1
|
Ewerling A, May-Simera HL. Evolutionary trajectory for nuclear functions of ciliary transport complex proteins. Microbiol Mol Biol Rev 2024:e0000624. [PMID: 38995044 DOI: 10.1128/mmbr.00006-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024] Open
Abstract
SUMMARYCilia and the nucleus were two defining features of the last eukaryotic common ancestor. In early eukaryotic evolution, these structures evolved through the diversification of a common membrane-coating ancestor, the protocoatomer. While in cilia, the descendants of this protein complex evolved into parts of the intraflagellar transport complexes and BBSome, the nucleus gained its selectivity by recruiting protocoatomer-like proteins to the nuclear envelope to form the selective nuclear pore complexes. Recent studies show a growing number of proteins shared between the proteomes of the respective organelles, and it is currently unknown how ciliary transport proteins could acquire nuclear functions and vice versa. The nuclear functions of ciliary proteins are still observable today and remain relevant for the understanding of the disease mechanisms behind ciliopathies. In this work, we review the evolutionary history of cilia and nucleus and their respective defining proteins and integrate current knowledge into theories for early eukaryotic evolution. We postulate a scenario where both compartments co-evolved and that fits current models of eukaryotic evolution, explaining how ciliary proteins and nucleoporins acquired their dual functions.
Collapse
Affiliation(s)
- Alexander Ewerling
- Faculty of Biology, Institute of Molecular Physiology, Johannes Gutenberg-University, Mainz, Germany
| | - Helen Louise May-Simera
- Faculty of Biology, Institute of Molecular Physiology, Johannes Gutenberg-University, Mainz, Germany
| |
Collapse
|
2
|
Hufft-Martinez BM, Wang HH, Saadi I, Tran PV. Actin cytoskeletal regulation of ciliogenesis in development and disease. Dev Dyn 2024. [PMID: 38958410 DOI: 10.1002/dvdy.724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 05/29/2024] [Accepted: 06/15/2024] [Indexed: 07/04/2024] Open
Abstract
Primary cilia are antenna-like sensory organelles that are evolutionarily conserved in nearly all modern eukaryotes, from the single-celled green alga, Chlamydomonas reinhardtii, to vertebrates and mammals. Cilia are microtubule-based cellular projections that have adapted to perform a broad range of species-specific functions, from cell motility to detection of light and the transduction of extracellular mechanical and chemical signals. These functions render cilia essential for organismal development and survival. The high conservation of cilia has allowed for discoveries in C. reinhardtii to inform our understanding of the basic biology of mammalian primary cilia, and to provide insight into the genetic etiology of ciliopathies. Over the last two decades, a growing number of studies has revealed that multiple aspects of ciliary homeostasis are regulated by the actin cytoskeleton, including centrosome migration and positioning, vesicle transport to the basal body, ectocytosis, and ciliary-mediated signaling. Here, we review actin regulation of ciliary homeostasis, and highlight conserved and divergent mechanisms in C. reinhardtii and mammalian cells. Further, we compare the disease manifestations of patients with ciliopathies to those with mutations in actin and actin-associated genes, and propose that primary cilia defects caused by genetic alteration of the actin cytoskeleton may underlie certain birth defects.
Collapse
Affiliation(s)
- Brittany M Hufft-Martinez
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Henry H Wang
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Irfan Saadi
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, Kansas, USA
- Institute of Reproductive and Developmental Sciences, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Pamela V Tran
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, Kansas, USA
- Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| |
Collapse
|
3
|
Moran AL, Louzao-Martinez L, Norris DP, Peters DJM, Blacque OE. Transport and barrier mechanisms that regulate ciliary compartmentalization and ciliopathies. Nat Rev Nephrol 2024; 20:83-100. [PMID: 37872350 DOI: 10.1038/s41581-023-00773-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2023] [Indexed: 10/25/2023]
Abstract
Primary cilia act as cell surface antennae, coordinating cellular responses to sensory inputs and signalling molecules that regulate developmental and homeostatic pathways. Cilia are therefore critical to physiological processes, and defects in ciliary components are associated with a large group of inherited pleiotropic disorders - known collectively as ciliopathies - that have a broad spectrum of phenotypes and affect many or most tissues, including the kidney. A central feature of the cilium is its compartmentalized structure, which imparts its unique molecular composition and signalling environment despite its membrane and cytosol being contiguous with those of the cell. Such compartmentalization is achieved via active transport pathways that bring protein cargoes to and from the cilium, as well as gating pathways at the ciliary base that establish diffusion barriers to protein exchange into and out of the organelle. Many ciliopathy-linked proteins, including those involved in kidney development and homeostasis, are components of the compartmentalizing machinery. New insights into the major compartmentalizing pathways at the cilium, namely, ciliary gating, intraflagellar transport, lipidated protein flagellar transport and ciliary extracellular vesicle release pathways, have improved our understanding of the mechanisms that underpin ciliary disease and associated renal disorders.
Collapse
Affiliation(s)
- Ailis L Moran
- School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Laura Louzao-Martinez
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Dorien J M Peters
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland.
| |
Collapse
|
4
|
Kiørboe T. Predation in a Microbial World: Mechanisms and Trade-Offs of Flagellate Foraging. ANNUAL REVIEW OF MARINE SCIENCE 2024; 16:361-381. [PMID: 37368955 DOI: 10.1146/annurev-marine-020123-102001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Heterotrophic nanoflagellates are the main consumers of bacteria and picophytoplankton in the ocean and thus play a key role in ocean biogeochemistry. They are found in all major branches of the eukaryotic tree of life but are united by all being equipped with one or a few flagella that they use to generate a feeding current. These microbial predators are faced with the challenges that viscosity at this small scale impedes predator-prey contact and that their foraging activity disturbs the ambient water and thus attracts their own flow-sensing predators. Here, I describe some of the diverse adaptations of the flagellum to produce sufficient force to overcome viscosity and of the flagellar arrangement to minimize fluid disturbances, and thus of the various solutions to optimize the foraging-predation risk trade-off. I demonstrate how insights into this trade-off can be used to develop robust trait-based models of microbial food webs.
Collapse
Affiliation(s)
- Thomas Kiørboe
- Centre for Ocean Life, DTU Aqua, Technical University of Denmark, Kongens Lyngby, Denmark;
| |
Collapse
|
5
|
Ewerling A, Maissl V, Wickstead B, May-Simera HL. Neofunctionalization of ciliary BBS proteins to nuclear roles is likely a frequent innovation across eukaryotes. iScience 2023; 26:106410. [PMID: 37034981 PMCID: PMC10074162 DOI: 10.1016/j.isci.2023.106410] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 07/20/2022] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
The eukaryotic BBSome is a transport complex within cilia and assembled by chaperonin-like BBS proteins. Recent work indicates nuclear functions for BBS proteins in mammals, but it is unclear how common these are in extant proteins or when they evolved. We screened for BBS orthologues across a diverse set of eukaryotes, consolidated nuclear association via signal sequence predictions and permutation analysis, and validated nuclear localization in mammalian cells via fractionation and immunocytochemistry. BBS proteins are-with exceptions-conserved as a set in ciliated species. Predictions highlight five most likely nuclear proteins and suggest that nuclear roles evolved independently of nuclear access during mitosis. Nuclear localization was confirmed in human cells. These findings suggest that nuclear BBS functions are potentially not restricted to mammals, but may be a common frequently co-opted eukaryotic feature. Understanding the functional spectrum of BBS proteins will help elucidating their role in gene regulation, development, and disease.
Collapse
Affiliation(s)
- Alexander Ewerling
- Institute of Molecular Physiology, Faculty of Biology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Vanessa Maissl
- Institute of Molecular Physiology, Faculty of Biology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Bill Wickstead
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Helen Louise May-Simera
- Institute of Molecular Physiology, Faculty of Biology, Johannes Gutenberg-University Mainz, Mainz, Germany
| |
Collapse
|
6
|
Hesketh SJ, Mukhopadhyay AG, Nakamura D, Toropova K, Roberts AJ. IFT-A structure reveals carriages for membrane protein transport into cilia. Cell 2022; 185:4971-4985.e16. [PMID: 36462505 DOI: 10.1016/j.cell.2022.11.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/13/2022] [Accepted: 11/09/2022] [Indexed: 12/05/2022]
Abstract
Intraflagellar transport (IFT) trains are massive molecular machines that traffic proteins between cilia and the cell body. Each IFT train is a dynamic polymer of two large complexes (IFT-A and -B) and motor proteins, posing a formidable challenge to mechanistic understanding. Here, we reconstituted the complete human IFT-A complex and obtained its structure using cryo-EM. Combined with AlphaFold prediction and genome-editing studies, our results illuminate how IFT-A polymerizes, interacts with IFT-B, and uses an array of β-propeller and TPR domains to create "carriages" of the IFT train that engage TULP adaptor proteins. We show that IFT-A⋅TULP carriages are essential for cilia localization of diverse membrane proteins, as well as ICK-the key kinase regulating IFT train turnaround. These data establish a structural link between IFT-A's distinct functions, provide a blueprint for IFT-A in the train, and shed light on how IFT evolved from a proto-coatomer ancestor.
Collapse
Affiliation(s)
- Sophie J Hesketh
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck University of London, London, WC1E 7HX, UK
| | - Aakash G Mukhopadhyay
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck University of London, London, WC1E 7HX, UK
| | - Dai Nakamura
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck University of London, London, WC1E 7HX, UK
| | - Katerina Toropova
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck University of London, London, WC1E 7HX, UK.
| | - Anthony J Roberts
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck University of London, London, WC1E 7HX, UK.
| |
Collapse
|
7
|
Meleppattu S, Zhou H, Dai J, Gui M, Brown A. Mechanism of IFT-A polymerization into trains for ciliary transport. Cell 2022; 185:4986-4998.e12. [PMID: 36563665 PMCID: PMC9794116 DOI: 10.1016/j.cell.2022.11.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/14/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
Intraflagellar transport (IFT) is the highly conserved process by which proteins are transported along ciliary microtubules by a train-like polymeric assembly of IFT-A and IFT-B complexes. IFT-A is sandwiched between IFT-B and the ciliary membrane, consistent with its putative role in transporting transmembrane and membrane-associated cargoes. Here, we have used single-particle analysis electron cryomicroscopy (cryo-EM) to determine structures of native IFT-A complexes. We show that subcomplex rearrangements enable IFT-A to polymerize laterally on anterograde IFT trains, revealing a cooperative assembly mechanism. Surprisingly, we discover that binding of IFT-A to IFT-B shields the preferred lipid-binding interface from the ciliary membrane but orients an interconnected network of β-propeller domains with the capacity to accommodate diverse cargoes toward the ciliary membrane. This work provides a mechanistic basis for understanding IFT-train assembly and cargo interactions.
Collapse
Affiliation(s)
- Shimi Meleppattu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Haixia Zhou
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Jin Dai
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Miao Gui
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Alan Brown
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
| |
Collapse
|
8
|
Quidwai T, Wang J, Hall EA, Petriman NA, Leng W, Kiesel P, Wells JN, Murphy LC, Keighren MA, Marsh JA, Lorentzen E, Pigino G, Mill P. A WDR35-dependent coat protein complex transports ciliary membrane cargo vesicles to cilia. eLife 2021; 10:e69786. [PMID: 34734804 PMCID: PMC8754431 DOI: 10.7554/elife.69786] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
Intraflagellar transport (IFT) is a highly conserved mechanism for motor-driven transport of cargo within cilia, but how this cargo is selectively transported to cilia is unclear. WDR35/IFT121 is a component of the IFT-A complex best known for its role in ciliary retrograde transport. In the absence of WDR35, small mutant cilia form but fail to enrich in diverse classes of ciliary membrane proteins. In Wdr35 mouse mutants, the non-core IFT-A components are degraded and core components accumulate at the ciliary base. We reveal deep sequence homology of WDR35 and other IFT-A subunits to α and ß' COPI coatomer subunits and demonstrate an accumulation of 'coat-less' vesicles that fail to fuse with Wdr35 mutant cilia. We determine that recombinant non-core IFT-As can bind directly to lipids and provide the first in situ evidence of a novel coat function for WDR35, likely with other IFT-A proteins, in delivering ciliary membrane cargo necessary for cilia elongation.
Collapse
Affiliation(s)
- Tooba Quidwai
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Jiaolong Wang
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
| | - Emma A Hall
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Narcis A Petriman
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
| | - Weihua Leng
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Petra Kiesel
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Jonathan N Wells
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Laura C Murphy
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Margaret A Keighren
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Joseph A Marsh
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
| | - Gaia Pigino
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Human TechnopoleMilanItaly
| | - Pleasantine Mill
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| |
Collapse
|
9
|
Warren B, Nowotny M. Bridging the Gap Between Mammal and Insect Ears – A Comparative and Evolutionary View of Sound-Reception. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.667218] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Insects must wonder why mammals have ears only in their head and why they evolved only one common principle of ear design—the cochlea. Ears independently evolved at least 19 times in different insect groups and therefore can be found in completely different body parts. The morphologies and functional characteristics of insect ears are as wildly diverse as the ecological niches they exploit. In both, insects and mammals, hearing organs are constrained by the same biophysical principles and their respective molecular processes for mechanotransduction are thought to share a common evolutionary origin. Due to this, comparative knowledge of hearing across animal phyla provides crucial insight into fundamental processes of auditory transduction, especially at the biomechanical and molecular level. This review will start by comparing hearing between insects and mammals in an evolutionary context. It will then discuss current findings about sound reception will help to bridge the gap between both research fields.
Collapse
|
10
|
Abstract
All living cells interact dynamically with a constantly changing world. Eukaryotes, in particular, evolved radically new ways to sense and react to their environment. These advances enabled new and more complex forms of cellular behaviour in eukaryotes, including directional movement, active feeding, mating, and responses to predation. But what are the key events and innovations during eukaryogenesis that made all of this possible? Here we describe the ancestral repertoire of eukaryotic excitability and discuss five major cellular innovations that enabled its evolutionary origin. The innovations include a vastly expanded repertoire of ion channels, the emergence of cilia and pseudopodia, endomembranes as intracellular capacitors, a flexible plasma membrane and the relocation of chemiosmotic ATP synthesis to mitochondria, which liberated the plasma membrane for more complex electrical signalling involved in sensing and reacting. We conjecture that together with an increase in cell size, these new forms of excitability greatly amplified the degrees of freedom associated with cellular responses, allowing eukaryotes to vastly outperform prokaryotes in terms of both speed and accuracy. This comprehensive new perspective on the evolution of excitability enriches our view of eukaryogenesis and emphasizes behaviour and sensing as major contributors to the success of eukaryotes. This article is part of the theme issue 'Basal cognition: conceptual tools and the view from the single cell'.
Collapse
Affiliation(s)
- Kirsty Y. Wan
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| |
Collapse
|
11
|
Labat-de-Hoz L, Rubio-Ramos A, Casares-Arias J, Bernabé-Rubio M, Correas I, Alonso MA. A Model for Primary Cilium Biogenesis by Polarized Epithelial Cells: Role of the Midbody Remnant and Associated Specialized Membranes. Front Cell Dev Biol 2021; 8:622918. [PMID: 33585461 PMCID: PMC7873843 DOI: 10.3389/fcell.2020.622918] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/09/2020] [Indexed: 12/14/2022] Open
Abstract
Primary cilia are solitary, microtubule-based protrusions surrounded by a ciliary membrane equipped with selected receptors that orchestrate important signaling pathways that control cell growth, differentiation, development and homeostasis. Depending on the cell type, primary cilium assembly takes place intracellularly or at the cell surface. The intracellular route has been the focus of research on primary cilium biogenesis, whereas the route that occurs at the cell surface, which we call the "alternative" route, has been much less thoroughly characterized. In this review, based on recent experimental evidence, we present a model of primary ciliogenesis by the alternative route in which the remnant of the midbody generated upon cytokinesis acquires compact membranes, that are involved in compartmentalization of biological membranes. The midbody remnant delivers part of those membranes to the centrosome in order to assemble the ciliary membrane, thereby licensing primary cilium formation. The midbody remnant's involvement in primary cilium formation, the regulation of its inheritance by the ESCRT machinery, and the assembly of the ciliary membrane from the membranes originally associated with the remnant are discussed in the context of the literature concerning the ciliary membrane, the emerging roles of the midbody remnant, the regulation of cytokinesis, and the role of membrane compartmentalization. We also present a model of cilium emergence during evolution, and summarize the directions for future research.
Collapse
Affiliation(s)
- Leticia Labat-de-Hoz
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Armando Rubio-Ramos
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Javier Casares-Arias
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel Bernabé-Rubio
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Isabel Correas
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
- Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel A. Alonso
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| |
Collapse
|
12
|
Evolution of the centrosome, from the periphery to the center. Curr Opin Struct Biol 2020; 66:96-103. [PMID: 33242728 DOI: 10.1016/j.sbi.2020.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/13/2020] [Accepted: 10/18/2020] [Indexed: 11/24/2022]
Abstract
Centrosomes are central organelles that organize microtubules (MTs) in animals, fungi and several other eukaryotic lineages. Despite an important diversity of structure, the centrosomes of different lineages share the same functions and part of their molecular components. To uncover how divergent centrosomes are related to each other, we need to trace the evolutionary history of MT organization. Careful assessment of cytoskeletal architecture in extant eukaryotic species can help us infer the ancestral state and identify the subsequent changes that took place during evolution. This led to the finding that the last common ancestor of all eukaryotes was very likely a biflagellate cell with a surprisingly complex cytoskeletal organization. Centrosomes are likely derived from the basal bodies of such flagellate, but when and how many times this happened remains unclear. Here, we discuss different hypotheses for how centrosomes evolved in a eukaryotic lineage called Amorphea, to which animals, fungi and amoebozoans belong.
Collapse
|
13
|
Vitre B, Guesdon A, Delaval B. Non-ciliary Roles of IFT Proteins in Cell Division and Polycystic Kidney Diseases. Front Cell Dev Biol 2020; 8:578239. [PMID: 33072760 PMCID: PMC7536321 DOI: 10.3389/fcell.2020.578239] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 08/26/2020] [Indexed: 12/30/2022] Open
Abstract
Cilia are small organelles present at the surface of most differentiated cells where they act as sensors for mechanical or biochemical stimuli. Cilia assembly and function require the Intraflagellar Transport (IFT) machinery, an intracellular transport system that functions in association with microtubules and motors. If IFT proteins have long been studied for their ciliary roles, recent evidences indicate that their functions are not restricted to the cilium. Indeed, IFT proteins are found outside the ciliary compartment where they are involved in a variety of cellular processes in association with non-ciliary motors. Recent works also provide evidence that non-ciliary roles of IFT proteins could be responsible for the development of ciliopathies related phenotypes including polycystic kidney diseases. In this review, we will discuss the interactions of IFT proteins with microtubules and motors as well as newly identified non-ciliary functions of IFT proteins, focusing on their roles in cell division. We will also discuss the potential contribution of non-ciliary IFT proteins functions to the etiology of kidney diseases.
Collapse
|
14
|
Cavalier-Smith T, Chao EEY. Multidomain ribosomal protein trees and the planctobacterial origin of neomura (eukaryotes, archaebacteria). PROTOPLASMA 2020. [PMID: 31900730 DOI: 10.1007/s00709-019-01442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Palaeontologically, eubacteria are > 3× older than neomura (eukaryotes, archaebacteria). Cell biology contrasts ancestral eubacterial murein peptidoglycan walls and derived neomuran N-linked glycoprotein coats/walls. Misinterpreting long stems connecting clade neomura to eubacteria on ribosomal sequence trees (plus misinterpreted protein paralogue trees) obscured this historical pattern. Universal multiprotein ribosomal protein (RP) trees, more accurate than rRNA trees, are taxonomically undersampled. To reduce contradictions with genically richer eukaryote trees and improve eubacterial phylogeny, we constructed site-heterogeneous and maximum-likelihood universal three-domain, two-domain, and single-domain trees for 143 eukaryotes (branching now congruent with 187-protein trees), 60 archaebacteria, and 151 taxonomically representative eubacteria, using 51 and 26 RPs. Site-heterogeneous trees greatly improve eubacterial phylogeny and higher classification, e.g. showing gracilicute monophyly, that many 'rDNA-phyla' belong in Proteobacteria, and reveal robust new phyla Synthermota and Aquithermota. Monoderm Posibacteria and Mollicutes (two separate wall losses) are both polyphyletic: multiple outer membrane losses in Endobacteria occurred separately from Actinobacteria; neither phylum is related to Chloroflexi, the most divergent prokaryotes, which originated photosynthesis (new model proposed). RP trees support an eozoan root for eukaryotes and are consistent with archaebacteria being their sisters and rooted between Filarchaeota (=Proteoarchaeota, including 'Asgardia') and Euryarchaeota sensu-lato (including ultrasimplified 'DPANN' whose long branches often distort trees). Two-domain trees group eukaryotes within Planctobacteria, and archaebacteria with Planctobacteria/Sphingobacteria. Integrated molecular/palaeontological evidence favours negibacterial ancestors for neomura and all life. Unique presence of key pre-neomuran characters favours Planctobacteria only as ancestral to neomura, which apparently arose by coevolutionary repercussions (explained here in detail, including RP replacement) of simultaneous outer membrane and murein loss. Planctobacterial C-1 methanotrophic enzymes are likely ancestral to archaebacterial methanogenesis and β-propeller-α-solenoid proteins to eukaryotic vesicle coats, nuclear-pore-complexes, and intraciliary transport. Planctobacterial chaperone-independent 4/5-protofilament microtubules and MamK actin-ancestors prepared for eukaryote intracellular motility, mitosis, cytokinesis, and phagocytosis. We refute numerous wrong ideas about the universal tree.
Collapse
Affiliation(s)
| | - Ema E-Yung Chao
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| |
Collapse
|
15
|
|
16
|
Cavalier-Smith T, Chao EEY. Multidomain ribosomal protein trees and the planctobacterial origin of neomura (eukaryotes, archaebacteria). PROTOPLASMA 2020; 257:621-753. [PMID: 31900730 PMCID: PMC7203096 DOI: 10.1007/s00709-019-01442-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 09/19/2019] [Indexed: 05/02/2023]
Abstract
Palaeontologically, eubacteria are > 3× older than neomura (eukaryotes, archaebacteria). Cell biology contrasts ancestral eubacterial murein peptidoglycan walls and derived neomuran N-linked glycoprotein coats/walls. Misinterpreting long stems connecting clade neomura to eubacteria on ribosomal sequence trees (plus misinterpreted protein paralogue trees) obscured this historical pattern. Universal multiprotein ribosomal protein (RP) trees, more accurate than rRNA trees, are taxonomically undersampled. To reduce contradictions with genically richer eukaryote trees and improve eubacterial phylogeny, we constructed site-heterogeneous and maximum-likelihood universal three-domain, two-domain, and single-domain trees for 143 eukaryotes (branching now congruent with 187-protein trees), 60 archaebacteria, and 151 taxonomically representative eubacteria, using 51 and 26 RPs. Site-heterogeneous trees greatly improve eubacterial phylogeny and higher classification, e.g. showing gracilicute monophyly, that many 'rDNA-phyla' belong in Proteobacteria, and reveal robust new phyla Synthermota and Aquithermota. Monoderm Posibacteria and Mollicutes (two separate wall losses) are both polyphyletic: multiple outer membrane losses in Endobacteria occurred separately from Actinobacteria; neither phylum is related to Chloroflexi, the most divergent prokaryotes, which originated photosynthesis (new model proposed). RP trees support an eozoan root for eukaryotes and are consistent with archaebacteria being their sisters and rooted between Filarchaeota (=Proteoarchaeota, including 'Asgardia') and Euryarchaeota sensu-lato (including ultrasimplified 'DPANN' whose long branches often distort trees). Two-domain trees group eukaryotes within Planctobacteria, and archaebacteria with Planctobacteria/Sphingobacteria. Integrated molecular/palaeontological evidence favours negibacterial ancestors for neomura and all life. Unique presence of key pre-neomuran characters favours Planctobacteria only as ancestral to neomura, which apparently arose by coevolutionary repercussions (explained here in detail, including RP replacement) of simultaneous outer membrane and murein loss. Planctobacterial C-1 methanotrophic enzymes are likely ancestral to archaebacterial methanogenesis and β-propeller-α-solenoid proteins to eukaryotic vesicle coats, nuclear-pore-complexes, and intraciliary transport. Planctobacterial chaperone-independent 4/5-protofilament microtubules and MamK actin-ancestors prepared for eukaryote intracellular motility, mitosis, cytokinesis, and phagocytosis. We refute numerous wrong ideas about the universal tree.
Collapse
Affiliation(s)
| | - Ema E-Yung Chao
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| |
Collapse
|
17
|
Riparbelli MG, Persico V, Dallai R, Callaini G. Centrioles and Ciliary Structures during Male Gametogenesis in Hexapoda: Discovery of New Models. Cells 2020; 9:E744. [PMID: 32197383 PMCID: PMC7140630 DOI: 10.3390/cells9030744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/08/2020] [Accepted: 03/10/2020] [Indexed: 12/12/2022] Open
Abstract
Centrioles are-widely conserved barrel-shaped organelles present in most organisms. They are indirectly involved in the organization of the cytoplasmic microtubules both in interphase and during the cell division by recruiting the molecules needed for microtubule nucleation. Moreover, the centrioles are required to assemble cilia and flagella by the direct elongation of their microtubule wall. Due to the importance of the cytoplasmic microtubules in several aspects of the cell life, any defect in centriole structure can lead to cell abnormalities that in humans may result in significant diseases. Many aspects of the centriole dynamics and function have been clarified in the last years, but little attention has been paid to the exceptions in centriole structure that occasionally appeared within the animal kingdom. Here, we focused our attention on non-canonical aspects of centriole architecture within the Hexapoda. The Hexapoda is one of the major animal groups and represents a good laboratory in which to examine the evolution and the organization of the centrioles. Although these findings represent obvious exceptions to the established rules of centriole organization, they may contribute to advance our understanding of the formation and the function of these organelles.
Collapse
Affiliation(s)
- Maria Giovanna Riparbelli
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (M.G.R.); (V.P.); (R.D.)
| | - Veronica Persico
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (M.G.R.); (V.P.); (R.D.)
| | - Romano Dallai
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (M.G.R.); (V.P.); (R.D.)
| | - Giuliano Callaini
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (M.G.R.); (V.P.); (R.D.)
- Department of Medical Biotechnologies, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| |
Collapse
|
18
|
Beeby M, Ferreira JL, Tripp P, Albers SV, Mitchell DR. Propulsive nanomachines: the convergent evolution of archaella, flagella and cilia. FEMS Microbiol Rev 2020; 44:253-304. [DOI: 10.1093/femsre/fuaa006] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 03/06/2020] [Indexed: 02/06/2023] Open
Abstract
ABSTRACT
Echoing the repeated convergent evolution of flight and vision in large eukaryotes, propulsive swimming motility has evolved independently in microbes in each of the three domains of life. Filamentous appendages – archaella in Archaea, flagella in Bacteria and cilia in Eukaryotes – wave, whip or rotate to propel microbes, overcoming diffusion and enabling colonization of new environments. The implementations of the three propulsive nanomachines are distinct, however: archaella and flagella rotate, while cilia beat or wave; flagella and cilia assemble at their tips, while archaella assemble at their base; archaella and cilia use ATP for motility, while flagella use ion-motive force. These underlying differences reflect the tinkering required to evolve a molecular machine, in which pre-existing machines in the appropriate contexts were iteratively co-opted for new functions and whose origins are reflected in their resultant mechanisms. Contemporary homologies suggest that archaella evolved from a non-rotary pilus, flagella from a non-rotary appendage or secretion system, and cilia from a passive sensory structure. Here, we review the structure, assembly, mechanism and homologies of the three distinct solutions as a foundation to better understand how propulsive nanomachines evolved three times independently and to highlight principles of molecular evolution.
Collapse
Affiliation(s)
- Morgan Beeby
- Department of Life Sciences, Frankland Road, Imperial College of London, London, SW7 2AZ, UK
| | - Josie L Ferreira
- Department of Life Sciences, Frankland Road, Imperial College of London, London, SW7 2AZ, UK
| | - Patrick Tripp
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Schaenzlestrasse 1, 79211 Freiburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Schaenzlestrasse 1, 79211 Freiburg, Germany
| | - David R Mitchell
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
| |
Collapse
|
19
|
Yang H, Huang K. Dissecting the Vesicular Trafficking Function of IFT Subunits. Front Cell Dev Biol 2020; 7:352. [PMID: 32010685 PMCID: PMC6974671 DOI: 10.3389/fcell.2019.00352] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 12/05/2019] [Indexed: 12/22/2022] Open
Abstract
Intraflagellar transport (IFT) was initially identified as a transport machine with multiple protein subunits, and it is essential for the assembly, disassembly, and maintenance of cilium/flagellum, which serves as the nexus of extracellular-to-intracellular signal integration. To date, in addition to its well-established and indispensable roles in ciliated cells, most IFT subunits have presented more general functions of vesicular trafficking in the non-ciliated cells. Thus, this review aims to summarize the recent progress on the vesicular trafficking functions of the IFT subunits and to highlight the issues that may arise in future research.
Collapse
Affiliation(s)
- Huihui Yang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Institute of Hydrobiology, University of Chinese Academy of Sciences, Beijing, China
| | - Kaiyao Huang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| |
Collapse
|
20
|
Oswald F, Prevo B, Acar S, Peterman EJG. Interplay between Ciliary Ultrastructure and IFT-Train Dynamics Revealed by Single-Molecule Super-resolution Imaging. Cell Rep 2020; 25:224-235. [PMID: 30282031 DOI: 10.1016/j.celrep.2018.09.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 08/08/2018] [Accepted: 09/07/2018] [Indexed: 01/10/2023] Open
Abstract
Cilia are built and maintained by intraflagellar transport (IFT), driving IFT trains back and forth along the ciliary axoneme. How IFT brings about the intricate ciliary structure and how this structure affects IFT are not well understood. We identify, using single-molecule super-resolution imaging of IFT components in living C. elegans, ciliary subdomains, enabling correlation of IFT-train dynamics to ciliary ultra-structure. In the transition zone, IFT dynamics are impaired, resulting in frequent pauses. At the ciliary base and tip, IFT trains show intriguing turnaround dynamics. Surprisingly, deletion of IFT motor kinesin-II not only affects IFT-train dynamics but also alters ciliary structure. Super-resolution imaging in these mutant animals suggests that the arrangement of IFT trains with respect to the axonemal microtubules is different than in wild-type animals. Our results reveal a complex, mutual interplay between ciliary ultrastructure and IFT-train dynamics, highlighting the importance of physical cues in the control of IFT dynamics.
Collapse
Affiliation(s)
- Felix Oswald
- Department of Physics and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, 1081HV, the Netherlands
| | - Bram Prevo
- Department of Physics and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, 1081HV, the Netherlands
| | - Seyda Acar
- Department of Physics and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, 1081HV, the Netherlands
| | - Erwin J G Peterman
- Department of Physics and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, 1081HV, the Netherlands.
| |
Collapse
|
21
|
Abstract
Cilia are specialized cellular organelles that are united in structure and implicated in diverse key life processes across eukaryotes. In both unicellular and multicellular organisms, variations on the same ancestral form mediate sensing, locomotion and the production of physiological flows. As we usher in a new, more interdisciplinary era, the way we study cilia is changing. This special theme issue brings together biologists, biophysicists and mathematicians to highlight the remarkable range of systems in which motile cilia fulfil vital functions, and to inspire and define novel strategies for future research. This article is part of the Theo Murphy meeting issue 'Unity and diversity of cilia in locomotion and transport'.
Collapse
Affiliation(s)
- Kirsty Y Wan
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| |
Collapse
|
22
|
Finetti F, Capitani N, Baldari CT. Emerging Roles of the Intraflagellar Transport System in the Orchestration of Cellular Degradation Pathways. Front Cell Dev Biol 2019; 7:292. [PMID: 31803744 PMCID: PMC6877659 DOI: 10.3389/fcell.2019.00292] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/06/2019] [Indexed: 12/27/2022] Open
Abstract
Ciliated cells exploit a specific transport system, the intraflagellar transport (IFT) system, to ensure the traffic of molecules from the cell body to the cilium. However, it is now clear that IFT activity is not restricted to cilia-related functions. This is strikingly exemplified by the observation that IFT proteins play important roles in cells lacking a primary cilium, such as lymphocytes. Indeed, in T cells the IFT system regulates the polarized transport of endosome-associated T cell antigen receptors and signaling mediators during assembly of the immune synapse, a specialized interface that forms on encounter with a cognate antigen presenting cell and on which T cell activation and effector function crucially depend. Cellular degradation pathways have recently emerged as new extraciliary functions of the IFT system. IFT proteins have been demonstrated to regulate autophagy in ciliated cells through their ability to recruit the autophagy machinery to the base of the cilium. We have now implicated the IFT component IFT20 in another central degradation process that also controls the latest steps in autophagy, namely lysosome function, by regulating the cation-independent mannose-6-phosphate receptor (CI-MPR)-dependent lysosomal targeting of acid hydrolases. This involves the ability of IFT20 to act as an adaptor coupling the CI-MPR to dynein for retrograde transport to the trans-Golgi network. In this short review we will discuss the emerging roles of IFT proteins in cellular degradation pathways.
Collapse
Affiliation(s)
| | - Nagaja Capitani
- Department of Life Sciences, University of Siena, Siena, Italy
| | | |
Collapse
|
23
|
Satir P, Satir BH. The conserved ancestral signaling pathway from cilium to nucleus. J Cell Sci 2019; 132:132/15/jcs230441. [PMID: 31375541 DOI: 10.1242/jcs.230441] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 07/02/2019] [Indexed: 12/13/2022] Open
Abstract
Many signaling molecules are localized to both the primary cilium and nucleus. Localization of specific transmembrane receptors and their signaling scaffold molecules in the cilium is necessary for correct physiological function. After a specific signaling event, signaling molecules leave the cilium, usually in the form of an endocytic vesicle scaffold, and move to the nucleus, where they dissociate from the scaffold and enter the nucleus to affect gene expression. This ancient pathway probably arose very early in eukaryotic evolution as the nucleus and cilium co-evolved. Because there are similarities in molecular composition of the nuclear and ciliary pores the entry and exit of proteins in both organelles rely on similar mechanisms. In this Hypothesis, we propose that the pathway is a dynamic universal cilia-based signaling pathway with some variations from protists to man. Everywhere the cilium functions as an important organelle for molecular storage of certain key receptors and selection and concentration of their associated signaling molecules that move from cilium to nucleus. This could also have important implications for human diseases such as Huntington disease.
Collapse
Affiliation(s)
- Peter Satir
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, New York, NY 10461 .,B&P Nanobiology Consultants, 7 Byfield Lane, Greenwich, CT 06830, USA
| | - Birgit H Satir
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, New York, NY 10461.,B&P Nanobiology Consultants, 7 Byfield Lane, Greenwich, CT 06830, USA
| |
Collapse
|
24
|
Cassioli C, Baldari CT. A Ciliary View of the Immunological Synapse. Cells 2019; 8:E789. [PMID: 31362462 PMCID: PMC6721628 DOI: 10.3390/cells8080789] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/15/2019] [Accepted: 07/25/2019] [Indexed: 12/28/2022] Open
Abstract
The primary cilium has gone from being a vestigial organelle to a crucial signaling hub of growing interest given the association between a group of human disorders, collectively known as ciliopathies, and defects in its structure or function. In recent years many ciliogenesis proteins have been observed at extraciliary sites in cells and likely perform cilium-independent functions ranging from regulation of the cytoskeleton to vesicular trafficking. Perhaps the most striking example is the non-ciliated T lymphocyte, in which components of the ciliary machinery are repurposed for the assembly and function of the immunological synapse even in the absence of a primary cilium. Furthermore, the specialization traits described at the immunological synapse are similar to those seen in the primary cilium. Here, we review common regulators and features shared by the immunological synapse and the primary cilium that document the remarkable homology between these structures.
Collapse
Affiliation(s)
- Chiara Cassioli
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | - Cosima T Baldari
- Department of Life Sciences, University of Siena, 53100 Siena, Italy.
| |
Collapse
|
25
|
Finetti F, Cassioli C, Cianfanelli V, Onnis A, Paccagnini E, Kabanova A, Baldari CT. The intraflagellar transport protein IFT20 controls lysosome biogenesis by regulating the post-Golgi transport of acid hydrolases. Cell Death Differ 2019; 27:310-328. [PMID: 31142807 DOI: 10.1038/s41418-019-0357-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 04/16/2019] [Accepted: 05/14/2019] [Indexed: 01/08/2023] Open
Abstract
The assembly and function of the primary cilium depends on multimolecular intraflagellar transport (IFT) complexes that shuttle their cargo along the axonemal microtubules through their interaction with molecular motors. The IFT system has been moreover recently implicated in a reciprocal interplay between autophagy and ciliogenesis. We have previously reported that IFT20 and other components of the IFT complexes participate in the assembly of the immune synapse in the non-ciliated T cell, suggesting that other cellular processes regulated by the IFT system in ciliated cells, including autophagy, may be shared by cells lacking a cilium. Starting from the observation of a defect in autophagic clearance and an accumulation of lipid droplets in IFT20-deficient T cells, we show that IFT20 is required for lysosome biogenesis and function by controlling the lysosomal targeting of acid hydrolases. This function involves its ability to regulate the retrograde traffic of the cation-independent mannose-6-phosphate receptor (CI-MPR) to the trans-Golgi network, which is achieved by coupling recycling CI-MPRs to the microtubule motor dynein. Consistent with the lysosomal defect, an upregulation of the TFEB-dependent expression of the lysosomal gene network can be observed in IFT20-deficient cells, which is associated with defective tonic T-cell antigen receptor signaling and mTOR activity. We additionally show that the lysosome-related function of IFT20 extends to non-ciliated cells other than T cells, as well as to ciliated cells. Our findings provide the first evidence that a component of the IFT system that controls ciliogenesis is implicated in the biogenesis of lysosomes.
Collapse
Affiliation(s)
- Francesca Finetti
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100, Siena, Italy.
| | - Chiara Cassioli
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100, Siena, Italy
| | - Valentina Cianfanelli
- Cell Stress and Survival Unit, Danish Cancer Society Research Center, 2100, Copenhagen, Denmark
| | - Anna Onnis
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100, Siena, Italy
| | - Eugenio Paccagnini
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100, Siena, Italy
| | - Anna Kabanova
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100, Siena, Italy
| | - Cosima T Baldari
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100, Siena, Italy.
| |
Collapse
|
26
|
Trafficking of ciliary membrane proteins by the intraflagellar transport/BBSome machinery. Essays Biochem 2018; 62:753-763. [PMID: 30287585 DOI: 10.1042/ebc20180030] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/04/2018] [Accepted: 09/19/2018] [Indexed: 12/13/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a rare inherited disease caused by defects in the BBSome, an octameric complex of BBS proteins. The BBSome is conserved in most organisms with cilia, which are microtubule (MT)-based cell organelles that protrude from the cell surface and function in motility and sensing. Cilia assembly, maintenance, and function require intraflagellar transport (IFT), a bidirectional motility of multi-megadalton IFT trains propelled by molecular motors along the ciliary MTs. IFT has been shown to transport structural proteins, including tubulin, into growing cilia. The BBSome is an adapter for the transport of ciliary membrane proteins and cycles through cilia via IFT. While both the loss and the abnormal accumulation of ciliary membrane proteins have been observed in bbs mutants, recent data converge on a model where the BBSome mainly functions as a cargo adapter for the removal of certain transmembrane and peripheral membrane proteins from cilia. Here, we review recent data on the ultrastructure of the BBSome and how the BBSome recognizes its cargoes and mediates their removal from cilia.
Collapse
|
27
|
Membrane association and remodeling by intraflagellar transport protein IFT172. Nat Commun 2018; 9:4684. [PMID: 30409972 PMCID: PMC6224603 DOI: 10.1038/s41467-018-07037-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 10/14/2018] [Indexed: 01/03/2023] Open
Abstract
The cilium is an organelle used for motility and cellular signaling. Intraflagellar transport (IFT) is a process to move ciliary building blocks and signaling components into the cilium. How IFT controls the movement of ciliary components is currently poorly understood. IFT172 is the largest IFT subunit essential for ciliogenesis. Due to its large size, the characterization of IFT172 has been challenging. Using giant unilamellar vesicles (GUVs), we show that IFT172 is a membrane-interacting protein with the ability to remodel large membranes into small vesicles. Purified IFT172 has an architecture of two globular domains with a long rod-like protrusion, resembling the domain organization of coatomer proteins such as COPI-II or clathrin. IFT172 adopts two different conformations that can be manipulated by lipids or detergents: 1) an extended elongated conformation and 2) a globular closed architecture. Interestingly, the association of IFT172 with membranes is mutually exclusive with IFT57, implicating multiple functions for IFT172 within IFT. Cilia formation requires Intraflagellar transport (IFT) to move ciliary building blocks and signaling components into the cilium. Here authors use in vitro reconstitution and electron microscopy on IFT172 and reveal its ability to remodel large membrane surfaces into small vesicles.
Collapse
|
28
|
Bornens M. Cell polarity: having and making sense of direction-on the evolutionary significance of the primary cilium/centrosome organ in Metazoa. Open Biol 2018; 8:180052. [PMID: 30068565 PMCID: PMC6119866 DOI: 10.1098/rsob.180052] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 07/05/2018] [Indexed: 12/13/2022] Open
Abstract
Cell-autonomous polarity in Metazoans is evolutionarily conserved. I assume that permanent polarity in unicellular eukaryotes is required for cell motion and sensory reception, integration of these two activities being an evolutionarily constrained function. Metazoans are unique in making cohesive multicellular organisms through complete cell divisions. They evolved a primary cilium/centrosome (PC/C) organ, ensuring similar functions to the basal body/flagellum of unicellular eukaryotes, but in different cells, or in the same cell at different moments. The possibility that this innovation contributed to the evolution of individuality, in being instrumental in the early specification of the germ line during development, is further discussed. Then, using the example of highly regenerative organisms like planarians, which have lost PC/C organ in dividing cells, I discuss the possibility that part of the remodelling necessary to reach a new higher-level unit of selection in multi-cellular organisms has been triggered by conflicts among individual cell polarities to reach an organismic polarity. Finally, I briefly consider organisms with a sensorimotor organ like the brain that requires exceedingly elongated polarized cells for its activity. I conclude that beyond critical consequences for embryo development, the conservation of cell-autonomous polarity in Metazoans had far-reaching implications for the evolution of individuality.
Collapse
Affiliation(s)
- Michel Bornens
- Institut Curie, PSL Research University, CNRS - UMR 144, 75005 Paris, France
| |
Collapse
|
29
|
Hua K, Ferland RJ. Primary Cilia Reconsidered in the Context of Ciliopathies: Extraciliary and Ciliary Functions of Cilia Proteins Converge on a Polarity theme? Bioessays 2018; 40:e1700132. [PMID: 29882973 PMCID: PMC6239423 DOI: 10.1002/bies.201700132] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 05/09/2018] [Indexed: 12/13/2022]
Abstract
Once dismissed as vestigial organelles, primary cilia have garnered the interest of scientists, given their importance in development/signaling, and for their implication in a new disease category known as ciliopathies. However, many, if not all, "cilia" proteins also have locations/functions outside of the primary cilium. These extraciliary functions can complicate the interpretation of a particular ciliopathy phenotype: it may be a result of defects at the cilium and/or at extraciliary locations, and it could be broadly related to a unifying cellular process for these proteins, such as polarity. Assembly of a cilium has many similarities to the development of other polarized structures. This evolutionarily preserved process for the assembly of polarized cell structures offers a perspective on how the cilium may have evolved. We hypothesize that cilia proteins are critical for cell polarity, and that core polarity proteins may have been specialized to form various cellular protrusions, including primary cilia.
Collapse
Affiliation(s)
- Kiet Hua
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA, 12208
| | - Russell J Ferland
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA, 12208
- Department of Neurology, Albany Medical College, Albany, New York, USA, 12208
| |
Collapse
|
30
|
Lee N, Park J, Bae YC, Lee JH, Kim CH, Moon SJ. Time-Lapse Live-Cell Imaging Reveals Dual Function of Oseg4, Drosophila WDR35, in Ciliary Protein Trafficking. Mol Cells 2018; 41:676-683. [PMID: 29983040 PMCID: PMC6078859 DOI: 10.14348/molcells.2018.0179] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 06/01/2018] [Accepted: 06/04/2018] [Indexed: 11/27/2022] Open
Abstract
Cilia are highly specialized antennae-like organelles that extend from the cell surface and act as cell signaling hubs. Intraflagellar transport (IFT) is a specialized form of intracellular protein trafficking that is required for the assembly and maintenance of cilia. Because cilia are so important, mutations in several IFT components lead to human disease. Thus, clarifying the molecular functions of the IFT proteins is a high priority in cilia biology. Live imaging in various species and cellular preparations has proven to be an important technique in both the discovery of IFT and the mechanisms by which it functions. Live imaging of Drosophila cilia, however, has not yet been reported. Here, we have visualized the movement of IFT in Drosophila cilia using time-lapse live imaging for the first time. We found that NOMPB-GFP (IFT88) moves according to distinct parameters depending on the ciliary segment. NOMPB-GFP moves at a similar speed in proximal and distal cilia toward the tip (~0.45 μm/s). As it returns to the ciliary base, however, NOMPB-GFP moves at ~0.12 μm/s in distal cilia, accelerating to ~0.70 μm/s in proximal cilia. Furthermore, while live imaging NOMPB-GFP, we observed one of the IFT proteins required for retrograde movement, Oseg4 (WDR35), is also required for anterograde movement in distal cilia. We anticipate our time-lapse live imaging analysis technique in Drosophila cilia will be a good starting point for a more sophisticated analysis of IFT and its molecular mechanisms.
Collapse
Affiliation(s)
- Nayoung Lee
- Department of Oral Biology, BK21 PLUS, Yonsei University College of Dentistry, Seoul 03722,
Korea
| | - Jina Park
- Department of Oral Biology, BK21 PLUS, Yonsei University College of Dentistry, Seoul 03722,
Korea
- Laboratory of Low Dose Risk Assessment, National Radiation Emergency Medical Center, Korea Institute of Radiological & Medical Sciences, Seoul 01812,
Korea
| | - Yong Chul Bae
- Department of Oral Anatomy and Neurobiology, BK21, School of Dentistry, Kyungpook National University, Daegu 41940,
Korea
| | - Jung Ho Lee
- Department of Pharmacology, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Chul Hoon Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Seok Jun Moon
- Department of Oral Biology, BK21 PLUS, Yonsei University College of Dentistry, Seoul 03722,
Korea
| |
Collapse
|
31
|
Cell-cell communication via ciliary extracellular vesicles: clues from model systems. Essays Biochem 2018; 62:205-213. [PMID: 29717060 DOI: 10.1042/ebc20170085] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/21/2018] [Accepted: 03/26/2018] [Indexed: 12/14/2022]
Abstract
In this short review, we will focus on the uniqueness of ciliary extracellular vesicles (EVs). In particular, we will review what has been learned regarding EVs produced by cilia of model organisms. Model systems including Chlamydomonas, Caenorhabditis elegans, and mouse revealed the fundamental biology of cilia and flagella and provide a paradigm to understand the roles of cilia and flagella in human development, health, and disease. Likewise, we propose that general principles learned from model systems regarding ciliary EV biogenesis and functions may provide a framework to explore the roles of ciliary EVs in human development, health, and disease.
Collapse
|
32
|
Ye F, Nager AR, Nachury MV. BBSome trains remove activated GPCRs from cilia by enabling passage through the transition zone. J Cell Biol 2018; 217:1847-1868. [PMID: 29483145 PMCID: PMC5940304 DOI: 10.1083/jcb.201709041] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 12/27/2017] [Accepted: 01/29/2018] [Indexed: 02/08/2023] Open
Abstract
A diffusion barrier at the transition zone enables the compartmentalization of signaling molecules by cilia. The BBSome and the small guanosine triphosphatase Arl6, which triggers BBSome coat polymerization, are required for the exit of activated signaling receptors from cilia, but how diffusion barriers are crossed when membrane proteins exit cilia remains to be determined. In this study, we found that activation of the ciliary G protein-coupled receptors (GPCRs) Smoothened and SSTR3 drove the Arl6-dependent assembly of large, highly processive, and cargo-laden retrograde BBSome trains. Single-molecule imaging revealed that the assembly of BBSome trains enables the lateral transport of ciliary GPCRs across the transition zone. However, the removal of activated GPCRs from cilia was inefficient because a second periciliary diffusion barrier was infrequently crossed. We conclude that exit from cilia is a two-step process in which BBSome/Arl6 trains first move activated GPCRs through the transition zone before a periciliary barrier can be crossed.
Collapse
Affiliation(s)
- Fan Ye
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA
| | - Andrew R Nager
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA
| | - Maxence V Nachury
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA
| |
Collapse
|
33
|
Taschner M, Lorentzen A, Mourão A, Collins T, Freke GM, Moulding D, Basquin J, Jenkins D, Lorentzen E. Crystal structure of intraflagellar transport protein 80 reveals a homo-dimer required for ciliogenesis. eLife 2018; 7:33067. [PMID: 29658880 PMCID: PMC5931796 DOI: 10.7554/elife.33067] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 04/13/2018] [Indexed: 12/16/2022] Open
Abstract
Oligomeric assemblies of intraflagellar transport (IFT) particles build cilia through sequential recruitment and transport of ciliary cargo proteins within cilia. Here we present the 1.8 Å resolution crystal structure of the Chlamydomonas IFT-B protein IFT80, which reveals the architecture of two N-terminal β-propellers followed by an α-helical extension. The N-terminal β-propeller tethers IFT80 to the IFT-B complex via IFT38 whereas the second β-propeller and the C-terminal α-helical extension result in IFT80 homo-dimerization. Using CRISPR/Cas to create biallelic Ift80 frameshift mutations in IMCD3 mouse cells, we demonstrate that IFT80 is absolutely required for ciliogenesis. Structural mapping and rescue experiments reveal that human disease-causing missense mutations do not cluster within IFT80 and form functional IFT particles. Unlike missense mutant forms of IFT80, deletion of the C-terminal dimerization domain prevented rescue of ciliogenesis. Taken together our results may provide a first insight into higher order IFT complex formation likely required for IFT train formation.
Collapse
Affiliation(s)
- Michael Taschner
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Anna Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - André Mourão
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Toby Collins
- Genetics and Genomic Medicine, University College London, London, United Kingdom
| | - Grace M Freke
- Genetics and Genomic Medicine, University College London, London, United Kingdom
| | - Dale Moulding
- Developmental Biology and Cancer Programmes, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Jerome Basquin
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - Dagan Jenkins
- Genetics and Genomic Medicine, University College London, London, United Kingdom
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| |
Collapse
|
34
|
Satir P. Chirality of the cytoskeleton in the origins of cellular asymmetry. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0408. [PMID: 27821520 DOI: 10.1098/rstb.2015.0408] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2016] [Indexed: 02/06/2023] Open
Abstract
Self-assembly of two important components of the cytoskeleton of eukaryotic cells, actin microfilaments and microtubules (MTs) results in polar filaments of one chirality. As is true for bacterial flagella, in actin microfilaments, screw direction is important for assembly processes and motility. For MTs, polar orientation within the cell is paramount. The alignment of these elements in the cell cytoplasm gives rise to emergent properties, including the potential for cell differentiation and specialization. Complex MTs with a characteristic chirality are found in basal bodies and centrioles; this chirality is preserved in cilia. In motile cilia, it is reflected in the direction of the effective stroke. The positioning of the basal body or cilia on the cell surface depends on polarity proteins. In evolution, survival depends on global polarity information relayed to the cell in part by orientation of the MT and actin filament cytoskeletons and the chirality of the basal body to determine left and right coordinates within a defined anterior-posterior cell and tissue axis.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
Collapse
Affiliation(s)
- Peter Satir
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| |
Collapse
|
35
|
Fu W, Wang L, Kim S, Li J, Dynlacht BD. Role for the IFT-A Complex in Selective Transport to the Primary Cilium. Cell Rep 2017; 17:1505-1517. [PMID: 27806291 DOI: 10.1016/j.celrep.2016.10.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/05/2016] [Accepted: 10/05/2016] [Indexed: 11/27/2022] Open
Abstract
Intraflagellar transport sub-complex A (IFT-A) is known to regulate retrograde IFT in the cilium. To rigorously assess its other possible roles, we knocked out an IFT-A subunit, IFT121/WDR35, in mammalian cells and screened the localization of more than 50 proteins. We found that Wdr35 regulates cilium assembly by selectively regulating transport of distinct cargoes. Beyond its role in retrograde transport, we show that Wdr35 functions in fusion of Rab8 vesicles at the nascent cilium, protein exit from the cilium, and centriolar satellite organization. Furthermore, we show that Wdr35 is essential for entry of many membrane proteins into the cilium through robust interactions with cargoes and other IFT-A subunits, but the actin network functions to dampen this transport. Wdr35 is mutated in several ciliopathies, and we find that certain disease mutations impair interactions with cargo and other IFT-A subunits. Together, our data link defects in IFT-A mediated cargo transport with disease.
Collapse
Affiliation(s)
- Wenxiang Fu
- Department of Pathology and Perlmutter Cancer Center, NYU School of Medicine, Smilow Research Building, 522 First Avenue, New York, NY 10016, USA
| | - Lei Wang
- Department of Pathology and Perlmutter Cancer Center, NYU School of Medicine, Smilow Research Building, 522 First Avenue, New York, NY 10016, USA
| | - Sehyun Kim
- Department of Pathology and Perlmutter Cancer Center, NYU School of Medicine, Smilow Research Building, 522 First Avenue, New York, NY 10016, USA
| | - Ji Li
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA
| | - Brian David Dynlacht
- Department of Pathology and Perlmutter Cancer Center, NYU School of Medicine, Smilow Research Building, 522 First Avenue, New York, NY 10016, USA.
| |
Collapse
|
36
|
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: 134] [Impact Index Per Article: 19.1] [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
|
37
|
Ding J, Shao L, Yao Y, Tong X, Liu H, Yue S, Xie L, Cheng SY. DGKδ triggers endoplasmic reticulum release of IFT88-containing vesicles destined for the assembly of primary cilia. Sci Rep 2017; 7:5296. [PMID: 28706295 PMCID: PMC5509727 DOI: 10.1038/s41598-017-05680-8] [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: 01/09/2017] [Accepted: 06/01/2017] [Indexed: 11/16/2022] Open
Abstract
The morphogenic factor Sonic hedgehog (Shh) signals through the primary cilium, which relies on intraflagellar transport to maintain its structural integrity and function. However, the process by which protein and lipid cargos are delivered to the primary cilium from their sites of synthesis still remains poorly characterized. Here, we report that diacylglycerol kinase δ (DGKδ), a residential lipid kinase in the endoplasmic reticulum, triggers the release of IFT88-containing vesicles from the ER exit sites (ERES), thereby setting forth their movement to the primary cilium. Encoded by the gene whose mutations originally implicated the primary cilium as the venue of Shh signaling, IFT88 is known to be part of the complex B that drives the anterograde transport within cilia. We show that IFT88 interacts with DGKδ, and is associated with COPII-coated vesicles at the ERES. Using a combination of RNAi silencing and gene knockout strategies, we further show that DGKδ is required for supporting Shh signaling both in vitro and in vivo, demonstrating the physiological significance of this regulation.
Collapse
Affiliation(s)
- Jie Ding
- Department of Developmental Genetics, School of Basic Medical Sciences, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu, 211166, China
| | - Lei Shao
- Department of Developmental Genetics, School of Basic Medical Sciences, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu, 211166, China
| | - Yixing Yao
- Department of Developmental Genetics, School of Basic Medical Sciences, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu, 211166, China
| | - Xin Tong
- Department of Developmental Genetics, School of Basic Medical Sciences, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu, 211166, China
| | - Huaize Liu
- Department of Developmental Genetics, School of Basic Medical Sciences, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu, 211166, China
| | - Shen Yue
- Department of Developmental Genetics, School of Basic Medical Sciences, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu, 211166, China
| | - Lu Xie
- Department of Developmental Genetics, School of Basic Medical Sciences, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu, 211166, China
| | - Steven Y Cheng
- Department of Developmental Genetics, School of Basic Medical Sciences, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu, 211166, China.
| |
Collapse
|
38
|
Shi L, Koll F, Arnaiz O, Cohen J. The Ciliary Protein IFT57 in the Macronucleus of Paramecium. J Eukaryot Microbiol 2017; 65:12-27. [DOI: 10.1111/jeu.12423] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 04/20/2017] [Accepted: 04/22/2017] [Indexed: 01/10/2023]
Affiliation(s)
- Lei Shi
- Institute for Integrative Biology of the Cell (I2BC), formerly Centre de Génétique Moléculaire; Université Paris Saclay; CEA; CNRS; 1 Avenue de la Terrasse 91198 Gif sur Yvette France
- Department of Biochemical and Molecular Biology; School of Basic Medical Sciences; Xinxiang Medical University; Xinxiang 453003 China
| | - France Koll
- Institute for Integrative Biology of the Cell (I2BC), formerly Centre de Génétique Moléculaire; Université Paris Saclay; CEA; CNRS; 1 Avenue de la Terrasse 91198 Gif sur Yvette France
| | - Olivier Arnaiz
- Institute for Integrative Biology of the Cell (I2BC), formerly Centre de Génétique Moléculaire; Université Paris Saclay; CEA; CNRS; 1 Avenue de la Terrasse 91198 Gif sur Yvette France
| | - Jean Cohen
- Institute for Integrative Biology of the Cell (I2BC), formerly Centre de Génétique Moléculaire; Université Paris Saclay; CEA; CNRS; 1 Avenue de la Terrasse 91198 Gif sur Yvette France
| |
Collapse
|
39
|
Kumar D, Strenkert D, Patel-King RS, Leonard MT, Merchant SS, Mains RE, King SM, Eipper BA. A bioactive peptide amidating enzyme is required for ciliogenesis. eLife 2017; 6. [PMID: 28513435 PMCID: PMC5461114 DOI: 10.7554/elife.25728] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 05/15/2017] [Indexed: 02/06/2023] Open
Abstract
The pathways controlling cilium biogenesis in different cell types have not been fully elucidated. We recently identified peptidylglycine α-amidating monooxygenase (PAM), an enzyme required for generating amidated bioactive signaling peptides, in Chlamydomonas and mammalian cilia. Here, we show that PAM is required for the normal assembly of motile and primary cilia in Chlamydomonas, planaria and mice. Chlamydomonas PAM knockdown lines failed to assemble cilia beyond the transition zone, had abnormal Golgi architecture and altered levels of cilia assembly components. Decreased PAM gene expression reduced motile ciliary density on the ventral surface of planaria and resulted in the appearance of cytosolic axonemes lacking a ciliary membrane. The architecture of primary cilia on neuroepithelial cells in Pam-/- mouse embryos was also aberrant. Our data suggest that PAM activity and alterations in post-Golgi trafficking contribute to the observed ciliogenesis defects and provide an unanticipated, highly conserved link between PAM, amidation and ciliary assembly.
Collapse
Affiliation(s)
- Dhivya Kumar
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, United States
| | - Daniela Strenkert
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, United States
| | - Ramila S Patel-King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, United States
| | - Michael T Leonard
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, United States
| | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, United States.,Institute for Genomics and Proteomics, University of California, Los Angeles, Los Angeles, United States
| | - Richard E Mains
- Department of Neuroscience, University of Connecticut Health Center, Farmington, United States
| | - Stephen M King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, United States
| | - Betty A Eipper
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, United States.,Department of Neuroscience, University of Connecticut Health Center, Farmington, United States
| |
Collapse
|
40
|
May-Simera H, Nagel-Wolfrum K, Wolfrum U. Cilia - The sensory antennae in the eye. Prog Retin Eye Res 2017; 60:144-180. [PMID: 28504201 DOI: 10.1016/j.preteyeres.2017.05.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 05/04/2017] [Accepted: 05/08/2017] [Indexed: 12/21/2022]
Abstract
Cilia are hair-like projections found on almost all cells in the human body. Originally believed to function merely in motility, the function of solitary non-motile (primary) cilia was long overlooked. Recent research has demonstrated that primary cilia function as signalling hubs that sense environmental cues and are pivotal for organ development and function, tissue hoemoestasis, and maintenance of human health. Cilia share a common anatomy and their diverse functional features are achieved by evolutionarily conserved functional modules, organized into sub-compartments. Defects in these functional modules are responsible for a rapidly growing list of human diseases collectively termed ciliopathies. Ocular pathogenesis is common in virtually all classes of syndromic ciliopathies, and disruptions in cilia genes have been found to be causative in a growing number of non-syndromic retinal dystrophies. This review will address what is currently known about cilia contribution to visual function. We will focus on the molecular and cellular functions of ciliary proteins and their role in the photoreceptor sensory cilia and their visual phenotypes. We also highlight other ciliated cell types in tissues of the eye (e.g. lens, RPE and Müller glia cells) discussing their possible contribution to disease progression. Progress in basic research on the cilia function in the eye is paving the way for therapeutic options for retinal ciliopathies. In the final section we describe the latest advancements in gene therapy, read-through of non-sense mutations and stem cell therapy, all being adopted to treat cilia dysfunction in the retina.
Collapse
Affiliation(s)
- Helen May-Simera
- Institute of Molecular Physiology, Cilia Biology, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Kerstin Nagel-Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany.
| |
Collapse
|
41
|
Adler PN, Wallingford JB. From Planar Cell Polarity to Ciliogenesis and Back: The Curious Tale of the PPE and CPLANE proteins. Trends Cell Biol 2017; 27:379-390. [PMID: 28153580 DOI: 10.1016/j.tcb.2016.12.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/28/2016] [Accepted: 12/23/2016] [Indexed: 12/29/2022]
Abstract
Why some genes are more popular than others remains an open question, but one example of this phenomenon involves the genes controlling planar cell polarity (PCP), the polarization of cells within a plane of a tissue. Indeed, the so-called 'core' PCP genes such as dishevelled, frizzled, and prickle have been extensively studied both in animal models and by human genetics. By contrast, other genes that influence PCP signaling have received far less attention. Among the latter are inturned, fuzzy, and fritz, but recent work should bring these once obscure regulators into the limelight. We provide here a brief history of planar polarity effector (PPE) and CPLANE (ciliogenesis and planar polarity effector) proteins, discuss recent advances in understanding their molecular mechanisms of action, and describe their roles in human disease.
Collapse
Affiliation(s)
- Paul N Adler
- Departments of Biology and Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.
| |
Collapse
|
42
|
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.
Collapse
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
| |
Collapse
|
43
|
Mourão A, Christensen ST, Lorentzen E. The intraflagellar transport machinery in ciliary signaling. Curr Opin Struct Biol 2016; 41:98-108. [PMID: 27393972 DOI: 10.1016/j.sbi.2016.06.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/07/2016] [Indexed: 01/12/2023]
Abstract
Cilia and flagella on eukaryotic cells are slender microtubule-based projections surrounded by a membrane with a unique lipid and protein composition. It is now appreciated that cilia in addition to their established roles in motility also constitute hubs for cellular signaling by sensing external environmental cues necessary for organ development and maintenance of human health. Pathways reported to rely on the cilium organelle include Hedgehog, TGF-β, Wnt, PDGFRα, integrin and DNA damage repair signaling. An emerging theme in ciliary signaling is the requirement for active transport of signaling components into and out of the cilium proper. Here, we review the current state-of-the-art regarding the importance of intraflagellar transport and BBSome multi-subunit complexes in ciliary signaling.
Collapse
Affiliation(s)
- André Mourão
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Søren T Christensen
- Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100 Copenhagen, Denmark.
| | - Esben Lorentzen
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.
| |
Collapse
|
44
|
Imhof S, Fragoso C, Hemphill A, von Schubert C, Li D, Legant W, Betzig E, Roditi I. Flagellar membrane fusion and protein exchange in trypanosomes; a new form of cell-cell communication? F1000Res 2016; 5:682. [PMID: 27239276 PMCID: PMC4870996 DOI: 10.12688/f1000research.8249.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/01/2016] [Indexed: 11/20/2022] Open
Abstract
Diverse structures facilitate direct exchange of proteins between cells, including plasmadesmata in plants and tunnelling nanotubes in bacteria and higher eukaryotes. Here we describe a new mechanism of protein transfer, flagellar membrane fusion, in the unicellular parasite
Trypanosoma brucei. When fluorescently tagged trypanosomes were co-cultured, a small proportion of double-positive cells were observed. The formation of double-positive cells was dependent on the presence of extracellular calcium and was enhanced by placing cells in medium supplemented with fresh bovine serum. Time-lapse microscopy revealed that double-positive cells arose by bidirectional protein exchange in the absence of nuclear transfer. Furthermore, super-resolution microscopy showed that this process occurred in ≤1 minute, the limit of temporal resolution in these experiments. Both cytoplasmic and membrane proteins could be transferred provided they gained access to the flagellum. Intriguingly, a component of the RNAi machinery (Argonaute) was able to move between cells, raising the possibility that small interfering RNAs are transported as cargo. Transmission electron microscopy showed that shared flagella contained two axonemes and two paraflagellar rods bounded by a single membrane. In some cases flagellar fusion was partial and interactions between cells were transient. In other cases fusion occurred along the entire length of the flagellum, was stable for several hours and might be irreversible. Fusion did not appear to be deleterious for cell function: paired cells were motile and could give rise to progeny while fused. The motile flagella of unicellular organisms are related to the sensory cilia of higher eukaryotes, raising the possibility that protein transfer between cells via cilia or flagella occurs more widely in nature.
Collapse
Affiliation(s)
- Simon Imhof
- Institute of Cell Biology, University of Bern, Bern, Switzerland; Graduate School of Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Cristina Fragoso
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Conrad von Schubert
- Division of Molecular Pathobiology, DCR-VPH, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Dong Li
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Wesley Legant
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Eric Betzig
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Isabel Roditi
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| |
Collapse
|
45
|
Gould SB, Garg SG, Martin WF. Bacterial Vesicle Secretion and the Evolutionary Origin of the Eukaryotic Endomembrane System. Trends Microbiol 2016; 24:525-534. [PMID: 27040918 DOI: 10.1016/j.tim.2016.03.005] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 03/08/2016] [Accepted: 03/11/2016] [Indexed: 12/21/2022]
Abstract
Eukaryotes possess an elaborate endomembrane system with endoplasmic reticulum, nucleus, Golgi, lysosomes, peroxisomes, autophagosomes, and dynamic vesicle traffic. Theories addressing the evolutionary origin of eukaryotic endomembranes have overlooked the outer membrane vesicles (OMVs) that bacteria, archaea, and mitochondria secrete into their surroundings. We propose that the eukaryotic endomembrane system originated from bacterial OMVs released by the mitochondrial ancestor within the cytosol of its archaeal host at eukaryote origin. Confined within the host's cytosol, OMVs accumulated naturally, fusing either with each other or with the host's plasma membrane. This matched the host's archaeal secretory pathway for cotranslational protein insertion with outward bound mitochondrial-derived vesicles consisting of bacterial lipids, forging a primordial, secretory endoplasmic reticulum as the cornerstone of the eukaryotic endomembrane system. VIDEO ABSTRACT.
Collapse
Affiliation(s)
- Sven B Gould
- Institute for Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany.
| | - Sriram G Garg
- Institute for Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany
| | - William F Martin
- Institute for Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany.
| |
Collapse
|
46
|
Promponas VJ, Katsani KR, Blencowe BJ, Ouzounis CA. Sequence evidence for common ancestry of eukaryotic endomembrane coatomers. Sci Rep 2016; 6:22311. [PMID: 26931514 PMCID: PMC4773986 DOI: 10.1038/srep22311] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 02/12/2016] [Indexed: 12/27/2022] Open
Abstract
Eukaryotic cells are defined by compartments through which the trafficking of macromolecules is mediated by large complexes, such as the nuclear pore, transport vesicles and intraflagellar transport. The assembly and maintenance of these complexes is facilitated by endomembrane coatomers, long suspected to be divergently related on the basis of structural and more recently phylogenomic analysis. By performing supervised walks in sequence space across coatomer superfamilies, we uncover subtle sequence patterns that have remained elusive to date, ultimately unifying eukaryotic coatomers by divergent evolution. The conserved residues shared by 3,502 endomembrane coatomer components are mapped onto the solenoid superhelix of nucleoporin and COPII protein structures, thus determining the invariant elements of coatomer architecture. This ancient structural motif can be considered as a universal signature connecting eukaryotic coatomers involved in multiple cellular processes across cell physiology and human disease.
Collapse
Affiliation(s)
- Vasilis J. Promponas
- Bioinformatics Research Laboratory, Department of Biological Sciences, New Campus, University of Cyprus, PO Box 20537, CY-1678 Nicosia, Cyprus
| | - Katerina R. Katsani
- Department of Molecular Biology & Genetics, Democritus University of Thrace, GR-68100 Alexandroupolis, Greece
| | - Benjamin J. Blencowe
- Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada
| | - Christos A. Ouzounis
- Bioinformatics Research Laboratory, Department of Biological Sciences, New Campus, University of Cyprus, PO Box 20537, CY-1678 Nicosia, Cyprus
- Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada
- Biological Computation & Process Laboratory (BCPL), Chemical Process Research Institute (CPERI), Centre for Research & Technology (CERTH), PO Box 361, GR-57001 Thessalonica, Greece
| |
Collapse
|
47
|
Brunet T, Arendt D. From damage response to action potentials: early evolution of neural and contractile modules in stem eukaryotes. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150043. [PMID: 26598726 PMCID: PMC4685582 DOI: 10.1098/rstb.2015.0043] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2015] [Indexed: 12/14/2022] Open
Abstract
Eukaryotic cells convert external stimuli into membrane depolarization, which in turn triggers effector responses such as secretion and contraction. Here, we put forward an evolutionary hypothesis for the origin of the depolarization-contraction-secretion (DCS) coupling, the functional core of animal neuromuscular circuits. We propose that DCS coupling evolved in unicellular stem eukaryotes as part of an 'emergency response' to calcium influx upon membrane rupture. We detail how this initial response was subsequently modified into an ancient mechanosensory-effector arc, present in the last eukaryotic common ancestor, which enabled contractile amoeboid movement that is widespread in extant eukaryotes. Elaborating on calcium-triggered membrane depolarization, we reason that the first action potentials evolved alongside the membrane of sensory-motile cilia, with the first voltage-sensitive sodium/calcium channels (Nav/Cav) enabling a fast and coordinated response of the entire cilium to mechanosensory stimuli. From the cilium, action potentials then spread across the entire cell, enabling global cellular responses such as concerted contraction in several independent eukaryote lineages. In animals, this process led to the invention of mechanosensory contractile cells. These gave rise to mechanosensory receptor cells, neurons and muscle cells by division of labour and can be regarded as the founder cell type of the nervous system.
Collapse
Affiliation(s)
- Thibaut Brunet
- European Molecular Biology Laboratory, Developmental Biology Unit, Heidelberg 69012, Germany
| | - Detlev Arendt
- European Molecular Biology Laboratory, Developmental Biology Unit, Heidelberg 69012, Germany
| |
Collapse
|
48
|
Loss of the BBSome perturbs endocytic trafficking and disrupts virulence of Trypanosoma brucei. Proc Natl Acad Sci U S A 2015; 113:632-7. [PMID: 26721397 DOI: 10.1073/pnas.1518079113] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cilia (eukaryotic flagella) are present in diverse eukaryotic lineages and have essential motility and sensory functions. The cilium's capacity to sense and transduce extracellular signals depends on dynamic trafficking of ciliary membrane proteins. This trafficking is often mediated by the Bardet-Biedl Syndrome complex (BBSome), a protein complex for which the precise subcellular distribution and mechanisms of action are unclear. In humans, BBSome defects perturb ciliary membrane protein distribution and manifest clinically as Bardet-Biedl Syndrome. Cilia are also important in several parasites that cause tremendous human suffering worldwide, yet biology of the parasite BBSome remains largely unexplored. We examined BBSome functions in Trypanosoma brucei, a flagellated protozoan parasite that causes African sleeping sickness in humans. We report that T. brucei BBS proteins assemble into a BBSome that interacts with clathrin and is localized to membranes of the flagellar pocket and adjacent cytoplasmic vesicles. Using BBS gene knockouts and a mouse infection model, we show the T. brucei BBSome is dispensable for flagellar assembly, motility, bulk endocytosis, and cell viability but required for parasite virulence. Quantitative proteomics reveal alterations in the parasite surface proteome of BBSome mutants, suggesting that virulence defects are caused by failure to maintain fidelity of the host-parasite interface. Interestingly, among proteins altered are those with ubiquitination-dependent localization, and we find that the BBSome interacts with ubiquitin. Collectively, our data indicate that the BBSome facilitates endocytic sorting of select membrane proteins at the base of the cilium, illuminating BBSome roles at a critical host-pathogen interface and offering insights into BBSome molecular mechanisms.
Collapse
|
49
|
Oakley TH, Speiser DI. How Complexity Originates: The Evolution of Animal Eyes. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2015. [DOI: 10.1146/annurev-ecolsys-110512-135907] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Todd H. Oakley
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California 93106;
| | - Daniel I. Speiser
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208
| |
Collapse
|
50
|
Finetti F, Patrussi L, Galgano D, Cassioli C, Perinetti G, Pazour GJ, Baldari CT. The small GTPase Rab8 interacts with VAMP-3 to regulate the delivery of recycling T-cell receptors to the immune synapse. J Cell Sci 2015; 128:2541-52. [PMID: 26034069 DOI: 10.1242/jcs.171652] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 05/22/2015] [Indexed: 12/31/2022] Open
Abstract
IFT20, a component of the intraflagellar transport (IFT) system that controls ciliogenesis, regulates immune synapse assembly in the non-ciliated T-cell by promoting T-cell receptor (TCR) recycling. Here, we have addressed the role of Rab8 (for which there are two isoforms Rab8a and Rab8b), a small GTPase implicated in ciliogenesis, in TCR traffic to the immune synapse. We show that Rab8, which colocalizes with IFT20 in Rab11(+) endosomes, is required for TCR recycling. Interestingly, as opposed to in IFT20-deficient T-cells, TCR(+) endosomes polarized normally beneath the immune synapse membrane in the presence of dominant-negative Rab8, but were unable to undergo the final docking or fusion step. This could be accounted for by the inability of the vesicular (v)-SNARE VAMP-3 to cluster at the immune synapse in the absence of functional Rab8, which is responsible for its recruitment. Of note, and similar to in T-cells, VAMP-3 interacts with Rab8 at the base of the cilium in NIH-3T3 cells, where it regulates ciliary growth and targeting of the protein smoothened. The results identify Rab8 as a new player in vesicular traffic to the immune synapse and provide insight into the pathways co-opted by different cell types for immune synapse assembly and ciliogenesis.
Collapse
Affiliation(s)
- Francesca Finetti
- Department of Life Sciences, University of Siena, Siena 53100, Italy
| | - Laura Patrussi
- Department of Life Sciences, University of Siena, Siena 53100, Italy
| | - Donatella Galgano
- Department of Life Sciences, University of Siena, Siena 53100, Italy
| | - Chiara Cassioli
- Department of Life Sciences, University of Siena, Siena 53100, Italy
| | - Giuseppe Perinetti
- Department of Medical, Surgical and Health Sciences, School of Dentistry, University of Trieste, Trieste 34129, Italy
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Cosima T Baldari
- Department of Life Sciences, University of Siena, Siena 53100, Italy
| |
Collapse
|