETICS AND PHYSIOLOGY 2017. [DOI: 10.1007/978-3-319-66365-4_8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
32
|
Abstract
In this review we discuss the history and the current state of ideas related to the mechanism of size regulation of the thick (myosin) and thin (actin) filaments in vertebrate striated muscles. Various hypotheses have been considered during of more than half century of research, recently mostly involving titin and nebulin acting as templates or 'molecular rulers', terminating exact assembly. These two giant, single-polypeptide, filamentous proteins are bound in situ along the thick and thin filaments, respectively, with an almost perfect match in the respective lengths and structural periodicities. However, evidence still questions the possibility that the proteins function as templates, or scaffolds, on which the thin and thick filaments could be assembled. In addition, the progress in muscle research during the last decades highlighted a number of other factors that could potentially be involved in the mechanism of length regulation: molecular chaperones that may guide folding and assembly of actin and myosin; capping proteins that can influence the rates of assembly-disassembly of the myofilaments; Ca2+ transients that can activate or deactivate protein interactions, etc. The entire mechanism of sarcomere assembly appears complex and highly dynamic. This mechanism is also capable of producing filaments of about the correct size without titin and nebulin. What then is the role of these proteins? Evidence points to titin and nebulin stabilizing structures of the respective filaments. This stabilizing effect, based on linear proteins of a fixed size, implies that titin and nebulin are indeed molecular rulers of the filaments. Although the proteins may not function as templates in the assembly of the filaments, they measure and stabilize exactly the same size of the functionally important for the muscles segments in each of the respective filaments.
Collapse
|
33
|
Abstract
Primary cilia are small, antenna-like structures that detect mechanical and chemical cues and transduce extracellular signals. While mammalian primary cilia were first reported in the late 1800s, scientific interest in these sensory organelles has burgeoned since the beginning of the twenty-first century with recognition that primary cilia are essential to human health. Among the most common clinical manifestations of ciliary dysfunction are renal cysts. The molecular mechanisms underlying renal cystogenesis are complex, involving multiple aberrant cellular processes and signaling pathways, while initiating molecular events remain undefined. Autosomal Dominant Polycystic Kidney Disease is the most common renal cystic disease, caused by disruption of polycystin-1 and polycystin-2 transmembrane proteins, which evidence suggests must localize to primary cilia for proper function. To understand how the absence of these proteins in primary cilia may be remediated, we review intracellular trafficking of polycystins to the primary cilium. We also examine the controversial mechanisms by which primary cilia transduce flow-mediated mechanical stress into intracellular calcium. Further, to better understand ciliary function in the kidney, we highlight the LKB1/AMPK, Wnt, and Hedgehog developmental signaling pathways mediated by primary cilia and misregulated in renal cystic disease.
Collapse
|
34
|
Bickerton P, Sello S, Brownlee C, Pittman JK, Wheeler GL. Spatial and temporal specificity of Ca 2+ signalling in Chlamydomonas reinhardtii in response to osmotic stress. THE NEW PHYTOLOGIST 2016; 212:920-933. [PMID: 27516045 PMCID: PMC5111745 DOI: 10.1111/nph.14128] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 06/25/2016] [Indexed: 05/06/2023]
Abstract
Ca2+ -dependent signalling processes enable plants to perceive and respond to diverse environmental stressors, such as osmotic stress. A clear understanding of the role of spatiotemporal Ca2+ signalling in green algal lineages is necessary in order to understand how the Ca2+ signalling machinery has evolved in land plants. We used single-cell imaging of Ca2+ -responsive fluorescent dyes in the unicellular green alga Chlamydomonas reinhardtii to examine the specificity of spatial and temporal dynamics of Ca2+ elevations in the cytosol and flagella in response to salinity and osmotic stress. We found that salt stress induced a single Ca2+ elevation that was modulated by the strength of the stimulus and originated in the apex of the cell, spreading as a fast Ca2+ wave. By contrast, hypo-osmotic stress induced a series of repetitive Ca2+ elevations in the cytosol that were spatially uniform. Hypo-osmotic stimuli also induced Ca2+ elevations in the flagella that occurred independently from those in the cytosol. Our results indicate that the requirement for Ca2+ signalling in response to osmotic stress is conserved between land plants and green algae, but the distinct spatial and temporal dynamics of osmotic Ca2+ elevations in C. reinhardtii suggest important mechanistic differences between the two lineages.
Collapse
Affiliation(s)
- Peter Bickerton
- Marine Biological AssociationCitadel HillPlymouthPL1 2PBUK
- Faculty of Life SciencesUniversity of ManchesterOxford RoadManchesterM13 9PTUK
| | - Simone Sello
- Marine Biological AssociationCitadel HillPlymouthPL1 2PBUK
- Department of BiologyUniversity of PadovaVia U. Bassi 58/B35131PadovaItaly
| | - Colin Brownlee
- Marine Biological AssociationCitadel HillPlymouthPL1 2PBUK
- School of Ocean and Earth ScienceUniversity of SouthamptonSouthamptonSO14 3ZHUK
| | - Jon K. Pittman
- Faculty of Life SciencesUniversity of ManchesterOxford RoadManchesterM13 9PTUK
| | | |
Collapse
|
35
|
Reck J, Schauer AM, VanderWaal Mills K, Bower R, Tritschler D, Perrone CA, Porter ME. The role of the dynein light intermediate chain in retrograde IFT and flagellar function in Chlamydomonas. Mol Biol Cell 2016; 27:2404-22. [PMID: 27251063 PMCID: PMC4966982 DOI: 10.1091/mbc.e16-03-0191] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/26/2016] [Indexed: 12/28/2022] Open
Abstract
The assembly of cilia and flagella depends on the activity of two microtubule motor complexes, kinesin-2 and dynein-2/1b, but the specific functions of the different subunits are poorly defined. Here we analyze Chlamydomonas strains expressing different amounts of the dynein 1b light intermediate chain (D1bLIC). Disruption of D1bLIC alters the stability of the dynein 1b complex and reduces both the frequency and velocity of retrograde intraflagellar transport (IFT), but it does not eliminate retrograde IFT. Flagellar assembly, motility, gliding, and mating are altered in a dose-dependent manner. iTRAQ-based proteomics identifies a small subset of proteins that are significantly reduced or elevated in d1blic flagella. Transformation with D1bLIC-GFP rescues the mutant phenotypes, and D1bLIC-GFP assembles into the dynein 1b complex at wild-type levels. D1bLIC-GFP is transported with anterograde IFT particles to the flagellar tip, dissociates into smaller particles, and begins processive retrograde IFT in <2 s. These studies demonstrate the role of D1bLIC in facilitating the recycling of IFT subunits and other proteins, identify new components potentially involved in the regulation of IFT, flagellar assembly, and flagellar signaling, and provide insight into the role of D1bLIC and retrograde IFT in other organisms.
Collapse
Affiliation(s)
- Jaimee Reck
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455 R&D Systems, Minneapolis, MN 55413
| | - Alexandria M Schauer
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455 College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108
| | - Kristyn VanderWaal Mills
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455 Anoka Technical College, Anoka, MN 55303
| | - Raqual Bower
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455
| | - Douglas Tritschler
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455
| | - Catherine A Perrone
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455 Medtronic, Minneapolis, MN 55432
| | - Mary E Porter
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455
| |
Collapse
|
36
|
De Loof A, Schoofs L, Huybrechts R. The endocrine system controlling sexual reproduction in animals: Part of the evolutionary ancient but well conserved immune system? Gen Comp Endocrinol 2016; 226:56-71. [PMID: 26707056 DOI: 10.1016/j.ygcen.2015.12.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 12/08/2015] [Accepted: 12/15/2015] [Indexed: 12/14/2022]
Abstract
Drastic changes in hormone titers, in particular of steroid hormones, are intuitively interpreted as necessary and beneficial for optimal functioning of animals. Peaks in progesterone- and estradiol titers that accompany the estrus cycle in female vertebrates as well as in ecdysteroids at each molt and during metamorphosis of holometabolous insects are prominent examples. A recent analysis of insect metamorphosis yielded the view that, in general, a sharp rise in sex steroid hormone titer signals that somewhere in the body some tissue(s) is undergoing programmed cell death/apoptosis. Increased steroid production is part of this process. Typical examples are ovarian follicle cells in female vertebrates and invertebrates and the prothoracic gland cells, the main production site of ecdysteroids in larval insects. A duality emerges: programmed cell death-apoptosis is deleterious at the cellular level, but it may yield beneficial effects at the organismal level. Reconciling both opposites requires reevaluating the probable evolutionary origin and role of peptidic brain hormones that direct steroid hormone synthesis. Do e.g. Luteinizing Hormone in vertebrates and Prothoracicotropic Hormone (PTTH: acting through the Torso receptor) in insects still retain an ancient role as toxins in the early immune system? Does the functional link of some neuropeptides with Ca(2+)-induced apoptosis make sense in endocrine archeology? The endocrine system as a remnant of the ancient immune system is undoubtedly counterintuitive. Yet, we will argue that such paradigm enables the logical framing of many aspects, the endocrine one inclusive of both male and female reproductive physiology.
Collapse
Affiliation(s)
- Arnold De Loof
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven-University of Leuven, Belgium.
| | - Liliane Schoofs
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven-University of Leuven, Belgium
| | - Roger Huybrechts
- Insect Physiology and Molecular Ethology Group, Department of Biology, KU Leuven-University of Leuven, Belgium
| |
Collapse
|
37
|
Abstract
The assembly of cilia and eukaryotic flagella (interchangeable terms) requires the import of numerous proteins from the cell body into the growing organelle. Proteins move into and inside cilia by diffusion and by motor-based intraflagellar transport (IFT). Many aspects of ciliary protein transport such as the distribution of unloading sites and the frequency of transport can be analyzed using direct in vivo imaging of fluorescently tagged proteins. Here, we will describe how to use total internal reflection fluorescence microcopy (TIRFM) to analyze protein transport in the flagella of the unicellular alga Chlamydomonas reinhardtii, a widely used model for cilia and cilia-related disease.
Collapse
|
38
|
Lechtreck KF. IFT-Cargo Interactions and Protein Transport in Cilia. Trends Biochem Sci 2015; 40:765-778. [PMID: 26498262 PMCID: PMC4661101 DOI: 10.1016/j.tibs.2015.09.003] [Citation(s) in RCA: 230] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/07/2015] [Accepted: 09/11/2015] [Indexed: 12/30/2022]
Abstract
The motile and sensory functions of cilia and flagella are indispensable for human health. Cilia assembly requires a dedicated protein shuttle, intraflagellar transport (IFT), a bidirectional motility of multi-megadalton protein arrays along ciliary microtubules. IFT functions as a protein carrier delivering hundreds of distinct proteins into growing cilia. IFT-based protein import and export continue in fully grown cilia and are required for ciliary maintenance and sensing. Large ciliary building blocks might depend on IFT to move through the transition zone, which functions as a ciliary gate. Smaller, freely diffusing proteins, such as tubulin, depend on IFT to be concentrated or removed from cilia. As I discuss here, recent work provides insights into how IFT interacts with its cargoes and how the transport is regulated.
Collapse
Affiliation(s)
- Karl F Lechtreck
- Department of Cellular Biology, University of Georgia, 635C Biological Science Building, 1000 Cedar Street, Athens, GA 30602, USA.
| |
Collapse
|
39
|
Jiang YY, Lechtreck K, Gaertig J. Total internal reflection fluorescence microscopy of intraflagellar transport in Tetrahymena thermophila. Methods Cell Biol 2015; 127:445-56. [PMID: 25837403 DOI: 10.1016/bs.mcb.2015.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Live imaging has become a powerful tool in studies of ciliary proteins. Tetrahymena thermophila is an established ciliated model with well-developed genetic and biochemical approaches, but its large size, complex shape, and the large number of short and overlapping cilia, have made live imaging of ciliary proteins challenging. Here we describe a method that combines paralysis of cilia by nickel ions and total internal reflection microscopy for live imaging of fluorescent proteins inside cilia of Tetrahymena. Using this method, we quantitatively documented the intraflagellar transport in Tetrahymena.
Collapse
Affiliation(s)
- Yu-Yang Jiang
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| |
Collapse
|
40
|
Craft JM, Harris JA, Hyman S, Kner P, Lechtreck KF. Tubulin transport by IFT is upregulated during ciliary growth by a cilium-autonomous mechanism. ACTA ACUST UNITED AC 2015; 208:223-37. [PMID: 25583998 PMCID: PMC4298693 DOI: 10.1083/jcb.201409036] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In Chlamydomonas cilia, IFT concentrates soluble tubulin by regulating IFT train occupancy and thereby promotes elongation of axonemal microtubules. The assembly of the axoneme, the structural scaffold of cilia and flagella, requires translocation of a vast quantity of tubulin into the growing cilium, but the mechanisms that regulate the targeting, quantity, and timing of tubulin transport are largely unknown. In Chlamydomonas, GFP-tagged α-tubulin enters cilia as an intraflagellar transport (IFT) cargo and by diffusion. IFT-based transport of GFP-tubulin is elevated in growing cilia and IFT trains carry more tubulin. Cells possessing both nongrowing and growing cilia selectively target GFP-tubulin into the latter. The preferential delivery of tubulin boosts the concentration of soluble tubulin in the matrix of growing versus steady-state cilia. Cilia length mutants show abnormal kinetics of tubulin transport. We propose that cells regulate the extent of occupancy of IFT trains by tubulin cargoes. During ciliary growth, IFT concentrates soluble tubulin in cilia and thereby promotes elongation of the axonemal microtubules.
Collapse
Affiliation(s)
- Julie M Craft
- Department of Cellular Biology and College of Engineering, University of Georgia, Athens, GA 30602
| | - J Aaron Harris
- Department of Cellular Biology and College of Engineering, University of Georgia, Athens, GA 30602
| | - Sebastian Hyman
- Department of Cellular Biology and College of Engineering, University of Georgia, Athens, GA 30602
| | - Peter Kner
- Department of Cellular Biology and College of Engineering, University of Georgia, Athens, GA 30602
| | - Karl F Lechtreck
- Department of Cellular Biology and College of Engineering, University of Georgia, Athens, GA 30602
| |
Collapse
|
41
|
Warburton-Pitt SRF, Silva M, Nguyen KCQ, Hall DH, Barr MM. The nphp-2 and arl-13 genetic modules interact to regulate ciliogenesis and ciliary microtubule patterning in C. elegans. PLoS Genet 2014; 10:e1004866. [PMID: 25501555 PMCID: PMC4263411 DOI: 10.1371/journal.pgen.1004866] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 10/31/2014] [Indexed: 12/14/2022] Open
Abstract
Cilia are microtubule-based cellular organelles that mediate signal transduction. Cilia are organized into several structurally and functionally distinct compartments: the basal body, the transition zone (TZ), and the cilia shaft. In vertebrates, the cystoprotein Inversin localizes to a portion of the cilia shaft adjacent to the TZ, a region termed the "Inversin compartment" (InvC). The mechanisms that establish and maintain the InvC are unknown. In the roundworm C. elegans, the cilia shafts of amphid channel and phasmid sensory cilia are subdivided into two regions defined by different microtubule ultrastructure: a proximal doublet-based region adjacent to the TZ, and a distal singlet-based region. It has been suggested that C. elegans cilia also possess an InvC, similarly to mammalian primary cilia. Here we explored the biogenesis, structure, and composition of the C. elegans ciliary doublet region and InvC. We show that the InvC is conserved and distinct from the doublet region. nphp-2 (the C. elegans Inversin homolog) and the doublet region genes arl-13, klp-11, and unc-119 are redundantly required for ciliogenesis. InvC and doublet region genes can be sorted into two modules-nphp-2+klp-11 and arl-13+unc-119-which are both antagonized by the hdac-6 deacetylase. The genes of this network modulate the sizes of the NPHP-2 InvC and ARL-13 doublet region. Glutamylation, a tubulin post-translational modification, is not required for ciliary targeting of InvC and doublet region components; rather, glutamylation is modulated by nphp-2, arl-13, and unc-119. The ciliary targeting and restricted localization of NPHP-2, ARL-13, and UNC-119 does not require TZ-, doublet region, and InvC-associated genes. NPHP-2 does require its calcium binding EF hand domain for targeting to the InvC. We conclude that the C. elegans InvC is distinct from the doublet region, and that components in these two regions interact to regulate ciliogenesis via cilia placement, ciliary microtubule ultrastructure, and protein localization.
Collapse
Affiliation(s)
- Simon R. F. Warburton-Pitt
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Malan Silva
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Ken C. Q. Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - David H. Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Maureen M. Barr
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- * E-mail:
| |
Collapse
|
42
|
Abstract
Cilia and flagella are assembled and maintained by the motor-driven, bidirectional traffic of large protein complexes in a process termed intraflagellar transport (IFT). In this issue of Developmental Cell, Liang et al. (2014) report that IFT is regulated in part by the phosphorylation status of the kinesin-II subunit FLA8/KIF3B.
Collapse
Affiliation(s)
- Branch Craige
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - George B Witman
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
| |
Collapse
|
43
|
Docampo R, Huang G. Calcium signaling in trypanosomatid parasites. Cell Calcium 2014; 57:194-202. [PMID: 25468729 DOI: 10.1016/j.ceca.2014.10.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/27/2014] [Accepted: 10/29/2014] [Indexed: 11/29/2022]
Abstract
Calcium ion (Ca(2+)) is an important second messenger in trypanosomatids and essential for their survival although prolonged high intracellular Ca(2+) levels lead to cell death. As other eukaryotic cells, trypanosomes use two sources of Ca(2+) for generating signals: Ca(2+) release from intracellular stores and Ca(2+) entry across the plasma membrane. Ca(2+) release from intracellular stores is controlled by the inositol 1,4,5-trisphosphate receptor (IP3R) that is located in acidocalcisomes, acidic organelles that are the primary Ca(2+) reservoir in these cells. A plasma membrane Ca(2+)-ATPase controls the cytosolic Ca(2+) levels and a number of pumps and exchangers are responsible for Ca(2+) uptake and release from intracellular compartments. The trypanosomatid genomes contain a wide variety of signaling and regulatory proteins that bind Ca(2+) as well as many Ca(2+)-binding proteins that await further characterization. The mitochondrial Ca(2+) transporters of trypanosomatids have an important role in the regulation of cell bioenergetics and flagellar Ca(2+) appears to have roles in sensing the environment. In trypanosomatids in which an intracellular life cycle is present, Ca(2+) signaling is important for host cell invasion.
Collapse
Affiliation(s)
- Roberto Docampo
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, GA 30620, USA; Departamento de Patologia Clínica, State University of Campinas, Campinas, SP 13083, Brazil.
| | - Guozhong Huang
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, GA 30620, USA
| |
Collapse
|
44
|
Liang Y, Pang Y, Wu Q, Hu Z, Han X, Xu Y, Deng H, Pan J. FLA8/KIF3B Phosphorylation Regulates Kinesin-II Interaction with IFT-B to Control IFT Entry and Turnaround. Dev Cell 2014; 30:585-97. [DOI: 10.1016/j.devcel.2014.07.019] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/15/2014] [Accepted: 07/23/2014] [Indexed: 11/28/2022]
|
45
|
Centrin 2 is required for mouse olfactory ciliary trafficking and development of ependymal cilia planar polarity. J Neurosci 2014; 34:6377-88. [PMID: 24790208 DOI: 10.1523/jneurosci.0067-14.2014] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Centrins are ancient calmodulin-related Ca(2+)-binding proteins associated with basal bodies. In lower eukaryotes, Centrin2 (CETN2) is required for basal body replication and positioning, although its function in mammals is undefined. We generated a germline CETN2 knock-out (KO) mouse presenting with syndromic ciliopathy including dysosmia and hydrocephalus. Absence of CETN2 leads to olfactory cilia loss, impaired ciliary trafficking of olfactory signaling proteins, adenylate cyclase III (ACIII), and cyclic nucleotide-gated (CNG) channel, as well as disrupted basal body apical migration in postnatal olfactory sensory neurons (OSNs). In mutant OSNs, cilia base-anchoring of intraflagellar transport components IFT88, the kinesin-II subunit KIF3A, and cytoplasmic dynein 2 appeared compromised. Although the densities of mutant ependymal and respiratory cilia were largely normal, the planar polarity of mutant ependymal cilia was disrupted, resulting in uncoordinated flow of CSF. Transgenic expression of GFP-CETN2 rescued the Cetn2-deficiency phenotype. These results indicate that mammalian basal body replication and ciliogenesis occur independently of CETN2; however, mouse CETN2 regulates protein trafficking of olfactory cilia and participates in specifying planar polarity of ependymal cilia.
Collapse
|
46
|
Guemez-Gamboa A, Coufal NG, Gleeson JG. Primary cilia in the developing and mature brain. Neuron 2014; 82:511-21. [PMID: 24811376 DOI: 10.1016/j.neuron.2014.04.024] [Citation(s) in RCA: 195] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Primary cilia were the largely neglected nonmotile counterparts of their better-known cousin, the motile cilia. For years these nonmotile cilia were considered evolutionary remnants of little consequence to cellular function. Fast forward 10 years and we now recognize primary cilia as key integrators of extracellular ligand-based signaling and cellular polarity, which regulate neuronal cell fate, migration, differentiation, as well as a host of adult behaviors. Important future questions will focus on structure-function relationships, their roles in signaling and disease and as areas of target for treatments.
Collapse
Affiliation(s)
- Alicia Guemez-Gamboa
- Howard Hughes Medical Institute, Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nicole G Coufal
- Howard Hughes Medical Institute, Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joseph G Gleeson
- Howard Hughes Medical Institute, Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
47
|
Huang L, Lipschutz JH. Cilia and polycystic kidney disease, kith and kin. ACTA ACUST UNITED AC 2014; 102:174-85. [PMID: 24898006 DOI: 10.1002/bdrc.21066] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2014] [Indexed: 11/11/2022]
Abstract
In the past decade, cilia have been found to play important roles in renal cystogenesis. Many genes, such as PKD1 and PKD2 which, when mutated, cause autosomal dominant polycystic kidney disease (ADPKD), have been found to localize to primary cilia. The cilium functions as a sensor to transmit extracellular signals into the cell. Abnormal cilia structure and function are associated with the development of polyscystic kidney disease (PKD). Cilia assembly includes centriole migration to the apical surface of the cell, ciliary vesicle docking and fusion with the cell membrane at the intended site of cilium outgrowth, and microtubule growth from the basal body. This review summarizes the most recent advances in cilia and PKD research, with special emphasis on the mechanisms of cytoplasmic and intraciliary protein transport during ciliogenesis.
Collapse
Affiliation(s)
- Liwei Huang
- Department of Medicine, Eastern Virginia Medical School, Norfolk, Virginia
| | | |
Collapse
|