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Limerick A, McCabe EA, Turner JS, Kuang KW, Brautigan DL, Hao Y, Chu CY, Fu SH, Ahmadi S, Xu W, Fu Z. An Epilepsy-Associated CILK1 Variant Compromises KATNIP Regulation and Impairs Primary Cilia and Hedgehog Signaling. Cells 2024; 13:1258. [PMID: 39120290 PMCID: PMC11311665 DOI: 10.3390/cells13151258] [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: 05/30/2024] [Revised: 07/17/2024] [Accepted: 07/23/2024] [Indexed: 08/10/2024] Open
Abstract
Mutations in human CILK1 (ciliogenesis associated kinase 1) are linked to ciliopathies and epilepsy. Homozygous point and nonsense mutations that extinguish kinase activity impair primary cilia function, whereas mutations outside the kinase domain are not well understood. Here, we produced a knock-in mouse equivalent to the human CILK1 A615T variant identified in juvenile myoclonic epilepsy (JME). This residue is in the intrinsically disordered C-terminal region of CILK1 separate from the kinase domain. Mouse embryo fibroblasts (MEFs) with either heterozygous or homozygous A612T mutant alleles exhibited a higher ciliation rate, shorter individual cilia, and upregulation of ciliary Hedgehog signaling. Thus, a single A612T mutant allele was sufficient to impair primary cilia and ciliary signaling in MEFs. Gene expression profiles of wild-type versus mutant MEFs revealed profound changes in cilia-related molecular functions and biological processes. The CILK1 A615T mutant protein was not increased to the same level as the wild-type protein when co-expressed with scaffold protein KATNIP (katanin-interacting protein). Our data show that KATNIP regulation of a JME-associated single-residue variant of CILK1 is compromised, and this impairs the maintenance of primary cilia and Hedgehog signaling.
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Affiliation(s)
- Ana Limerick
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA; (A.L.); (E.A.M.); (J.S.T.); (K.W.K.); (C.Y.C.); (S.H.F.); (S.A.)
| | - Ellie A. McCabe
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA; (A.L.); (E.A.M.); (J.S.T.); (K.W.K.); (C.Y.C.); (S.H.F.); (S.A.)
| | - Jacob S. Turner
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA; (A.L.); (E.A.M.); (J.S.T.); (K.W.K.); (C.Y.C.); (S.H.F.); (S.A.)
| | - Kevin W. Kuang
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA; (A.L.); (E.A.M.); (J.S.T.); (K.W.K.); (C.Y.C.); (S.H.F.); (S.A.)
| | - David L. Brautigan
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA; (D.L.B.); (W.X.)
| | - Yi Hao
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA;
| | - Cheuk Ying Chu
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA; (A.L.); (E.A.M.); (J.S.T.); (K.W.K.); (C.Y.C.); (S.H.F.); (S.A.)
| | - Sean H. Fu
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA; (A.L.); (E.A.M.); (J.S.T.); (K.W.K.); (C.Y.C.); (S.H.F.); (S.A.)
| | - Sean Ahmadi
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA; (A.L.); (E.A.M.); (J.S.T.); (K.W.K.); (C.Y.C.); (S.H.F.); (S.A.)
| | - Wenhao Xu
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA; (D.L.B.); (W.X.)
| | - Zheng Fu
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA; (A.L.); (E.A.M.); (J.S.T.); (K.W.K.); (C.Y.C.); (S.H.F.); (S.A.)
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2
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Yoshida S, Kawamura A, Aoki K, Wiriyasermkul P, Sugimoto S, Tomiyoshi J, Tajima A, Ishida Y, Katoh Y, Tsukada T, Tsuneoka Y, Yamada K, Nagamori S, Nakayama K, Yoshida K. Positive regulation of Hedgehog signaling via phosphorylation of GLI2/GLI3 by DYRK2 kinase. Proc Natl Acad Sci U S A 2024; 121:e2320070121. [PMID: 38968120 PMCID: PMC11252808 DOI: 10.1073/pnas.2320070121] [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: 11/16/2023] [Accepted: 06/02/2024] [Indexed: 07/07/2024] Open
Abstract
Hedgehog (Hh) signaling, an evolutionarily conserved pathway, plays an essential role in development and tumorigenesis, making it a promising drug target. Multiple negative regulators are known to govern Hh signaling; however, how activated Smoothened (SMO) participates in the activation of downstream GLI2 and GLI3 remains unclear. Herein, we identified the ciliary kinase DYRK2 as a positive regulator of the GLI2 and GLI3 transcription factors for Hh signaling. Transcriptome and interactome analyses demonstrated that DYRK2 phosphorylates GLI2 and GLI3 on evolutionarily conserved serine residues at the ciliary base, in response to activation of the Hh pathway. This phosphorylation induces the dissociation of GLI2/GLI3 from suppressor, SUFU, and their translocation into the nucleus. Loss of Dyrk2 in mice causes skeletal malformation, but neural tube development remains normal. Notably, DYRK2-mediated phosphorylation orchestrates limb development by controlling cell proliferation. Taken together, the ciliary kinase DYRK2 governs the activation of Hh signaling through the regulation of two processes: phosphorylation of GLI2 and GLI3 downstream of SMO and cilia formation. Thus, our findings of a unique regulatory mechanism of Hh signaling expand understanding of the control of Hh-associated diseases.
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Affiliation(s)
- Saishu Yoshida
- Department of Biochemistry, The Jikei University School of Medicine, Tokyo105-8461, Japan
| | - Akira Kawamura
- Department of Biochemistry, The Jikei University School of Medicine, Tokyo105-8461, Japan
| | - Katsuhiko Aoki
- Radioisotope Research Facilities, The Jikei University School of Medicine, Tokyo105-8461, Japan
| | - Pattama Wiriyasermkul
- Center for Stable Isotope Medical Research, The Jikei University School of Medicine, Tokyo105-8461, Japan
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo105-8461, Japan
| | - Shinya Sugimoto
- Department of Bacteriology, The Jikei University School of Medicine, Tokyo105-8461, Japan
- Center for Biofilm Science and Technology, The Jikei University School of Medicine, Tokyo105-8461, Japan
- Laboratory of Amyloid Regulation, The Jikei University School of Medicine, Tokyo105-8461, Japan
| | - Junnosuke Tomiyoshi
- Department of Biochemistry, The Jikei University School of Medicine, Tokyo105-8461, Japan
| | - Ayasa Tajima
- Center for Stable Isotope Medical Research, The Jikei University School of Medicine, Tokyo105-8461, Japan
- Department of Molecular Biology, The Jikei University School of Medicine, Tokyo105-8461, Japan
| | - Yamato Ishida
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto606-8501, Japan
| | - Takehiro Tsukada
- Department of Biomolecular Science, Toho University, Chiba274-8510, Japan
| | - Yousuke Tsuneoka
- Department of Anatomy, Faculty of Medicine, Toho University, Tokyo143-8540, Japan
| | - Kohji Yamada
- Department of Biochemistry, The Jikei University School of Medicine, Tokyo105-8461, Japan
| | - Shushi Nagamori
- Center for Stable Isotope Medical Research, The Jikei University School of Medicine, Tokyo105-8461, Japan
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo105-8461, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto606-8501, Japan
| | - Kiyotsugu Yoshida
- Department of Biochemistry, The Jikei University School of Medicine, Tokyo105-8461, Japan
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3
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Chiang HJ, Nishiwaki Y, Chiang WC, Masai I. Male germ cell-associated kinase is required for axoneme formation during ciliogenesis in zebrafish photoreceptors. Dis Model Mech 2024; 17:dmm050618. [PMID: 38813692 PMCID: PMC11273301 DOI: 10.1242/dmm.050618] [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: 11/22/2023] [Accepted: 05/16/2024] [Indexed: 05/31/2024] Open
Abstract
Vertebrate photoreceptors are highly specialized retinal neurons that have cilium-derived membrane organelles called outer segments, which function as platforms for phototransduction. Male germ cell-associated kinase (MAK) is a cilium-associated serine/threonine kinase, and its genetic mutation causes photoreceptor degeneration in mice and retinitis pigmentosa in humans. However, the role of MAK in photoreceptors is not fully understood. Here, we report that zebrafish mak mutants show rapid photoreceptor degeneration during embryonic development. In mak mutants, both cone and rod photoreceptors completely lacked outer segments and underwent apoptosis. Interestingly, zebrafish mak mutants failed to generate axonemes during photoreceptor ciliogenesis, whereas basal bodies were specified. These data suggest that Mak contributes to axoneme development in zebrafish, in contrast to mouse Mak mutants, which have elongated photoreceptor axonemes. Furthermore, the kinase activity of Mak was found to be critical in ciliary axoneme development and photoreceptor survival. Thus, Mak is required for ciliogenesis and outer segment formation in zebrafish photoreceptors to ensure intracellular protein transport and photoreceptor survival.
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Affiliation(s)
- Hung-Ju Chiang
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Tancha, Okinawa 904-0495, Japan
| | - Yuko Nishiwaki
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Tancha, Okinawa 904-0495, Japan
| | - Wei-Chieh Chiang
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Tancha, Okinawa 904-0495, Japan
| | - Ichiro Masai
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Tancha, Okinawa 904-0495, Japan
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4
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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.
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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.
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5
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Hiyamizu S, Qiu H, Vuolo L, Stevenson NL, Shak C, Heesom KJ, Hamada Y, Tsurumi Y, Chiba S, Katoh Y, Stephens DJ, Nakayama K. Multiple interactions of the dynein-2 complex with the IFT-B complex are required for effective intraflagellar transport. J Cell Sci 2023; 136:286934. [PMID: 36632779 PMCID: PMC10110421 DOI: 10.1242/jcs.260462] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 01/04/2023] [Indexed: 01/13/2023] Open
Abstract
The dynein-2 complex must be transported anterogradely within cilia to then drive retrograde trafficking of the intraflagellar transport (IFT) machinery containing IFT-A and IFT-B complexes. Here, we screened for potential interactions between the dynein-2 and IFT-B complexes and found multiple interactions among the dynein-2 and IFT-B subunits. In particular, WDR60 (also known as DYNC2I1) and the DYNC2H1-DYNC2LI1 dimer from dynein-2, and IFT54 (also known as TRAF3IP1) and IFT57 from IFT-B contribute to the dynein-2-IFT-B interactions. WDR60 interacts with IFT54 via a conserved region N-terminal to its light chain-binding regions. Expression of the WDR60 constructs in WDR60-knockout (KO) cells revealed that N-terminal truncation mutants lacking the IFT54-binding site fail to rescue abnormal phenotypes of WDR60-KO cells, such as aberrant accumulation of the IFT machinery around the ciliary tip and on the distal side of the transition zone. However, a WDR60 construct specifically lacking just the IFT54-binding site substantially restored the ciliary defects. In line with the current docking model of dynein-2 with the anterograde IFT trains, these results indicate that extensive interactions involving multiple subunits from the dynein-2 and IFT-B complexes participate in their connection.
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Affiliation(s)
- Shunya Hiyamizu
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hantian Qiu
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - 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
| | - Caroline Shak
- Cell Biology Laboratories, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Kate J Heesom
- Proteomics Facility, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Yuki Hamada
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yuta Tsurumi
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shuhei Chiba
- Department of Genetic Disease Research, Graduate School of Medicine, Osaka City University, Abeno-ku, Osaka 545-8585, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - David J Stephens
- Cell Biology Laboratories, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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6
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Gonçalves-Santos F, De-Castro MJG, De-Castro ARG, Dantas TJ. Building train carriages for ciliary transport: (IFT-)A complex task. Commun Biol 2023; 6:91. [PMID: 36690675 PMCID: PMC9870902 DOI: 10.1038/s42003-023-04426-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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
| | - 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
| | - 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
| | - 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.
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7
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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: 30] [Impact Index Per Article: 15.0] [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.
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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.
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8
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Mul W, Mitra A, Peterman EJG. Mechanisms of Regulation in Intraflagellar Transport. Cells 2022; 11:2737. [PMID: 36078145 PMCID: PMC9454703 DOI: 10.3390/cells11172737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [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.
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Affiliation(s)
| | | | - Erwin J. G. Peterman
- Department of Physics and Astronomy, and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
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9
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Vinay L, Belleannée C. EV duty vehicles: Features and functions of ciliary extracellular vesicles. Front Genet 2022; 13:916233. [PMID: 36061180 PMCID: PMC9438925 DOI: 10.3389/fgene.2022.916233] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/08/2022] [Indexed: 12/12/2022] Open
Abstract
The primary cilium is a microtubule-based organelle that extends from a basal body at the surface of most cells. This antenna is an efficient sensor of the cell micro-environment and is instrumental to the proper development and homeostatic control of organs. Recent compelling studies indicate that, in addition to its role as a sensor, the primary cilium also emits signals through the release of bioactive extracellular vesicles (EVs). While some primary-cilium derived EVs are released through an actin-dependent ectocytosis and are called ectosomes (or large EVs, 350–500 nm), others originate from the exocytosis of multivesicular bodies and are smaller (small EVs, 50–100 nm). Ciliary EVs carry unique signaling factors, including protein markers and microRNAs (miRNAs), and participate in intercellular communication in different organism models. This review discusses the mechanism of release, the molecular features, and functions of EVs deriving from cilia, based on the existing literature.
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10
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Satoda Y, Noguchi T, Fujii T, Taniguchi A, Katoh Y, Nakayama K. BROMI/TBC1D32 together with CCRK/CDK20 and FAM149B1/JBTS36 contributes to intraflagellar transport turnaround involving ICK/CILK1. Mol Biol Cell 2022; 33:ar79. [PMID: 35609210 PMCID: PMC9582636 DOI: 10.1091/mbc.e22-03-0089] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Primary cilia are antenna-like organelles that contain specific proteins, and are crucial for tissue morphogenesis. Anterograde and retrograde trafficking of ciliary proteins are mediated by the intraflagellar transport (IFT) machinery. BROMI/TBC1D32 interacts with CCRK/CDK20, which phosphorylates and activates the intestinal cell kinase (ICK)/CILK1 kinase, to regulate the change in direction of the IFT machinery at the ciliary tip. Mutations in BROMI, CCRK, and ICK in humans cause ciliopathies, and mice defective in these genes are also known to demonstrate ciliopathy phenotypes. We show here that BROMI interacts not only with CCRK but also with CFAP20, an evolutionarily conserved ciliary protein, and with FAM149B1/ Joubert syndrome (JBTS)36, a protein in which mutations cause JBTS. In addition, we show that FAM149B1 interacts directly with CCRK as well as with BROMI. Ciliary defects observed in CCRK-knockout (KO), BROMI-KO, and FAM149B1-KO cells, including abnormally long cilia and accumulation of the IFT machinery and ICK at the ciliary tip, resembled one another, and BROMI mutants that are defective in binding to CCRK and CFAP20 were unable to rescue the ciliary defects of BROMI-KO cells. These data indicate that CCRK, BROMI, FAM149B1, and probably CFAP20 altogether regulate the IFT turnaround process under the control of ICK.
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Affiliation(s)
- Yuuki Satoda
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Tatsuro Noguchi
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Taiju Fujii
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Aoi Taniguchi
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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11
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Ishida Y, Tasaki K, Katoh Y, Nakayama K. Molecular basis underlying the ciliary defects caused by IFT52 variations found in skeletal ciliopathies. Mol Biol Cell 2022; 33:ar83. [PMID: 35704471 PMCID: PMC9582644 DOI: 10.1091/mbc.e22-05-0188] [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] [Indexed: 11/25/2022] Open
Abstract
Bidirectional protein trafficking within cilia is mediated by the intraflagellar transport (IFT) machinery, which contains the IFT-A and IFT-B complexes powered by the kinesin-2 and dynein-2 motors. Mutations in genes encoding subunits of the IFT-A and dynein-2 complexes cause skeletal ciliopathies. Some subunits of the IFT-B complex, including IFT52, IFT80, and IFT172, are also mutated in skeletal ciliopathies. We here show that IFT52 variants found in individuals with short-rib polydactyly syndrome (SRPS) are compromised in terms of formation of the IFT-B holocomplex from two subcomplexes and its interaction with heterotrimeric kinesin-II. IFT52-knockout (KO) cells expressing IFT52 variants that mimic the cellular conditions of individuals with SRPS demonstrated mild ciliogenesis defects and a decrease in ciliary IFT-B level. Furthermore, in IFT52-KO cells expressing an SRPS variant of IFT52, ciliary tip localization of ICK/CILK1 and KIF17, both of which are likely to be transported to the tip via binding to the IFT-B complex, was significantly impaired. Altogether these results indicate that impaired anterograde trafficking caused by a decrease in the ciliary level of IFT-B or in its binding to kinesin-II underlies the ciliary defects found in skeletal ciliopathies caused by IFT52 variations.
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Affiliation(s)
- Yamato Ishida
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Koshi Tasaki
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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12
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Kumari D, Ray K. Phosphoregulation of Kinesins Involved in Long-Range Intracellular Transport. Front Cell Dev Biol 2022; 10:873164. [PMID: 35721476 PMCID: PMC9203973 DOI: 10.3389/fcell.2022.873164] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/29/2022] [Indexed: 12/28/2022] Open
Abstract
Kinesins, the microtubule-dependent mechanochemical enzymes, power a variety of intracellular movements. Regulation of Kinesin activity and Kinesin-Cargo interactions determine the direction, timing and flux of various intracellular transports. This review examines how phosphorylation of Kinesin subunits and adaptors influence the traffic driven by Kinesin-1, -2, and -3 family motors. Each family of Kinesins are phosphorylated by a partially overlapping set of serine/threonine kinases, and each event produces a unique outcome. For example, phosphorylation of the motor domain inhibits motility, and that of the stalk and tail domains induces cargo loading and unloading effects according to the residue and context. Also, the association of accessory subunits with cargo and adaptor proteins with the motor, respectively, is disrupted by phosphorylation. In some instances, phosphorylation by the same kinase on different Kinesins elicited opposite outcomes. We discuss how this diverse range of effects could manage the logistics of Kinesin-dependent, long-range intracellular transport.
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13
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Noguchi T, Nakamura K, Satoda Y, Katoh Y, Nakayama K. CCRK/CDK20 regulates ciliary retrograde protein trafficking via interacting with BROMI/TBC1D32. PLoS One 2021; 16:e0258497. [PMID: 34624068 PMCID: PMC8500422 DOI: 10.1371/journal.pone.0258497] [Citation(s) in RCA: 3] [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: 06/08/2021] [Accepted: 09/28/2021] [Indexed: 01/02/2023] Open
Abstract
CCRK/CDK20 was reported to interact with BROMI/TBC1D32 and regulate ciliary Hedgehog signaling. In various organisms, mutations in the orthologs of CCRK and those of the kinase ICK/CILK1, which is phosphorylated by CCRK, are known to result in cilia elongation. Furthermore, we recently showed that ICK regulates retrograde ciliary protein trafficking and/or the turnaround event at the ciliary tips, and that its mutations result in the elimination of intraflagellar transport (IFT) proteins that have overaccumulated at the bulged ciliary tips as extracellular vesicles, in addition to cilia elongation. However, how these proteins cooperate to regulate ciliary protein trafficking has remained unclear. We here show that the phenotypes of CCRK-knockout (KO) cells closely resemble those of ICK-KO cells; namely, the overaccumulation of IFT proteins at the bulged ciliary tips, which appear to be eliminated as extracellular vesicles, and the enrichment of GPR161 and Smoothened on the ciliary membrane. The abnormal phenotypes of CCRK-KO cells were rescued by the exogenous expression of wild-type CCRK but not its kinase-dead mutant or a mutant defective in BROMI binding. These results together indicate that CCRK regulates the turnaround process at the ciliary tips in concert with BROMI and probably via activating ICK.
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Affiliation(s)
- Tatsuro Noguchi
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Kentaro Nakamura
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Yuuki Satoda
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
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14
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Abstract
TRIP6, a member of the ZYXIN-family of LIM domain proteins, is a focal adhesion component. Trip6 deletion in the mouse, reported here, reveals a function in the brain: ependymal and choroid plexus epithelial cells are carrying, unexpectedly, fewer and shorter cilia, are poorly differentiated, and the mice develop hydrocephalus. TRIP6 carries numerous protein interaction domains and its functions require homodimerization. Indeed, TRIP6 disruption in vitro (in a choroid plexus epithelial cell line), via RNAi or inhibition of its homodimerization, confirms its function in ciliogenesis. Using super-resolution microscopy, we demonstrate TRIP6 localization at the pericentriolar material and along the ciliary axoneme. The requirement for homodimerization which doubles its interaction sites, its punctate localization along the axoneme, and its co-localization with other cilia components suggest a scaffold/co-transporter function for TRIP6 in cilia. Thus, this work uncovers an essential role of a LIM-domain protein assembly factor in mammalian ciliogenesis.
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15
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Abraham SP, Nita A, Krejci P, Bosakova M. Cilia kinases in skeletal development and homeostasis. Dev Dyn 2021; 251:577-608. [PMID: 34582081 DOI: 10.1002/dvdy.426] [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: 07/07/2021] [Revised: 09/22/2021] [Accepted: 09/22/2021] [Indexed: 11/08/2022] Open
Abstract
Primary cilia are dynamic compartments that regulate multiple aspects of cellular signaling. The production, maintenance, and function of cilia involve more than 1000 genes in mammals, and their mutations disrupt the ciliary signaling which manifests in a plethora of pathological conditions-the ciliopathies. Skeletal ciliopathies are genetic disorders affecting the development and homeostasis of the skeleton, and encompass a broad spectrum of pathologies ranging from isolated polydactyly to lethal syndromic dysplasias. The recent advances in forward genetics allowed for the identification of novel regulators of skeletogenesis, and revealed a growing list of ciliary proteins that are critical for signaling pathways implicated in bone physiology. Among these, a group of protein kinases involved in cilia assembly, maintenance, signaling, and disassembly has emerged. In this review, we summarize the functions of cilia kinases in skeletal development and disease, and discuss the available and upcoming treatment options.
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Affiliation(s)
- Sara P Abraham
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Alexandru Nita
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Pavel Krejci
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic.,Institute of Animal Physiology and Genetics of the CAS, Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic
| | - Michaela Bosakova
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic.,Institute of Animal Physiology and Genetics of the CAS, Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic
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16
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Fujisawa S, Qiu H, Nozaki S, Chiba S, Katoh Y, Nakayama K. ARL3 and ARL13B GTPases participate in distinct steps of INPP5E targeting to the ciliary membrane. Biol Open 2021; 10:bio058843. [PMID: 34447983 PMCID: PMC8496693 DOI: 10.1242/bio.058843] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 08/19/2021] [Indexed: 01/02/2023] Open
Abstract
INPP5E, a phosphoinositide 5-phosphatase, localizes on the ciliary membrane via its C-terminal prenyl moiety, and maintains the distinct ciliary phosphoinositide composition. The ARL3 GTPase contributes to the ciliary membrane localization of INPP5E by stimulating the release of PDE6D bound to prenylated INPP5E. Another GTPase, ARL13B, which is localized on the ciliary membrane, contributes to the ciliary membrane retention of INPP5E by directly binding to its ciliary targeting sequence. However, as ARL13B was shown to act as a guanine nucleotide exchange factor (GEF) for ARL3, it is also possible that ARL13B indirectly mediates the ciliary INPP5E localization via activating ARL3. We here show that INPP5E is delocalized from cilia in both ARL3-knockout (KO) and ARL13B-KO cells. However, some of the abnormal phenotypes were different between these KO cells, while others were found to be common, indicating the parallel roles of ARL3 and ARL13B, at least concerning some cellular functions. For several variants of ARL13B, their ability to interact with INPP5E, rather than their ability as an ARL3-GEF, was associated with whether they could rescue the ciliary localization of INPP5E in ARL13B-KO cells. These observations together indicate that ARL13B determines the ciliary localization of INPP5E, mainly by its direct binding to INPP5E.
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Affiliation(s)
- Sayaka Fujisawa
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hantian Qiu
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shohei Nozaki
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shuhei Chiba
- Department of Genetic Disease Research, Graduate School of Medicine, Osaka City University, Abeno-ku, Osaka 545-8585, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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17
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Kasahara K, Inagaki M. Primary ciliary signaling: links with the cell cycle. Trends Cell Biol 2021; 31:954-964. [PMID: 34420822 DOI: 10.1016/j.tcb.2021.07.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 02/07/2023]
Abstract
Primary cilia are solitary, microtubule-based structures emanating from the surface of most vertebrate cells. Although it is understood that ciliary assembly and disassembly both depend upon and impact cell cycle progression, critical mechanistic details of these links remain unresolved. Accumulating evidence shows that the signaling pathways downstream of receptor tyrosine kinases and lysophosphatidic acid receptors control the dynamics of primary cilia. It has also become clear that primary cilia not only serve as signaling hubs but also regulate the composition of the surrounding membrane, which is likely to affect the response to growth factors. Here, we overview recent advances in understanding the interplay between primary cilia and the cell cycle, with a focus on growth factor signaling pathways.
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Affiliation(s)
- Kousuke Kasahara
- Department of Physiology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan
| | - Masaki Inagaki
- Department of Physiology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan.
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18
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Wang W, Jack BM, Wang HH, Kavanaugh MA, Maser RL, Tran PV. Intraflagellar Transport Proteins as Regulators of Primary Cilia Length. Front Cell Dev Biol 2021; 9:661350. [PMID: 34095126 PMCID: PMC8170031 DOI: 10.3389/fcell.2021.661350] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 04/06/2021] [Indexed: 12/21/2022] Open
Abstract
Primary cilia are small, antenna-like organelles that detect and transduce chemical and mechanical cues in the extracellular environment, regulating cell behavior and, in turn, tissue development and homeostasis. Primary cilia are assembled via intraflagellar transport (IFT), which traffics protein cargo bidirectionally along a microtubular axoneme. Ranging from 1 to 10 μm long, these organelles typically reach a characteristic length dependent on cell type, likely for optimum fulfillment of their specific roles. The importance of an optimal cilia length is underscored by the findings that perturbation of cilia length can be observed in a number of cilia-related diseases. Thus, elucidating mechanisms of cilia length regulation is important for understanding the pathobiology of ciliary diseases. Since cilia assembly/disassembly regulate cilia length, we review the roles of IFT in processes that affect cilia assembly/disassembly, including ciliary transport of structural and membrane proteins, ectocytosis, and tubulin posttranslational modification. Additionally, since the environment of a cell influences cilia length, we also review the various stimuli encountered by renal epithelia in healthy and diseased states that alter cilia length and IFT.
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Affiliation(s)
- Wei Wang
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, United States
| | - Brittany M Jack
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, United States
| | - Henry H Wang
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, United States
| | - Matthew A Kavanaugh
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, United States
| | - Robin L Maser
- Department of Clinical Laboratory Sciences, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, United States
| | - Pamela V Tran
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, United States
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19
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Chaya T, Furukawa T. Post-translational modification enzymes as key regulators of ciliary protein trafficking. J Biochem 2021; 169:633-642. [PMID: 33681987 PMCID: PMC8423421 DOI: 10.1093/jb/mvab024] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 02/24/2021] [Indexed: 12/14/2022] Open
Abstract
Primary cilia are evolutionarily conserved microtubule-based organelles that protrude from the surface of almost all cell types and decode a variety of extracellular stimuli. Ciliary dysfunction causes human diseases named ciliopathies, which span a wide range of symptoms, such as developmental and sensory abnormalities. The assembly, disassembly, maintenance and function of cilia rely on protein transport systems including intraflagellar transport (IFT) and lipidated protein intraflagellar targeting (LIFT). IFT is coordinated by three multisubunit protein complexes with molecular motors along the ciliary axoneme, while LIFT is mediated by specific chaperones that directly recognize lipid chains. Recently, it has become clear that several post-translational modification enzymes play crucial roles in the regulation of IFT and LIFT. Here, we review our current understanding of the roles of these post-translational modification enzymes in the regulation of ciliary protein trafficking as well as their regulatory mechanisms, physiological significance and involvement in human diseases.
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Affiliation(s)
- Taro Chaya
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, Osaka, 565-0871, Japan
| | - Takahisa Furukawa
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, Osaka, 565-0871, Japan
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20
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Ishida Y, Kobayashi T, Chiba S, Katoh Y, Nakayama K. Molecular basis of ciliary defects caused by compound heterozygous IFT144/WDR19 mutations found in cranioectodermal dysplasia. Hum Mol Genet 2021; 30:213-225. [PMID: 33517396 DOI: 10.1093/hmg/ddab034] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/28/2020] [Accepted: 01/20/2021] [Indexed: 12/17/2022] Open
Abstract
Primary cilia contain specific proteins to achieve their functions as cellular antennae. Ciliary protein trafficking is mediated by the intraflagellar transport (IFT) machinery containing the IFT-A and IFT-B complexes. Mutations in genes encoding the IFT-A subunits (IFT43, IFT121/WDR35, IFT122, IFT139/TTC21B, IFT140 and IFT144/WDR19) often result in skeletal ciliopathies, including cranioectodermal dysplasia (CED). We here characterized the molecular and cellular defects of CED caused by compound heterozygous mutations in IFT144 [the missense variant IFT144(L710S) and the nonsense variant IFT144(R1103*)]. These two variants were distinct with regard to their interactions with other IFT-A subunits and with the IFT-B complex. When exogenously expressed in IFT144-knockout (KO) cells, IFT144(L710S) as well as IFT144(WT) rescued both moderately compromised ciliogenesis and the abnormal localization of ciliary proteins. As the homozygous IFT144(L710S) mutation was found to cause autosomal recessive retinitis pigmentosa, IFT144(L710S) is likely to be hypomorphic at the cellular level. In striking contrast, the exogenous expression of IFT144(R1103*) in IFT144-KO cells exacerbated the ciliogenesis defects. The expression of IFT144(R1103*) together with IFT144(WT) restored the abnormal phenotypes of IFT144-KO cells. However, the coexpression of IFT144(R1103*) with the hypomorphic IFT144(L710S) variant in IFT144-KO cells, which mimics the genotype of compound heterozygous CED patients, resulted in severe ciliogenesis defects. Taken together, these observations demonstrate that compound heterozygous mutations in IFT144 cause severe ciliary defects via a complicated mechanism, where one allele can cause severe ciliary defects when combined with a hypomorphic allele.
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Affiliation(s)
- Yamato Ishida
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Takuya Kobayashi
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shuhei Chiba
- Department of Genetic Disease Research, Graduate School of Medicine, Osaka City University, Abeno-ku, Osaka 545-8585, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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21
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Kobayashi T, Ishida Y, Hirano T, Katoh Y, Nakayama K. Cooperation of the IFT-A complex with the IFT-B complex is required for ciliary retrograde protein trafficking and GPCR import. Mol Biol Cell 2021; 32:45-56. [PMID: 33175651 PMCID: PMC8098818 DOI: 10.1091/mbc.e20-08-0556] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/22/2020] [Accepted: 11/03/2020] [Indexed: 12/20/2022] Open
Abstract
Cilia sense and transduce extracellular signals via specific receptors. The intraflagellar transport (IFT) machinery mediates not only bidirectional protein trafficking within cilia but also the import/export of ciliary proteins across the ciliary gate. The IFT machinery is known to comprise two multisubunit complexes, namely, IFT-A and IFT-B; however, little is known about how the two complexes cooperate to mediate ciliary protein trafficking. We here show that IFT144-IFT122 from IFT-A and IFT88-IFT52 from IFT-B make major contributions to the interface between the two complexes. Exogenous expression of the IFT88(Δα) mutant, which has decreased binding to IFT-A, partially restores the ciliogenesis defect of IFT88-knockout (KO) cells. However, IFT88(Δα)-expressing IFT88-KO cells demonstrate a defect in IFT-A entry into cilia, aberrant accumulation of IFT-B proteins at the bulged ciliary tips, and impaired import of ciliary G protein-coupled receptors (GPCRs). Furthermore, overaccumulated IFT proteins at the bulged tips appeared to be released as extracellular vesicles. These phenotypes of IFT88(Δα)-expressing IFT88-KO cells resembled those of IFT144-KO cells. These observations together indicate that the IFT-A complex cooperates with the IFT-B complex to mediate the ciliary entry of GPCRs as well as retrograde trafficking of the IFT machinery from the ciliary tip.
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Affiliation(s)
- Takuya Kobayashi
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yamato Ishida
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Tomoaki Hirano
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
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