1
|
Mitra A, Loseva E, Peterman EJG. IFT cargo and motors associate sequentially with IFT trains to enter cilia of C. elegans. Nat Commun 2024; 15:3456. [PMID: 38658528 PMCID: PMC11043347 DOI: 10.1038/s41467-024-47807-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 04/12/2024] [Indexed: 04/26/2024] Open
Abstract
Intraflagellar transport (IFT) orchestrates entry of proteins into primary cilia. At the ciliary base, assembled IFT trains, driven by kinesin-2 motors, can transport cargo proteins into the cilium, across the crowded transition zone. How trains assemble at the base and how proteins associate with them is far from understood. Here, we use single-molecule imaging in the cilia of C. elegans chemosensory neurons to directly visualize the entry of kinesin-2 motors, kinesin-II and OSM-3, as well as anterograde cargo proteins, IFT dynein and tubulin. Single-particle tracking shows that IFT components associate with trains sequentially, both in time and space. Super-resolution maps of IFT components in wild-type and mutant worms reveal ciliary ultrastructure and show that kinesin-II is essential for axonemal organization. Finally, imaging cilia lacking kinesin-II and/or transition zone function uncovers the interplay of kinesin-II and OSM-3 in driving efficient transport of IFT trains across the transition zone.
Collapse
Affiliation(s)
- Aniruddha Mitra
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Elizaveta Loseva
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Erwin J G Peterman
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| |
Collapse
|
2
|
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
|
3
|
Gonçalves-Santos F, De-Castro ARG, Rodrigues DRM, De-Castro MJG, Gassmann R, Abreu CMC, Dantas TJ. Hot-wiring dynein-2 establishes roles for IFT-A in retrograde train assembly and motility. Cell Rep 2023; 42:113337. [PMID: 37883232 DOI: 10.1016/j.celrep.2023.113337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/08/2023] [Accepted: 10/09/2023] [Indexed: 10/28/2023] Open
Abstract
Intraflagellar transport (IFT) trains, built around IFT-A and IFT-B complexes, are carried by opposing motors to import and export ciliary cargo. While transported by kinesin-2 on anterograde IFT trains, the dynein-2 motor adopts an autoinhibitory conformation until it needs to be activated at the ciliary tip to power retrograde IFT. Growing evidence has linked the IFT-A complex to retrograde IFT; however, its roles in this process remain unknown. Here, we use CRISPR-Cas9-mediated genome editing to disable the dynein-2 autoinhibition mechanism in Caenorhabditis elegans and assess its impact on IFT with high-resolution live imaging and photobleaching analyses. Remarkably, this dynein-2 "hot-wiring" approach reignites retrograde motility inside IFT-A-deficient cilia without triggering tug-of-war events. In addition to providing functional evidence that multiple mechanisms maintain dynein-2 inhibited during anterograde IFT, our data establish key roles for IFT-A in mediating motor-train coupling during IFT turnaround, promoting retrograde IFT initiation, and modulating dynein-2 retrograde motility.
Collapse
Affiliation(s)
- Francisco Gonçalves-Santos
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Ana R G De-Castro
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Diogo R M Rodrigues
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Maria J G De-Castro
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Reto Gassmann
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Carla M C Abreu
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
| | - Tiago J Dantas
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
| |
Collapse
|
4
|
Jafari G, Khan LA, Zhang H, Membreno E, Yan S, Dempsey G, Gobel V. Branched-chain actin dynamics polarizes vesicle trajectories and partitions apicobasal epithelial membrane domains. SCIENCE ADVANCES 2023; 9:eade4022. [PMID: 37379384 PMCID: PMC10306301 DOI: 10.1126/sciadv.ade4022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 05/24/2023] [Indexed: 06/30/2023]
Abstract
In prevailing epithelial polarity models, membrane- and junction-based polarity cues such as the partitioning-defective PARs specify the positions of apicobasal membrane domains. Recent findings indicate, however, that intracellular vesicular trafficking can determine the position of the apical domain, upstream of membrane-based polarity cues. These findings raise the question of how vesicular trafficking becomes polarized independent of apicobasal target membrane domains. Here, we show that the apical directionality of vesicle trajectories depends on actin dynamics during de novo polarized membrane biogenesis in the C. elegans intestine. We find that actin, powered by branched-chain actin modulators, determines the polarized distribution of apical membrane components, PARs, and itself. Using photomodulation, we demonstrate that F-actin travels through the cytoplasm and along the cortex toward the future apical domain. Our findings support an alternative polarity model where actin-directed trafficking asymmetrically inserts the nascent apical domain into the growing epithelial membrane to partition apicobasal membrane domains.
Collapse
Affiliation(s)
- Gholamali Jafari
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, MGHfC, Harvard Medical School, Boston, MA, USA
| | - Liakot A. Khan
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, MGHfC, Harvard Medical School, Boston, MA, USA
| | - Hongjie Zhang
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, MGHfC, Harvard Medical School, Boston, MA, USA
- Faculty of Health Sciences, University of Macau, Taipa, Macau, China
| | - Edward Membreno
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, MGHfC, Harvard Medical School, Boston, MA, USA
| | - Siyang Yan
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, MGHfC, Harvard Medical School, Boston, MA, USA
| | - Graham Dempsey
- Chemistry and Chemical Biology Department, Harvard University, Cambridge, MA, USA
| | - Verena Gobel
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, MGHfC, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
5
|
Weiss LE, Love JF, Yoon J, Comerci CJ, Milenkovic L, Kanie T, Jackson PK, Stearns T, Gustavsson AK. Single-molecule imaging in the primary cilium. Methods Cell Biol 2023; 176:59-83. [PMID: 37164543 PMCID: PMC10509820 DOI: 10.1016/bs.mcb.2023.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
The primary cilium is an important signaling organelle critical for normal development and tissue homeostasis. Its small dimensions and complexity necessitate advanced imaging approaches to uncover the molecular mechanisms behind its function. Here, we outline how single-molecule fluorescence microscopy can be used for tracking molecular dynamics and interactions and for super-resolution imaging of nanoscale structures in the primary cilium. Specifically, we describe in detail how to capture and quantify the 2D dynamics of individual transmembrane proteins PTCH1 and SMO and how to map the 3D nanoscale distributions of the inversin compartment proteins INVS, ANKS6, and NPHP3. This protocol can, with minor modifications, be adapted for studies of other proteins and cell lines to further elucidate the structure and function of the primary cilium at the molecular level.
Collapse
Affiliation(s)
- Lucien E Weiss
- Department of Engineering Physics, Polytechnique Montréal, Montreal, QC, Canada.
| | - Julia F Love
- Department of Chemistry, Rice University, Houston, TX, United States
| | | | - Colin J Comerci
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States
| | | | - Tomoharu Kanie
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma, OK, United States
| | - Peter K Jackson
- Baxter Laboratory, Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA, United States; Department of Pathology, Stanford University School of Medicine, Stanford, CA, United States
| | - Tim Stearns
- Department of Biology, Stanford University, Stanford, CA, United States; Rockefeller University, New York City, NY, United States
| | - Anna-Karin Gustavsson
- Department of Chemistry, Rice University, Houston, TX, United States; Department of BioSciences, Rice University, Houston, TX, United States; Institute of Biosciences and Bioengineering, Rice University, Houston, TX, United States; Smalley-Curl Institute, Rice University, Houston, TX, United States.
| |
Collapse
|
6
|
Marshall WF. The flagellar length control system: exploring the physical biology of organelle size. Phys Biol 2023; 20:10.1088/1478-3975/acb18d. [PMID: 36623317 PMCID: PMC9877179 DOI: 10.1088/1478-3975/acb18d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 01/09/2023] [Indexed: 01/11/2023]
Abstract
How cells build and maintain dynamic structures of defined size is currently an important unsolved problem in quantitative cell biology. The flagella of the unicellular green algaChlamydomonasprovide a highly tractable model system to investigate this general question, but while the powerful genetics of this organism have revealed numerous genes required for proper flagellar length, in most cases we do not understand their mechanistic role in length control. Flagellar length can be viewed as the steady state solution of a dynamical system involving assembly and disassembly of axonemal microtubules, with assembly depending on an active transport process known as intraflagellar transport (IFT). The inherent length dependence of IFT gives rise to a family of simple models for length regulation that can account for many previously described phenomena such as the ability of flagella to maintain equal lengths. But these models requires that the cell has a way to measure flagellar length in order to adjust IFT rates accordingly. Several models for length sensing have been modeled theoretically and evaluated experimentally, allowing them to be ruled out. Current data support a model in which the diffusive return of the kinesin motor driving IFT provides a length dependence that ultimately is the basis for length regulation. By combining models of length sensing with a more detailed representation of cargo transport and availability, it is now becoming possible to formulate concrete hypotheses to explain length altering mutants.
Collapse
Affiliation(s)
- Wallace F Marshall
- Department Biochemistry & Biophysics, University of California San Francisco, San Francisco, CA, United States of America
| |
Collapse
|
7
|
Pratelli A, Corbo D, Lupetti P, Mencarelli C. The distal central pair segment is structurally specialised and contributes to IFT turnaround and assembly of the tip capping structures in Chlamydomonas flagella. Biol Cell 2022; 114:349-364. [PMID: 36101924 DOI: 10.1111/boc.202200038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/25/2022] [Accepted: 08/29/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND INFORMATION Cilia and flagella are dynamic organelles whose assembly and maintenance depend on an activetrafficking process known as the IntraFlagellar Transport (IFT), during which trains of IFT protein particles are moved by specific motors and carry flagellar precursors and turnover products along the axoneme. IFT consists of an anterograde (from base to tip) and a retrograde (from tip to base) phase. During IFT turnaround at the flagellar tip, anterograde trains release their cargoes and remodel to form the retrograde trains. Thus, turnaround is crucial for correct IFT. However, current knowledge of its mechanisms is limited. RESULTS We show here that in Chlamydomonas flagella the distal ∼200 nm central pair (CP) segment is structurally differentiated for the presence of a ladder-like structure (LLS). During IFT turnaround, the IFT172 subunit dissociates from the IFT- B protein complex and binds to the LLS-containing CP segment, while the IFT-B complex participates in the assembly of the CP capping structures. The IFT scaffolding function played by the LLS-containing CP segment relies on anchoring components other than the CP microtubules, since IFT turnaround occurs also in the CP-devoid pf18 mutant flagella. CONCLUSIONS During IFT turnaround in Chlamydomonas flagella, i) the LLS and the CP terminal plates act as anchoring platforms for IFT172 and the IFT-B complex, respectively, and ii) during its remodeling, the IFT-B complex contributes to the assembly of the CP capping structures. SIGNIFICANCE Our results indicate that in full length Chlamydomonas flagella IFT remodeling occurs by a specialized mechanism that involves flagellar tip structures and is distinct from the previously proposed model in which the capability to reverse motility would be intrinsic of IFT train and independent by any other flagellar structure.
Collapse
Affiliation(s)
- Ambra Pratelli
- Department of Life Sciences, University of Siena, Siena, Italy
| | - Dalia Corbo
- Department of Life Sciences, University of Siena, Siena, Italy
| | - Pietro Lupetti
- Department of Life Sciences, University of Siena, Siena, Italy
| | | |
Collapse
|
8
|
Mechanisms of Regulation in Intraflagellar Transport. Cells 2022; 11:cells11172737. [PMID: 36078145 PMCID: PMC9454703 DOI: 10.3390/cells11172737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 08/30/2022] [Accepted: 08/31/2022] [Indexed: 11/30/2022] Open
Abstract
Cilia are eukaryotic organelles essential for movement, signaling or sensing. Primary cilia act as antennae to sense a cell’s environment and are involved in a wide range of signaling pathways essential for development. Motile cilia drive cell locomotion or liquid flow around the cell. Proper functioning of both types of cilia requires a highly orchestrated bi-directional transport system, intraflagellar transport (IFT), which is driven by motor proteins, kinesin-2 and IFT dynein. In this review, we explore how IFT is regulated in cilia, focusing from three different perspectives on the issue. First, we reflect on how the motor track, the microtubule-based axoneme, affects IFT. Second, we focus on the motor proteins, considering the role motor action, cooperation and motor-train interaction plays in the regulation of IFT. Third, we discuss the role of kinases in the regulation of the motor proteins. Our goal is to provide mechanistic insights in IFT regulation in cilia and to suggest directions of future research.
Collapse
|
9
|
van Krugten J, Danné N, Peterman EJG. A local interplay between diffusion and intraflagellar transport distributes TRPV-channel OCR-2 along C. elegans chemosensory cilia. Commun Biol 2022; 5:720. [PMID: 35858995 PMCID: PMC9300729 DOI: 10.1038/s42003-022-03683-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 07/06/2022] [Indexed: 02/07/2023] Open
Abstract
To survive, Caenorhabditis elegans depends on sensing soluble chemicals with transmembrane proteins (TPs) in the cilia of its chemosensory neurons. Cilia rely on intraflagellar transport (IFT) to facilitate the distribution of cargo, such as TPs, along the ciliary axoneme. Here, we use fluorescence imaging of living worms and perform single-molecule tracking experiments to elucidate the dynamics underlying the ciliary distribution of the sensory TP OCR-2. Quantitative analysis reveals that the ciliary distribution of OCR-2 depends on an intricate interplay between transport modes that depends on the specific location in the cilium: in dendrite and transition zone, directed transport is predominant. Along the cilium motion is mostly due to normal diffusion together with a small fraction of directed transport, while at the ciliary tip subdiffusion dominates. These insights in the role of IFT and diffusion in ciliary dynamics contribute to a deeper understanding of ciliary signal transduction and chemosensing. Single-molecule tracking of the sensory transmembrane protein OCR-2 in C. elegans reveals an interplay of transport modes during intraflagellar transport in the cilium.
Collapse
Affiliation(s)
- Jaap van Krugten
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan, 1081 HV, Amsterdam, The Netherlands
| | - Noémie Danné
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan, 1081 HV, Amsterdam, The Netherlands
| | - Erwin J G Peterman
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan, 1081 HV, Amsterdam, The Netherlands.
| |
Collapse
|
10
|
De-Castro ARG, Rodrigues DRM, De-Castro MJG, Vieira N, Vieira C, Carvalho AX, Gassmann R, Abreu CMC, Dantas TJ. WDR60-mediated dynein-2 loading into cilia powers retrograde IFT and transition zone crossing. J Cell Biol 2022; 221:212746. [PMID: 34739033 PMCID: PMC8576871 DOI: 10.1083/jcb.202010178] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 09/20/2021] [Accepted: 10/13/2021] [Indexed: 12/30/2022] Open
Abstract
The dynein-2 motor complex drives retrograde intraflagellar transport (IFT), playing a pivotal role in the assembly and functions of cilia. However, the mechanisms that regulate dynein-2 motility remain poorly understood. Here, we identify the Caenorhabditis elegans WDR60 homologue, WDR-60, and dissect the roles of this intermediate chain using genome editing and live imaging of endogenous dynein-2/IFT components. We find that loss of WDR-60 impairs dynein-2 recruitment to cilia and its incorporation onto anterograde IFT trains, reducing retrograde motor availability at the ciliary tip. Consistent with this, we show that fewer dynein-2 motors power WDR-60–deficient retrograde IFT trains, which move at reduced velocities and fail to exit cilia, accumulating on the distal side of the transition zone. Remarkably, disrupting the transition zone’s NPHP module almost fully restores ciliary exit of underpowered retrograde trains in wdr-60 mutants. This work establishes WDR-60 as a major contributor to IFT, and the NPHP module as a roadblock to dynein-2 passage through the transition zone.
Collapse
Affiliation(s)
- Ana R G De-Castro
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Diogo R M Rodrigues
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Maria J G De-Castro
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Neide Vieira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus Gualtar, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Cármen Vieira
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Ana X Carvalho
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Reto Gassmann
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Carla M C Abreu
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Tiago J Dantas
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| |
Collapse
|
11
|
Direct imaging of intraflagellar-transport turnarounds reveals that motors detach, diffuse, and reattach to opposite-direction trains. Proc Natl Acad Sci U S A 2021; 118:2115089118. [PMID: 34732580 PMCID: PMC8609318 DOI: 10.1073/pnas.2115089118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2021] [Indexed: 12/16/2022] Open
Abstract
Primary cilia are important organelles that exist in almost all eukaryotic cells. Intraflagellar transport (IFT) is a motor-protein–driven bidirectional intracellular transport mechanism in cilia. Previous studies have shown that motors in Caenorhabditis elegans chemosensory cilia undergo rapid turnarounds to effectively work together in driving orderly IFT. The mechanism of motor turnarounds has, however, remained unclear. Here, using a combination of advanced fluorescence imaging and single-molecule analysis, we directly show that the individual turnarounds are due to motors switching between opposite-direction IFT trains. Furthermore, we show that switching events consist of motors detaching from a train, diffusing to another one followed by attachment. This directly demonstrates that motors switch trains by diffusion, which clarifies the mechanism of motor turnarounds. Intraflagellar transport (IFT), a bidirectional intracellular transport mechanism in cilia, relies on the cooperation of kinesin-2 and IFT-dynein motors. In Caenorhabditis elegans chemosensory cilia, motors undergo rapid turnarounds to effectively work together in driving IFT. Here, we push the envelope of fluorescence imaging to obtain insight into the underlying mechanism of motor turnarounds. We developed an alternating dual-color imaging system that allows simultaneous single-molecule imaging of kinesin-II turnarounds and ensemble imaging of IFT trains. This approach allowed direct visualization of motor detachment and reattachment during turnarounds and accordingly demonstrated that the turnarounds are actually single-motor switching between opposite-direction IFT trains rather than the behaviors of motors moving independently of IFT trains. We further improved the time resolution of single-motor imaging up to 30 ms to zoom into motor turnarounds, revealing diffusion during motor turnarounds, which unveils the mechanism of motor switching trains: detach–diffuse–attach. The subsequent single-molecule analysis of turnarounds unveiled location-dependent diffusion coefficients and diffusion times for both kinesin-2 and IFT-dynein motors. From correlating the diffusion times with IFT train frequencies, we estimated that kinesins tend to attach to the next train passing in the opposite direction. IFT-dynein, however, diffuses longer and lets one or two trains pass before attaching. This might be a direct consequence of the lower diffusion coefficient of the larger IFT-dynein. Our results provide important insights into how motors can cooperate to drive intracellular transport.
Collapse
|
12
|
Wingfield JL, Mekonnen B, Mengoni I, Liu P, Jordan M, Diener D, Pigino G, Lechtreck K. In vivo imaging shows continued association of several IFT-A, IFT-B and dynein complexes while IFT trains U-turn at the tip. J Cell Sci 2021; 134:271904. [PMID: 34415027 DOI: 10.1242/jcs.259010] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/12/2021] [Indexed: 01/05/2023] Open
Abstract
Flagellar assembly depends on intraflagellar transport (IFT), a bidirectional motility of protein carriers, the IFT trains. The trains are periodic assemblies of IFT-A and IFT-B subcomplexes and the motors kinesin-2 and IFT dynein. At the tip, anterograde trains are remodeled for retrograde IFT, a process that in Chlamydomonas involves kinesin-2 release and train fragmentation. However, the degree of train disassembly at the tip remains unknown. Here, we performed two-color imaging of fluorescent protein-tagged IFT components, which indicates that IFT-A and IFT-B proteins from a given anterograde train usually return in the same set of retrograde trains. Similarly, concurrent turnaround was typical for IFT-B proteins and the IFT dynein subunit D1bLIC-GFP but severance was observed as well. Our data support a simple model of IFT turnaround, in which IFT-A, IFT-B and IFT dynein typically remain associated at the tip and segments of the anterograde trains convert directly into retrograde trains. Continuous association of IFT-A, IFT-B and IFT dynein during tip remodeling could balance protein entry and exit, preventing the build-up of IFT material in flagella.
Collapse
Affiliation(s)
- Jenna L Wingfield
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Betlehem Mekonnen
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Ilaria Mengoni
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Peiwei Liu
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Mareike Jordan
- Max Planck Institute of Molecular Cell Biology and Genetics, D-01307 Dresden, Germany
| | - Dennis Diener
- Max Planck Institute of Molecular Cell Biology and Genetics, D-01307 Dresden, Germany
| | - Gaia Pigino
- Max Planck Institute of Molecular Cell Biology and Genetics, D-01307 Dresden, Germany.,Human Technopole, Via Cristina Belgioioso 171, 20157 Milan, Italy
| | - Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| |
Collapse
|
13
|
Abstract
The intraflagellar transport (IFT) system is a remarkable molecular machine used by cells to assemble and maintain the cilium, a long organelle extending from eukaryotic cells that gives rise to motility, sensing and signaling. IFT plays a critical role in building the cilium by shuttling structural components and signaling receptors between the ciliary base and tip. To provide effective transport, IFT-A and IFT-B adaptor protein complexes assemble into highly repetitive polymers, called IFT trains, that are powered by the motors kinesin-2 and IFT-dynein to move bidirectionally along the microtubules. This dynamic system must be precisely regulated to shuttle different cargo proteins between the ciliary tip and base. In this Cell Science at a Glance article and the accompanying poster, we discuss the current structural and mechanistic understanding of IFT trains and how they function as macromolecular machines to assemble the structure of the cilium.
Collapse
Affiliation(s)
- Mareike A Jordan
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Gaia Pigino
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Pfotenhauerstraße 108, 01307 Dresden, Germany.,Human Technopole, Via Cristina Belgioioso 171, 20157 Milan, Italy
| |
Collapse
|
14
|
Santarossa CC, Mickolajczyk KJ, Steinman JB, Urnavicius L, Chen N, Hirata Y, Fukase Y, Coudray N, Ekiert DC, Bhabha G, Kapoor TM. Targeting allostery in the Dynein motor domain with small molecule inhibitors. Cell Chem Biol 2021; 28:1460-1473.e15. [PMID: 34015309 DOI: 10.1016/j.chembiol.2021.04.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/24/2021] [Accepted: 04/28/2021] [Indexed: 10/21/2022]
Abstract
Cytoplasmic dyneins are AAA (ATPase associated with diverse cellular activities) motor proteins responsible for microtubule minus-end-directed intracellular transport. Dynein's unusually large size, four distinct nucleotide-binding sites, and conformational dynamics pose challenges for the design of potent and selective chemical inhibitors. Here we use structural approaches to develop a model for the inhibition of a well-characterized S. cerevisiae dynein construct by pyrazolo-pyrimidinone-based compounds. These data, along with functional assays of dynein motility and mutagenesis studies, suggest that the compounds inhibit dynein by engaging the regulatory ATPase sites in the AAA3 and AAA4 domains, and not by interacting with dynein's main catalytic site in the AAA1 domain. A double Walker B mutation of the AAA3 and AAA4 sites substantially reduces enzyme activity, suggesting that targeting these regulatory domains is sufficient to inhibit dynein. Our findings reveal how chemical inhibitors can be designed to disrupt allosteric communication across dynein's AAA domains.
Collapse
Affiliation(s)
- Cristina C Santarossa
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, USA; Tri-Institutional PhD program in Chemical Biology, The Rockefeller University, New York, NY 10065, USA
| | - Keith J Mickolajczyk
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Jonathan B Steinman
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Linas Urnavicius
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Nan Chen
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Yasuhiro Hirata
- Tri-Institutional Therapeutics Discovery Institute, New York, NY 10065, USA
| | - Yoshiyuki Fukase
- Tri-Institutional Therapeutics Discovery Institute, New York, NY 10065, USA
| | - Nicolas Coudray
- Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA; Applied Bioinformatics Laboratories, New York University School of Medicine, New York, NY 10016, USA
| | - Damian C Ekiert
- Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Gira Bhabha
- Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA.
| | - Tarun M Kapoor
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065, USA.
| |
Collapse
|
15
|
Bauer D, Ishikawa H, Wemmer KA, Hendel NL, Kondev J, Marshall WF. Analysis of biological noise in the flagellar length control system. iScience 2021; 24:102354. [PMID: 33898946 PMCID: PMC8059064 DOI: 10.1016/j.isci.2021.102354] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 02/06/2023] Open
Abstract
Any proposed mechanism for organelle size control should be able to account not only for average size but also for the variation in size. We analyzed cell-to-cell variation and within-cell variation of length for the two flagella in Chlamydomonas, finding that cell-to-cell variation is dominated by cell size, whereas within-cell variation results from dynamic fluctuations. Fluctuation analysis suggests tubulin assembly is not directly coupled with intraflagellar transport (IFT) and that the observed length fluctuations reflect tubulin assembly and disassembly events involving large numbers of tubulin dimers. Length variation is increased in long-flagella mutants, an effect consistent with theoretical models for flagellar length regulation. Cells with unequal flagellar lengths show impaired swimming but improved gliding, raising the possibility that cells have evolved mechanisms to tune biological noise in flagellar length. Analysis of noise at the level of organelle size provides a way to probe the mechanisms determining cell geometry.
Collapse
Affiliation(s)
- David Bauer
- Department of Biochemistry & Biophysics, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
| | - Hiroaki Ishikawa
- Department of Biochemistry & Biophysics, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
| | - Kimberly A. Wemmer
- Department of Biochemistry & Biophysics, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
| | - Nathan L. Hendel
- Department of Biochemistry & Biophysics, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
| | - Jane Kondev
- Department of Physics, Brandeis University, Abelson-Bass-Yalem Building, 97-301, Waltham, MA, USA
| | - Wallace F. Marshall
- Department of Biochemistry & Biophysics, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
- Center for Cellular Construction, University of California, San Francisco, 600 16th St., San Francisco, CA, USA
| |
Collapse
|
16
|
Webb S, Mukhopadhyay AG, Roberts AJ. Intraflagellar transport trains and motors: Insights from structure. Semin Cell Dev Biol 2020; 107:82-90. [PMID: 32684327 PMCID: PMC7561706 DOI: 10.1016/j.semcdb.2020.05.021] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/19/2020] [Accepted: 05/26/2020] [Indexed: 11/17/2022]
Abstract
Intraflagellar transport (IFT) sculpts the proteome of cilia and flagella; the antenna-like organelles found on the surface of virtually all human cell types. By delivering proteins to the growing ciliary tip, recycling turnover products, and selectively transporting signalling molecules, IFT has critical roles in cilia biogenesis, quality control, and signal transduction. IFT involves long polymeric arrays, termed IFT trains, which move to and from the ciliary tip under the power of the microtubule-based motor proteins kinesin-II and dynein-2. Recent top-down and bottom-up structural biology approaches are converging on the molecular architecture of the IFT train machinery. Here we review these studies, with a focus on how kinesin-II and dynein-2 assemble, attach to IFT trains, and undergo precise regulation to mediate bidirectional transport.
Collapse
Affiliation(s)
- Stephanie Webb
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London, United Kingdom
| | - Aakash G Mukhopadhyay
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London, United Kingdom
| | - Anthony J Roberts
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London, United Kingdom.
| |
Collapse
|
17
|
Vuolo L, Stevenson NL, Mukhopadhyay AG, Roberts AJ, Stephens DJ. Cytoplasmic dynein-2 at a glance. J Cell Sci 2020; 133:133/6/jcs240614. [DOI: 10.1242/jcs.240614] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
ABSTRACT
Cytoplasmic dynein-2 is a motor protein complex that drives the movement of cargoes along microtubules within cilia, facilitating the assembly of these organelles on the surface of nearly all mammalian cells. Dynein-2 is crucial for ciliary function, as evidenced by deleterious mutations in patients with skeletal abnormalities. Long-standing questions include how the dynein-2 complex is assembled, regulated, and switched between active and inactive states. A combination of model organisms, in vitro cell biology, live-cell imaging, structural biology and biochemistry has advanced our understanding of the dynein-2 motor. In this Cell Science at a Glance article and the accompanying poster, we discuss the current understanding of dynein-2 and its roles in ciliary assembly and function.
Collapse
Affiliation(s)
- Laura Vuolo
- Cell Biology Laboratories, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Nicola L. Stevenson
- Cell Biology Laboratories, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Aakash G. Mukhopadhyay
- 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
| | - David J. Stephens
- Cell Biology Laboratories, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| |
Collapse
|
18
|
Mijalkovic J, Girard J, van Krugten J, van Loo J, Zhang Z, Loseva E, Oswald F, Peterman EJG. Cutting off ciliary protein import: intraflagellar transport after dendritic femtosecond-laser ablation. Mol Biol Cell 2020; 31:324-334. [PMID: 31940255 PMCID: PMC7183794 DOI: 10.1091/mbc.e18-06-0399] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Primary cilia, organelles protruding from the surface of eukaryotic cells, act as cellular antennae to detect and transmit signals from the extracellular environment. They are built and maintained by continuous cycles of intraflagellar transport (IFT), where ciliary proteins are transported between the ciliary base and tip. These proteins originate from the cell body because cilia lack protein synthesis machinery. How input from the cell body affects IFT and ciliary function is not well understood. Here, we use femtosecond-laser ablation to perturb the dendritic input of proteins to chemosensory cilia in living Caenorhabditis elegans. Using fluorescence microscopy, we visualize and quantify the real-time response of ciliary proteins to dendritic ablation. We find that the response occurs in three distinct stages. First, IFT dynein is activated within seconds, redistributing IFT components toward the ciliary base; second, the ciliary axoneme shortens and motors slow down; and third, motors leave the cilium. Depletion of ATP by adding azide also results in IFT slowdown and IFT components leaving the cilium, but not in activation of retrograde IFT. These results indicate that laser ablation triggers a specific mechanism important for IFT regulation that allows the cilium to rapidly adapt to changes in the outside environment.
Collapse
Affiliation(s)
- Jona Mijalkovic
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Jules Girard
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Jaap van Krugten
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Jasmijn van Loo
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Zhiqing Zhang
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Elizaveta Loseva
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Felix Oswald
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Erwin J G Peterman
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| |
Collapse
|
19
|
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
|
20
|
Mijalkovic J, van Krugten J, Oswald F, Acar S, Peterman EJG. Single-Molecule Turnarounds of Intraflagellar Transport at the C. elegans Ciliary Tip. Cell Rep 2019; 25:1701-1707.e2. [PMID: 30428341 DOI: 10.1016/j.celrep.2018.10.050] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 04/13/2018] [Accepted: 10/12/2018] [Indexed: 11/17/2022] Open
Abstract
Cilia are microtubule-based sensing hubs that rely on intraflagellar transport (IFT) for their development, maintenance, and function. Kinesin-2 motors transport IFT trains, consisting of IFT proteins and cargo, from ciliary base to tip. There, trains turn around and are transported back by IFT dynein. The mechanism of tip turnaround has remained elusive. Here, we employ single-molecule fluorescence microscopy of IFT components in the tips of phasmid cilia of living C. elegans. Analysis of the trajectories reveals that while motor proteins and IFT-A particle component CHE-11 mostly turn around immediately, the IFT-B particle component OSM-6 pauses for several seconds. Our data indicate that IFT trains disassemble into at least IFT-A, IFT-B, IFT-dynein, and OSM-3 complexes at the tip, where OSM-6 is temporarily retained or undergoes modification, prior to train reassembly and retrograde transport. The single-molecule approach used here is a valuable tool to study how directional switches occur in microtubule-based transport processes.
Collapse
Affiliation(s)
- Jona Mijalkovic
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Jaap van Krugten
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Felix Oswald
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Seyda Acar
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Erwin J G Peterman
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands.
| |
Collapse
|
21
|
Structure of the dynein-2 complex and its assembly with intraflagellar transport trains. Nat Struct Mol Biol 2019; 26:823-829. [PMID: 31451806 PMCID: PMC6774794 DOI: 10.1038/s41594-019-0286-y] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 07/24/2019] [Indexed: 12/12/2022]
Abstract
Dynein-2 assembles with polymeric intraflagellar transport (IFT) trains to form a transport machinery that is crucial for cilia biogenesis and signaling. Here we recombinantly expressed the ~1.4-MDa human dynein-2 complex and solved its cryo-EM structure to near-atomic resolution. The two identical copies of the dynein-2 heavy chain are contorted into different conformations by a WDR60-WDR34 heterodimer and a block of two RB and six LC8 light chains. One heavy chain is steered into a zig-zag conformation, which matches the periodicity of the anterograde IFT-B train. Contacts between adjacent dyneins along the train indicate a cooperative mode of assembly. Removal of the WDR60-WDR34-light chain subcomplex renders dynein-2 monomeric and relieves autoinhibition of its motility. Our results converge on a model in which an unusual stoichiometry of non-motor subunits controls dynein-2 assembly, asymmetry, and activity, giving mechanistic insight into the interaction of dynein-2 with IFT trains and the origin of diverse functions in the dynein family.
Collapse
|
22
|
Kumar D, Mains RE, Eipper BA, King SM. Ciliary and cytoskeletal functions of an ancient monooxygenase essential for bioactive amidated peptide synthesis. Cell Mol Life Sci 2019; 76:2329-2348. [PMID: 30879092 PMCID: PMC6529398 DOI: 10.1007/s00018-019-03065-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 02/28/2019] [Accepted: 03/07/2019] [Indexed: 02/07/2023]
Abstract
Many secreted peptides used for cell-cell communication require conversion of a C-terminal glycine to an amide for bioactivity. This reaction is catalyzed only by the integral membrane protein peptidylglycine α-amidating monooxygenase (PAM). PAM has been highly conserved and is found throughout the metazoa; PAM-like sequences are also present in choanoflagellates, filastereans, unicellular and colonial chlorophyte green algae, dinoflagellates and haptophytes. Recent studies have revealed that in addition to playing a key role in peptidergic signaling, PAM also regulates ciliogenesis in vertebrates, planaria and chlorophyte algae, and is required for the stability of actin-based microvilli. Here we briefly introduce the basic principles involved in ciliogenesis, the sequential reactions catalyzed by PAM and the trafficking of PAM through the secretory and endocytic pathways. We then discuss the multi-faceted roles this enzyme plays in the formation and maintenance of cytoskeleton-based cellular protrusions and propose models for how PAM protein and amidating activity might contribute to ciliogenesis. Finally, we consider why some ciliated organisms lack PAM, and discuss the potential ramifications of ciliary localized PAM for the endocrine features commonly observed in patients with ciliopathies.
Collapse
Affiliation(s)
- Dhivya Kumar
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Richard E Mains
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - Betty A Eipper
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - Stephen M King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA.
| |
Collapse
|
23
|
Yang TT, Tran MNT, Chong WM, Huang CE, Liao JC. Single-particle tracking localization microscopy reveals nonaxonemal dynamics of intraflagellar transport proteins at the base of mammalian primary cilia. Mol Biol Cell 2019; 30:828-837. [PMID: 30759057 PMCID: PMC6589787 DOI: 10.1091/mbc.e18-10-0654] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Primary cilia play a vital role in cellular sensing and signaling. An essential component of ciliogenesis is intraflagellar transport (IFT), which is involved in IFT protein recruitment, axonemal engagement of IFT protein complexes, and so on. The mechanistic understanding of these processes at the ciliary base was largely missing, because it is challenging to observe the motion of IFT proteins in this crowded region using conventional microscopy. Here, we report short-trajectory tracking of IFT proteins at the base of mammalian primary cilia by optimizing single-particle tracking photoactivated localization microscopy for IFT88-mEOS4b in live human retinal pigment epithelial cells. Intriguingly, we found that mobile IFT proteins “switched gears” multiple times from the distal appendages (DAPs) to the ciliary compartment (CC), moving slowly in the DAPs, relatively fast in the proximal transition zone (TZ), slowly again in the distal TZ, and then much faster in the CC. They could travel through the space between the DAPs and the axoneme without following DAP structures. We further revealed that BBS2 and IFT88 were highly populated at the distal TZ, a potential assembly site. Together, our live-cell single-particle tracking revealed region-dependent slowdown of IFT proteins at the ciliary base, shedding light on staged control of ciliary homeostasis.
Collapse
Affiliation(s)
- T Tony Yang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Minh Nguyet Thi Tran
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Weng Man Chong
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Chia-En Huang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Jung-Chi Liao
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.,Genome and Systems Biology Program, National Taiwan University, Taipei 10617, Taiwan
| |
Collapse
|
24
|
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
|
25
|
Vuolo L, Stevenson NL, Heesom KJ, Stephens DJ. Dynein-2 intermediate chains play crucial but distinct roles in primary cilia formation and function. eLife 2018; 7:39655. [PMID: 30320547 PMCID: PMC6211827 DOI: 10.7554/elife.39655] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/14/2018] [Indexed: 12/16/2022] Open
Abstract
The dynein-2 microtubule motor is the retrograde motor for intraflagellar transport. Mutations in dynein-2 components cause skeletal ciliopathies, notably Jeune syndrome. Dynein-2 contains a heterodimer of two non-identical intermediate chains, WDR34 and WDR60. Here, we use knockout cell lines to demonstrate that each intermediate chain has a distinct role in cilium function. Using quantitative proteomics, we show that WDR34 KO cells can assemble a dynein-2 motor complex that binds IFT proteins yet fails to extend an axoneme, indicating complex function is stalled. In contrast, WDR60 KO cells do extend axonemes but show reduced assembly of dynein-2 and binding to IFT proteins. Both proteins are required to maintain a functional transition zone and for efficient bidirectional intraflagellar transport. Our results indicate that the subunit asymmetry within the dynein-2 complex is matched with a functional asymmetry between the dynein-2 intermediate chains. Furthermore, this work reveals that loss of function of dynein-2 leads to defects in transition zone architecture, as well as intraflagellar transport. Almost all cells in the human body are covered in tiny hair-like structures known as primary cilia. These structures act as antennae to receive signals from outside the cell that regulate how the body grows and develops. The cell has to deliver new proteins and other molecules to precise locations within its cilia to ensure that they work properly. Each cilium is separated from the rest of the cell by a selective barrier known as the transition zone, which controls the movement of molecules to and from the rest of the cell. Dynein-2 is a motor protein that moves other proteins and cell materials within cilia. It includes two subunits known as WDR34 and WDR60. The genes that produce these subunits are mutated in Jeune and short rib polydactyly syndromes that primarily affect how the skeleton forms. However, little is known about the roles the individual subunits play within the motor protein. Vuolo et al. used a gene editing technique called CRISPR-Cas9 to remove one or both of the genes encoding the dynein-2 subunits from human cells. The experiments show that the two subunits have very different roles in cilia. WDR34 is required for cells to build a cilium whereas WDR60 is not. Instead, WDR60 is needed to move proteins and other materials within an established cilium. Unexpectedly, the experiments suggest that dynein-2 is also required to maintain the transition zone. This work provides the foundations for future studies on the role of dynein-2 in building and maintaining the structure of cilia. This could ultimately help to develop new treatments to reduce the symptoms of Jeune syndrome and other diseases caused by defects in cilia.
Collapse
Affiliation(s)
- Laura Vuolo
- Cell Biology Laboratories, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Nicola L Stevenson
- Cell Biology Laboratories, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Kate J Heesom
- Proteomics Facility, Faculty of Biomedical Sciences, University of Bristol, Bristol, United Kingdom
| | - David J Stephens
- Cell Biology Laboratories, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
26
|
Scheidel N, Blacque OE. Intraflagellar Transport Complex A Genes Differentially Regulate Cilium Formation and Transition Zone Gating. Curr Biol 2018; 28:3279-3287.e2. [PMID: 30293716 DOI: 10.1016/j.cub.2018.08.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 06/08/2018] [Accepted: 08/07/2018] [Indexed: 02/03/2023]
Abstract
Cilia are found on most eukaryotic cell types, serving motility, environment sensing, and signaling (cell-cell) functions, and defects cause genetic diseases (ciliopathies), affecting the development of many tissues [1]. Cilia are built by intraflagellar transport (IFT), a bidirectional microtubule-based motility driven by kinesin-2 anterograde (toward ciliary tip) and IFT-dynein retrograde (toward ciliary base) motors together with IFT-A and IFT-B cargo adaptor complexes that control retrograde and anterograde IFT, respectively [2]. Ciliary composition is also facilitated by the transition zone (TZ) at the ciliary base and the associated Meckel-Gruber syndrome (MKS) and nephronophthisis (NPHP) modules that establish protein diffusion barriers and regulate cilium structure [3]. Although the molecular architecture of the IFT machine is emerging [2], how individual components contribute to cilium subtype formation and IFT remains relatively unexplored, especially in vivo. In addition, little is known about functional interactions between IFT and TZ modules. Here, in Caenorhabditis elegans (roundworms), we identify cell-type-specific mechanisms by which IFT-A sculpts the structures of discrete ciliary subtypes and regulates IFT. We also uncover differential roles for IFT-A subunits in controlling the TZ restriction of MKS module components and ciliary exclusion (gating) of periciliary membrane proteins, with IFT-140 controlling their ciliary entry and IFT-43/121/139 controlling their ciliary removal. Furthermore, we determine that IFT-A and MKS module components synergistically interact to determine cilium structure. Overall, this work provides insight into the functional architecture of a metazoan IFT-A complex in different cell types and uncovers new relationships between ciliopathy-associated IFT-A and TZ modules.
Collapse
Affiliation(s)
- Noémie Scheidel
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Oliver E Blacque
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
| |
Collapse
|
27
|
Bertiaux E, Mallet A, Fort C, Blisnick T, Bonnefoy S, Jung J, Lemos M, Marco S, Vaughan S, Trépout S, Tinevez JY, Bastin P. Bidirectional intraflagellar transport is restricted to two sets of microtubule doublets in the trypanosome flagellum. J Cell Biol 2018; 217:4284-4297. [PMID: 30275108 PMCID: PMC6279389 DOI: 10.1083/jcb.201805030] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/06/2018] [Accepted: 09/21/2018] [Indexed: 12/22/2022] Open
Abstract
Intraflagellar transport (IFT) is the movement of large protein complexes responsible for the construction of cilia and flagella. Using a combination of three-dimensional electron microscopy and high-resolution live imaging, Bertiaux et al. show that IFT takes place on only four microtubule doublets out of the nine available in the trypanosome flagellum. Intraflagellar transport (IFT) is the rapid bidirectional movement of large protein complexes driven by kinesin and dynein motors along microtubule doublets of cilia and flagella. In this study, we used a combination of high-resolution electron and light microscopy to investigate how and where these IFT trains move within the flagellum of the protist Trypanosoma brucei. Focused ion beam scanning electron microscopy (FIB-SEM) analysis of trypanosomes showed that trains are found almost exclusively along two sets of doublets (3–4 and 7–8) and distribute in two categories according to their length. High-resolution live imaging of cells expressing mNeonGreen::IFT81 or GFP::IFT52 revealed for the first time IFT trafficking on two parallel lines within the flagellum. Anterograde and retrograde IFT occurs on each of these lines. At the distal end, a large individual anterograde IFT train is converted in several smaller retrograde trains in the space of 3–4 s while remaining on the same side of the axoneme.
Collapse
Affiliation(s)
- Eloïse Bertiaux
- Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, Paris, France.,Université Pierre et Marie Curie Paris 6, Cellule Pasteur, Paris, France
| | - Adeline Mallet
- Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, Paris, France.,Université Pierre et Marie Curie Paris 6, Cellule Pasteur, Paris, France.,UtechS Ultrastructural Bioimaging (Ultrapole), Institut Pasteur, Paris, France
| | - Cécile Fort
- Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, Paris, France.,Université Pierre et Marie Curie Paris 6, Cellule Pasteur, Paris, France
| | - Thierry Blisnick
- Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, Paris, France
| | - Serge Bonnefoy
- Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, Paris, France
| | - Jamin Jung
- Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, Paris, France
| | - Moara Lemos
- Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, Paris, France
| | - Sergio Marco
- Université Paris Sud, Université Paris-Saclay, Centre National de la Recherche Scientifique, UMR 9187, Orsay, France.,Institut Curie, Paris Sciences et Lettres Research University, INSERM U1196, Orsay, France
| | - Sue Vaughan
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford, UK
| | - Sylvain Trépout
- Université Paris Sud, Université Paris-Saclay, Centre National de la Recherche Scientifique, UMR 9187, Orsay, France.,Institut Curie, Paris Sciences et Lettres Research University, INSERM U1196, Orsay, France
| | - Jean-Yves Tinevez
- UtechS Photonic Bioimaging (Imagopole), Institut Pasteur, Paris, France.,Image Analysis Hub, Institut Pasteur, Paris, France
| | - Philippe Bastin
- Trypanosome Cell Biology Unit, INSERM U1201, Institut Pasteur, Paris, France
| |
Collapse
|
28
|
Roberts AJ. Emerging mechanisms of dynein transport in the cytoplasm versus the cilium. Biochem Soc Trans 2018; 46:967-982. [PMID: 30065109 PMCID: PMC6103457 DOI: 10.1042/bst20170568] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 06/13/2018] [Accepted: 06/18/2018] [Indexed: 02/08/2023]
Abstract
Two classes of dynein power long-distance cargo transport in different cellular contexts. Cytoplasmic dynein-1 is responsible for the majority of transport toward microtubule minus ends in the cell interior. Dynein-2, also known as intraflagellar transport dynein, moves cargoes along the axoneme of eukaryotic cilia and flagella. Both dyneins operate as large ATP-driven motor complexes, whose dysfunction is associated with a group of human disorders. But how similar are their mechanisms of action and regulation? To examine this question, this review focuses on recent advances in dynein-1 and -2 research, and probes to what extent the emerging principles of dynein-1 transport could apply to or differ from those of the less well-understood dynein-2 mechanoenzyme.
Collapse
Affiliation(s)
- Anthony J Roberts
- Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London, U.K.
| |
Collapse
|
29
|
Hamada Y, Tsurumi Y, Nozaki S, Katoh Y, Nakayama K. Interaction of WDR60 intermediate chain with TCTEX1D2 light chain of the dynein-2 complex is crucial for ciliary protein trafficking. Mol Biol Cell 2018; 29:1628-1639. [PMID: 29742051 PMCID: PMC6080652 DOI: 10.1091/mbc.e18-03-0173] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 05/02/2018] [Accepted: 05/04/2018] [Indexed: 11/20/2022] Open
Abstract
The dynein-2 complex mediates trafficking of ciliary proteins by powering the intraflagellar transport (IFT) machinery containing IFT-A and IFT-B complexes. Although 11 subunits are known to constitute the dynein-2 complex, with several light-chain subunits shared by the dynein-1 complex, the overall architecture of the dynein-2 complex has not been fully clarified. Utilizing the visible immunoprecipitation assay, we demonstrated the interaction modes among the dynein-2 subunits, including previously undefined interactions, such as that between WDR60 and the TCTEX1D2-DYNLT1/DYNLT3 dimer. The dynein-2 complex can be divided into three subcomplexes, namely DYNC2H1-DYNC2LI1, WDR34-DYNLL1/DYNLL2-DYNLRB1/DYNLRB2, and WDR60-TCTEX1D2-DYNLT1/DYNLT3. We established cell lines lacking WDR60 or TCTEX1D2, both of which are dynein-2-specific subunits encoded by ciliopathy-causing genes, and found that both WDR60-knockout (KO) and TCTEX1D2-KO cells show defects in retrograde ciliary protein trafficking, with WDR60-KO cells demonstrating more severe defects probably due to failed assembly of the dynein-2 complex. The exogenous expression of a WDR60 mutant lacking TCTEX1D2 binding partially restored retrograde trafficking to a level comparable to that of TCTEX1D2-KO cells. Thus, our results demonstrated that WDR60 plays a major role and TCTEX1D2 plays an auxiliary role in the dynein-2 complex to mediate retrograde ciliary protein trafficking.
Collapse
Affiliation(s)
- Yuki Hamada
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yuta Tsurumi
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shohei Nozaki
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| |
Collapse
|
30
|
Abstract
A new imaging technique sheds light on how cilia regulate their length and growth.
Collapse
Affiliation(s)
- Dhivya Kumar
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Stephen M King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, United States
| |
Collapse
|
31
|
Chien A, Shih SM, Bower R, Tritschler D, Porter ME, Yildiz A. Dynamics of the IFT machinery at the ciliary tip. eLife 2017; 6:28606. [PMID: 28930071 PMCID: PMC5662288 DOI: 10.7554/elife.28606] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 09/12/2017] [Indexed: 12/15/2022] Open
Abstract
Intraflagellar transport (IFT) is essential for the elongation and maintenance of eukaryotic cilia and flagella. Due to the traffic jam of multiple trains at the ciliary tip, how IFT trains are remodeled in these turnaround zones cannot be determined by conventional imaging. Using PhotoGate, we visualized the full range of movement of single IFT trains and motors in Chlamydomonas flagella. Anterograde trains split apart and IFT complexes mix with each other at the tip to assemble retrograde trains. Dynein-1b is carried to the tip by kinesin-II as inactive cargo on anterograde trains. Unlike dynein-1b, kinesin-II detaches from IFT trains at the tip and diffuses in flagella. As the flagellum grows longer, diffusion delays return of kinesin-II to the basal body, depleting kinesin-II available for anterograde transport. Our results suggest that dissociation of kinesin-II from IFT trains serves as a negative feedback mechanism that facilitates flagellar length control in Chlamydomonas.
Collapse
Affiliation(s)
- Alexander Chien
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, United States
| | - Sheng Min Shih
- Physics Department, University of California, Berkeley, Berkeley, United States
| | - Raqual Bower
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States
| | - Douglas Tritschler
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States
| | - Mary E Porter
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States
| | - Ahmet Yildiz
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, United States.,Physics Department, University of California, Berkeley, Berkeley, United States.,Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| |
Collapse
|
32
|
Wingfield JL, Mengoni I, Bomberger H, Jiang YY, Walsh JD, Brown JM, Picariello T, Cochran DA, Zhu B, Pan J, Eggenschwiler J, Gaertig J, Witman GB, Kner P, Lechtreck K. IFT trains in different stages of assembly queue at the ciliary base for consecutive release into the cilium. eLife 2017; 6. [PMID: 28562242 PMCID: PMC5451262 DOI: 10.7554/elife.26609] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/16/2017] [Indexed: 12/13/2022] Open
Abstract
Intraflagellar transport (IFT) trains, multimegadalton assemblies of IFT proteins and motors, traffic proteins in cilia. To study how trains assemble, we employed fluorescence protein-tagged IFT proteins in Chlamydomonas reinhardtii. IFT-A and motor proteins are recruited from the cell body to the basal body pool, assembled into trains, move through the cilium, and disperse back into the cell body. In contrast to this ‘open’ system, IFT-B proteins from retrograde trains reenter the pool and a portion is reused directly in anterograde trains indicating a ‘semi-open’ system. Similar IFT systems were also observed in Tetrahymena thermophila and IMCD3 cells. FRAP analysis indicated that IFT proteins and motors of a given train are sequentially recruited to the basal bodies. IFT dynein and tubulin cargoes are loaded briefly before the trains depart. We conclude that the pool contains IFT trains in multiple stages of assembly queuing for successive release into the cilium upon completion. DOI:http://dx.doi.org/10.7554/eLife.26609.001
Collapse
Affiliation(s)
- Jenna L Wingfield
- Department of Cellular Biology, University of Georgia, Athens, United States
| | - Ilaria Mengoni
- Department of Cellular Biology, University of Georgia, Athens, United States
| | - Heather Bomberger
- Department of Cellular Biology, University of Georgia, Athens, United States.,College of Engineering, University of Georgia, Athens, United States
| | - Yu-Yang Jiang
- Department of Cellular Biology, University of Georgia, Athens, United States
| | - Jonathon D Walsh
- Department of Genetics, University of Georgia, Athens, United States
| | - Jason M Brown
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, United States.,Department of Biology, Salem State University, Salem, United States
| | - Tyler Picariello
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, United States
| | - Deborah A Cochran
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, United States
| | - Bing Zhu
- MOE Key Laboratory of Protein Sciences, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Junmin Pan
- MOE Key Laboratory of Protein Sciences, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | | | - Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, United States
| | - George B Witman
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, United States
| | - Peter Kner
- College of Engineering, University of Georgia, Athens, United States
| | - Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, United States
| |
Collapse
|
33
|
Steinman JB, Santarossa CC, Miller RM, Yu LS, Serpinskaya AS, Furukawa H, Morimoto S, Tanaka Y, Nishitani M, Asano M, Zalyte R, Ondrus AE, Johnson AG, Ye F, Nachury MV, Fukase Y, Aso K, Foley MA, Gelfand VI, Chen JK, Carter AP, Kapoor TM. Chemical structure-guided design of dynapyrazoles, cell-permeable dynein inhibitors with a unique mode of action. eLife 2017; 6. [PMID: 28524820 PMCID: PMC5478271 DOI: 10.7554/elife.25174] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 05/17/2017] [Indexed: 12/11/2022] Open
Abstract
Cytoplasmic dyneins are motor proteins in the AAA+ superfamily that transport cellular cargos toward microtubule minus-ends. Recently, ciliobrevins were reported as selective cell-permeable inhibitors of cytoplasmic dyneins. As is often true for first-in-class inhibitors, the use of ciliobrevins has in part been limited by low potency. Moreover, suboptimal chemical properties, such as the potential to isomerize, have hindered efforts to improve ciliobrevins. Here, we characterized the structure of ciliobrevins and designed conformationally constrained isosteres. These studies identified dynapyrazoles, inhibitors more potent than ciliobrevins. At single-digit micromolar concentrations dynapyrazoles block intraflagellar transport in the cilium and lysosome motility in the cytoplasm, processes that depend on cytoplasmic dyneins. Further, we find that while ciliobrevins inhibit both dynein's microtubule-stimulated and basal ATPase activity, dynapyrazoles strongly block only microtubule-stimulated activity. Together, our studies suggest that chemical-structure-based analyses can lead to inhibitors with improved properties and distinct modes of inhibition. DOI:http://dx.doi.org/10.7554/eLife.25174.001
Collapse
Affiliation(s)
- Jonathan B Steinman
- Laboratory of Chemistry and Cell Biology, Rockefeller University, New York, United States
| | - Cristina C Santarossa
- Laboratory of Chemistry and Cell Biology, Rockefeller University, New York, United States
| | - Rand M Miller
- Laboratory of Chemistry and Cell Biology, Rockefeller University, New York, United States
| | - Lola S Yu
- Laboratory of Chemistry and Cell Biology, Rockefeller University, New York, United States
| | - Anna S Serpinskaya
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Hideki Furukawa
- Tri-Institutitional Therapeutics Discovery Institute, New York, United States
| | - Sachie Morimoto
- Tri-Institutitional Therapeutics Discovery Institute, New York, United States
| | - Yuta Tanaka
- Tri-Institutitional Therapeutics Discovery Institute, New York, United States
| | | | - Moriteru Asano
- Tri-Institutitional Therapeutics Discovery Institute, New York, United States
| | - Ruta Zalyte
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Alison E Ondrus
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| | - Alex G Johnson
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, United States
| | - Fan Ye
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, United States
| | - Maxence V Nachury
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, United States
| | - Yoshiyuki Fukase
- Tri-Institutitional Therapeutics Discovery Institute, New York, United States
| | - Kazuyoshi Aso
- Tri-Institutitional Therapeutics Discovery Institute, New York, United States
| | - Michael A Foley
- Tri-Institutitional Therapeutics Discovery Institute, New York, United States
| | - Vladimir I Gelfand
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - James K Chen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, United States
| | - Andrew P Carter
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Tarun M Kapoor
- Laboratory of Chemistry and Cell Biology, Rockefeller University, New York, United States
| |
Collapse
|
34
|
Yi P, Li WJ, Dong MQ, Ou G. Dynein-Driven Retrograde Intraflagellar Transport Is Triphasic in C. elegans Sensory Cilia. Curr Biol 2017; 27:1448-1461.e7. [PMID: 28479320 DOI: 10.1016/j.cub.2017.04.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/24/2017] [Accepted: 04/10/2017] [Indexed: 11/25/2022]
Abstract
Cytoplasmic dynein-2 powers retrograde intraflagellar transport that is essential for cilium formation and maintenance. Inactivation of dynein-2 by mutations in DYNC2H1 causes skeletal dysplasias, and it remains unclear how the dynein-2 heavy chain moves in cilia. Here, using the genome-editing technique to produce fluorescent dynein-2 heavy chain in Caenorhabditis elegans, we show by high-resolution live microscopy that dynein-2 moves in a surprising way along distinct ciliary domains. Dynein-2 shows triphasic movement in the retrograde direction: dynein-2 accelerates in the ciliary distal region and then moves at maximum velocity and finally decelerates adjacent to the base, which may represent a physical obstacle due to transition zone barriers. By knocking the conserved ciliopathy-related mutations into the C. elegans dynein-2 heavy chain, we find that these mutations reduce its transport speed and frequency. Disruption of the dynein-2 tail domain, light intermediate chain, or intraflagellar transport (IFT)-B complex abolishes dynein-2's ciliary localization, revealing their important roles in ciliary entry of dynein-2. Furthermore, our affinity purification and genetic analyses show that IFT-A subunits IFT-139 and IFT-43 function redundantly to promote dynein-2 motility. These results reveal the molecular regulation of dynein-2 movement in sensory cilia.
Collapse
Affiliation(s)
- Peishan Yi
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China
| | - Wen-Jun Li
- National Institute of Biological Science, 7 Science Park Road, ZGC Life Science Park, Beijing 102206, China
| | - Meng-Qiu Dong
- National Institute of Biological Science, 7 Science Park Road, ZGC Life Science Park, Beijing 102206, China
| | - Guangshuo Ou
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China.
| |
Collapse
|