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Takahashi K, Sudharsan R, Beltran WA. Mapping protein distribution in the canine photoreceptor sensory cilium and calyceal processes by ultrastructure expansion microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.27.600953. [PMID: 38979372 PMCID: PMC11230445 DOI: 10.1101/2024.06.27.600953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Photoreceptors are highly polarized sensory neurons, possessing a unique ciliary structure known as the photoreceptor sensory cilium (PSC). Vertebrates have two subtypes of photoreceptors: rods, which are responsible for night vision, and cones, which support daylight vision and color perception. Despite identifying functional and morphological differences between these subtypes, ultrastructural analyses of the PSC molecular architecture in rods and cones are still lacking. In this study, we employed ultrastructure expansion microscopy (U-ExM) to characterize the molecular architecture of the PSC in canine retina. We demonstrated that U-ExM is applicable to both fresh and cryopreserved retinal tissues with standard paraformaldehyde fixation. Using this validated U-ExM protocol, we revealed the molecular localization of numerous ciliopathy-related proteins in canine photoreceptors. Furthermore, we identified significant architectural differences in the PSC, ciliary rootlet, and calyceal processes between canine rods and cones. These findings pave the way for a better understanding of alterations in the molecular architecture of the PSC in canine models of retinal ciliopathies.
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Tingey M, Ruba A, Jiang Z, Yang W. Deciphering vesicle-assisted transport mechanisms in cytoplasm to cilium trafficking. Front Cell Neurosci 2024; 18:1379976. [PMID: 38860265 PMCID: PMC11163138 DOI: 10.3389/fncel.2024.1379976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 05/13/2024] [Indexed: 06/12/2024] Open
Abstract
The cilium, a pivotal organelle crucial for cell signaling and proper cell function, relies on meticulous macromolecular transport from the cytoplasm for its formation and maintenance. While the intraflagellar transport (IFT) pathway has traditionally been the focus of extensive study concerning ciliogenesis and ciliary maintenance, recent research highlights a complementary and alternative mechanism-vesicle-assisted transport (VAT) in cytoplasm to cilium trafficking. Despite its potential significance, the VAT pathway remains largely uncharacterized. This review explores recent studies providing evidence for the dynamics of vesicle-related diffusion and transport within the live primary cilium, employing high-speed super-resolution light microscopy. Additionally, we analyze the spatial distribution of vesicles in the cilium, mainly relying on electron microscopy data. By scrutinizing the VAT pathways that facilitate cargo transport into the cilium, with a specific emphasis on recent advancements and imaging data, our objective is to synthesize a comprehensive model of ciliary transport through the integration of IFT-VAT mechanisms.
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Affiliation(s)
| | | | | | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, PA, United States
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3
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Mill P, Christensen ST, Pedersen LB. Primary cilia as dynamic and diverse signalling hubs in development and disease. Nat Rev Genet 2023; 24:421-441. [PMID: 37072495 PMCID: PMC7615029 DOI: 10.1038/s41576-023-00587-9] [Citation(s) in RCA: 61] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2023] [Indexed: 04/20/2023]
Abstract
Primary cilia, antenna-like sensory organelles protruding from the surface of most vertebrate cell types, are essential for regulating signalling pathways during development and adult homeostasis. Mutations in genes affecting cilia cause an overlapping spectrum of >30 human diseases and syndromes, the ciliopathies. Given the immense structural and functional diversity of the mammalian cilia repertoire, there is a growing disconnect between patient genotype and associated phenotypes, with variable severity and expressivity characteristic of the ciliopathies as a group. Recent technological developments are rapidly advancing our understanding of the complex mechanisms that control biogenesis and function of primary cilia across a range of cell types and are starting to tackle this diversity. Here, we examine the structural and functional diversity of primary cilia, their dynamic regulation in different cellular and developmental contexts and their disruption in disease.
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Affiliation(s)
- Pleasantine Mill
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, Scotland
| | | | - Lotte B Pedersen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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4
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Hibbard JVK, Vázquez N, Wallingford JB. Cilia proteins getting to work - how do they commute from the cytoplasm to the base of cilia? J Cell Sci 2022; 135:jcs259444. [PMID: 36073764 PMCID: PMC9482345 DOI: 10.1242/jcs.259444] [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: 11/20/2022] Open
Abstract
Cilia are multifunctional organelles that originated with the last eukaryotic common ancestor and play central roles in the life cycles of diverse organisms. The motile flagella that move single cells like sperm or unicellular organisms, the motile cilia on animal multiciliated cells that generate fluid flow in organs, and the immotile primary cilia that decorate nearly all cells in animals share many protein components in common, yet each also requires specialized proteins to perform their specialized functions. Despite a now-advanced understanding of how such proteins are transported within cilia, we still know very little about how they are transported from their sites of synthesis through the cytoplasm to the ciliary base. Here, we review the literature concerning this underappreciated topic in ciliary cell biology. We discuss both general mechanisms, as well as specific examples of motor-driven active transport and passive transport via diffusion-and-capture. We then provide deeper discussion of specific, illustrative examples, such as the diverse array of protein subunits that together comprise the intraflagellar transport (IFT) system and the multi-protein axonemal dynein motors that drive beating of motile cilia. We hope this Review will spur further work, shedding light not only on ciliogenesis and ciliary signaling, but also on intracellular transport in general.
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Affiliation(s)
| | | | - John B. Wallingford
- Department of Molecular Biosciences, University of Texas, Austin, TX 78751, USA
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van den Hoek H, Klena N, Jordan MA, Alvarez Viar G, Righetto RD, Schaffer M, Erdmann PS, Wan W, Geimer S, Plitzko JM, Baumeister W, Pigino G, Hamel V, Guichard P, Engel BD. In situ architecture of the ciliary base reveals the stepwise assembly of intraflagellar transport trains. Science 2022; 377:543-548. [PMID: 35901159 DOI: 10.1126/science.abm6704] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The cilium is an antenna-like organelle that performs numerous cellular functions, including motility, sensing, and signaling. The base of the cilium contains a selective barrier that regulates the entry of large intraflagellar transport (IFT) trains, which carry cargo proteins required for ciliary assembly and maintenance. However, the native architecture of the ciliary base and the process of IFT train assembly remain unresolved. In this work, we used in situ cryo-electron tomography to reveal native structures of the transition zone region and assembling IFT trains at the ciliary base in Chlamydomonas. We combined this direct cellular visualization with ultrastructure expansion microscopy to describe the front-to-back stepwise assembly of IFT trains: IFT-B forms the backbone, onto which bind IFT-A, dynein-1b, and finally kinesin-2 before entry into the cilium.
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Affiliation(s)
- Hugo van den Hoek
- Biozentrum, University of Basel, 4056 Basel, Switzerland.,Helmholtz Pioneer Campus, Helmholtz Munich, 85764 Neuherberg, Germany.,Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Nikolai Klena
- Department of Molecular and Cellular Biology, Section of Biology, University of Geneva, 1211 Geneva, Switzerland.,Human Technopole, 20157 Milan, Italy
| | - Mareike A Jordan
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Gonzalo Alvarez Viar
- Human Technopole, 20157 Milan, Italy.,Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Ricardo D Righetto
- Biozentrum, University of Basel, 4056 Basel, Switzerland.,Helmholtz Pioneer Campus, Helmholtz Munich, 85764 Neuherberg, Germany
| | - Miroslava Schaffer
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | | | - William Wan
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Stefan Geimer
- Cell Biology and Electron Microscopy, University of Bayreuth, 95447 Bayreuth, Germany
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Wolfgang Baumeister
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Gaia Pigino
- Human Technopole, 20157 Milan, Italy.,Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Virginie Hamel
- Department of Molecular and Cellular Biology, Section of Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Paul Guichard
- Department of Molecular and Cellular Biology, Section of Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Benjamin D Engel
- Biozentrum, University of Basel, 4056 Basel, Switzerland.,Helmholtz Pioneer Campus, Helmholtz Munich, 85764 Neuherberg, Germany
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6
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Pan J. Cilia are not created equal-restriction of IFT on microtubule tracks for cilia diversification. Bioessays 2022; 44:e2200082. [PMID: 35595681 DOI: 10.1002/bies.202200082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Junmin Pan
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province, China
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Niziolek M, Bicka M, Osinka A, Samsel Z, Sekretarska J, Poprzeczko M, Bazan R, Fabczak H, Joachimiak E, Wloga D. PCD Genes-From Patients to Model Organisms and Back to Humans. Int J Mol Sci 2022; 23:ijms23031749. [PMID: 35163666 PMCID: PMC8836003 DOI: 10.3390/ijms23031749] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/25/2022] [Accepted: 01/31/2022] [Indexed: 01/27/2023] Open
Abstract
Primary ciliary dyskinesia (PCD) is a hereditary genetic disorder caused by the lack of motile cilia or the assembxly of dysfunctional ones. This rare human disease affects 1 out of 10,000-20,000 individuals and is caused by mutations in at least 50 genes. The past twenty years brought significant progress in the identification of PCD-causative genes and in our understanding of the connections between causative mutations and ciliary defects observed in affected individuals. These scientific advances have been achieved, among others, due to the extensive motile cilia-related research conducted using several model organisms, ranging from protists to mammals. These are unicellular organisms such as the green alga Chlamydomonas, the parasitic protist Trypanosoma, and free-living ciliates, Tetrahymena and Paramecium, the invertebrate Schmidtea, and vertebrates such as zebrafish, Xenopus, and mouse. Establishing such evolutionarily distant experimental models with different levels of cell or body complexity was possible because both basic motile cilia ultrastructure and protein composition are highly conserved throughout evolution. Here, we characterize model organisms commonly used to study PCD-related genes, highlight their pros and cons, and summarize experimental data collected using these models.
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Affiliation(s)
- Michal Niziolek
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Marta Bicka
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Faculty of Chemistry, University of Warsaw, 1 Pasteur Street, 02-093 Warsaw, Poland
| | - Anna Osinka
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Zuzanna Samsel
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Justyna Sekretarska
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Martyna Poprzeczko
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Laboratory of Immunology, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawinskiego Street, 02-106 Warsaw, Poland
| | - Rafal Bazan
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Hanna Fabczak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Correspondence: (E.J.); (D.W.); Tel.: +48-22-58-92-338 (E.J. & D.W.)
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland; (M.N.); (M.B.); (A.O.); (Z.S.); (J.S.); (M.P.); (R.B.); (H.F.)
- Correspondence: (E.J.); (D.W.); Tel.: +48-22-58-92-338 (E.J. & D.W.)
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Frikstad KA, Schink K, Gilani S, Pedersen L, Patzke S. 3D-Structured Illumination Microscopy of Centrosomes in Human Cell Lines. Bio Protoc 2022; 12:e4360. [DOI: 10.21769/bioprotoc.4360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 11/22/2021] [Accepted: 02/07/2022] [Indexed: 11/02/2022] Open
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9
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Ift88, but not Kif3a, is required for establishment of the periciliary membrane compartment. Biochem Biophys Res Commun 2021; 584:19-25. [PMID: 34753064 DOI: 10.1016/j.bbrc.2021.10.075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 10/29/2021] [Indexed: 11/22/2022]
Abstract
The primary cilium is a sensory organelle at the cell surface with integral functions in cell signaling. It contains a microtubular axoneme that is rooted in the basal body (BB) and serves as a scaffold for the movement of intraflagellar transport (IFT) particles by Kinesin-2 along the cilium. Ift88, a member of the anterograde moving IFT-B1 complex, as well as the Kinesin-2 subunit Kif3a are required for cilia formation. To facilitate signaling, the cilium restricts the access of molecules to its membrane ("ciliary gate"). This is thought to be mediated by cytoskeletal barriers ("subciliary domains") originating from the BB subdistal/distal appendages, the periciliary membrane compartment (PCMC) as well as the transition fibers and zone (TF/TZ). The PCMC is a poorly characterized membrane domain surrounding the ciliary base with exclusion of certain apical membrane proteins. Here we describe that Ift88, but not Kinesin-2, is required for the establishment of the PCMC in MDCK cells. Likewise, in C. elegans mutants of the Ift88 ortholog osm-5 fail to establish the PCMC, while Kinesin-2 deficient osm-3 mutants form PCMCs normally. Furthermore, disruption of IFT-B1 into two subcomplexes, while disrupting ciliogenesis, does not interfere with PCMC formation. Our findings suggest that cilia are not a prerequisite for the formation of the PCMC, and that separate machineries with partially overlapping functions are required for the establishment of each.
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