1
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Leggere JC, Hibbard JV, Papoulas O, Lee C, Pearson CG, Marcotte EM, Wallingford JB. Label-free proteomic comparison reveals ciliary and nonciliary phenotypes of IFT-A mutants. Mol Biol Cell 2024; 35:ar39. [PMID: 38170584 PMCID: PMC10916875 DOI: 10.1091/mbc.e23-03-0084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 12/11/2023] [Accepted: 12/18/2023] [Indexed: 01/05/2024] Open
Abstract
DIFFRAC is a powerful method for systematically comparing proteome content and organization between samples in a high-throughput manner. By subjecting control and experimental protein extracts to native chromatography and quantifying the contents of each fraction using mass spectrometry, it enables the quantitative detection of alterations to protein complexes and abundances. Here, we applied DIFFRAC to investigate the consequences of genetic loss of Ift122, a subunit of the intraflagellar transport-A (IFT-A) protein complex that plays a vital role in the formation and function of cilia and flagella, on the proteome of Tetrahymena thermophila. A single DIFFRAC experiment was sufficient to detect changes in protein behavior that mirrored known effects of IFT-A loss and revealed new biology. We uncovered several novel IFT-A-regulated proteins, which we validated through live imaging in Xenopus multiciliated cells, shedding new light on both the ciliary and non-ciliary functions of IFT-A. Our findings underscore the robustness of DIFFRAC for revealing proteomic changes in response to genetic or biochemical perturbation.
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Affiliation(s)
- Janelle C. Leggere
- Department of Molecular Biosciences, University of Texas at Austin, TX 78712
| | - Jaime V.K. Hibbard
- Department of Molecular Biosciences, University of Texas at Austin, TX 78712
| | - Ophelia Papoulas
- Department of Molecular Biosciences, University of Texas at Austin, TX 78712
| | - Chanjae Lee
- Department of Molecular Biosciences, University of Texas at Austin, TX 78712
| | - Chad G. Pearson
- Anschutz Medical Campus, Department of Cell and Developmental Biology, University of Colorado, Aurora, CO 80045
| | - Edward M. Marcotte
- Department of Molecular Biosciences, University of Texas at Austin, TX 78712
| | - John B. Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, TX 78712
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2
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Kalot R, Sentell Z, Kitzler TM, Torban E. Primary cilia and actin regulatory pathways in renal ciliopathies. FRONTIERS IN NEPHROLOGY 2024; 3:1331847. [PMID: 38292052 PMCID: PMC10824913 DOI: 10.3389/fneph.2023.1331847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 12/20/2023] [Indexed: 02/01/2024]
Abstract
Ciliopathies are a group of rare genetic disorders caused by defects to the structure or function of the primary cilium. They often affect multiple organs, leading to brain malformations, congenital heart defects, and anomalies of the retina or skeletal system. Kidney abnormalities are among the most frequent ciliopathic phenotypes manifesting as smaller, dysplastic, and cystic kidneys that are often accompanied by renal fibrosis. Many renal ciliopathies cause chronic kidney disease and often progress to end-stage renal disease, necessitating replacing therapies. There are more than 35 known ciliopathies; each is a rare hereditary condition, yet collectively they account for a significant proportion of chronic kidney disease worldwide. The primary cilium is a tiny microtubule-based organelle at the apex of almost all vertebrate cells. It serves as a "cellular antenna" surveying environment outside the cell and transducing this information inside the cell to trigger multiple signaling responses crucial for tissue morphogenesis and homeostasis. Hundreds of proteins and unique cellular mechanisms are involved in cilia formation. Recent evidence suggests that actin remodeling and regulation at the base of the primary cilium strongly impacts ciliogenesis. In this review, we provide an overview of the structure and function of the primary cilium, focusing on the role of actin cytoskeleton and its regulators in ciliogenesis. We then describe the key clinical, genetic, and molecular aspects of renal ciliopathies. We highlight what is known about actin regulation in the pathogenesis of these diseases with the aim to consider these recent molecular findings as potential therapeutic targets for renal ciliopathies.
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Affiliation(s)
- Rita Kalot
- Department of Medicine and Department of Physiology, McGill University, Montreal, QC, Canada
- The Research Institute of the McGill University Health Center, Montreal, QC, Canada
| | - Zachary Sentell
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Thomas M. Kitzler
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- McGill University Health Center, Montreal, QC, Canada
| | - Elena Torban
- Department of Medicine and Department of Physiology, McGill University, Montreal, QC, Canada
- The Research Institute of the McGill University Health Center, Montreal, QC, Canada
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3
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Jiang M, Palicharla VR, Miller D, Hwang SH, Zhu H, Hixson P, Mukhopadhyay S, Sun J. Human IFT-A complex structures provide molecular insights into ciliary transport. Cell Res 2023; 33:288-298. [PMID: 36775821 PMCID: PMC10066299 DOI: 10.1038/s41422-023-00778-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 01/11/2023] [Indexed: 02/14/2023] Open
Abstract
Intraflagellar transport (IFT) complexes, IFT-A and IFT-B, form bidirectional trains that move along the axonemal microtubules and are essential for assembling and maintaining cilia. Mutations in IFT subunits lead to numerous ciliopathies involving multiple tissues. However, how IFT complexes assemble and mediate cargo transport lacks mechanistic understanding due to missing high-resolution structural information of the holo-complexes. Here we report cryo-EM structures of human IFT-A complexes in the presence and absence of TULP3 at overall resolutions of 3.0-3.9 Å. IFT-A adopts a "lariat" shape with interconnected core and peripheral subunits linked by structurally vital zinc-binding domains. TULP3, the cargo adapter, interacts with IFT-A through its N-terminal region, and interface mutations disrupt cargo transport. We also determine the molecular impacts of disease mutations on complex formation and ciliary transport. Our work reveals IFT-A architecture, sheds light on ciliary transport and IFT train formation, and enables the rationalization of disease mutations in ciliopathies.
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Affiliation(s)
- Meiqin Jiang
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Vivek Reddy Palicharla
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Darcie Miller
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Sun-Hee Hwang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Hanwen Zhu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Patricia Hixson
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Ji Sun
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.
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4
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Ma Y, He J, Li S, Yao D, Huang C, Wu J, Lei M. Structural insight into the intraflagellar transport complex IFT-A and its assembly in the anterograde IFT train. Nat Commun 2023; 14:1506. [PMID: 36932088 PMCID: PMC10023715 DOI: 10.1038/s41467-023-37208-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 03/06/2023] [Indexed: 03/19/2023] Open
Abstract
Intraflagellar transport (IFT) trains, the polymers composed of two multi-subunit complexes, IFT-A and IFT-B, carry out bidirectional intracellular transport in cilia, vital for cilia biogenesis and signaling. IFT-A plays crucial roles in the ciliary import of membrane proteins and the retrograde cargo trafficking. However, the molecular architecture of IFT-A and the assembly mechanism of the IFT-A into the IFT trains in vivo remains elusive. Here, we report the cryo-electron microscopic structures of the IFT-A complex from protozoa Tetrahymena thermophila. We find that IFT-A complexes present two distinct, elongated and folded states. Remarkably, comparison with the in situ cryo-electron tomography structure of the anterograde IFT train unveils a series of adjustments of the flexible arms in apo IFT-A when incorporated into the anterograde train. Our results provide an atomic-resolution model for the IFT-A complex and valuable insights into the assembly mechanism of anterograde IFT trains.
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Affiliation(s)
- Yuanyuan Ma
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
- Shanghai Institute of Precision Medicine, Shanghai, 200125, China
| | - Jun He
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
- Shanghai Institute of Precision Medicine, Shanghai, 200125, China
| | - Shaobai Li
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
- Shanghai Institute of Precision Medicine, Shanghai, 200125, China
| | - Deqiang Yao
- Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200032, China
| | - Chenhui Huang
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
- Shanghai Institute of Precision Medicine, Shanghai, 200125, China
| | - Jian Wu
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.
- Shanghai Institute of Precision Medicine, Shanghai, 200125, China.
| | - Ming Lei
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.
- Shanghai Institute of Precision Medicine, Shanghai, 200125, China.
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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5
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Leggere JC, Hibbard JVK, Papoulas O, Lee C, Pearson CG, Marcotte EM, Wallingford JB. Label-free proteomic comparison reveals ciliary and non-ciliary phenotypes of IFT-A mutants. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.08.531778. [PMID: 36945534 PMCID: PMC10028850 DOI: 10.1101/2023.03.08.531778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
DIFFRAC is a powerful method for systematically comparing proteome content and organization between samples in a high-throughput manner. By subjecting control and experimental protein extracts to native chromatography and quantifying the contents of each fraction using mass spectrometry, it enables the quantitative detection of alterations to protein complexes and abundances. Here, we applied DIFFRAC to investigate the consequences of genetic loss of Ift122, a subunit of the intraflagellar transport-A (IFT-A) protein complex that plays a vital role in the formation and function of cilia and flagella, on the proteome of Tetrahymena thermophila . A single DIFFRAC experiment was sufficient to detect changes in protein behavior that mirrored known effects of IFT-A loss and revealed new biology. We uncovered several novel IFT-A-regulated proteins, which we validated through live imaging in Xenopus multiciliated cells, shedding new light on both the ciliary and non-ciliary functions of IFT-A. Our findings underscore the robustness of DIFFRAC for revealing proteomic changes in response to genetic or biochemical perturbation.
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6
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Palicharla VR, Hwang SH, Somatilaka BN, Legué E, Shimada IS, Familiari NE, Tran VM, Woodruff JB, Liem KF, Mukhopadhyay S. Interactions between TULP3 tubby domain and ARL13B amphipathic helix promote lipidated protein transport to cilia. Mol Biol Cell 2023; 34:ar18. [PMID: 36652335 PMCID: PMC10011728 DOI: 10.1091/mbc.e22-10-0473] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The primary cilium is a nexus for cell signaling and relies on specific protein trafficking for function. The tubby family protein TULP3 transports integral membrane proteins into cilia through interactions with the intraflagellar transport complex-A (IFT-A) and phosphoinositides. It was previously shown that short motifs called ciliary localization sequences (CLSs) are necessary and sufficient for TULP3-dependent ciliary trafficking of transmembrane cargoes. However, the mechanisms by which TULP3 regulates ciliary compartmentalization of nonintegral, membrane-associated proteins and whether such trafficking requires TULP3-dependent CLSs is unknown. Here we show that TULP3 is required for ciliary transport of the Joubert syndrome-linked palmitoylated GTPase ARL13B through a CLS. An N-terminal amphipathic helix, preceding the GTPase domain of ARL13B, couples with the TULP3 tubby domain for ciliary trafficking, irrespective of palmitoylation. ARL13B transport requires TULP3 binding to IFT-A but not to phosphoinositides, indicating strong membrane-proximate interactions, unlike transmembrane cargo transport requiring both properties of TULP3. TULP3-mediated trafficking of ARL13B also regulates ciliary enrichment of farnesylated and myristoylated downstream effectors of ARL13B. The lipidated cargoes show distinctive depletion kinetics from kidney epithelial cilia with relation to Tulp3 deletion-induced renal cystogenesis. Overall, these findings indicate an expanded role of the tubby domain in capturing analogous helical secondary structural motifs from diverse cargoes.
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Affiliation(s)
- Vivek Reddy Palicharla
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Sun-Hee Hwang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | | | - Emilie Legué
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520
| | - Issei S Shimada
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Nicole E Familiari
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Vanna M Tran
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Jeffrey B Woodruff
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Karel F Liem
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520
| | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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7
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Lu Q, Westlake CJ. Multi-color live-cell fluorescence imaging of primary ciliary membrane assembly and dynamics. Methods Cell Biol 2023; 176:235-250. [PMID: 37164540 DOI: 10.1016/bs.mcb.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
The ciliary membrane is continuous with the plasma membrane but has distinct lipid and protein composition, which is key to defining the function of the primary cilium. Ciliary membranes dynamically assemble and disassemble in association with the cell cycle and directly transmit signals and molecules through budding membranes. Various imaging approaches have greatly advanced the understanding of the ciliary membrane function. In particular, fluorescence live-cell imaging has revealed important insights into the dynamics of ciliary membrane assembly by monitoring the changes of fluorescent-tagged ciliary proteins. Protein dynamics can be tracked simultaneously using multi-color live cell imaging by coupling ciliary-associated factors with different colored fluorescent tags. Ciliary membrane and membrane associated-proteins such as Smoothened, 5-HTr6, SSTR3, Rab8a, and Arl13b have been used to track ciliary membranes and centriole proteins like Centrin1/2, CEP164, and CEP83 are often used to mark the ciliary basal body. Here, we describe a method for studying ciliogenesis membrane dynamics using spinning disk confocal live-cell imaging.
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Affiliation(s)
- Quanlong Lu
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States.
| | - Christopher J Westlake
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States.
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8
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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: 4] [Impact Index Per Article: 2.0] [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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9
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Abstract
The assembly and maintenance of most cilia and eukaryotic flagella depends on intraflagellar transport (IFT), the bidirectional movement of multi-megadalton IFT trains along the axonemal microtubules. These IFT trains function as carriers, moving ciliary proteins between the cell body and the organelle. Whereas tubulin, the principal protein of cilia, binds directly to IFT particle proteins, the transport of other ciliary proteins and complexes requires adapters that link them to the trains. Large axonemal substructures, such as radial spokes, outer dynein arms and inner dynein arms, assemble in the cell body before attaching to IFT trains, using the adapters ARMC2, ODA16 and IDA3, respectively. Ciliary import of several membrane proteins involves the putative adapter tubby-like protein 3 (TULP3), whereas membrane protein export involves the BBSome, an octameric complex that co-migrates with IFT particles. Thus, cells employ a variety of adapters, each of which is substoichiometric to the core IFT machinery, to expand the cargo range of the IFT trains. This Review summarizes the individual and shared features of the known cargo adapters and discusses their possible role in regulating the transport capacity of the IFT pathway.
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Affiliation(s)
- Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
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10
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Zhang X, Zhou J, Wang X, Geng J, Chen Y, Sun Y. IFT140 +/K14 + cells function as stem/progenitor cells in salivary glands. Int J Oral Sci 2022; 14:49. [PMID: 36216809 PMCID: PMC9550827 DOI: 10.1038/s41368-022-00200-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 07/31/2022] [Accepted: 09/05/2022] [Indexed: 11/27/2022] Open
Abstract
Stem/progenitor cells are important for salivary gland development, homeostasis maintenance, and regeneration following injury. Keratin-14+ (K14+) cells have been recognized as bona fide salivary gland stem/progenitor cells. However, K14 is also expressed in terminally differentiated myoepithelial cells; therefore, more accurate molecular markers for identifying salivary stem/progenitor cells are required. The intraflagellar transport (IFT) protein IFT140 is a core component of the IFT system that functions in signaling transduction through the primary cilia. It is reportedly expressed in mesenchymal stem cells and plays a role in bone formation. In this study, we demonstrated that IFT140 was intensively expressed in K14+ stem/progenitor cells during the developmental period and early regeneration stage following ligation-induced injuries in murine submandibular glands. In addition, we demonstrated that IFT140+/ K14+ could self-renew and differentiate into granular duct cells at the developmental stage in vivo. The conditional deletion of Ift140 from K14+ cells caused abnormal epithelial structure and function during salivary gland development and inhibited regeneration. IFT140 partly coordinated the function of K14+ stem/progenitor cells by modulating ciliary membrane trafficking. Our investigation identified a combined marker, IFT140+/K14+, for salivary gland stem/progenitor cells and elucidated the essential role of IFT140 and cilia in regulating salivary stem/progenitor cell differentiation and gland regeneration.
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Affiliation(s)
- Xueming Zhang
- Department of Oral and Maxillofacial Surgery, Stomatological Hospital and Dental School of Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, No. 399, YanChang Middle Road, Shanghai, China
| | - Ji Zhou
- Department of Implantology, Stomatological Hospital and Dental School of Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, No. 399, YanChang Middle Road, Shanghai, China
| | - Xinyu Wang
- Department of Implantology, Stomatological Hospital and Dental School of Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, No. 399, YanChang Middle Road, Shanghai, China
| | - Jiangyu Geng
- Department of Implantology, Stomatological Hospital and Dental School of Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, No. 399, YanChang Middle Road, Shanghai, China
| | - Yubei Chen
- Department of Implantology, Stomatological Hospital and Dental School of Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, No. 399, YanChang Middle Road, Shanghai, China
| | - Yao Sun
- Department of Implantology, Stomatological Hospital and Dental School of Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, No. 399, YanChang Middle Road, Shanghai, China.
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11
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Primary Cilia Influence Progenitor Function during Cortical Development. Cells 2022; 11:cells11182895. [PMID: 36139475 PMCID: PMC9496791 DOI: 10.3390/cells11182895] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/29/2022] [Accepted: 09/13/2022] [Indexed: 11/29/2022] Open
Abstract
Corticogenesis is an intricate process controlled temporally and spatially by many intrinsic and extrinsic factors. Alterations during this important process can lead to severe cortical malformations. Apical neuronal progenitors are essential cells able to self-amplify and also generate basal progenitors and/or neurons. Apical radial glia (aRG) are neuronal progenitors with a unique morphology. They have a long basal process acting as a support for neuronal migration to the cortical plate and a short apical process directed towards the ventricle from which protrudes a primary cilium. This antenna-like structure allows aRG to sense cues from the embryonic cerebrospinal fluid (eCSF) helping to maintain cell shape and to influence several key functions of aRG such as proliferation and differentiation. Centrosomes, major microtubule organising centres, are crucial for cilia formation. In this review, we focus on how primary cilia influence aRG function during cortical development and pathologies which may arise due to defects in this structure. Reporting and cataloguing a number of ciliary mutant models, we discuss the importance of primary cilia for aRG function and cortical development.
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12
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Hibbard JVK, Vázquez N, Wallingford JB. Cilia proteins getting to work - how do they commute from the cytoplasm to the base of cilia? J Cell Sci 2022; 135:jcs259444. [PMID: 36073764 PMCID: PMC9482345 DOI: 10.1242/jcs.259444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cilia are multifunctional organelles that originated with the last eukaryotic common ancestor and play central roles in the life cycles of diverse organisms. The motile flagella that move single cells like sperm or unicellular organisms, the motile cilia on animal multiciliated cells that generate fluid flow in organs, and the immotile primary cilia that decorate nearly all cells in animals share many protein components in common, yet each also requires specialized proteins to perform their specialized functions. Despite a now-advanced understanding of how such proteins are transported within cilia, we still know very little about how they are transported from their sites of synthesis through the cytoplasm to the ciliary base. Here, we review the literature concerning this underappreciated topic in ciliary cell biology. We discuss both general mechanisms, as well as specific examples of motor-driven active transport and passive transport via diffusion-and-capture. We then provide deeper discussion of specific, illustrative examples, such as the diverse array of protein subunits that together comprise the intraflagellar transport (IFT) system and the multi-protein axonemal dynein motors that drive beating of motile cilia. We hope this Review will spur further work, shedding light not only on ciliogenesis and ciliary signaling, but also on intracellular transport in general.
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Affiliation(s)
| | | | - John B. Wallingford
- Department of Molecular Biosciences, University of Texas, Austin, TX 78751, USA
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13
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Wang W, Silva LM, Wang HH, Kavanaugh MA, Pottorf TS, Allard BA, Jacobs DT, Dong R, Cornelius JT, Chaturvedi A, Swenson-Fields KI, Fields TA, Pritchard MT, Sharma M, Slawson C, Wallace DP, Calvet JP, Tran PV. Ttc21b deficiency attenuates autosomal dominant polycystic kidney disease in a kidney tubular- and maturation-dependent manner. Kidney Int 2022; 102:577-591. [PMID: 35644283 PMCID: PMC9398994 DOI: 10.1016/j.kint.2022.04.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 04/21/2022] [Accepted: 04/29/2022] [Indexed: 01/26/2023]
Abstract
Primary cilia are sensory organelles built and maintained by intraflagellar transport (IFT) multiprotein complexes. Deletion of several IFT-B genes attenuates polycystic kidney disease (PKD) severity in juvenile and adult autosomal dominant polycystic kidney disease (ADPKD) mouse models. However, deletion of an IFT-A adaptor, Tulp3, attenuates PKD severity in adult mice only. These studies indicate that dysfunction of specific cilia components has potential therapeutic value. To broaden our understanding of cilia dysfunction and its therapeutic potential, we investigate the role of global deletion of an IFT-A gene, Ttc21b, in juvenile and adult mouse models of ADPKD. Both juvenile (postnatal day 21) and adult (six months of age) ADPKD mice exhibited kidney cysts, increased kidney weight/body weight ratios, lengthened kidney cilia, inflammation, and increased levels of the nutrient sensor, O-linked β-N-acetylglucosamine (O-GlcNAc). Deletion of Ttc21b in juvenile ADPKD mice reduced cortical collecting duct cystogenesis and kidney weight/body weight ratios, increased proximal tubular and glomerular dilations, but did not reduce cilia length, inflammation, nor O-GlcNAc levels. In contrast, Ttc21b deletion in adult ADPKD mice markedly attenuated kidney cystogenesis and reduced cilia length, inflammation, and O-GlcNAc levels. Thus, unlike IFT-B, the effect of Ttc21b deletion in mouse models of ADPKD is development-specific. Unlike an IFT-A adaptor, deleting Ttc21b in juvenile ADPKD mice is partially ameliorative. Thus, our studies suggest that different microenvironmental factors, found in distinct nephron segments and in developing versus mature stages, modify ciliary homeostasis and ADPKD pathobiology. Further, elevated levels of O-GlcNAc, which regulates cellular metabolism and ciliogenesis, may be a pathological feature of ADPKD.
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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, Kansas, USA
| | - Luciane M Silva
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Henry H Wang
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Matthew A Kavanaugh
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Tana S Pottorf
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Bailey A Allard
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Damon T Jacobs
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Rouchen Dong
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Joseph T Cornelius
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Aakriti Chaturvedi
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Katherine I Swenson-Fields
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Timothy A Fields
- Department of Pathology and Laboratory Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Michele T Pritchard
- Pharmacology, Toxicology and Therapeutics, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Madhulika Sharma
- Department of Internal Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Chad Slawson
- Department of Biochemistry and Molecular Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Darren P Wallace
- Department of Internal Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - James P Calvet
- Department of Biochemistry and Molecular Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Pamela V Tran
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA.
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14
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Norcia LF, Watanabe EM, Hamamoto Filho PT, Hasimoto CN, Pelafsky L, de Oliveira WK, Sassaki LY. Polycystic Liver Disease: Pathophysiology, Diagnosis and Treatment. Hepat Med 2022; 14:135-161. [PMID: 36200122 PMCID: PMC9528914 DOI: 10.2147/hmer.s377530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 09/07/2022] [Indexed: 11/25/2022] Open
Abstract
Polycystic liver disease (PLD) is a clinical condition characterized by the presence of more than 10 cysts in the liver. It is a rare disease Of genetic etiology that presents as an isolated disease or assoc\iated with polycystic kidney disease. Ductal plate malformation, ciliary dysfunction, and changes in cell signaling are the main factors involved in its pathogenesis. Most patients with PLD are asymptomatic, but in 2–5% of cases the disease has disabling symptoms and a significant reduction in quality of life. The diagnosis is based on family history of hepatic and/or renal polycystic disease, clinical manifestations, patient age, and polycystic liver phenotype shown on imaging examinations. PLD treatment has evolved considerably in the last decades. Somatostatin analogues hold promise in controlling disease progression, but liver transplantation remains a unique curative treatment modality.
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Affiliation(s)
- Luiz Fernando Norcia
- Department of Surgery, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
- Correspondence: Luiz Fernando Norcia, Department of Surgery, São Paulo State University (UNESP), Medical School, 783 Pedro Delmanto Street, Botucatu, São Paulo, 18610-303, Brazil, Tel +55 19982840542, Email
| | - Erika Mayumi Watanabe
- Department of Radiology, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
| | - Pedro Tadao Hamamoto Filho
- Department of Neurology, Psychology and Psychiatry, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
| | - Claudia Nishida Hasimoto
- Department of Surgery, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
| | - Leonardo Pelafsky
- Department of Surgery, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
| | - Walmar Kerche de Oliveira
- Department of Surgery, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
| | - Ligia Yukie Sassaki
- Department of Internal Medicine, São Paulo State University (Unesp), Medical School, Botucatu, São Paulo, Brazil
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15
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Walker RV, Maranto A, Palicharla VR, Hwang SH, Mukhopadhyay S, Qian F. Cilia-Localized Counterregulatory Signals as Drivers of Renal Cystogenesis. Front Mol Biosci 2022; 9:936070. [PMID: 35832738 PMCID: PMC9272769 DOI: 10.3389/fmolb.2022.936070] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 05/30/2022] [Indexed: 12/18/2022] Open
Abstract
Primary cilia play counterregulatory roles in cystogenesis—they inhibit cyst formation in the normal renal tubule but promote cyst growth when the function of polycystins is impaired. Key upstream cilia-specific signals and components involved in driving cystogenesis have remained elusive. Recent studies of the tubby family protein, Tubby-like protein 3 (TULP3), have provided new insights into the cilia-localized mechanisms that determine cyst growth. TULP3 is a key adapter of the intraflagellar transport complex A (IFT-A) in the trafficking of multiple proteins specifically into the ciliary membrane. Loss of TULP3 results in the selective exclusion of its cargoes from cilia without affecting their extraciliary pools and without disrupting cilia or IFT-A complex integrity. Epistasis analyses have indicated that TULP3 inhibits cystogenesis independently of the polycystins during kidney development but promotes cystogenesis in adults when polycystins are lacking. In this review, we discuss the current model of the cilia-dependent cyst activation (CDCA) mechanism in autosomal dominant polycystic kidney disease (ADPKD) and consider the possible roles of ciliary and extraciliary polycystins in regulating CDCA. We then describe the limitations of this model in not fully accounting for how cilia single knockouts cause significant cystic changes either in the presence or absence of polycystins. Based on available data from TULP3/IFT-A-mediated differential regulation of cystogenesis in kidneys with deletion of polycystins either during development or in adulthood, we hypothesize the existence of cilia-localized components of CDCA (cCDCA) and cilia-localized cyst inhibition (CLCI) signals. We develop the criteria for cCDCA/CLCI signals and discuss potential TULP3 cargoes as possible cilia-localized components that determine cystogenesis in kidneys during development and in adult mice.
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Affiliation(s)
- Rebecca V. Walker
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Anthony Maranto
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | | | - Sun-Hee Hwang
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, United States
| | - Saikat Mukhopadhyay
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, United States
| | - Feng Qian
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
- *Correspondence: Feng Qian,
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16
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Abstract
Primary cilia play a key role in the ability of cells to respond to extracellular stimuli, such as signaling molecules and environmental cues. These sensory organelles are crucial to the development of many organ systems, and defects in primary ciliogenesis lead to multisystemic genetic disorders, known as ciliopathies. Here, we review recent advances in the understanding of several key aspects of the regulation of ciliogenesis. Primary ciliogenesis is thought to take different pathways depending on cell type, and some recent studies shed new light on the cell-type-specific mechanisms regulating ciliogenesis at the apical surface in polarized epithelial cells, which are particularly relevant for many ciliopathies. Furthermore, recent findings have demonstrated the importance of actin cytoskeleton dynamics in positively and negatively regulating multiple stages of ciliogenesis, including the vesicular trafficking of ciliary components and the positioning and docking of the basal body. Finally, studies on the formation of motile cilia in multiciliated epithelial cells have revealed requirements for actin remodeling in this process too, as well as showing evidence of an additional alternative ciliogenesis pathway.
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Affiliation(s)
- Huxley K Hoffman
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Rytis Prekeris
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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17
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Quidwai T, Wang J, Hall EA, Petriman NA, Leng W, Kiesel P, Wells JN, Murphy LC, Keighren MA, Marsh JA, Lorentzen E, Pigino G, Mill P. A WDR35-dependent coat protein complex transports ciliary membrane cargo vesicles to cilia. eLife 2021; 10:e69786. [PMID: 34734804 PMCID: PMC8754431 DOI: 10.7554/elife.69786] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
Intraflagellar transport (IFT) is a highly conserved mechanism for motor-driven transport of cargo within cilia, but how this cargo is selectively transported to cilia is unclear. WDR35/IFT121 is a component of the IFT-A complex best known for its role in ciliary retrograde transport. In the absence of WDR35, small mutant cilia form but fail to enrich in diverse classes of ciliary membrane proteins. In Wdr35 mouse mutants, the non-core IFT-A components are degraded and core components accumulate at the ciliary base. We reveal deep sequence homology of WDR35 and other IFT-A subunits to α and ß' COPI coatomer subunits and demonstrate an accumulation of 'coat-less' vesicles that fail to fuse with Wdr35 mutant cilia. We determine that recombinant non-core IFT-As can bind directly to lipids and provide the first in situ evidence of a novel coat function for WDR35, likely with other IFT-A proteins, in delivering ciliary membrane cargo necessary for cilia elongation.
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Affiliation(s)
- Tooba Quidwai
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Jiaolong Wang
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
| | - Emma A Hall
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Narcis A Petriman
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
| | - Weihua Leng
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Petra Kiesel
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Jonathan N Wells
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Laura C Murphy
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Margaret A Keighren
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Joseph A Marsh
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
| | - Gaia Pigino
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Human TechnopoleMilanItaly
| | - Pleasantine Mill
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
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18
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Niu Y, Stadler FJ, Yang X, Deng F, Liu G, Xia H. HA-coated collagen nanofibers for urethral regeneration via in situ polarization of M2 macrophages. J Nanobiotechnology 2021; 19:283. [PMID: 34551762 PMCID: PMC8456673 DOI: 10.1186/s12951-021-01000-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/15/2021] [Indexed: 12/16/2022] Open
Abstract
In situ tissue engineering utilizes the regenerative potential of the human body to control cell function for tissue regeneration and has shown considerable prospect in urology. However, many problems are still to be understood, especially the interactions between scaffolds and host macrophages at the wound site and how these interactions direct tissue integration and regeneration. This study was designed to evaluate the efficacy of hyaluronic acid (HA) functionalized collagen nanofibers in modulating the pro-healing phenotype expression of macrophages for urethral regeneration. Tubular HA-collagen nanofibers with HA-coating were prepared by coaxial electrospinning. The formation of a thin HA-coating atop each collagen nanofiber endowed its nanofibrous mats with higher anisotropic wettability and mechanical softness. The macrophages growing on the surface of HA-collagen nanofibers showed an elongated shape, while collagen nanofibers' surface exhibited a pancake shape. Immunofluorescence and ELISA analysis showed that elongation could promote the expression of M2 phenotype marker and reduce the secretion of inflammatory cytokines. In vivo experiments showed that tubular HA-collagen nanofibers significantly facilitate male puppy urethral regeneration after injury. In the regenerated urethra bridged by tubular HA-collagen nanofibers, anti-inflammatory M2 macrophages are recruited to the surface of the scaffold, which can promote angiogenesis and endogenous urothelial progenitor cell proliferation.
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Affiliation(s)
- Yuqing Niu
- Department of Pediatric Surgery, Guangdong Provincial Key Laboratory of Research in Structural Birth Defect Disease, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, Guangdong, China
| | - Florian J Stadler
- Nanshan District Key Lab for Biopolymers and Safety Evaluation, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, Guangdong, China
| | - Xu Yang
- Department of Pediatric Surgery, Guangdong Provincial Key Laboratory of Research in Structural Birth Defect Disease, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, Guangdong, China
| | - Fuming Deng
- Department of Pediatric Surgery, Guangdong Provincial Key Laboratory of Research in Structural Birth Defect Disease, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, Guangdong, China
| | - Guochang Liu
- Department of Pediatric Surgery, Guangdong Provincial Key Laboratory of Research in Structural Birth Defect Disease, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, Guangdong, China
| | - Huimin Xia
- Department of Pediatric Surgery, Guangdong Provincial Key Laboratory of Research in Structural Birth Defect Disease, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, Guangdong, China.
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19
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Wang W, Pottorf TS, Wang HH, Dong R, Kavanaugh MA, Cornelius JT, Dennis KL, Apte U, Pritchard MT, Sharma M, Tran PV. IFT-A deficiency in juvenile mice impairs biliary development and exacerbates ADPKD liver disease. J Pathol 2021; 254:289-302. [PMID: 33900625 DOI: 10.1002/path.5685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 04/16/2021] [Indexed: 02/06/2023]
Abstract
Polycystic liver disease (PLD) is characterized by the growth of numerous biliary cysts and presents in patients with autosomal dominant polycystic kidney disease (ADPKD), causing significant morbidity. Interestingly, deletion of intraflagellar transport-B (IFT-B) complex genes in adult mouse models of ADPKD attenuates the severity of PKD and PLD. Here we examine the role of deletion of an IFT-A gene, Thm1, in PLD of juvenile and adult Pkd2 conditional knockout mice. Perinatal deletion of Thm1 resulted in disorganized and expanded biliary regions, biliary fibrosis, increased serum bile acids, and a shortened primary cilium on cytokeratin 19+ (CK19+) epithelial cells. In contrast, perinatal deletion of Pkd2 caused PLD, with multiple CK19+ epithelial cell-lined cysts, fibrosis, lengthened primary cilia, and increased Notch and ERK signaling. Perinatal deletion of Thm1 in Pkd2 conditional knockout mice increased hepatomegaly, liver necrosis, as well as serum bilirubin and bile acid levels, indicating enhanced liver disease severity. In contrast to effects in the developing liver, deletion of Thm1 alone in adult mice did not cause a biliary phenotype. Combined deletion of Pkd2 and Thm1 caused variable hepatic cystogenesis at 4 months of age, but differences in hepatic cystogenesis between Pkd2- and Pkd2;Thm1 knockout mice were not observed by 6 months of age. Similar to juvenile PLD, Notch and ERK signaling were increased in adult Pkd2 conditional knockout cyst-lining epithelial cells. Taken together, Thm1 is required for biliary tract development, and proper biliary development restricts PLD severity. Unlike IFT-B genes, Thm1 does not markedly attenuate hepatic cystogenesis, suggesting differences in regulation of signaling and cystogenic processes in the liver by IFT-B and -A. Notably, increased Notch signaling in cyst-lining epithelial cells may indicate that aberrant activation of this pathway promotes hepatic cystogenesis, presenting as a novel potential therapeutic target. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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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, USA
| | - Tana S Pottorf
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Henry H Wang
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Ruochen Dong
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Matthew A Kavanaugh
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Joseph T Cornelius
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Katie L Dennis
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, USA
| | - Udayan Apte
- Department of Pharmacology, Toxicology and Therapeutics, The Liver Center, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Michele T Pritchard
- Department of Pharmacology, Toxicology and Therapeutics, The Liver Center, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Madhulika Sharma
- Department of Internal Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Pamela V Tran
- Department of Anatomy and Cell Biology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
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20
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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: 22] [Impact Index Per Article: 7.3] [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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21
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A complex of distal appendage-associated kinases linked to human disease regulates ciliary trafficking and stability. Proc Natl Acad Sci U S A 2021; 118:2018740118. [PMID: 33846249 PMCID: PMC8072220 DOI: 10.1073/pnas.2018740118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Primary cilia (PC) are sensory organelles essential for the development and maintenance of adult tissues. Accordingly, dysfunction of PC causes human disorders called ciliopathies. Hence, a thorough understanding of the molecular regulation of PC is critical. Our findings highlight CSNK2A1 as a modulator of cilia trafficking and stability, tightly related to TTBK2 function. Enriched at the centrosome, CSNK2A1 prevents abnormal accumulation of key ciliary proteins, instability at the tip, and aberrant activation of the Sonic Hedgehog pathway. Furthermore, we establish that Csnk2a1 mutations associated with Okur-Chung neurodevelopmental disorder (OCNDS) alter cilia morphology. Thus, we report a potential linkage between CSNK2A1 ciliary function and OCNDS. Cilia biogenesis is a complex, multistep process involving the coordination of multiple cellular trafficking pathways. Despite the importance of ciliogenesis in mediating the cellular response to cues from the microenvironment, we have only a limited understanding of the regulation of cilium assembly. We previously identified Tau tubulin kinase 2 (TTBK2) as a key regulator of ciliogenesis. Here, using CRISPR kinome and biotin identification screening, we identify the CK2 catalytic subunit CSNK2A1 as an important modulator of TTBK2 function in cilia trafficking. Superresolution microscopy reveals that CSNK2A1 is a centrosomal protein concentrated at the mother centriole and associated with the distal appendages. Csnk2a1 mutant cilia are longer than those of control cells, showing instability at the tip associated with ciliary actin cytoskeleton changes. These cilia also abnormally accumulate key cilia assembly and SHH-related proteins. De novo mutations of Csnk2a1 were recently linked to the human genetic disorder Okur-Chung neurodevelopmental syndrome (OCNDS). Consistent with the role of CSNK2A1 in cilium stability, we find that expression of OCNDS-associated Csnk2a1 variants in wild-type cells causes ciliary structural defects. Our findings provide insights into mechanisms involved in ciliary length regulation, trafficking, and stability that in turn shed light on the significance of cilia instability in human disease.
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22
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Hazime KS, Zhou Z, Joachimiak E, Bulgakova NA, Wloga D, Malicki JJ. STORM imaging reveals the spatial arrangement of transition zone components and IFT particles at the ciliary base in Tetrahymena. Sci Rep 2021; 11:7899. [PMID: 33846423 PMCID: PMC8041816 DOI: 10.1038/s41598-021-86909-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 03/22/2021] [Indexed: 11/17/2022] Open
Abstract
The base of the cilium comprising the transition zone (TZ) and transition fibers (TF) acts as a selecting gate to regulate the intraflagellar transport (IFT)-dependent trafficking of proteins to and from cilia. Before entering the ciliary compartment, IFT complexes and transported cargoes accumulate at or near the base of the cilium. The spatial organization of IFT proteins at the cilia base is key for understanding cilia formation and function. Using stochastic optical reconstruction microscopy (STORM) and computational averaging, we show that seven TZ, nine IFT, three Bardet–Biedl syndrome (BBS), and one centrosomal protein, form 9-clustered rings at the cilium base of a ciliate Tetrahymena thermophila. In the axial dimension, analyzed TZ proteins localize to a narrow region of about 30 nm while IFT proteins dock approximately 80 nm proximal to TZ. Moreover, the IFT-A subcomplex is positioned peripheral to the IFT-B subcomplex and the investigated BBS proteins localize near the ciliary membrane. The positioning of the HA-tagged N- and C-termini of the selected proteins enabled the prediction of the spatial orientation of protein particles and likely cargo interaction sites. Based on the obtained data, we built a comprehensive 3D-model showing the arrangement of the investigated ciliary proteins.
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Affiliation(s)
- Khodor S Hazime
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
| | - Zhu Zhou
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, 3 Pasteur Street, 02-093, Warsaw, Poland
| | - Natalia A Bulgakova
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, 3 Pasteur Street, 02-093, Warsaw, Poland.
| | - Jarema J Malicki
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
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23
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Hibbard JVK, Vazquez N, Satija R, Wallingford JB. Protein turnover dynamics suggest a diffusion-to-capture mechanism for peri-basal body recruitment and retention of intraflagellar transport proteins. Mol Biol Cell 2021; 32:1171-1180. [PMID: 33826363 PMCID: PMC8351562 DOI: 10.1091/mbc.e20-11-0717] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Intraflagellar transport (IFT) is essential for construction and maintenance of cilia. IFT proteins concentrate at the basal body where they are thought to assemble into trains and bind cargoes for transport. To study the mechanisms of IFT recruitment to this peri-basal body pool, we quantified protein dynamics of eight IFT proteins, as well as five other basal body localizing proteins using fluorescence recovery after photobleaching in vertebrate multiciliated cells. We found that members of the IFT-A and IFT-B protein complexes show distinct turnover kinetics from other basal body components. Additionally, known IFT subcomplexes displayed shared dynamics, suggesting shared basal body recruitment and/or retention mechanisms. Finally, we evaluated the mechanisms of basal body recruitment by depolymerizing cytosolic MTs, which suggested that IFT proteins are recruited to basal bodies through a diffusion-to-capture mechanism. Our survey of IFT protein dynamics provides new insights into IFT recruitment to basal bodies, a crucial step in ciliogenesis and ciliary signaling.
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Affiliation(s)
- Jaime V K Hibbard
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
| | - Neftali Vazquez
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
| | - Rohit Satija
- California Institute of Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712
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24
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Allard BA, Wang W, Pottorf TS, Mumtaz H, Jack BM, Wang HH, Silva LM, Jacobs DT, Wang J, Bumann EE, Tran PV. Thm2 interacts with paralog, Thm1, and sensitizes to Hedgehog signaling in postnatal skeletogenesis. Cell Mol Life Sci 2021; 78:3743-3762. [PMID: 33683377 DOI: 10.1007/s00018-021-03806-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 02/06/2021] [Accepted: 02/27/2021] [Indexed: 11/25/2022]
Abstract
Mutations in the intraflagellar transport-A (IFT-A) gene, THM1, have been identified in skeletal ciliopathies. Here, we report a genetic interaction between Thm1, and its paralog, Thm2, in postnatal skeletogenesis. THM2 localizes to primary cilia, but Thm2 deficiency does not affect ciliogenesis and Thm2-null mice survive into adulthood. However, by postnatal day 14, Thm2-/-; Thm1aln/+ mice exhibit small stature and small mandible. Radiography and microcomputed tomography reveal Thm2-/-; Thm1aln/+ tibia are less opaque and have reduced cortical and trabecular bone mineral density. In the mutant tibial growth plate, the proliferation zone is expanded and the hypertrophic zone is diminished, indicating impaired chondrocyte differentiation. Additionally, mutant growth plate chondrocytes show increased Hedgehog signaling. Yet deletion of one allele of Gli2, a major transcriptional activator of the Hedgehog pathway, exacerbated the Thm2-/-; Thm1aln/+ small phenotype, and further revealed that Thm2-/-; Gli2+/- mice have small stature. In Thm2-/-; Thm1aln/+ primary osteoblasts, a Hedgehog signaling defect was not detected, but bone nodule formation was markedly impaired. This indicates a signaling pathway is altered, and we propose that this pathway may potentially interact with Gli2. Together, our data reveal that loss of Thm2 with one allele of Thm1, Gli2, or both, present new IFT mouse models of osteochondrodysplasia. Our data also suggest Thm2 as a modifier of Hedgehog signaling in postnatal skeletal development.
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Affiliation(s)
- Bailey A Allard
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., MS #3038, Kansas City, KS, 66160, USA
| | - Wei Wang
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., MS #3038, Kansas City, KS, 66160, USA
| | - Tana S Pottorf
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., MS #3038, Kansas City, KS, 66160, USA
| | - Hammad Mumtaz
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Brittany M Jack
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., MS #3038, Kansas City, KS, 66160, USA
| | - Henry H Wang
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., MS #3038, Kansas City, KS, 66160, USA
| | - Luciane M Silva
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., MS #3038, Kansas City, KS, 66160, USA
| | - Damon T Jacobs
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., MS #3038, Kansas City, KS, 66160, USA
| | - Jinxi Wang
- Department of Orthopedic Surgery, Medical Center, University of Kansas, Kansas City, KS, 66160, USA
| | - Erin E Bumann
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Pamela V Tran
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., MS #3038, Kansas City, KS, 66160, USA.
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25
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WDR35 is involved in subcellular localization of acetylated tubulin in 293T cells. Biochem Biophys Res Commun 2021; 547:169-175. [PMID: 33610917 DOI: 10.1016/j.bbrc.2021.01.092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 01/26/2021] [Indexed: 11/23/2022]
Abstract
WDR35/IFT121 is an intraflagellar transport protein in primary cilia, which is associated with RagA, an mTORC1-activating protein. To elucidate the functions of the interaction between WDR35 and RagA in primary cilia, as well as mTOR signaling, we identified WDR35-interacting proteins using mass spectrometry. We found that WDR35 associates with CCT complex proteins including TCP1/CCT1, which act as molecular chaperones for α-tubulin folding. Immunostaining showed that acetylated α-tubulin was concentrated in the vicinity of primary cilia in 293T cells. In contrast, acetylated tubulin was dispersed in WDR35 partial knockout cells established from 293T cells. Similarly, scattered subcellular localization of acetylated tubulin was observed in RagA knockout cells. RagA was present in the primary cilia of NIH3T3 cells, and the GDP form of RagA exhibited strong binding to WDR35 and negative regulation of primary cilium formation. These results suggest that WDR35 is involved in the subcellular localization of acetylated tubulin in primary cilia via its interactions with TCP1 and/or RagA family proteins.
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Zhang R, Boareto M, Engler A, Louvi A, Giachino C, Iber D, Taylor V. Id4 Downstream of Notch2 Maintains Neural Stem Cell Quiescence in the Adult Hippocampus. Cell Rep 2020; 28:1485-1498.e6. [PMID: 31390563 DOI: 10.1016/j.celrep.2019.07.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 04/14/2019] [Accepted: 07/02/2019] [Indexed: 12/31/2022] Open
Abstract
Neural stem cells (NSCs) in the adult mouse hippocampal dentate gyrus (DG) are mostly quiescent, and only a few are in cell cycle at any point in time. DG NSCs become increasingly dormant with age and enter mitosis less frequently, which impinges on neurogenesis. How NSC inactivity is maintained is largely unknown. Here, we found that Id4 is a downstream target of Notch2 signaling and maintains DG NSC quiescence by blocking cell-cycle entry. Id4 expression is sufficient to promote DG NSC quiescence and Id4 knockdown rescues Notch2-induced inhibition of NSC proliferation. Id4 deletion activates NSC proliferation in the DG without evoking neuron generation, and overexpression increases NSC maintenance while promoting astrogliogenesis at the expense of neurogenesis. Together, our findings indicate that Id4 is a major effector of Notch2 signaling in NSCs and a Notch2-Id4 axis promotes NSC quiescence in the adult DG, uncoupling NSC activation from neuronal differentiation.
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Affiliation(s)
- Runrui Zhang
- Embryology and Stem Cell Biology Lab, Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Marcelo Boareto
- Computational Biology Group, D-BSSE, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland; Swiss Institute of Bioinformatics (SIB), Mattenstrasse 26, 4058 Basel, Switzerland
| | - Anna Engler
- Embryology and Stem Cell Biology Lab, Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Angeliki Louvi
- Departments of Neurosurgery and Neuroscience, Yale Program on Neurogenetics, Yale School of Medicine, New Haven, CT 06520, USA
| | - Claudio Giachino
- Embryology and Stem Cell Biology Lab, Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Dagmar Iber
- Computational Biology Group, D-BSSE, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland; Swiss Institute of Bioinformatics (SIB), Mattenstrasse 26, 4058 Basel, Switzerland
| | - Verdon Taylor
- Embryology and Stem Cell Biology Lab, Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland.
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27
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Wang W, Allard BA, Pottorf TS, Wang HH, Vivian JL, Tran PV. Genetic interaction of mammalian IFT-A paralogs regulates cilia disassembly, ciliary entry of membrane protein, Hedgehog signaling, and embryogenesis. FASEB J 2020; 34:6369-6381. [PMID: 32167205 DOI: 10.1096/fj.201902611r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 02/15/2020] [Accepted: 03/01/2020] [Indexed: 12/17/2022]
Abstract
Primary cilia are sensory organelles that are essential for eukaryotic development and health. These antenna-like structures are synthesized by intraflagellar transport protein complexes, IFT-B and IFT-A, which mediate bidirectional protein trafficking along the ciliary axoneme. Here using mouse embryonic fibroblasts (MEF), we investigate the ciliary roles of two mammalian orthologues of Chlamydomonas IFT-A gene, IFT139, namely Thm1 (also known as Ttc21b) and Thm2 (Ttc21a). Thm1 loss causes perinatal lethality, and Thm2 loss allows survival into adulthood. At E14.5, the number of Thm1;Thm2 double mutant embryos is lower than that for a Mendelian ratio, indicating deletion of Thm1 and Thm2 causes mid-gestational lethality. We examined the ciliary phenotypes of mutant MEF. Thm1-mutant MEF show decreased cilia assembly, increased cilia disassembly, shortened primary cilia, a retrograde IFT defect for IFT and BBS proteins, and reduced ciliary entry of membrane-associated proteins. Thm1-mutant cilia also show a retrograde transport defect for the Hedgehog transducer, Smoothened, and an impaired response to Smoothened agonist, SAG. Thm2-null MEF show normal ciliary dynamics and Hedgehog signaling, but additional loss of a Thm1 allele impairs response to SAG. Further, Thm1;Thm2 double-mutant MEF show enhanced cilia disassembly, and increased impairment of INPP5E ciliary import. Thus, Thm1 and Thm2 have unique and redundant roles in MEF. Thm1 regulates cilia assembly, and alone and together with Thm2, regulates cilia disassembly, ciliary entry of membrane-associated protein, Hedgehog signaling, and embryogenesis. These findings shed light on mechanisms underlying Thm1-, Thm2- or IFT-A-mediated ciliopathies.
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Affiliation(s)
- Wei Wang
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Bailey A Allard
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Tana S Pottorf
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Henry H Wang
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Jay L Vivian
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, USA
| | - Pamela V Tran
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
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28
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Establishing and regulating the composition of cilia for signal transduction. Nat Rev Mol Cell Biol 2020; 20:389-405. [PMID: 30948801 DOI: 10.1038/s41580-019-0116-4] [Citation(s) in RCA: 226] [Impact Index Per Article: 56.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The primary cilium is a hair-like surface-exposed organelle of the eukaryotic cell that decodes a variety of signals - such as odorants, light and Hedgehog morphogens - by altering the local concentrations and activities of signalling proteins. Signalling within the cilium is conveyed through a diverse array of second messengers, including conventional signalling molecules (such as cAMP) and some unusual intermediates (such as sterols). Diffusion barriers at the ciliary base establish the unique composition of this signalling compartment, and cilia adapt their proteome to signalling demands through regulated protein trafficking. Much progress has been made on the molecular understanding of regulated ciliary trafficking, which encompasses not only exchanges between the cilium and the rest of the cell but also the shedding of signalling factors into extracellular vesicles.
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29
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Pottorf TS, Fagan MP, Burkey BF, Cho DJ, Vath JE, Tran PV. MetAP2 inhibition reduces food intake and body weight in a ciliopathy mouse model of obesity. JCI Insight 2020; 5:134278. [PMID: 31877115 DOI: 10.1172/jci.insight.134278] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 12/18/2019] [Indexed: 12/13/2022] Open
Abstract
The ciliopathies Bardet-Biedl syndrome and Alström syndrome are genetically inherited pleiotropic disorders with hyperphagia and obesity as primary clinical features. Methionine aminopeptidase 2 inhibitors (MetAP2i) have been shown in preclinical and clinical studies to reduce food intake, body weight, and adiposity. Here, we investigated the effects of MetAP2i administration in a mouse model of ciliopathy produced by conditional deletion of the Thm1 gene in adulthood. Thm1 conditional knockout (cko) mice showed decreased hypothalamic proopiomelanocortin expression as well as hyperphagia, obesity, metabolic disease, and hepatic steatosis. In obese Thm1-cko mice, 2-week administration of MetAP2i reduced daily food intake and reduced body weight 17.1% from baseline (vs. 5% reduction for vehicle). This was accompanied by decreased levels of blood glucose, insulin, and leptin. Further, MetAP2i reduced gonadal adipose depots and adipocyte size and improved liver morphology. This is the first report to our knowledge of MetAP2i reducing hyperphagia and body weight and ameliorating metabolic indices in a mouse model of ciliopathy. These results support further investigation of MetAP2 inhibition as a potential therapeutic strategy for ciliary-mediated forms of obesity.
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Affiliation(s)
- Tana S Pottorf
- Jared Grantham Kidney Institute and.,Department of Anatomy and Cell Biology, University of Kansas Medical Center (KUMC), Kansas City, Kansas, USA
| | | | | | - David J Cho
- Jared Grantham Kidney Institute and.,Department of Anatomy and Cell Biology, University of Kansas Medical Center (KUMC), Kansas City, Kansas, USA
| | | | - Pamela V Tran
- Jared Grantham Kidney Institute and.,Department of Anatomy and Cell Biology, University of Kansas Medical Center (KUMC), Kansas City, Kansas, USA
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30
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Actin-based regulation of ciliogenesis - The long and the short of it. Semin Cell Dev Biol 2019; 102:132-138. [PMID: 31862221 DOI: 10.1016/j.semcdb.2019.12.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/23/2019] [Accepted: 12/07/2019] [Indexed: 12/11/2022]
Abstract
The primary cilia is found on the mammalian cell surface where it serves as an antenna for the reception and transmission of a variety of cellular signaling pathways. At its core the cilium is a microtubule-based organelle, but it is clear that its assembly and function are dependent upon the coordinated regulation of both actin and microtubule dynamics. In particular, the discovery that the centrosome is able to act as both a microtubule and actin organizing centre implies that both cytoskeletal networks are acting directly on the process of cilia assembly. In this review, we set our recent results with the formin FHDC1 in the context of current reports that show each stage of ciliogenesis is impacted by changes in actin dynamics. These include direct effects of actin filament assembly on basal body positioning, vesicle trafficking to and entry into the cilium, cilia length, cilia membrane organization and cilia-dependent signaling.
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31
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Mijalkovic J, van Krugten J, Oswald F, Acar S, Peterman EJG. Single-Molecule Turnarounds of Intraflagellar Transport at the C. elegans Ciliary Tip. Cell Rep 2019; 25:1701-1707.e2. [PMID: 30428341 DOI: 10.1016/j.celrep.2018.10.050] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 04/13/2018] [Accepted: 10/12/2018] [Indexed: 11/17/2022] Open
Abstract
Cilia are microtubule-based sensing hubs that rely on intraflagellar transport (IFT) for their development, maintenance, and function. Kinesin-2 motors transport IFT trains, consisting of IFT proteins and cargo, from ciliary base to tip. There, trains turn around and are transported back by IFT dynein. The mechanism of tip turnaround has remained elusive. Here, we employ single-molecule fluorescence microscopy of IFT components in the tips of phasmid cilia of living C. elegans. Analysis of the trajectories reveals that while motor proteins and IFT-A particle component CHE-11 mostly turn around immediately, the IFT-B particle component OSM-6 pauses for several seconds. Our data indicate that IFT trains disassemble into at least IFT-A, IFT-B, IFT-dynein, and OSM-3 complexes at the tip, where OSM-6 is temporarily retained or undergoes modification, prior to train reassembly and retrograde transport. The single-molecule approach used here is a valuable tool to study how directional switches occur in microtubule-based transport processes.
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Affiliation(s)
- Jona Mijalkovic
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Jaap van Krugten
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Felix Oswald
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Seyda Acar
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Erwin J G Peterman
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands.
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32
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Abstract
Primary cilia project in a single copy from the surface of most vertebrate cell types; they detect and transmit extracellular cues to regulate diverse cellular processes during development and to maintain tissue homeostasis. The sensory capacity of primary cilia relies on the coordinated trafficking and temporal localization of specific receptors and associated signal transduction modules in the cilium. The canonical Hedgehog (HH) pathway, for example, is a bona fide ciliary signalling system that regulates cell fate and self-renewal in development and tissue homeostasis. Specific receptors and associated signal transduction proteins can also localize to primary cilia in a cell type-dependent manner; available evidence suggests that the ciliary constellation of these proteins can temporally change to allow the cell to adapt to specific developmental and homeostatic cues. Consistent with important roles for primary cilia in signalling, mutations that lead to their dysfunction underlie a pleiotropic group of diseases and syndromic disorders termed ciliopathies, which affect many different tissues and organs of the body. In this Review, we highlight central mechanisms by which primary cilia coordinate HH, G protein-coupled receptor, WNT, receptor tyrosine kinase and transforming growth factor-β (TGFβ)/bone morphogenetic protein (BMP) signalling and illustrate how defects in the balanced output of ciliary signalling events are coupled to developmental disorders and disease progression.
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33
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Jacobs DT, Allard BA, Pottorf TS, Silva LM, Wang W, Al-Naamani A, Agborbesong E, Wang T, Carr DA, Tran PV. Intraflagellar-transport A dysfunction causes hyperphagia-induced systemic insulin resistance in a pre-obese state. FASEB J 2019; 34:148-160. [PMID: 31914634 DOI: 10.1096/fj.201900751r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 10/04/2019] [Accepted: 10/21/2019] [Indexed: 12/13/2022]
Abstract
Deletion of murine Thm1, an intraflagellar transport A (IFT-A) component that mediates ciliary protein trafficking, causes hyperphagia, obesity, and metabolic syndrome. The role of Thm1 or IFT-A in adipogenesis and insulin sensitivity is unknown. Here, we report that Thm1 knockdown in 3T3-L1 pre-adipocytes promotes adipogenesis and enhances insulin sensitivity in vitro. Yet, pre-obese Thm1 conditional knockout mice show systemic insulin resistance. While insulin-induced AKT activation in Thm1 mutant adipose depots and skeletal muscle are similar to those of control littermates, an attenuated insulin response arises in the mutant liver. Insulin treatment of control and Thm1 mutant primary hepatocytes results in similar AKT activation. Moreover, pair-feeding Thm1 conditional knockout mice produces a normal insulin response, both in the liver and systemically. Thus, hyperphagia caused by a cilia defect, induces hepatic insulin resistance via a non-cell autonomous mechanism. In turn, hepatic insulin resistance drives systemic insulin resistance prior to an obese phenotype. These data demonstrate that insulin signaling across cell types is regulated differentially, and that the liver is particularly susceptible to hyperphagia-induced insulin resistance and a critical determinant of systemic insulin resistance.
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Affiliation(s)
- Damon T Jacobs
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Bailey A Allard
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Tana S Pottorf
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Luciane M Silva
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Wei Wang
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Aisha Al-Naamani
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Ewud Agborbesong
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Tao Wang
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Dajanae A Carr
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Pamela V Tran
- Department of Anatomy and Cell Biology, Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
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34
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Gpr63 is a modifier of microcephaly in Ttc21b mouse mutants. PLoS Genet 2019; 15:e1008467. [PMID: 31730647 PMCID: PMC6881074 DOI: 10.1371/journal.pgen.1008467] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/27/2019] [Accepted: 10/08/2019] [Indexed: 11/19/2022] Open
Abstract
The primary cilium is a signaling center critical for proper embryonic development. Previous studies have demonstrated that mice lacking Ttc21b have impaired retrograde trafficking within the cilium and multiple organogenesis phenotypes, including microcephaly. Interestingly, the severity of the microcephaly in Ttc21baln/aln homozygous null mutants is considerably affected by the genetic background and mutants on an FVB/NJ (FVB) background develop a forebrain significantly smaller than mutants on a C57BL/6J (B6) background. We performed a Quantitative Trait Locus (QTL) analysis to identify potential genetic modifiers and identified two regions linked to differential forebrain size: modifier of alien QTL1 (Moaq1) on chromosome 4 at 27.8 Mb and Moaq2 on chromosome 6 at 93.6 Mb. These QTLs were validated by constructing congenic strains. Further analysis of Moaq1 identified an orphan G-protein coupled receptor (GPCR), Gpr63, as a candidate gene. We identified a SNP that is polymorphic between the FVB and B6 strains in Gpr63 and creates a missense mutation predicted to be deleterious in the FVB protein. We used CRISPR-Cas9 genome editing to create two lines of FVB congenic mice: one with the B6 sequence of Gpr63 and the other with a deletion allele leading to a truncation of the GPR63 C-terminal tail. We then demonstrated that Gpr63 can localize to the cilium in vitro. These alleles affect ciliary localization of GPR63 in vitro and genetically interact with Ttc21baln/aln as Gpr63;Ttc21b double mutants show unique phenotypes including spina bifida aperta and earlier embryonic lethality. This validated Gpr63 as a modifier of multiple Ttc21b neural phenotypes and strongly supports Gpr63 as a causal gene (i.e., a quantitative trait gene, QTG) within the Moaq1 QTL. TTC21B in humans is a known ciliopathy gene and contributes to the pathophysiology of a number of ciliopathies. Mice homozygous for a null allele of Ttc21b also have a spectrum of ciliopathy phenotypes, including microcephaly (small brain). Further work has shown that the severity of the microcephaly significantly depends on the genetic background of the mouse model. The genetic mechanisms of the Ttc21b pathophysiology and the interacting gene network remain far from understood. As an initial attempt to understand the underlying mechanism(s) underlying the variable effects on brain size, we performed a quantitative trait locus (QTL) analysis and found two regions of genomic significance that correlated with smaller brain size. We confirmed both QTLs with congenic lines. One of the two regions was small enough that we considered candidate genes and hypothesized Gpr63 might be a contributing locus for a number of reasons. We evaluated this hypothesis directly with precise variant creation using genome editing and provide evidence that Ttc21b and Gpr63 do indeed genetically interact. Thus, we have been able to combine classical QTL analysis and genome editing to directly test the resulting hypothesis.
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35
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ERICH3 in Primary Cilia Regulates Cilium Formation and the Localisations of Ciliary Transport and Sonic Hedgehog Signaling Proteins. Sci Rep 2019; 9:16519. [PMID: 31712586 PMCID: PMC6848114 DOI: 10.1038/s41598-019-52830-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 10/23/2019] [Indexed: 01/05/2023] Open
Abstract
Intraflagellar transport (IFT) is essential for the formation and function of the microtubule-based primary cilium, which acts as a sensory and signalling device at the cell surface. Consisting of IFT-A/B and BBSome cargo adaptors that associate with molecular motors, IFT transports protein into (anterograde IFT) and out of (retrograde IFT) the cilium. In this study, we identify the mostly uncharacterised ERICH3 protein as a component of the mammalian primary cilium. Loss of ERICH3 causes abnormally short cilia and results in the accumulation of IFT-A/B proteins at the ciliary tip, together with reduced ciliary levels of retrograde transport regulators, ARL13B, INPP5E and BBS5. We also show that ERICH3 ciliary localisations require ARL13B and BBSome components. Finally, ERICH3 loss causes positive (Smoothened) and negative (GPR161) regulators of sonic hedgehog signaling (Shh) to accumulate at abnormally high levels in the cilia of pathway-stimulated cells. Together, these findings identify ERICH3 as a novel component of the primary cilium that regulates cilium length and the ciliary levels of Shh signaling molecules. We propose that ERICH3 functions within retrograde IFT-associated pathways to remove signaling proteins from cilia.
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36
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Muñoz-Estrada J, Ferland RJ. Ahi1 promotes Arl13b ciliary recruitment, regulates Arl13b stability and is required for normal cell migration. J Cell Sci 2019; 132:jcs.230680. [PMID: 31391239 DOI: 10.1242/jcs.230680] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 07/24/2019] [Indexed: 12/14/2022] Open
Abstract
Mutations in the Abelson-helper integration site 1 (AHI1) gene are associated with neurological/neuropsychiatric disorders, and cause the neurodevelopmental ciliopathy Joubert syndrome (JBTS). Here, we show that deletion of the transition zone (TZ) protein Ahi1 in mouse embryonic fibroblasts (MEFs) has a small effect on cilia formation. However, Ahi1 loss in these cells results in: (1) reduced localization of the JBTS-associated protein Arl13b to the ciliary membrane, (2) decreased sonic hedgehog signaling, (3) and an abnormally elongated ciliary axoneme accompanied by an increase in ciliary IFT88 concentrations. While no changes in Arl13b levels are detected in crude cell membrane extracts, loss of Ahi1 significantly reduced the level of non-membrane-associated Arl13b and its stability via the proteasome pathway. Exogenous expression of Ahi1-GFP in Ahi1-/- MEFs restored ciliary length, increased ciliary recruitment of Arl13b and augmented Arl13b stability. Finally, Ahi1-/- MEFs displayed defects in cell motility and Pdgfr-α-dependent migration. Overall, our findings support molecular mechanisms underlying JBTS etiology that involve: (1) disruptions at the TZ resulting in defects of membrane- and non-membrane-associated proteins to localize to primary cilia, and (2) defective cell migration.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Jesús Muñoz-Estrada
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - Russell J Ferland
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA .,Department of Neurology, Albany Medical College, Albany, NY 12208, USA
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37
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Cassioli C, Baldari CT. A Ciliary View of the Immunological Synapse. Cells 2019; 8:E789. [PMID: 31362462 PMCID: PMC6721628 DOI: 10.3390/cells8080789] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/15/2019] [Accepted: 07/25/2019] [Indexed: 12/28/2022] Open
Abstract
The primary cilium has gone from being a vestigial organelle to a crucial signaling hub of growing interest given the association between a group of human disorders, collectively known as ciliopathies, and defects in its structure or function. In recent years many ciliogenesis proteins have been observed at extraciliary sites in cells and likely perform cilium-independent functions ranging from regulation of the cytoskeleton to vesicular trafficking. Perhaps the most striking example is the non-ciliated T lymphocyte, in which components of the ciliary machinery are repurposed for the assembly and function of the immunological synapse even in the absence of a primary cilium. Furthermore, the specialization traits described at the immunological synapse are similar to those seen in the primary cilium. Here, we review common regulators and features shared by the immunological synapse and the primary cilium that document the remarkable homology between these structures.
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Affiliation(s)
- Chiara Cassioli
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | - Cosima T Baldari
- Department of Life Sciences, University of Siena, 53100 Siena, Italy.
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38
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DiTirro D, Philbrook A, Rubino K, Sengupta P. The Caenorhabditis elegans Tubby homolog dynamically modulates olfactory cilia membrane morphogenesis and phospholipid composition. eLife 2019; 8:48789. [PMID: 31259686 PMCID: PMC6624019 DOI: 10.7554/elife.48789] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 06/21/2019] [Indexed: 12/13/2022] Open
Abstract
Plasticity in sensory signaling is partly mediated via regulated trafficking of signaling molecules to and from primary cilia. Tubby-related proteins regulate ciliary protein transport; however, their roles in remodeling cilia properties are not fully understood. We find that the C. elegans TUB-1 Tubby homolog regulates membrane morphogenesis and signaling protein transport in specialized sensory cilia. In particular, TUB-1 is essential for sensory signaling-dependent reshaping of olfactory cilia morphology. We show that compromised sensory signaling alters cilia membrane phosphoinositide composition via TUB-1-dependent trafficking of a PIP5 kinase. TUB-1 regulates localization of this lipid kinase at the cilia base in part via localization of the AP-2 adaptor complex subunit DPY-23. Our results describe new functions for Tubby proteins in the dynamic regulation of cilia membrane lipid composition, morphology, and signaling protein content, and suggest that this conserved family of proteins plays a critical role in mediating cilia structural and functional plasticity.
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Affiliation(s)
- Danielle DiTirro
- Department of Biology, Brandeis University, Waltham, United States
| | - Alison Philbrook
- Department of Biology, Brandeis University, Waltham, United States
| | - Kendrick Rubino
- Department of Biology, Brandeis University, Waltham, United States
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, United States
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39
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Abstract
Primary cilia are singular, sensory organelles that extend from the plasma membrane of most quiescent mammalian cells. These slender, microtubule-based organelles receive and transduce extracellular cues and regulate signaling pathways. Primary cilia are critical to the development and function of many tissue types, and mutation of ciliary genes causes multi-system disorders, termed ciliopathies. Notably, renal cystic disease is one of the most common clinical features of ciliopathies, highlighting a central role for primary cilia in the kidney. Additionally, acute kidney injury and chronic kidney disease are associated with altered primary cilia lengths on renal epithelial cells, suggesting ciliary dynamics and renal physiology are linked. Here we describe methods to examine primary cilia in kidney tissue and in cultured renal cells. We include immunofluorescence and scanning electron microscopy to determine ciliary localization of proteins and cilia structure. Further, we detail cellular assays to measure cilia assembly and disassembly, which regulate cilia length.
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40
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Tao D, Xue H, Zhang C, Li G, Sun Y. The Role of IFT140 in Osteogenesis of Adult Mice Long Bone. J Histochem Cytochem 2019; 67:601-611. [PMID: 31034313 DOI: 10.1369/0022155419847188] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Primary cilia have a pivotal role in bone development and the dysfunctions of primary cilia cause skeletal ciliopathies. Intraflagellar transport (IFT) proteins are conserved mediators of cilium signaling. IFT sub-complex A is known to regulate retrograde IFT in the cilium. As a core protein of IFT complex A, IFT140 has been shown to have a relationship with serious skeletal ciliopathies caused in humans. However, the effects and mechanisms of IFT140 in bone formation have not been systematically disclosed. To further investigate the potential role of IFT140 in osteogenesis, we established a mouse model by conditional deletion of IFT140 in pre-osteoblasts. The adult knock-out mice exhibited dwarf phenotypes, such as short bone length, less bone mass, and decreased bone mineral apposition rate. In addition, by IFT140 deletion, the expressions of several osteoblastic markers were decreased and loss of bone became severe with aging. These results suggest that cilia gene Ift140 is essential in bone development.
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Affiliation(s)
- Dike Tao
- Department of Implantology, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China.,Department of Implantology, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Hui Xue
- Department of Implantology, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China.,Department of Implantology, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Chenyang Zhang
- Department of Implantology, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China.,Department of Implantology, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Gongchen Li
- Department of Implantology, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China.,Department of Implantology, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Yao Sun
- Department of Implantology, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
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41
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Lin H, Zhang Z, Iomini C, Dutcher SK. Identifying RNA splicing factors using IFT genes in Chlamydomonas reinhardtii. Open Biol 2019. [PMID: 29514868 PMCID: PMC5881031 DOI: 10.1098/rsob.170211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Intraflagellar transport moves proteins in and out of flagella/cilia and it is essential for the assembly of these organelles. Using whole-genome sequencing, we identified splice site mutations in two IFT genes, IFT81 (fla9) and IFT121 (ift121-2), which lead to flagellar assembly defects in the unicellular green alga Chlamydomonas reinhardtii. The splicing defects in these ift mutants are partially corrected by mutations in two conserved spliceosome proteins, DGR14 and FRA10. We identified a dgr14 deletion mutant, which suppresses the 3′ splice site mutation in IFT81, and a frameshift mutant of FRA10, which suppresses the 5′ splice site mutation in IFT121. Surprisingly, we found dgr14-1 and fra10 mutations suppress both splice site mutations. We suggest these two proteins are involved in facilitating splice site recognition/interaction; in their absence some splice site mutations are tolerated. Nonsense mutations in SMG1, which is involved in nonsense-mediated decay, lead to accumulation of aberrant transcripts and partial restoration of flagellar assembly in the ift mutants. The high density of introns and the conservation of noncore splicing factors, together with the ease of scoring the ift mutant phenotype, make Chlamydomonas an attractive organism to identify new proteins involved in splicing through suppressor screening.
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Affiliation(s)
- Huawen Lin
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St Louis, MO 63110, USA
| | - Zhengyan Zhang
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St Louis, MO 63110, USA
| | - Carlo Iomini
- Department of Ophthalmology, Mount Sinai School of Medicine, New York, NY, USA
| | - Susan K Dutcher
- Department of Genetics, Washington University School of Medicine, 4523 Clayton Avenue, St Louis, MO 63110, USA
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42
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Picariello T, Brown JM, Hou Y, Swank G, Cochran DA, King OD, Lechtreck K, Pazour GJ, Witman GB. A global analysis of IFT-A function reveals specialization for transport of membrane-associated proteins into cilia. J Cell Sci 2019; 132:jcs220749. [PMID: 30659111 PMCID: PMC6382014 DOI: 10.1242/jcs.220749] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 01/02/2019] [Indexed: 12/28/2022] Open
Abstract
Intraflagellar transport (IFT), which is essential for the formation and function of cilia in most organisms, is the trafficking of IFT trains (i.e. assemblies of IFT particles) that carry cargo within the cilium. Defects in IFT cause several human diseases. IFT trains contain the complexes IFT-A and IFT-B. To dissect the functions of these complexes, we studied a Chlamydomonas mutant that is null for the IFT-A protein IFT140. The mutation had no effect on IFT-B but destabilized IFT-A, preventing flagella assembly. Therefore, IFT-A assembly requires IFT140. Truncated IFT140, which lacks the N-terminal WD repeats of the protein, partially rescued IFT and supported formation of half-length flagella that contained normal levels of IFT-B but greatly reduced amounts of IFT-A. The axonemes of these flagella had normal ultrastructure and, as investigated by SDS-PAGE, normal composition. However, composition of the flagellar 'membrane+matrix' was abnormal. Analysis of the latter fraction by mass spectrometry revealed decreases in small GTPases, lipid-anchored proteins and cell signaling proteins. Thus, IFT-A is specialized for the import of membrane-associated proteins. Abnormal levels of the latter are likely to account for the multiple phenotypes of patients with defects in IFT140.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Tyler Picariello
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Jason M Brown
- Department of Biology, Salem State University, Salem, MA 01970, USA
| | - Yuqing Hou
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Gregory Swank
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Deborah A Cochran
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Oliver D King
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Karl Lechtreck
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - George B Witman
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
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43
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Han S, Miyoshi K, Shikada S, Amano G, Wang Y, Yoshimura T, Katayama T. TULP3 is required for localization of membrane-associated proteins ARL13B and INPP5E to primary cilia. Biochem Biophys Res Commun 2019; 509:227-234. [PMID: 30583862 DOI: 10.1016/j.bbrc.2018.12.109] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 12/14/2018] [Indexed: 01/24/2023]
Abstract
The primary cilia are known as biosensors that transduce signals through the ciliary membrane proteins in vertebrate cells. The ciliary membrane contains transmembrane proteins and membrane-associated proteins. Tubby-like protein 3 (TULP3), a member of the tubby family, has been shown to interact with the intraflagellar transport-A complex (IFT-A) and to be involved in the ciliary localization of transmembrane proteins, although its role in the ciliary entry of membrane-associated proteins has remained unclear. Here, to determine whether TULP3 is required for the localization of ciliary membrane-associated proteins, we generated and analyzed TULP3-knockout (KO) hTERT RPE-1 (RPE1) cells. Immunofluorescence analysis demonstrated that ciliary formation was downregulated in TULP3-KO cells and that membrane-associated proteins, ADP-ribosylation factor-like 13B (ARL13B) and inositol polyphosphate-5-phosphatase E (INPP5E), failed to localize to primary cilia in TULP3-KO cells. These defects in the localization of ARL13B and INPP5E in TULP3-KO cells were rescued by the exogenous expression of wild-type TULP3, but not that of mutant TULP3 lacking the ability to bind IFT-A. In addition, the expression of TUB protein, another member of the tubby family whose endogenous expression is absent in RPE1 cells, also rescued the defective ciliary localization of ARL13B and INPP5E in TULP3-KO cells, suggesting that there is functional redundancy between TULP3 and TUB. Our findings indicate that TULP3 participates in ciliogenesis, and targets membrane-associated proteins to primary cilia via binding to IFT-A.
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Affiliation(s)
- Sarina Han
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Ko Miyoshi
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan.
| | - Sho Shikada
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Genki Amano
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Yinshengzhuoma Wang
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Takeshi Yoshimura
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Taiichi Katayama
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
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44
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Sekiguchi T, Furuno N, Ishii T, Hirose E, Sekiguchi F, Wang Y, Kobayashi H. RagA, an mTORC1 activator, interacts with a hedgehog signaling protein, WDR35/IFT121. Genes Cells 2019; 24:151-161. [DOI: 10.1111/gtc.12663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 12/12/2018] [Accepted: 12/13/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Takeshi Sekiguchi
- Department of Molecular Biology, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Nobuaki Furuno
- Laboratory for Amphibian Biology, Graduate School of Science Hiroshima University Higashihiroshima Japan
| | - Takashi Ishii
- Department of BiochemistryFukuoka Dental College Fukuoka Japan
| | - Eiji Hirose
- Faculty of Health Promotional Sciences Tokoha University Kitaku, Shizuoka Japan
| | - Fumiko Sekiguchi
- Department of Molecular Biology, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Yonggang Wang
- Department of Molecular Biology, Graduate School of Medical Sciences Kyushu University Fukuoka Japan
| | - Hideki Kobayashi
- Department of Human Nutrition, Faculty of Contemporary Life ScienceChugoku‐Gakuen University Okayama Japan
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45
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Stawicki TM, Linbo T, Hernandez L, Parkinson L, Bellefeuille D, Rubel EW, Raible DW. The role of retrograde intraflagellar transport genes in aminoglycoside-induced hair cell death. Biol Open 2019; 8:bio.038745. [PMID: 30578252 PMCID: PMC6361216 DOI: 10.1242/bio.038745] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Sensory hair cells are susceptible to numerous insults, including certain therapeutic medications like aminoglycoside antibiotics, and hearing and balance disorders are often a dose-limiting side effect of these medications. We show that mutations in multiple genes in both the retrograde intraflagellar transport (IFT) motor and adaptor complexes lead to resistance to aminoglycoside-induced hair cell death. These mutations also lead to defects in the entry of both aminoglycosides and the vital dye FM1-43 into hair cells, both processes that depend on hair cell mechanotransduction activity. However, the trafficking of proteins important for mechanotransduction activity is not altered by these mutations. Our data suggest that both retrograde IFT motor and adaptor complex genes are playing a role in aminoglycoside toxicity through affecting aminoglycoside uptake into hair cells. Summary: Here we show that both retrograde intraflagellar transport motor proteins and IFT-A adaptor molecules play a role in aminoglycoside-induced hair cell death, seemingly through regulating aminoglycoside uptake.
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Affiliation(s)
- Tamara M Stawicki
- Program in Neuroscience, Lafayette College, Easton, PA 18042, USA .,Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Tor Linbo
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Liana Hernandez
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Lauren Parkinson
- Program in Neuroscience, Lafayette College, Easton, PA 18042, USA
| | | | - Edwin W Rubel
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA 98195, USA
| | - David W Raible
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA.,Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA 98195, USA
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46
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Scheidel N, Blacque OE. Intraflagellar Transport Complex A Genes Differentially Regulate Cilium Formation and Transition Zone Gating. Curr Biol 2018; 28:3279-3287.e2. [PMID: 30293716 DOI: 10.1016/j.cub.2018.08.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 06/08/2018] [Accepted: 08/07/2018] [Indexed: 02/03/2023]
Abstract
Cilia are found on most eukaryotic cell types, serving motility, environment sensing, and signaling (cell-cell) functions, and defects cause genetic diseases (ciliopathies), affecting the development of many tissues [1]. Cilia are built by intraflagellar transport (IFT), a bidirectional microtubule-based motility driven by kinesin-2 anterograde (toward ciliary tip) and IFT-dynein retrograde (toward ciliary base) motors together with IFT-A and IFT-B cargo adaptor complexes that control retrograde and anterograde IFT, respectively [2]. Ciliary composition is also facilitated by the transition zone (TZ) at the ciliary base and the associated Meckel-Gruber syndrome (MKS) and nephronophthisis (NPHP) modules that establish protein diffusion barriers and regulate cilium structure [3]. Although the molecular architecture of the IFT machine is emerging [2], how individual components contribute to cilium subtype formation and IFT remains relatively unexplored, especially in vivo. In addition, little is known about functional interactions between IFT and TZ modules. Here, in Caenorhabditis elegans (roundworms), we identify cell-type-specific mechanisms by which IFT-A sculpts the structures of discrete ciliary subtypes and regulates IFT. We also uncover differential roles for IFT-A subunits in controlling the TZ restriction of MKS module components and ciliary exclusion (gating) of periciliary membrane proteins, with IFT-140 controlling their ciliary entry and IFT-43/121/139 controlling their ciliary removal. Furthermore, we determine that IFT-A and MKS module components synergistically interact to determine cilium structure. Overall, this work provides insight into the functional architecture of a metazoan IFT-A complex in different cell types and uncovers new relationships between ciliopathy-associated IFT-A and TZ modules.
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Affiliation(s)
- Noémie Scheidel
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Oliver E Blacque
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
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47
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Abstract
The primary cilium is an antenna-like organelle assembled on most types of quiescent and differentiated mammalian cells. This immotile structure is essential for interpreting extracellular signals that regulate growth, development and homeostasis. As such, ciliary defects produce a spectrum of human diseases, termed ciliopathies, and deregulation of this important organelle also plays key roles during tumor formation and progression. Recent studies have begun to clarify the key mechanisms that regulate ciliary assembly and disassembly in both normal and tumor cells, highlighting new possibilities for therapeutic intervention. Here, we review these exciting new findings, discussing the molecular factors involved in cilium formation and removal, the intrinsic and extrinsic control of cilium assembly and disassembly, and the relevance of these processes to mammalian cell growth and disease.
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Affiliation(s)
- Lei Wang
- Department of Pathology, New York University Cancer Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Brian D Dynlacht
- Department of Pathology, New York University Cancer Institute, New York University School of Medicine, New York, NY 10016, USA
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48
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Cilium structure, assembly, and disassembly regulated by the cytoskeleton. Biochem J 2018; 475:2329-2353. [PMID: 30064990 PMCID: PMC6068341 DOI: 10.1042/bcj20170453] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/02/2018] [Accepted: 07/04/2018] [Indexed: 12/17/2022]
Abstract
The cilium, once considered a vestigial structure, is a conserved, microtubule-based organelle critical for transducing extracellular chemical and mechanical signals that control cell polarity, differentiation, and proliferation. The cilium undergoes cycles of assembly and disassembly that are controlled by complex inter-relationships with the cytoskeleton. Microtubules form the core of the cilium, the axoneme, and are regulated by post-translational modifications, associated proteins, and microtubule dynamics. Although actin and septin cytoskeletons are not major components of the axoneme, they also regulate cilium organization and assembly state. Here, we discuss recent advances on how these different cytoskeletal systems affect cilium function, structure, and organization.
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49
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Lee N, Park J, Bae YC, Lee JH, Kim CH, Moon SJ. Time-Lapse Live-Cell Imaging Reveals Dual Function of Oseg4, Drosophila WDR35, in Ciliary Protein Trafficking. Mol Cells 2018; 41:676-683. [PMID: 29983040 PMCID: PMC6078859 DOI: 10.14348/molcells.2018.0179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 06/01/2018] [Accepted: 06/04/2018] [Indexed: 11/27/2022] Open
Abstract
Cilia are highly specialized antennae-like organelles that extend from the cell surface and act as cell signaling hubs. Intraflagellar transport (IFT) is a specialized form of intracellular protein trafficking that is required for the assembly and maintenance of cilia. Because cilia are so important, mutations in several IFT components lead to human disease. Thus, clarifying the molecular functions of the IFT proteins is a high priority in cilia biology. Live imaging in various species and cellular preparations has proven to be an important technique in both the discovery of IFT and the mechanisms by which it functions. Live imaging of Drosophila cilia, however, has not yet been reported. Here, we have visualized the movement of IFT in Drosophila cilia using time-lapse live imaging for the first time. We found that NOMPB-GFP (IFT88) moves according to distinct parameters depending on the ciliary segment. NOMPB-GFP moves at a similar speed in proximal and distal cilia toward the tip (~0.45 μm/s). As it returns to the ciliary base, however, NOMPB-GFP moves at ~0.12 μm/s in distal cilia, accelerating to ~0.70 μm/s in proximal cilia. Furthermore, while live imaging NOMPB-GFP, we observed one of the IFT proteins required for retrograde movement, Oseg4 (WDR35), is also required for anterograde movement in distal cilia. We anticipate our time-lapse live imaging analysis technique in Drosophila cilia will be a good starting point for a more sophisticated analysis of IFT and its molecular mechanisms.
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Affiliation(s)
- Nayoung Lee
- Department of Oral Biology, BK21 PLUS, Yonsei University College of Dentistry, Seoul 03722,
Korea
| | - Jina Park
- Department of Oral Biology, BK21 PLUS, Yonsei University College of Dentistry, Seoul 03722,
Korea
- Laboratory of Low Dose Risk Assessment, National Radiation Emergency Medical Center, Korea Institute of Radiological & Medical Sciences, Seoul 01812,
Korea
| | - Yong Chul Bae
- Department of Oral Anatomy and Neurobiology, BK21, School of Dentistry, Kyungpook National University, Daegu 41940,
Korea
| | - Jung Ho Lee
- Department of Pharmacology, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Chul Hoon Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Seok Jun Moon
- Department of Oral Biology, BK21 PLUS, Yonsei University College of Dentistry, Seoul 03722,
Korea
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50
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Morthorst SK, Christensen ST, Pedersen LB. Regulation of ciliary membrane protein trafficking and signalling by kinesin motor proteins. FEBS J 2018; 285:4535-4564. [PMID: 29894023 DOI: 10.1111/febs.14583] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/09/2018] [Accepted: 06/11/2018] [Indexed: 12/14/2022]
Abstract
Primary cilia are antenna-like sensory organelles that regulate a substantial number of cellular signalling pathways in vertebrates, both during embryonic development as well as in adulthood, and mutations in genes coding for ciliary proteins are causative of an expanding group of pleiotropic diseases known as ciliopathies. Cilia consist of a microtubule-based axoneme core, which is subtended by a basal body and covered by a bilayer lipid membrane of unique protein and lipid composition. Cilia are dynamic organelles, and the ability of cells to regulate ciliary protein and lipid content in response to specific cellular and environmental cues is crucial for balancing ciliary signalling output. Here we discuss mechanisms involved in regulation of ciliary membrane protein trafficking and signalling, with main focus on kinesin-2 and kinesin-3 family members.
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