1
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Lacey SE, Graziadei A, Pigino G. Extensive structural rearrangement of intraflagellar transport trains underpins bidirectional cargo transport. Cell 2024; 187:4621-4636.e18. [PMID: 39067443 DOI: 10.1016/j.cell.2024.06.041] [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: 02/13/2024] [Revised: 05/06/2024] [Accepted: 06/28/2024] [Indexed: 07/30/2024]
Abstract
Bidirectional transport in cilia is carried out by polymers of the IFTA and IFTB protein complexes, called anterograde and retrograde intraflagellar transport (IFT) trains. Anterograde trains deliver cargoes from the cell to the cilium tip, then convert into retrograde trains for cargo export. We set out to understand how the IFT complexes can perform these two directly opposing roles before and after conversion. We use cryoelectron tomography and in situ cross-linking mass spectrometry to determine the structure of retrograde IFT trains and compare it with the known structure of anterograde trains. The retrograde train is a 2-fold symmetric polymer organized around a central thread of IFTA complexes. We conclude that anterograde-to-retrograde remodeling involves global rearrangements of the IFTA/B complexes and requires complete disassembly of the anterograde train. Finally, we describe how conformational changes to cargo-binding sites facilitate unidirectional cargo transport in a bidirectional system.
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2
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Yang Z, Zhang L, Zhang W, Tian X, Lai W, Lin D, Feng Y, Jiang W, Zhang Z, Zhang Z. Identification of the principal neuropeptide MIP and its action pathway in larval settlement of the echiuran worm Urechis unicinctus. BMC Genomics 2024; 25:337. [PMID: 38641568 PMCID: PMC11027379 DOI: 10.1186/s12864-024-10228-y] [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: 12/30/2023] [Accepted: 03/15/2024] [Indexed: 04/21/2024] Open
Abstract
BACKGROUND Larval settlement and metamorphosis represent critical events in the life history of marine benthic animals. Myoinhibitory peptide (MIP) plays a pivotal role in larval settlement of marine invertebrates. However, the molecular mechanisms of MIP involved in this process are not well understood. RESULTS In this study, we evaluated the effects of thirteen MIP mature peptides on triggering the larval settlement of Urechis unicinctus (Xenopneusta, Urechidae), and determined that MIP2 was the principal neuropeptide. Transcriptomic analysis was employed to identify differentially expressed genes (DEGs) between the MIP2-treated larvae and normal early-segmentation larvae. Both cAMP and calcium signaling pathways were enriched in the DEGs of the MIP2-treated larvae, and two neuropeptide receptor genes (Spr, Fmrfar) were up-regulated in the MIP2-treated larvae. The activation of the SPR-cAMP pathway by MIP2 was experimentally validated in HEK293T cells. Furthermore, fourteen cilia-related genes, including Tctex1d2, Cfap45, Ift43, Ift74, Ift22, Cav1 and Mns1, etc. exhibited down-regulated expression in the MIP2-treated larvae. Whole-mount in situ hybridization identified two selected ciliary genes, Tctex1d2 and Cfap45, were specially expressed in circumoral ciliary cells of the early-segmentation larvae. Knocking down Tctex1d2 mRNA levels by in vivo RNA interference significantly increased the larval settlement rate. CONCLUSION Our findings suggest that MIP2 inhibits the function of the cilia-related genes, such as Tctex1d2, through the SPR-cAMP-PKA pathway, thereby inducing larval settlement in U. unicinctus. The study contributes important data to the understanding of neuropeptide regulation in larval settlement.
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Affiliation(s)
- Zhi Yang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Long Zhang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Wenqing Zhang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Xinhua Tian
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Wenyuan Lai
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Dawei Lin
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Yuxin Feng
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Wenwen Jiang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China
| | - Zhengrui Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.
| | - Zhifeng Zhang
- Key Laboratory of Tropical Aquatic Germplasm of Hainan Province, Sanya Ocean Institute, Ocean University of China, Sanya, China.
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.
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3
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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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4
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Song C, Zhang Z, Wei Y, Dou Y, Qi K, Li X, Yang F, Li X, Wang K, Qiao R, Han X. Proteomic analysis of boar sperm with differential ability of liquid preservation at 17 °C. Theriogenology 2024; 215:103-112. [PMID: 38029685 DOI: 10.1016/j.theriogenology.2023.11.017] [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: 06/30/2023] [Revised: 11/15/2023] [Accepted: 11/16/2023] [Indexed: 12/01/2023]
Abstract
Understanding the liquid preservation ability of boar sperm is pivotal for efficient management and breeding of livestock. Although sperm proteins play an important role in semen quality and freezability, how the levels of protein change in boar sperm with different liquid preservation abilities at 17 °C remains unclear. In this study, two groups of boar sperm with extreme difference in liquid preservation ability, namely the good preservation ability (GPA) and the poor preservation ability (PPA) groups, were selected by evaluating sperm motility parameters on the 7th day of liquid preservation at 17 °C. Quantitative proteomics based on tandem mass tag (TMT) labeling was used, sperm proteomic characteristics from two groups were analyzed, and potentially key proteins related to the fluid preservation ability of sperm were identified. A total of 187 differentially expressed proteins (DEPs) were identified among 2791 quantified proteins, including 85 upregulated, and 102 downregulated proteins. Further, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of the DEPs revealed that they were enriched in GO terms associated with response to oxidative stress, enzyme activity related to oxidative stress or redox reactions, and several metabolic activities. The significant KEGG pathways included peroxisome, metabolic pathways, selenocompound metabolism, and collection duct acid secretion. In addition, analysis of protein-protein interactions further identified 8 proteins that could be used as biomarker candidates, including GPX5, GLRX, ENO4, QPCT, BBS7, OXSR1, DHRS4 and AP2S1, which may play an essential role in indicating the liquid preservation ability of boar sperm. These findings in this study provide new insights into the underlying molecular mechanisms of the liquid preservation ability of boar sperm. Moreover, the selected candidate proteins can serve as a reference for evaluating sperm quality or preservation ability in boars and their application in related biotechnologies.
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Affiliation(s)
- Chenglei Song
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China
| | - Zhe Zhang
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China
| | - Yilin Wei
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China
| | - Yaqing Dou
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China
| | - Kunlong Qi
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China
| | - Xiuling Li
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China
| | - Feng Yang
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China
| | - Xinjian Li
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China
| | - Kejun Wang
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China
| | - Ruimin Qiao
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China
| | - Xuelei Han
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450046, China.
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5
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McCafferty CL, Papoulas O, Lee C, Bui KH, Taylor DW, Marcotte EM, Wallingford JB. An amino acid-resolution interactome for motile cilia illuminates the structure and function of ciliopathy protein complexes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.09.548259. [PMID: 37781579 PMCID: PMC10541116 DOI: 10.1101/2023.07.09.548259] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Motile cilia are ancient, evolutionarily conserved organelles whose dysfunction underlies motile ciliopathies, a broad class of human diseases. Motile cilia contain myriad different proteins that assemble into an array of distinct machines, so understanding the interactions and functional hierarchies among them presents an important challenge. Here, we defined the protein interactome of motile axonemes using cross-linking mass spectrometry (XL/MS) in Tetrahymena thermophila. From over 19,000 XLs, we identified 4,757 unique amino acid interactions among 1,143 distinct proteins, providing both macromolecular and atomic-scale insights into diverse ciliary machines, including the Intraflagellar Transport system, axonemal dynein arms, radial spokes, the 96 nm ruler, and microtubule inner proteins, among others. Guided by this dataset, we used vertebrate multiciliated cells to reveal novel functional interactions among several poorly-defined human ciliopathy proteins. The dataset therefore provides a powerful resource for studying the basic biology of an ancient organelle and the molecular etiology of human genetic disease.
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Affiliation(s)
- Caitlyn L. McCafferty
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Ophelia Papoulas
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Chanjae Lee
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Khanh Huy Bui
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences McGill University, Québec, Canada
| | - David W. Taylor
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Edward M. Marcotte
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - John B. Wallingford
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
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6
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Boegholm N, Petriman NA, Loureiro‐López M, Wang J, Vela MIS, Liu B, Kanie T, Ng R, Jackson PK, Andersen JS, Lorentzen E. The IFT81-IFT74 complex acts as an unconventional RabL2 GTPase-activating protein during intraflagellar transport. EMBO J 2023; 42:e111807. [PMID: 37606072 PMCID: PMC10505919 DOI: 10.15252/embj.2022111807] [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: 06/04/2022] [Revised: 07/24/2023] [Accepted: 08/03/2023] [Indexed: 08/23/2023] Open
Abstract
Cilia are important cellular organelles for signaling and motility and are constructed via intraflagellar transport (IFT). RabL2 is a small GTPase that localizes to the basal body of cilia via an interaction with the centriolar protein CEP19 before downstream association with the IFT machinery, which is followed by initiation of IFT. We reconstituted and purified RabL2 with CEP19 or IFT proteins to show that a reconstituted pentameric IFT complex containing IFT81/74 enhances the GTP hydrolysis rate of RabL2. The binding site on IFT81/74 that promotes GTP hydrolysis in RabL2 was mapped to a 70-amino-acid-long coiled-coil region of IFT81/74. We present structural models for RabL2-containing IFT complexes that we validate in vitro and in cellulo and demonstrate that Chlamydomonas IFT81/74 enhances GTP hydrolysis of human RabL2, suggesting an ancient evolutionarily conserved activity. Our results provide an architectural understanding of how RabL2 is incorporated into the IFT complex and a molecular rationale for why RabL2 dissociates from anterograde IFT trains soon after departure from the ciliary base.
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Affiliation(s)
- Niels Boegholm
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - Narcis A Petriman
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - Marta Loureiro‐López
- Department for Biochemistry and Molecular BiologyUniversity of Southern DenmarkOdense MDenmark
| | - Jiaolong Wang
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | | | - Beibei Liu
- Department of Cell BiologyUniversity of Oklahoma Health Science CenterOklahomaOKUSA
| | - Tomoharu Kanie
- Department of Cell BiologyUniversity of Oklahoma Health Science CenterOklahomaOKUSA
- Baxter Laboratory, Department of Microbiology & ImmunologyStanford University School of MedicineStanfordCAUSA
| | - Roy Ng
- Baxter Laboratory, Department of Microbiology & ImmunologyStanford University School of MedicineStanfordCAUSA
| | - Peter K Jackson
- Baxter Laboratory, Department of Microbiology & ImmunologyStanford University School of MedicineStanfordCAUSA
- Department of PathologyStanford University School of MedicineStanfordCAUSA
| | - Jens S Andersen
- Department for Biochemistry and Molecular BiologyUniversity of Southern DenmarkOdense MDenmark
| | - Esben Lorentzen
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
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7
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Tasaki K, Zhou Z, Ishida Y, Katoh Y, Nakayama K. Compound heterozygous IFT81 variations in a skeletal ciliopathy patient cause Bardet-Biedl syndrome-like ciliary defects. Hum Mol Genet 2023; 32:2887-2900. [PMID: 37427975 DOI: 10.1093/hmg/ddad112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/04/2023] [Accepted: 07/04/2023] [Indexed: 07/11/2023] Open
Abstract
Owing to their crucial roles in development and homeostasis, defects in cilia cause ciliopathies with diverse clinical manifestations. The intraflagellar transport (IFT) machinery, containing the IFT-A and IFT-B complexes, mediates not only the intraciliary bidirectional trafficking but also import and export of ciliary proteins together with the kinesin-2 and dynein-2 motor complexes. The BBSome, containing eight subunits encoded by causative genes of Bardet-Biedl syndrome (BBS), connects the IFT machinery to ciliary membrane proteins to mediate their export from cilia. Although mutations in subunits of the IFT-A and dynein-2 complexes cause skeletal ciliopathies, mutations in some IFT-B subunits are also known to cause skeletal ciliopathies. We here show that compound heterozygous variations of an IFT-B subunit, IFT81, found in a patient with skeletal ciliopathy cause defects in its interactions with other IFT-B subunits, and in ciliogenesis and ciliary protein trafficking when one of the two variants was expressed in IFT81-knockout (KO) cells. Notably, we found that IFT81-KO cells expressing IFT81(Δ490-519), which lacks the binding site for the IFT25-IFT27 dimer, causes ciliary defects reminiscent of those found in BBS cells and those in IFT74-KO cells expressing a BBS variant of IFT74, which forms a heterodimer with IFT81. In addition, IFT81-KO cells expressing IFT81(Δ490-519) in combination with the other variant, IFT81 (L645*), which mimics the cellular conditions of the above skeletal ciliopathy patient, demonstrated essentially the same phenotype as those expressing only IFT81(Δ490-519). Thus, our data indicate that BBS-like defects can be caused by skeletal ciliopathy variants of IFT81.
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Affiliation(s)
- Koshi Tasaki
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Zhuang Zhou
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yamato Ishida
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
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8
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Healy MD, McNally KE, Butkovič R, Chilton M, Kato K, Sacharz J, McConville C, Moody ERR, Shaw S, Planelles-Herrero VJ, Yadav SKN, Ross J, Borucu U, Palmer CS, Chen KE, Croll TI, Hall RJ, Caruana NJ, Ghai R, Nguyen THD, Heesom KJ, Saitoh S, Berger I, Schaffitzel C, Williams TA, Stroud DA, Derivery E, Collins BM, Cullen PJ. Structure of the endosomal Commander complex linked to Ritscher-Schinzel syndrome. Cell 2023; 186:2219-2237.e29. [PMID: 37172566 PMCID: PMC10187114 DOI: 10.1016/j.cell.2023.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/23/2023] [Accepted: 04/04/2023] [Indexed: 05/15/2023]
Abstract
The Commander complex is required for endosomal recycling of diverse transmembrane cargos and is mutated in Ritscher-Schinzel syndrome. It comprises two sub-assemblies: Retriever composed of VPS35L, VPS26C, and VPS29; and the CCC complex which contains twelve subunits: COMMD1-COMMD10 and the coiled-coil domain-containing (CCDC) proteins CCDC22 and CCDC93. Combining X-ray crystallography, electron cryomicroscopy, and in silico predictions, we have assembled a complete structural model of Commander. Retriever is distantly related to the endosomal Retromer complex but has unique features preventing the shared VPS29 subunit from interacting with Retromer-associated factors. The COMMD proteins form a distinctive hetero-decameric ring stabilized by extensive interactions with CCDC22 and CCDC93. These adopt a coiled-coil structure that connects the CCC and Retriever assemblies and recruits a 16th subunit, DENND10, to form the complete Commander complex. The structure allows mapping of disease-causing mutations and reveals the molecular features required for the function of this evolutionarily conserved trafficking machinery.
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Affiliation(s)
- Michael D Healy
- Centre for Cell Biology of Chronic Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Kerrie E McNally
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK; MRC Laboratory of Molecular Biology, CB2 0QH Cambridge, UK.
| | - Rebeka Butkovič
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK
| | - Molly Chilton
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK
| | - Kohji Kato
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK
| | - Joanna Sacharz
- Department of Biochemistry and Pharmacology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Calum McConville
- Department of Biochemistry and Pharmacology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Edmund R R Moody
- School of Biological Sciences, University of Bristol, BS8 1TD Bristol, UK
| | - Shrestha Shaw
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK
| | | | - Sathish K N Yadav
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK
| | - Jennifer Ross
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK
| | - Ufuk Borucu
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK
| | - Catherine S Palmer
- Department of Biochemistry and Pharmacology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Kai-En Chen
- Centre for Cell Biology of Chronic Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Tristan I Croll
- Cambridge Institute for Medical Research, University of Cambridge, CB2 0XY Cambridge, UK
| | - Ryan J Hall
- Centre for Cell Biology of Chronic Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Nikeisha J Caruana
- Department of Biochemistry and Pharmacology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia; Institute of Health and Sport (iHeS), Victoria University, Melbourne, VIC Australia
| | - Rajesh Ghai
- Centre for Cell Biology of Chronic Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Thi H D Nguyen
- MRC Laboratory of Molecular Biology, CB2 0QH Cambridge, UK
| | - Kate J Heesom
- Proteomics Facility, School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK
| | - Shinji Saitoh
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences and Medical School, Nagoya, Japan
| | - Imre Berger
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK; Max Planck Bristol Centre for Minimal Biology, Department of Chemistry, University of Bristol, BS8 1TS Bristol, UK
| | - Christiane Schaffitzel
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK
| | - Tom A Williams
- School of Biological Sciences, University of Bristol, BS8 1TD Bristol, UK
| | - David A Stroud
- Department of Biochemistry and Pharmacology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, VIC Australia
| | | | - Brett M Collins
- Centre for Cell Biology of Chronic Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia.
| | - Peter J Cullen
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, BS8 1TD Bristol, UK.
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9
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Perini F, Cendron F, Wu Z, Sevane N, Li Z, Huang C, Smith J, Lasagna E, Cassandro M, Penasa M. Genomics of Dwarfism in Italian Local Chicken Breeds. Genes (Basel) 2023; 14:genes14030633. [PMID: 36980905 PMCID: PMC10047989 DOI: 10.3390/genes14030633] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 03/06/2023] Open
Abstract
The identification of the dwarf phenotype in chicken is based on body weight, height, and shank length, leaving the differentiation between dwarf and small breeds ambiguous. The aims of the present study were to characterize the sequence variations associated with the dwarf phenotype in three Italian chicken breeds and to investigate the genes associated with their phenotype. Five hundred and forty-one chickens from 23 local breeds (from 20 to 24 animals per breed) were sampled. All animals were genotyped with the 600 K chicken SNP array. Three breeds were described as “dwarf”, namely, Mericanel della Brianza (MERI), Mugellese (MUG), and Pepoi (PPP). We compared MERI, MUG, and PPP with the four heaviest breeds in the dataset by performing genome-wide association studies. Results showed significant SNPs associated with dwarfism in the MERI and MUG breeds, which shared a candidate genomic region on chromosome 1. Due to this similarity, MERI and MUG were analyzed together as a meta-population, observing significant SNPs in the LEMD3 and HMGA2 genes, which were previously reported as being responsible for dwarfism in different species. In conclusion, MERI and MUG breeds seem to share a genetic basis of dwarfism, which differentiates them from the small PPP breed.
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Affiliation(s)
- Francesco Perini
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy
| | - Filippo Cendron
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, 35020 Legnaro, Italy
| | - Zhou Wu
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Natalia Sevane
- Department of Animal Production, Veterinary Faculty, Universidad Complutense de Madrid, Avenida Puerta de Hierro, 28040 Madrid, Spain
| | - Zhiqiang Li
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy
- College of Animal Science and Technology, Chengdu Campus, Sichuan Agricultural University, Chengdu 611130, China
| | - Chunhua Huang
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy
- College of Animal Science and Technology, Chengdu Campus, Sichuan Agricultural University, Chengdu 611130, China
| | - Jacqueline Smith
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Emiliano Lasagna
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy
- Correspondence: ; Tel.: +39-075-58517102
| | - Martino Cassandro
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, 35020 Legnaro, Italy
- Federazione delle Associazioni Nazionali di Razza e Specie, 00187 Roma, Italy
| | - Mauro Penasa
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, 35020 Legnaro, Italy
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10
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Liu YX, Zhang RK, Fan ZC. RABL4/IFT27 in a nucleotide-independent manner promotes phospholipase D ciliary retrieval via facilitating BBSome reassembly at the ciliary tip. J Cell Physiol 2023; 238:549-565. [PMID: 36852649 DOI: 10.1002/jcp.30945] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/24/2022] [Accepted: 01/02/2023] [Indexed: 03/01/2023]
Abstract
Certain ciliary transmembrane and membrane-associated signaling proteins export from cilia as intraflagellar transport (IFT) cargoes in a BBSome-dependent manner. Upon reaching the ciliary tip via anterograde IFT, the BBSome disassembles before being reassembled to form an intact entity for cargo phospholipase D (PLD) coupling. During this BBSome remodeling process, Chlamydomonas Rab-like 4 GTPase IFT27, by binding its partner IFT25 to form the heterodimeric IFT25/27, is indispensable for BBSome reassembly. Here, we show that IFT27 binds IFT25 in an IFT27 nucleotide-independent manner. IFT25/27 and the IFT subcomplexes IFT-A and -B are irrelevant for maintaining the stability of one another. GTP-loading onto IFT27 enhances the IFT25/27 affinity for binding to the IFT-B subcomplex core IFT-B1 entity in cytoplasm, while GDP-bound IFT27 does not prevent IFT25/27 from entering and cycling through cilia by integrating into IFT-B1. Upon at the ciliary tip, IFT25/27 cycles on and off IFT-B1 and this process is irrelevant with the nucleotide state of IFT27. During BBSome remodeling at the ciliary tip, IFT25/27 promotes BBSome reassembly independent of IFT27 nucleotide state, making postremodeled BBSomes available for PLD to interact with. Thus, IFT25/27 facilitates BBSome-dependent PLD export from cilia via controlling availability of intact BBSomes at the ciliary tip, while IFT27 nucleotide state does not participate in this regulatory event.
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Affiliation(s)
- Yan-Xia Liu
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Rui-Kai Zhang
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Zhen-Chuan Fan
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin, China
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11
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Lacey SE, Foster HE, Pigino G. The molecular structure of IFT-A and IFT-B in anterograde intraflagellar transport trains. Nat Struct Mol Biol 2023; 30:584-593. [PMID: 36593313 DOI: 10.1038/s41594-022-00905-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 12/01/2022] [Indexed: 01/03/2023]
Abstract
Anterograde intraflagellar transport (IFT) trains are essential for cilia assembly and maintenance. These trains are formed of 22 IFT-A and IFT-B proteins that link structural and signaling cargos to microtubule motors for import into cilia. It remains unknown how the IFT-A/-B proteins are arranged into complexes and how these complexes polymerize into functional trains. Here we use in situ cryo-electron tomography of Chlamydomonas reinhardtii cilia and AlphaFold2 protein structure predictions to generate a molecular model of the entire anterograde train. We show how the conformations of both IFT-A and IFT-B are dependent on lateral interactions with neighboring repeats, suggesting that polymerization is required to cooperatively stabilize the complexes. Following three-dimensional classification, we reveal how IFT-B extends two flexible tethers to maintain a connection with IFT-A that can withstand the mechanical stresses present in actively beating cilia. Overall, our findings provide a framework for understanding the fundamental processes that govern cilia assembly.
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12
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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: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/13/2022] [Accepted: 11/09/2022] [Indexed: 12/05/2022]
Abstract
Intraflagellar transport (IFT) trains are massive molecular machines that traffic proteins between cilia and the cell body. Each IFT train is a dynamic polymer of two large complexes (IFT-A and -B) and motor proteins, posing a formidable challenge to mechanistic understanding. Here, we reconstituted the complete human IFT-A complex and obtained its structure using cryo-EM. Combined with AlphaFold prediction and genome-editing studies, our results illuminate how IFT-A polymerizes, interacts with IFT-B, and uses an array of β-propeller and TPR domains to create "carriages" of the IFT train that engage TULP adaptor proteins. We show that IFT-A⋅TULP carriages are essential for cilia localization of diverse membrane proteins, as well as ICK-the key kinase regulating IFT train turnaround. These data establish a structural link between IFT-A's distinct functions, provide a blueprint for IFT-A in the train, and shed light on how IFT evolved from a proto-coatomer ancestor.
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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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13
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Meleppattu S, Zhou H, Dai J, Gui M, Brown A. Mechanism of IFT-A polymerization into trains for ciliary transport. Cell 2022; 185:4986-4998.e12. [PMID: 36563665 PMCID: PMC9794116 DOI: 10.1016/j.cell.2022.11.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/14/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
Intraflagellar transport (IFT) is the highly conserved process by which proteins are transported along ciliary microtubules by a train-like polymeric assembly of IFT-A and IFT-B complexes. IFT-A is sandwiched between IFT-B and the ciliary membrane, consistent with its putative role in transporting transmembrane and membrane-associated cargoes. Here, we have used single-particle analysis electron cryomicroscopy (cryo-EM) to determine structures of native IFT-A complexes. We show that subcomplex rearrangements enable IFT-A to polymerize laterally on anterograde IFT trains, revealing a cooperative assembly mechanism. Surprisingly, we discover that binding of IFT-A to IFT-B shields the preferred lipid-binding interface from the ciliary membrane but orients an interconnected network of β-propeller domains with the capacity to accommodate diverse cargoes toward the ciliary membrane. This work provides a mechanistic basis for understanding IFT-train assembly and cargo interactions.
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Affiliation(s)
- Shimi Meleppattu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Haixia Zhou
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Jin Dai
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Miao Gui
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Alan Brown
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
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14
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Petriman NA, Loureiro-López M, Taschner M, Zacharia NK, Georgieva MM, Boegholm N, Wang J, Mourão A, Russell RB, Andersen JS, Lorentzen E. Biochemically validated structural model of the 15-subunit intraflagellar transport complex IFT-B. EMBO J 2022; 41:e112440. [PMID: 36354106 PMCID: PMC9753473 DOI: 10.15252/embj.2022112440] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/17/2022] [Accepted: 10/20/2022] [Indexed: 11/11/2022] Open
Abstract
Cilia are ubiquitous eukaryotic organelles impotant for cellular motility, signaling, and sensory reception. Cilium formation requires intraflagellar transport of structural and signaling components and involves 22 different proteins organized into intraflagellar transport (IFT) complexes IFT-A and IFT-B that are transported by molecular motors. The IFT-B complex constitutes the backbone of polymeric IFT trains carrying cargo between the cilium and the cell body. Currently, high-resolution structures are only available for smaller IFT-B subcomplexes leaving > 50% structurally uncharacterized. Here, we used Alphafold to structurally model the 15-subunit IFT-B complex. The model was validated using cross-linking/mass-spectrometry data on reconstituted IFT-B complexes, X-ray scattering in solution, diffraction from crystals as well as site-directed mutagenesis and protein-binding assays. The IFT-B structure reveals an elongated and highly flexible complex consistent with cryo-electron tomographic reconstructions of IFT trains. The IFT-B complex organizes into IFT-B1 and IFT-B2 parts with binding sites for ciliary cargo and the inactive IFT dynein motor, respectively. Interestingly, our results are consistent with two different binding sites for IFT81/74 on IFT88/70/52/46 suggesting the possibility of different structural architectures for the IFT-B1 complex. Our data present a structural framework to understand IFT-B complex assembly, function, and ciliopathy variants.
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Affiliation(s)
- Narcis A Petriman
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Marta Loureiro-López
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Michael Taschner
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Nevin K Zacharia
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | | | - Niels Boegholm
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Jiaolong Wang
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - André Mourão
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Jens S Andersen
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
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15
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Yan X, Shen Y. Rab-like small GTPases in the regulation of ciliary Bardet-Biedl syndrome (BBS) complex transport. FEBS J 2022; 289:7359-7367. [PMID: 34655445 DOI: 10.1111/febs.16232] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/13/2021] [Accepted: 10/15/2021] [Indexed: 01/13/2023]
Abstract
Primary cilia, microtubule-based hair-like structures protruding from most cells, contain membranes enriched in signaling molecules and function as sensory and regulatory organelles critical for development and tissue homeostasis. Intraflagellar transport (IFT), cilia-specific bidirectional transport, is required for the assembly, maintenance, and function of cilia. BBSome, the coat complex, acts as the adaptor between the IFT complex and membrane proteins and is therefore essential for establishing the specific compartmentalization of signaling molecules in the cilia. Recent findings have revealed that three ciliary Rab-like small GTPases, IFT27, IFT22, and Rabl2, play critical regulatory roles in ciliary BBSome transport. In this review, we provide an overview of these three Rab-like small GTPases and their relationship with BBSome.
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Affiliation(s)
- Xiumin Yan
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Institute of Early Life Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, China
| | - Yidong Shen
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
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16
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Zhou Z, Katoh Y, Nakayama K. CEP19-RABL2-IFT-B axis controls BBSome-mediated ciliary GPCR export. Mol Biol Cell 2022; 33:ar126. [PMID: 36074075 PMCID: PMC9634966 DOI: 10.1091/mbc.e22-05-0161] [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: 01/18/2023] Open
Abstract
The intraflagellar transport (IFT) machinery mediates the import and export of ciliary proteins across the ciliary gate, as well as bidirectional protein trafficking within cilia. In addition to ciliary anterograde protein trafficking, the IFT-B complex participates in the export of membrane proteins together with the BBSome, which consists of eight subunits encoded by the causative genes of Bardet-Biedl syndrome (BBS). The IFT25-IFT27/BBS19 dimer in the IFT-B complex constitutes its interface with the BBSome. We show here that IFT25-IFT27 and the RABL2 GTPase bind the IFT74/BBS22-IFT81 dimer of the IFT-B complex in a mutually exclusive manner. Cells expressing GTP-locked RABL2 [RABL2(Q80L)], but not wild-type RABL2, phenocopied IFT27-knockout cells, that is, they demonstrated BBS-associated ciliary defects, including accumulation of LZTFL1/BBS17 and the BBSome within cilia and the suppression of export of the ciliary GPCRs GPR161 and Smoothened. RABL2(Q80L) enters cilia in a manner dependent on the basal body protein CEP19, but its entry into cilia is not necessary for causing BBS-associated ciliary defects. These observations suggest that GTP-bound RABL2 is likely to be required for recruitment of the IFT-B complex to the ciliary base, where it is replaced with IFT25-IFT27.
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Affiliation(s)
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan,*Address correspondence to: Kazuhisa Nakayama (); Yohei Katoh ()
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan,*Address correspondence to: Kazuhisa Nakayama (); Yohei Katoh ()
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17
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Langousis G, Cavadini S, Boegholm N, Lorentzen E, Kempf G, Matthias P. Structure of the ciliogenesis-associated CPLANE complex. SCIENCE ADVANCES 2022; 8:eabn0832. [PMID: 35427153 PMCID: PMC9012472 DOI: 10.1126/sciadv.abn0832] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
Dysfunctional cilia cause pleiotropic human diseases termed ciliopathies. These hereditary maladies are often caused by defects in cilia assembly, a complex event that is regulated by the ciliogenesis and planar polarity effector (CPLANE) proteins Wdpcp, Inturned, and Fuzzy. CPLANE proteins are essential for building the cilium and are mutated in multiple ciliopathies, yet their structure and molecular functions remain elusive. Here, we show that mammalian CPLANE proteins comprise a bona fide complex and report the near-atomic resolution structures of the human Wdpcp-Inturned-Fuzzy complex and of the mouse Wdpcp-Inturned-Fuzzy complex bound to the small guanosine triphosphatase Rsg1. Notably, the crescent-shaped CPLANE complex binds phospholipids such as phosphatidylinositol 3-phosphate via multiple modules and a CPLANE ciliopathy mutant exhibits aberrant lipid binding. Our study provides critical structural and functional insights into an enigmatic ciliogenesis-associated complex as well as unexpected molecular rationales for ciliopathies.
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Affiliation(s)
- Gerasimos Langousis
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Simone Cavadini
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Niels Boegholm
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark
| | - Georg Kempf
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Patrick Matthias
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
- Faculty of Sciences, University of Basel, 4031 Basel, Switzerland
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18
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Zhou Z, Qiu H, Castro-Araya RF, Takei R, Nakayama K, Katoh Y. Impaired cooperation between IFT74/BBS22-IFT81 and IFT25-IFT27/BBS19 causes Bardet-Biedl syndrome. Hum Mol Genet 2021; 31:1681-1693. [PMID: 34888642 DOI: 10.1093/hmg/ddab354] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/19/2021] [Accepted: 12/06/2021] [Indexed: 02/03/2023] Open
Abstract
The IFT-B complex mediates ciliary anterograde protein trafficking and membrane protein export together with the BBSome. Bardet-Biedl syndrome (BBS) is caused by mutations in not only all BBSome subunits, but also in some IFT-B subunits, including IFT74/BBS22 and IFT27/BBS19, which form heterodimers with IFT81 and IFT25, respectively. We found that the IFT25-IFT27 dimer bind the C-terminal region of the IFT74-IFT81 dimer, and that the IFT25-IFT27-binding region encompasses the region deleted in the BBS variants of IFT74. In addition, we found that the missense BBS variants of IFT27 are impaired in IFT74-IFT81 binding, and are unable to rescue the BBS-like phenotypes of IFT27-knockout cells. Furthermore, the BBS variants of IFT74 rescued the ciliogenesis defect of IFT74-knockout cells, but the rescued cells demonstrated BBS-like abnormal phenotypes. Taken together, we conclude that the impaired interaction between IFT74-IFT81 and IFT25-IFT27 causes the BBS-associated ciliary defects.
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Affiliation(s)
- Zhuang Zhou
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Hantian Qiu
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Roiner-Francisco Castro-Araya
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Ryota Takei
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
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19
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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.
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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
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20
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Deviant reporter expression and P2X4 passenger gene overexpression in the soluble EGFP BAC transgenic P2X7 reporter mouse model. Sci Rep 2020; 10:19876. [PMID: 33199725 PMCID: PMC7669894 DOI: 10.1038/s41598-020-76428-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/23/2020] [Indexed: 12/11/2022] Open
Abstract
The ATP-gated P2X7 receptor is highly expressed in microglia and has been involved in diverse brain diseases. P2X7 effects were also described in neurons and astrocytes but its localisation and function in these cell types has been challenging to demonstrate in situ. BAC transgenic mouse lines have greatly advanced neuroscience research and two BAC-transgenic P2X7 reporter mouse models exist in which either a soluble EGFP (sEGFP) or an EGFP-tagged P2X7 receptor (P2X7-EGFP) is expressed under the control of a BAC-derived P2rx7 promoter. Here we evaluate both mouse models and find striking differences in both P2X expression levels and EGFP reporter expression patterns. Most remarkably, the sEGFP model overexpresses a P2X4 passenger gene and sEGFP shows clear neuronal localisation but appears to be absent in microglia. Preliminary functional analysis in a status epilepticus model suggests functional consequences of the observed P2X receptor overexpression. In summary, an aberrant EGFP reporter pattern and possible effects of P2X4 and/or P2X7 protein overexpression need to be considered when working with this model. We further discuss reasons for the observed differences and possible caveats in BAC transgenic approaches.
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21
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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.
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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.
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22
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Vitre B, Guesdon A, Delaval B. Non-ciliary Roles of IFT Proteins in Cell Division and Polycystic Kidney Diseases. Front Cell Dev Biol 2020; 8:578239. [PMID: 33072760 PMCID: PMC7536321 DOI: 10.3389/fcell.2020.578239] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 08/26/2020] [Indexed: 12/30/2022] Open
Abstract
Cilia are small organelles present at the surface of most differentiated cells where they act as sensors for mechanical or biochemical stimuli. Cilia assembly and function require the Intraflagellar Transport (IFT) machinery, an intracellular transport system that functions in association with microtubules and motors. If IFT proteins have long been studied for their ciliary roles, recent evidences indicate that their functions are not restricted to the cilium. Indeed, IFT proteins are found outside the ciliary compartment where they are involved in a variety of cellular processes in association with non-ciliary motors. Recent works also provide evidence that non-ciliary roles of IFT proteins could be responsible for the development of ciliopathies related phenotypes including polycystic kidney diseases. In this review, we will discuss the interactions of IFT proteins with microtubules and motors as well as newly identified non-ciliary functions of IFT proteins, focusing on their roles in cell division. We will also discuss the potential contribution of non-ciliary IFT proteins functions to the etiology of kidney diseases.
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23
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Petriman NA, Lorentzen E. Structural insights into the architecture and assembly of eukaryotic flagella. MICROBIAL CELL (GRAZ, AUSTRIA) 2020; 7:289-299. [PMID: 33150161 PMCID: PMC7590530 DOI: 10.15698/mic2020.11.734] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/07/2020] [Accepted: 09/14/2020] [Indexed: 12/16/2022]
Abstract
Cilia and flagella are slender projections found on most eukaryotic cells including unicellular organisms such as Chlamydomonas, Trypanosoma and Tetrahymena, where they serve motility and signaling functions. The cilium is a large molecular machine consisting of hundreds of different proteins that are trafficked into the organelle to organize a repetitive microtubule-based axoneme. Several recent studies took advantage of improved cryo-EM methodology to unravel the high-resolution structures of ciliary complexes. These include the recently reported purification and structure determination of axonemal doublet microtubules from the green algae Chlamydomonas reinhardtii, which allows for the modeling of more than 30 associated protein factors to provide deep molecular insight into the architecture and repetitive nature of doublet microtubules. In addition, we will review several recent contributions that dissect the structure and function of ciliary trafficking complexes that ferry structural and signaling components between the cell body and the cilium organelle.
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Affiliation(s)
- Narcis-Adrian Petriman
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark
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24
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Douglas RL, Haltiwanger BM, Albisetti A, Wu H, Jeng RL, Mancuso J, Cande WZ, Welch MD. Trypanosomes have divergent kinesin-2 proteins that function differentially in flagellum biosynthesis and cell viability. J Cell Sci 2020; 133:jcs129213. [PMID: 32503938 DOI: 10.1242/jcs.129213] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 05/27/2020] [Indexed: 12/13/2022] Open
Abstract
Trypanosoma brucei, the causative agent of African sleeping sickness, has a flagellum that is crucial for motility, pathogenicity, and viability. In most eukaryotes, the intraflagellar transport (IFT) machinery drives flagellum biogenesis, and anterograde IFT requires kinesin-2 motor proteins. In this study, we investigated the function of the two T. brucei kinesin-2 proteins, TbKin2a and TbKin2b, in bloodstream form trypanosomes. We found that, compared to kinesin-2 proteins across other phyla, TbKin2a and TbKin2b show greater variation in neck, stalk and tail domain sequences. Both kinesins contributed additively to flagellar lengthening. Silencing TbKin2a inhibited cell proliferation, cytokinesis and motility, whereas silencing TbKin2b did not. TbKin2a was localized on the flagellum and colocalized with IFT components near the basal body, consistent with it performing a role in IFT. TbKin2a was also detected on the flagellar attachment zone, a specialized structure that connects the flagellum to the cell body. Our results indicate that kinesin-2 proteins in trypanosomes play conserved roles in flagellar biosynthesis and exhibit a specialized localization, emphasizing the evolutionary flexibility of motor protein function in an organism with a large complement of kinesins.
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Affiliation(s)
- Robert L Douglas
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Brett M Haltiwanger
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Anna Albisetti
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Haiming Wu
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Robert L Jeng
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Joel Mancuso
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - W Zacheus Cande
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Matthew D Welch
- Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
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Nakayama K, Katoh Y. Architecture of the IFT ciliary trafficking machinery and interplay between its components. Crit Rev Biochem Mol Biol 2020; 55:179-196. [PMID: 32456460 DOI: 10.1080/10409238.2020.1768206] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cilia and flagella serve as cellular antennae and propellers in various eukaryotic cells, and contain specific receptors and ion channels as well as components of axonemal microtubules and molecular motors to achieve their sensory and motile functions. Not only the bidirectional trafficking of specific proteins within cilia but also their selective entry and exit across the ciliary gate is mediated by the intraflagellar transport (IFT) machinery with the aid of motor proteins. The IFT-B complex, which is powered by the kinesin-2 motor, mediates anterograde protein trafficking from the base to the tip of cilia, whereas the IFT-A complex together with the dynein-2 complex mediates retrograde protein trafficking. The BBSome complex connects ciliary membrane proteins to the IFT machinery. Defects in any component of this trafficking machinery lead to abnormal ciliogenesis and ciliary functions, and results in a broad spectrum of disorders, collectively called the ciliopathies. In this review article, we provide an overview of the architectures of the components of the IFT machinery and their functional interplay in ciliary protein trafficking.
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Affiliation(s)
- Kazuhisa Nakayama
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Yohei Katoh
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
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Yang H, Huang K. Dissecting the Vesicular Trafficking Function of IFT Subunits. Front Cell Dev Biol 2020; 7:352. [PMID: 32010685 PMCID: PMC6974671 DOI: 10.3389/fcell.2019.00352] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 12/05/2019] [Indexed: 12/22/2022] Open
Abstract
Intraflagellar transport (IFT) was initially identified as a transport machine with multiple protein subunits, and it is essential for the assembly, disassembly, and maintenance of cilium/flagellum, which serves as the nexus of extracellular-to-intracellular signal integration. To date, in addition to its well-established and indispensable roles in ciliated cells, most IFT subunits have presented more general functions of vesicular trafficking in the non-ciliated cells. Thus, this review aims to summarize the recent progress on the vesicular trafficking functions of the IFT subunits and to highlight the issues that may arise in future research.
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Affiliation(s)
- Huihui Yang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Institute of Hydrobiology, University of Chinese Academy of Sciences, Beijing, China
| | - Kaiyao Huang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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27
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Intraflagellar transport protein RABL5/IFT22 recruits the BBSome to the basal body through the GTPase ARL6/BBS3. Proc Natl Acad Sci U S A 2020; 117:2496-2505. [PMID: 31953262 DOI: 10.1073/pnas.1901665117] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Bardet-Biedl syndrome (BBS) is a ciliopathy caused by defects in the assembly or distribution of the BBSome, a conserved protein complex. The BBSome cycles via intraflagellar transport (IFT) through cilia to transport signaling proteins. How the BBSome is recruited to the basal body for binding to IFT trains for ciliary entry remains unknown. Here, we show that the Rab-like 5 GTPase IFT22 regulates basal body targeting of the BBSome in Chlamydomonas reinhardtii Our functional, biochemical and single particle in vivo imaging assays show that IFT22 is an active GTPase with low intrinsic GTPase activity. IFT22 is part of the IFT-B1 subcomplex but is not required for ciliary assembly. Independent of its association to IFT-B1, IFT22 binds and stabilizes the Arf-like 6 GTPase BBS3, a BBS protein that is not part of the BBSome. IFT22/BBS3 associates with the BBSome through an interaction between BBS3 and the BBSome. When both IFT22 and BBS3 are in their guanosine triphosphate (GTP)-bound states they recruit the BBSome to the basal body for coupling with the IFT-B1 subcomplex. The GTP-bound BBS3 likely remains to be associated with the BBSome upon ciliary entry. In contrast, IFT22 is not required for the transport of BBSomes in cilia, indicating that the BBSome is transferred from IFT22 to the IFT trains at the ciliary base. In summary, our data propose that nucleotide-dependent recruitment of the BBSome to the basal body by IFT22 regulates BBSome entry into cilia.
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