1
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Lu Q, Westlake CJ. Multi-color live-cell fluorescence imaging of primary ciliary membrane assembly and dynamics. Methods Cell Biol 2023; 176:235-250. [PMID: 37164540 PMCID: PMC11302370 DOI: 10.1016/bs.mcb.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
The ciliary membrane is continuous with the plasma membrane but has distinct lipid and protein composition, which is key to defining the function of the primary cilium. Ciliary membranes dynamically assemble and disassemble in association with the cell cycle and directly transmit signals and molecules through budding membranes. Various imaging approaches have greatly advanced the understanding of the ciliary membrane function. In particular, fluorescence live-cell imaging has revealed important insights into the dynamics of ciliary membrane assembly by monitoring the changes of fluorescent-tagged ciliary proteins. Protein dynamics can be tracked simultaneously using multi-color live cell imaging by coupling ciliary-associated factors with different colored fluorescent tags. Ciliary membrane and membrane associated-proteins such as Smoothened, 5-HTr6, SSTR3, Rab8a, and Arl13b have been used to track ciliary membranes and centriole proteins like Centrin1/2, CEP164, and CEP83 are often used to mark the ciliary basal body. Here, we describe a method for studying ciliogenesis membrane dynamics using spinning disk confocal live-cell imaging.
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Affiliation(s)
- Quanlong Lu
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States.
| | - Christopher J Westlake
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States.
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2
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Binó L, Mikulenková E, Štepánek L, Bernatík O, Vysloužil D, Pejšková P, Gorilák P, Huranová M, Varga V, Čajánek L. A protocol for generation and live-cell imaging analysis of primary cilia reporter cell lines. STAR Protoc 2022; 3:101199. [PMID: 35257113 PMCID: PMC8897589 DOI: 10.1016/j.xpro.2022.101199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Primary cilia are hair-like sensory organelles protruding from the surface of most human cells. As cilia are dynamic, several aspects of their biology can only be revealed by real-time analysis in living cells. Here we describe the generation of primary cilia reporter cell lines. Furthermore, we provide a detailed protocol of how to use the reporter cell lines for live-cell imaging microscopy analysis of primary cilia to study their growth as well as intraciliary transport. For complete details on the use and execution of this protocol, please refer to Bernatik et al. (2020) and Pejskova et al. (2020).
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Affiliation(s)
- Lucia Binó
- Laboratory of Cilia and Centrosome Biology, Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Kamenice 3, 62500 Brno, Czechia
| | - Erika Mikulenková
- Laboratory of Cilia and Centrosome Biology, Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Kamenice 3, 62500 Brno, Czechia
| | - Luděk Štepánek
- Laboratory of Cell Motility, Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 14220 Prague, Czechia
| | - Ondřej Bernatík
- Laboratory of Cilia and Centrosome Biology, Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Kamenice 3, 62500 Brno, Czechia
| | - David Vysloužil
- Laboratory of Cilia and Centrosome Biology, Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Kamenice 3, 62500 Brno, Czechia
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czechia
| | - Petra Pejšková
- Laboratory of Cilia and Centrosome Biology, Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Kamenice 3, 62500 Brno, Czechia
| | - Peter Gorilák
- Laboratory of Cell Motility, Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 14220 Prague, Czechia
- Charles University, Faculty of Science, Albertov 6, 128 00 Prague, Czechia
| | - Martina Huranová
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 14220 Prague, Czechia
| | - Vladimír Varga
- Laboratory of Cell Motility, Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 14220 Prague, Czechia
| | - Lukáš Čajánek
- Laboratory of Cilia and Centrosome Biology, Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Kamenice 3, 62500 Brno, Czechia
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czechia
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3
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Duan S, Li H, Zhang Y, Yang S, Chen Y, Qiu B, Huang C, Wang J, Li J, Zhu X, Yan X. Rabl2 GTP hydrolysis licenses BBSome-mediated export to fine-tune ciliary signaling. EMBO J 2021; 40:e105499. [PMID: 33241915 PMCID: PMC7809784 DOI: 10.15252/embj.2020105499] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 10/19/2020] [Accepted: 10/23/2020] [Indexed: 01/04/2023] Open
Abstract
Cilia of higher animals sense various environmental stimuli. Proper ciliary signaling requires appropriate extent of BBSome-mediated export of membrane receptors across ciliary barrier transition zone (TZ) through retrograde intraflagellar transport (IFT) machinery. How the barrier passage is controlled, however, remains unknown. Here, we show that small GTPase Rabl2 functions as a molecular switch for the outward TZ passage. Rabl2-GTP enters cilia by binding to IFT-B complex. Its GTP hydrolysis enables the outward TZ passage of the BBSome and its cargos with retrograde IFT machinery, whereas its persistent association leads to their shedding from IFT-B during the passing process and consequently ciliary retention. Rabl2 deficiency or expression of a GTP-locked mutant impairs the ciliary hedgehog signaling without interfering with ciliation and respectively results in different spectrums of mouse developmental disorders. We propose that the switch role of Rabl2 ensures proper turnover of the BBSome and ciliary membrane receptors to fine-tune cilia-dependent signaling for normal embryonic development and organismic homeostasis.
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Affiliation(s)
- Shichao Duan
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
- Department of PathologyFirst Affiliated Hospital of Zhengzhou UniversityZhengzhouChina
| | - Hao Li
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Yirong Zhang
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Suming Yang
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Yawen Chen
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Benhua Qiu
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Cheng Huang
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Juan Wang
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Jinsong Li
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Xueliang Zhu
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
- School of Life ScienceHangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhouChina
| | - Xiumin Yan
- State Key Laboratory of Cell BiologyShanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghaiChina
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4
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Abstract
A recent study reports the three-dimensional structure of a primary cilium with unprecedented clarity. The results highlight the architectural differences with motile cilia and provoke a reassessment of the relationship between the ciliary cytoskeleton and microtubule-based transport in cilia.
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5
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Kiesel P, Alvarez Viar G, Tsoy N, Maraspini R, Gorilak P, Varga V, Honigmann A, Pigino G. The molecular structure of mammalian primary cilia revealed by cryo-electron tomography. Nat Struct Mol Biol 2020; 27:1115-1124. [PMID: 32989303 PMCID: PMC7610599 DOI: 10.1038/s41594-020-0507-4] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 08/12/2020] [Indexed: 01/09/2023]
Abstract
Primary cilia are microtubule-based organelles that are important for signaling and sensing in eukaryotic cells. Unlike the thoroughly studied motile cilia, the three-dimensional architecture and molecular composition of primary cilia are largely unexplored. Yet, studying these aspects is necessary to understand how primary cilia function in health and disease. We developed an enabling method for investigating the structure of primary cilia isolated from MDCK-II cells at molecular resolution by cryo-electron tomography. We show that the textbook '9 + 0' arrangement of microtubule doublets is only present at the primary cilium base. A few microns out, the architecture changes into an unstructured bundle of EB1-decorated microtubules and actin filaments, putting an end to a long debate on the presence or absence of actin filaments in primary cilia. Our work provides a plethora of insights into the molecular structure of primary cilia and offers a methodological framework to study these important organelles.
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Affiliation(s)
- Petra Kiesel
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | | | - Nikolai Tsoy
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Riccardo Maraspini
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Peter Gorilak
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Vladimir Varga
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Alf Honigmann
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Gaia Pigino
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
- Human Technopole, Milan, Italy.
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6
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Ha K, Nobuhara M, Wang Q, Walker RV, Qian F, Schartner C, Cao E, Delling M. The heteromeric PC-1/PC-2 polycystin complex is activated by the PC-1 N-terminus. eLife 2020; 9:60684. [PMID: 33164752 PMCID: PMC7728438 DOI: 10.7554/elife.60684] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/06/2020] [Indexed: 12/28/2022] Open
Abstract
Mutations in the polycystin proteins, PC-1 and PC-2, result in autosomal dominant polycystic kidney disease (ADPKD) and ultimately renal failure. PC-1 and PC-2 enrich on primary cilia, where they are thought to form a heteromeric ion channel complex. However, a functional understanding of the putative PC-1/PC-2 polycystin complex is lacking due to technical hurdles in reliably measuring its activity. Here we successfully reconstitute the PC-1/PC-2 complex in the plasma membrane of mammalian cells and show that it functions as an outwardly rectifying channel. Using both reconstituted and ciliary polycystin channels, we further show that a soluble fragment generated from the N-terminal extracellular domain of PC-1 functions as an intrinsic agonist that is necessary and sufficient for channel activation. We thus propose that autoproteolytic cleavage of the N-terminus of PC-1, a hotspot for ADPKD mutations, produces a soluble ligand in vivo. These findings establish a mechanistic framework for understanding the role of PC-1/PC-2 heteromers in ADPKD and suggest new therapeutic strategies that would expand upon the limited symptomatic treatments currently available for this progressive, terminal disease. On the surface of most animal and other eukaryotic cells are small rod-like protrusions known as primary cilia. Each cilium is encased by a specialized membrane which is enriched in protein complexes that help the cell sense its local environment. Some of these complexes help transport ions in out of the cell, while others act as receptors that receive chemical signals called ligands. A unique ion channel known as the polycystin complex is able to perform both of these roles as it contains a receptor called PC-1 in addition to an ion channel called PC-2. Various mutations in the genes that code for PC-1 and PC-2 can result in autosomal dominant polycystic kidney disease (ADPKD), which is the most common monogenetic disease in humans. However, due to the small size of primary cilia – which are less than a thousandth of a millimeter thick – little is known about how polycystin complexes are regulated and how mutations lead to ADPKD. To overcome this barrier, Ha et al. modified kidney cells grown in the lab so that PC-1 and PC-2 form a working channel in the plasma membrane which surrounds the entire cell. As the body of a cell is around 10,000 times bigger than the cilium, this allowed the movement of ions across the polycystin complex to be studied using conventional techniques. Experiments using this newly developed assay revealed that a region at one of the ends of the PC-1 protein, named the C-type lectin domain, is essential for stimulating polycystin complexes. Ha et al. found that this domain of PC-1 is able to cut itself from the protein complex. Further experiments showed that when fragments of PC-1, which contain the C-type lectin domain, are no longer bound to the membrane, they can activate the polycystin channels in cilia as well as the plasma membrane. This suggests that this region of PC-1 may also act as a secreted ligand that can activate other polycystin channels. Some of the genetic mutations that cause ADPKD likely disrupt the activity of the polycystin complex and reduce its ability to transport ions across the cilia membrane. Therefore, the cell assay created in this study could be used to screen for small molecules that can restore the activity of these ion channels in patients with ADPKD.
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Affiliation(s)
- Kotdaji Ha
- Department of Physiology, University of California, San Francisco, San Francisco, United States
| | - Mai Nobuhara
- Department of Physiology, University of California, San Francisco, San Francisco, United States
| | - Qinzhe Wang
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, United States
| | - Rebecca V Walker
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, United States
| | - Feng Qian
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, United States
| | - Christoph Schartner
- Department of Physiology, University of California, San Francisco, San Francisco, United States
| | - Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, United States
| | - Markus Delling
- Department of Physiology, University of California, San Francisco, San Francisco, United States
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7
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Santoso F, Farhan A, Castillo AL, Malhotra N, Saputra F, Kurnia KA, Chen KHC, Huang JC, Chen JR, Hsiao CD. An Overview of Methods for Cardiac Rhythm Detection in Zebrafish. Biomedicines 2020; 8:E329. [PMID: 32899676 PMCID: PMC7554775 DOI: 10.3390/biomedicines8090329] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 08/29/2020] [Accepted: 09/01/2020] [Indexed: 12/17/2022] Open
Abstract
The heart is the most important muscular organ of the cardiovascular system, which pumps blood and circulates, supplying oxygen and nutrients to peripheral tissues. Zebrafish have been widely explored in cardiotoxicity research. For example, the zebrafish embryo has been used as a human heart model due to its body transparency, surviving several days without circulation, and facilitating mutant identification to recapitulate human diseases. On the other hand, adult zebrafish can exhibit the amazing regenerative heart muscle capacity, while adult mammalian hearts lack this potential. This review paper offers a brief description of the major methodologies used to detect zebrafish cardiac rhythm at both embryonic and adult stages. The dynamic pixel change method was mostly performed for the embryonic stage. Other techniques, such as kymography, laser confocal microscopy, artificial intelligence, and electrocardiography (ECG) have also been applied to study heartbeat in zebrafish embryos. Nevertheless, ECG is widely used for heartbeat detection in adult zebrafish since ECG waveforms' similarity between zebrafish and humans is prominent. High-frequency ultrasound imaging (echocardiography) and modern electronic sensor tag also have been proposed. Despite the fact that each method has its benefits and limitations, it is proved that zebrafish have become a promising animal model for human cardiovascular disease, drug pharmaceutical, and toxicological research. Using those tools, we conclude that zebrafish behaviors as an excellent small animal model to perform real-time monitoring for the developmental heart process with transparent body appearance, to conduct the in vivo cardiovascular performance and gene function assays, as well as to perform high-throughput/high content drug screening.
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Affiliation(s)
- Fiorency Santoso
- Master Program in Nanotechnology, Chung Yuan Christian University, Chung-Li 320314, Taiwan;
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li 320314, Taiwan; (F.S.); (K.A.K.)
| | - Ali Farhan
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Punjab 38000, Pakistan;
| | - Agnes L. Castillo
- Faculty of Pharmacy, The Graduate School and Research Center for the Natural and Applied Sciences, University of Santo Tomas, Manila 1008, Philippines;
| | - Nemi Malhotra
- Department of Biomedical Engineering, Chung Yuan Christian University, Chung-Li 320314, Taiwan;
| | - Ferry Saputra
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li 320314, Taiwan; (F.S.); (K.A.K.)
| | - Kevin Adi Kurnia
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li 320314, Taiwan; (F.S.); (K.A.K.)
| | - Kelvin H.-C. Chen
- Department of Applied Chemistry, National Pingtung University, Pingtung 900391, Taiwan;
| | - Jong-Chin Huang
- Department of Applied Chemistry, National Pingtung University, Pingtung 900391, Taiwan;
| | - Jung-Ren Chen
- Department of Biological Science & Technology College of Medicine, I-Shou University, Kaohsiung 82445, Taiwan
| | - Chung-Der Hsiao
- Master Program in Nanotechnology, Chung Yuan Christian University, Chung-Li 320314, Taiwan;
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li 320314, Taiwan; (F.S.); (K.A.K.)
- Center of Nanotechnology, Chung Yuan Christian University, Chung-Li 320314, Taiwan
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8
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Hazime K, Malicki JJ. Apico-basal Polarity Determinants Encoded by crumbs Genes Affect Ciliary Shaft Protein Composition, IFT Movement Dynamics, and Cilia Length. Genetics 2017; 207:1041-1051. [PMID: 28882989 PMCID: PMC5676222 DOI: 10.1534/genetics.117.300260] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/23/2017] [Indexed: 02/04/2023] Open
Abstract
One of the most obvious manifestations of polarity in epithelia is the subdivision of the cell surface by cell junctions into apical and basolateral domains. crumbs genes are among key regulators of this form of polarity. Loss of crumbs function disrupts the apical cell junction belt and crumbs overexpression expands the apical membrane size. Crumbs proteins contain a single transmembrane domain and localize to cell junction area at the apical surface of epithelia. In some tissues, they are also found in cilia. To test their role in ciliogenesis, we investigated mutant phenotypes of zebrafish crumbs genes. In zebrafish, mutations of three crumbs genes, oko meduzy/crb2a, crb3a, and crb2b, affect cilia length in a subset of tissues. In oko meduzy (ome), this is accompanied by accumulation of other Crumbs proteins in the ciliary compartment. Moreover, intraflagellar transport (IFT) particle components accumulate in the ciliary shaft of ome;crb3a double mutants. Consistent with the above, Crb3 knockdown in mammalian cells affects the dynamics of IFT particle movement. These findings reveal crumbs-dependent mechanisms that regulate the localization of ciliary proteins, including Crumbs proteins themselves, and show that crumbs genes modulate intraflagellar transport and cilia elongation.
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Affiliation(s)
- Khodor Hazime
- Bateson Centre, Department of Biomedical Science, University of Sheffield, S10 2TN, United Kingdom
| | - Jarema J Malicki
- Bateson Centre, Department of Biomedical Science, University of Sheffield, S10 2TN, United Kingdom
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9
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Ishikawa H, Marshall WF. Testing the time-of-flight model for flagellar length sensing. Mol Biol Cell 2017; 28:3447-3456. [PMID: 28931591 PMCID: PMC5687043 DOI: 10.1091/mbc.e17-06-0384] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/08/2017] [Accepted: 09/11/2017] [Indexed: 11/23/2022] Open
Abstract
A combination of quantitative imaging, modeling, and genetics has been used to test a proposed mechanism for measuring the size of an organelle. One way to measure distance is to send a clock out on a train and measure the elapsed time when the train returns. We tested a molecular version of this model as a possible regulator of intraflagellar transport by altering the return speed of the transport machinery and probing the effect on a known length-dependent process. Cilia and flagella are microtubule-based organelles that protrude from the surface of most cells, are important to the sensing of extracellular signals, and make a driving force for fluid flow. Maintenance of flagellar length requires an active transport process known as intraflagellar transport (IFT). Recent studies reveal that the amount of IFT injection negatively correlates with the length of flagella. These observations suggest that a length-dependent feedback regulates IFT. However, it is unknown how cells recognize the length of flagella and control IFT. Several theoretical models try to explain this feedback system. We focused on one of the models, the “time-of-flight” model, which measures the length of flagella on the basis of the travel time of IFT protein in the flagellar compartment. We tested the time-of-flight model using Chlamydomonas dynein mutant cells, which show slower retrograde transport speed. The amount of IFT injection in dynein mutant cells was higher than that in control cells. This observation does not support the prediction of the time-of-flight model and suggests that Chlamydomonas uses another length-control feedback system rather than that described by the time-of-flight model.
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Affiliation(s)
- Hiroaki Ishikawa
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143
| | - Wallace F Marshall
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143
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10
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Shimada IS, Badgandi H, Somatilaka BN, Mukhopadhyay S. Using Primary Neurosphere Cultures to Study Primary Cilia. J Vis Exp 2017. [PMID: 28448009 DOI: 10.3791/55315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The primary cilium is fundamentally important for the proliferation of neural stem/progenitor cells and for neuronal differentiation during embryonic, postnatal, and adult life. In addition, most differentiated neurons possess primary cilia that house signaling receptors, such as G-protein-coupled receptors, and signaling molecules, such as adenylyl cyclases. The primary cilium determines the activity of multiple developmental pathways, including the sonic hedgehog pathway during embryonic neuronal development, and also functions in promoting compartmentalized subcellular signaling during adult neuronal function. Unsurprisingly, defects in primary cilium biogenesis and function have been linked to developmental anomalies of the brain, central obesity, and learning and memory deficits. Thus, it is imperative to study primary cilium biogenesis and ciliary trafficking in the context of neural stem/progenitor cells and differentiated neurons. However, culturing methods for primary neurons require considerable expertise and are not amenable to freeze-thaw cycles. In this protocol, we discuss culturing methods for mixed populations of neural stem/progenitor cells using primary neurospheres. The neurosphere-based culturing methods provide the combined benefits of studying primary neural stem/progenitor cells: amenability to multiple passages and freeze-thaw cycles, differentiation potential into neurons/glia, and transfectability. Importantly, we determined that neurosphere-derived neural stem/progenitor cells and differentiated neurons are ciliated in culture and localize signaling molecules relevant to ciliary function in these compartments. Utilizing these cultures, we further describe methods to study ciliogenesis and ciliary trafficking in neural stem/progenitor cells and differentiated neurons. These neurosphere-based methods allow us to study cilia-regulated cellular pathways, including G-protein-coupled receptor and sonic hedgehog signaling, in the context of neural stem/progenitor cells and differentiated neurons.
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Affiliation(s)
- Issei S Shimada
- Department of Cell Biology, University of Texas Southwestern Medical Center;
| | - Hemant Badgandi
- Department of Cell Biology, University of Texas Southwestern Medical Center
| | | | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center;
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11
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Taschner M, Lorentzen E. The Intraflagellar Transport Machinery. Cold Spring Harb Perspect Biol 2016; 8:cshperspect.a028092. [PMID: 27352625 DOI: 10.1101/cshperspect.a028092] [Citation(s) in RCA: 237] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Eukaryotic cilia and flagella are evolutionarily conserved organelles that protrude from the cell surface. The unique location and properties of cilia allow them to function in vital processes such as motility and signaling. Ciliary assembly and maintenance rely on intraflagellar transport (IFT), the bidirectional movement of a multicomponent transport system between the ciliary base and tip. Since its initial discovery more than two decades ago, considerable effort has been invested in dissecting the molecular mechanisms of IFT in a variety of model organisms. Importantly, IFT was shown to be essential for mammalian development, and defects in this process cause a number of human pathologies known as ciliopathies. Here, we review current knowledge of IFT with a particular emphasis on the IFT machinery and specific mechanisms of ciliary cargo recognition and transport.
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Affiliation(s)
- Michael Taschner
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, D-82152 Martinsried, Germany
| | - Esben Lorentzen
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, D-82152 Martinsried, Germany
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12
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Kamiyama D, Sekine S, Barsi-Rhyne B, Hu J, Chen B, Gilbert LA, Ishikawa H, Leonetti MD, Marshall WF, Weissman JS, Huang B. Versatile protein tagging in cells with split fluorescent protein. Nat Commun 2016; 7:11046. [PMID: 26988139 PMCID: PMC4802074 DOI: 10.1038/ncomms11046] [Citation(s) in RCA: 271] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/15/2016] [Indexed: 12/26/2022] Open
Abstract
In addition to the popular method of fluorescent protein fusion, live cell protein imaging has now seen more and more application of epitope tags. The small size of these tags may reduce functional perturbation and enable signal amplification. To address their background issue, we adapt self-complementing split fluorescent proteins as epitope tags for live cell protein labelling. The two tags, GFP11 and sfCherry11 are derived from the eleventh β-strand of super-folder GFP and sfCherry, respectively. The small size of FP11-tags enables a cost-effective and scalable way to insert them into endogenous genomic loci via CRISPR-mediated homology-directed repair. Tandem arrangement FP11-tags allows proportional enhancement of fluorescence signal in tracking intraflagellar transport particles, or reduction of photobleaching for live microtubule imaging. Finally, we show the utility of tandem GFP11-tag in scaffolding protein oligomerization. These experiments illustrate the versatility of FP11-tag as a labelling tool as well as a multimerization-control tool for both imaging and non-imaging applications. Tagging proteins with fluorescent proteins is a powerful method for both imaging and non-imaging applications. Here the authors use the eleventh β-strand of sfGFP and sfCherry as epitope tags for multicolour imaging and amplified signals by tandem arrangement; shortness of the tag enabled introduction into genomic loci using CRISPR/Cas9.
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Affiliation(s)
- Daichi Kamiyama
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, USA
| | - Sayaka Sekine
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, USA
| | - Benjamin Barsi-Rhyne
- Tetrad Graduate Program, University of California, San Francisco, California 94143, USA
| | - Jeffrey Hu
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, USA
| | - Baohui Chen
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, USA
| | - Luke A Gilbert
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94143, USA
| | - Hiroaki Ishikawa
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143, USA
| | - Manuel D Leonetti
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94143, USA
| | - Wallace F Marshall
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143, USA
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94143, USA.,Howard Hughes Medical Institute, San Francisco, California 94143, USA
| | - Bo Huang
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, USA.,Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143, USA
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13
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Abstract
Cilia and flagella are microtubule-based organelles that play important roles in human health by contributing to cellular motility as well as sensing and responding to environmental cues. Defects in cilia formation and function cause a broad class of human genetic diseases called ciliopathies. To carry out their specialized functions, cilia contain a unique complement of proteins that must be imported into the ciliary compartment. In this chapter, we describe methods to measure the permeability barrier of the ciliary gate by microinjection of fluorescent proteins and dextrans of different sizes into ciliated cells. We also describe a fluorescence recovery after photobleaching (FRAP) assay to measure the entry of ciliary proteins into the ciliary compartment. These assays can be used to determine the molecular mechanisms that regulate the formation and function of cilia in mammalian cells.
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Affiliation(s)
- Daisuke Takao
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI, 48109, USA
| | - Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI, 48109, USA.
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14
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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.
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15
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San Agustin JT, Pazour GJ, Witman GB. Intraflagellar transport is essential for mammalian spermiogenesis but is absent in mature sperm. Mol Biol Cell 2015; 26:4358-72. [PMID: 26424803 PMCID: PMC4666132 DOI: 10.1091/mbc.e15-08-0578] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 09/24/2015] [Indexed: 12/20/2022] Open
Abstract
Intraflagellar transport (IFT) is necessary for the assembly and maintenance of most cilia, with the exception of gametic flagella in some organisms. IFT is required for assembly of mouse sperm flagella, and defects in IFT lead to male infertility. However, mature sperm lack IFT proteins and thus do not require IFT for maintenance of the axoneme. Drosophila sperm are unusual in that they do not require the intraflagellar transport (IFT) system for assembly of their flagella. In the mouse, the IFT proteins are very abundant in testis, but we here show that mature sperm are completely devoid of them, making the importance of IFT to mammalian sperm development unclear. To address this question, we characterized spermiogenesis and fertility in the Ift88Tg737Rpw mouse. This mouse has a hypomorphic mutation in the gene encoding the IFT88 subunit of the IFT particle. This mutation is highly disruptive to ciliary assembly in other organs. Ift88−/− mice are completely sterile. They produce ∼350-fold fewer sperm than wild-type mice, and the remaining sperm completely lack or have very short flagella. The short flagella rarely have axonemes but assemble ectopic microtubules and outer dense fibers and accumulate improperly assembled fibrous sheath proteins. Thus IFT is essential for the formation but not the maintenance of mammalian sperm flagella.
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Affiliation(s)
- Jovenal T San Agustin
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - George B Witman
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655
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