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Fujii T, Liang L, Nakayama K, Katoh Y. Defects in diffusion barrier function of ciliary transition zone caused by ciliopathy variations of TMEM218. Hum Mol Genet 2024; 33:1442-1453. [PMID: 38751342 DOI: 10.1093/hmg/ddae083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/01/2024] [Accepted: 05/07/2024] [Indexed: 08/09/2024] Open
Abstract
Primary cilia are antenna-like structures protruding from the surface of various eukaryotic cells, and have distinct protein compositions in their membranes. This distinct protein composition is maintained by the presence of the transition zone (TZ) at the ciliary base, which acts as a diffusion barrier between the ciliary and plasma membranes. Defects in cilia and the TZ are known to cause a group of disorders collectively called the ciliopathies, which demonstrate a broad spectrum of clinical features, such as perinatally lethal Meckel syndrome (MKS), relatively mild Joubert syndrome (JBTS), and nonsyndromic nephronophthisis (NPHP). Proteins constituting the TZ can be grouped into the MKS and NPHP modules. The MKS module is composed of several transmembrane proteins and three soluble proteins. TMEM218 was recently reported to be mutated in individuals diagnosed as MKS and JBTS. However, little is known about how TMEM218 mutations found in MKS and JBTS affect the functions of cilia. In this study, we found that ciliary membrane proteins were not localized to cilia in TMEM218-knockout cells, indicating impaired barrier function of the TZ. Furthermore, the exogenous expression of JBTS-associated TMEM218 variants but not MKS-associated variants in TMEM218-knockout cells restored the localization of ciliary membrane proteins. In particular, when expressed in TMEM218-knockout cells, the TMEM218(R115H) variant found in JBTS was able to restore the barrier function of cells, whereas the MKS variant TMEM218(R115C) could not. Thus, the severity of symptoms of MKS and JBTS individuals appears to correlate with the degree of their ciliary defects at the cellular level.
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Affiliation(s)
- Taiju Fujii
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Luxiaoxue Liang
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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2
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Wolf MTF, Bonsib SM, Larsen CP, Hildebrandt F. Nephronophthisis: a pathological and genetic perspective. Pediatr Nephrol 2024; 39:1977-2000. [PMID: 37930417 DOI: 10.1007/s00467-023-06174-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 11/07/2023]
Abstract
Nephronophthisis (NPHP) is an autosomal recessive cystic kidney disease and is one of the most frequent genetic causes for kidney failure (KF) in children and adolescents. Over 20 genes cause NPHP and over 90 genes contribute to renal ciliopathies often involving multiple organs. About 15-20% of NPHP patients have additional extrarenal symptoms affecting other organs than the kidneys. The involvement of additional organ systems in syndromic forms of NPHP is explained by shared expression of most NPHP gene products in centrosomes and primary cilia, a sensory organelle present in most mammalian cells. This finding resulted in the classification of NPHP as a ciliopathy. If extrarenal symptoms are present in addition to NPHP, these disorders are defined as NPHP-related ciliopathies (NPHP-RC) and can involve the retina (e.g., with Senior-Løken syndrome), CNS (central nervous system) (e.g., with Joubert syndrome), liver (e.g., Boichis and Arima syndromes), or bone (e.g., Mainzer-Saldino and Sensenbrenner syndromes). This review focuses on the pathological findings and the recent genetic advances in NPHP and NPHP-RC. Different mechanisms and signaling pathways are involved in NPHP ranging from planar cell polarity, sonic hedgehog signaling (Shh), DNA damage response pathway, Hippo, mTOR, and cAMP signaling. A number of therapeutic interventions appear to be promising, ranging from vasopressin receptor 2 antagonists such as tolvaptan, cyclin-dependent kinase inhibitors such as roscovitine, Hh agonists such as purmorphamine, and mTOR inhibitors such as rapamycin.
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Affiliation(s)
- Matthias T F Wolf
- Division of Pediatric Nephrology, University of Texas, Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
- Division of Pediatric Nephrology, C.S. Mott Children's Hospital, University of Michigan, 1150 W. Medical Center Dr, Ann Arbor, MI, 48109, USA.
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3
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Reddy Palicharla V, Mukhopadhyay S. Molecular and structural perspectives on protein trafficking to the primary cilium membrane. Biochem Soc Trans 2024; 52:1473-1487. [PMID: 38864436 DOI: 10.1042/bst20231403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 05/23/2024] [Accepted: 05/24/2024] [Indexed: 06/13/2024]
Abstract
The primary cilium is a dynamic subcellular compartment templated from the mother centriole or basal body. Cilia are solitary and tiny, but remarkably consequential in cellular pathways regulating proliferation, differentiation, and maintenance. Multiple transmembrane proteins such as G-protein-coupled receptors, channels, enzymes, and membrane-associated lipidated proteins are enriched in the ciliary membrane. The precise regulation of ciliary membrane content is essential for effective signal transduction and maintenance of tissue homeostasis. Surprisingly, a few conserved molecular factors, intraflagellar transport complex A and the tubby family adapter protein TULP3, mediate the transport of most membrane cargoes into cilia. Recent advances in cryogenic electron microscopy provide fundamental insights into these molecular players. Here, we review the molecular players mediating cargo delivery into the ciliary membrane through the lens of structural biology. These mechanistic insights into ciliary transport provide a framework for understanding of disease variants in ciliopathies, enable precise manipulation of cilia-mediated pathways, and provide a platform for the development of targeted therapeutics.
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Affiliation(s)
- Vivek Reddy Palicharla
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, U.S.A
| | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, U.S.A
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4
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Heiman MG, Bülow HE. Dendrite morphogenesis in Caenorhabditis elegans. Genetics 2024; 227:iyae056. [PMID: 38785371 PMCID: PMC11151937 DOI: 10.1093/genetics/iyae056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 04/02/2024] [Indexed: 05/25/2024] Open
Abstract
Since the days of Ramón y Cajal, the vast diversity of neuronal and particularly dendrite morphology has been used to catalog neurons into different classes. Dendrite morphology varies greatly and reflects the different functions performed by different types of neurons. Significant progress has been made in our understanding of how dendrites form and the molecular factors and forces that shape these often elaborately sculpted structures. Here, we review work in the nematode Caenorhabditis elegans that has shed light on the developmental mechanisms that mediate dendrite morphogenesis with a focus on studies investigating ciliated sensory neurons and the highly elaborated dendritic trees of somatosensory neurons. These studies, which combine time-lapse imaging, genetics, and biochemistry, reveal an intricate network of factors that function both intrinsically in dendrites and extrinsically from surrounding tissues. Therefore, dendrite morphogenesis is the result of multiple tissue interactions, which ultimately determine the shape of dendritic arbors.
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Affiliation(s)
- Maxwell G Heiman
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Hannes E Bülow
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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5
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Houston BJ, Merriner DJ, Stathatos GG, Nguyen JH, O'Connor AE, Lopes AM, Conrad DF, Baker M, Dunleavy JE, O'Bryan MK. Genetic mutation of Cep76 results in male infertility due to abnormal sperm tail composition. Life Sci Alliance 2024; 7:e202302452. [PMID: 38570187 PMCID: PMC10992998 DOI: 10.26508/lsa.202302452] [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: 10/22/2023] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/05/2024] Open
Abstract
The transition zone is a specialised gate at the base of cilia/flagella, which separates the ciliary compartment from the cytoplasm and strictly regulates protein entry. We identified a potential new regulator of the male germ cell transition zone, CEP76. We demonstrated that CEP76 was involved in the selective entry and incorporation of key proteins required for sperm function and fertility into the ciliary compartment and ultimately the sperm tail. In the mutant, sperm tails were shorter and immotile as a consequence of deficits in essential sperm motility proteins including DNAH2 and AKAP4, which accumulated at the sperm neck in the mutant. Severe annulus, fibrous sheath, and outer dense fibre abnormalities were also detected in sperm lacking CEP76. Finally, we identified that CEP76 dictates annulus positioning and structure. This study suggests CEP76 as a male germ cell transition zone protein and adds further evidence to the hypothesis that the spermatid transition zone and annulus are part of the same functional structure.
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Affiliation(s)
- Brendan J Houston
- https://ror.org/01ej9dk98 School of BioSciences and Bio21 Molecular Sciences and Biotechnology Institute, The University of Melbourne, Parkville, Australia
| | - D Jo Merriner
- https://ror.org/01ej9dk98 School of BioSciences and Bio21 Molecular Sciences and Biotechnology Institute, The University of Melbourne, Parkville, Australia
| | - G Gemma Stathatos
- https://ror.org/01ej9dk98 School of BioSciences and Bio21 Molecular Sciences and Biotechnology Institute, The University of Melbourne, Parkville, Australia
| | - Joseph H Nguyen
- https://ror.org/01ej9dk98 School of BioSciences and Bio21 Molecular Sciences and Biotechnology Institute, The University of Melbourne, Parkville, Australia
| | - Anne E O'Connor
- https://ror.org/01ej9dk98 School of BioSciences and Bio21 Molecular Sciences and Biotechnology Institute, The University of Melbourne, Parkville, Australia
| | - Alexandra M Lopes
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Institute of Molecular Pathology & Immunology, University of Porto, Porto, Portugal
| | - Donald F Conrad
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR, USA
| | - Mark Baker
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, Australia
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, The University of Newcastle, Callaghan, Australia
| | - Jessica Em Dunleavy
- https://ror.org/01ej9dk98 School of BioSciences and Bio21 Molecular Sciences and Biotechnology Institute, The University of Melbourne, Parkville, Australia
| | - Moira K O'Bryan
- https://ror.org/01ej9dk98 School of BioSciences and Bio21 Molecular Sciences and Biotechnology Institute, The University of Melbourne, Parkville, Australia
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6
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Mercey O, Mukherjee S, Guichard P, Hamel V. The molecular architecture of the ciliary transition zones. Curr Opin Cell Biol 2024; 88:102361. [PMID: 38648677 DOI: 10.1016/j.ceb.2024.102361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 03/28/2024] [Accepted: 03/30/2024] [Indexed: 04/25/2024]
Abstract
Cilia and flagella are specialized eukaryotic organelles projecting from the surface of eukaryotic cells that play a central role in various physiological processes, including cell motility, sensory perception, and signal transduction. At the base of these structures lies the ciliary transition zone, a pivotal region that functions as a gatekeeper and communication hub for ciliary activities. Despite its crucial role, the intricacies of its architecture remain poorly understood, especially given the variations in its organization across different cell types and species. In this review, we explore the molecular architecture of the ciliary transition zone, with a particular focus on recent findings obtained using cryotomography and super-resolution imaging techniques.
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Affiliation(s)
- Olivier Mercey
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Souradip Mukherjee
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Paul Guichard
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.
| | - Virginie Hamel
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.
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7
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Tingey M, Ruba A, Jiang Z, Yang W. Deciphering vesicle-assisted transport mechanisms in cytoplasm to cilium trafficking. Front Cell Neurosci 2024; 18:1379976. [PMID: 38860265 PMCID: PMC11163138 DOI: 10.3389/fncel.2024.1379976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 05/13/2024] [Indexed: 06/12/2024] Open
Abstract
The cilium, a pivotal organelle crucial for cell signaling and proper cell function, relies on meticulous macromolecular transport from the cytoplasm for its formation and maintenance. While the intraflagellar transport (IFT) pathway has traditionally been the focus of extensive study concerning ciliogenesis and ciliary maintenance, recent research highlights a complementary and alternative mechanism-vesicle-assisted transport (VAT) in cytoplasm to cilium trafficking. Despite its potential significance, the VAT pathway remains largely uncharacterized. This review explores recent studies providing evidence for the dynamics of vesicle-related diffusion and transport within the live primary cilium, employing high-speed super-resolution light microscopy. Additionally, we analyze the spatial distribution of vesicles in the cilium, mainly relying on electron microscopy data. By scrutinizing the VAT pathways that facilitate cargo transport into the cilium, with a specific emphasis on recent advancements and imaging data, our objective is to synthesize a comprehensive model of ciliary transport through the integration of IFT-VAT mechanisms.
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Affiliation(s)
| | | | | | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, PA, United States
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Mitra A, Loseva E, Peterman EJG. IFT cargo and motors associate sequentially with IFT trains to enter cilia of C. elegans. Nat Commun 2024; 15:3456. [PMID: 38658528 PMCID: PMC11043347 DOI: 10.1038/s41467-024-47807-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 04/12/2024] [Indexed: 04/26/2024] Open
Abstract
Intraflagellar transport (IFT) orchestrates entry of proteins into primary cilia. At the ciliary base, assembled IFT trains, driven by kinesin-2 motors, can transport cargo proteins into the cilium, across the crowded transition zone. How trains assemble at the base and how proteins associate with them is far from understood. Here, we use single-molecule imaging in the cilia of C. elegans chemosensory neurons to directly visualize the entry of kinesin-2 motors, kinesin-II and OSM-3, as well as anterograde cargo proteins, IFT dynein and tubulin. Single-particle tracking shows that IFT components associate with trains sequentially, both in time and space. Super-resolution maps of IFT components in wild-type and mutant worms reveal ciliary ultrastructure and show that kinesin-II is essential for axonemal organization. Finally, imaging cilia lacking kinesin-II and/or transition zone function uncovers the interplay of kinesin-II and OSM-3 in driving efficient transport of IFT trains across the transition zone.
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Affiliation(s)
- Aniruddha Mitra
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Elizaveta Loseva
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Erwin J G Peterman
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
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9
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Lai B, Jiang H, Gao Y, Zhou X. Skeletal ciliopathy: pathogenesis and related signaling pathways. Mol Cell Biochem 2024; 479:811-823. [PMID: 37188988 DOI: 10.1007/s11010-023-04765-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 05/09/2023] [Indexed: 05/17/2023]
Abstract
Cilia are tiny organelles with conserved structures and components in eukaryotic cells. Ciliopathy is a set of diseases resulting from cilium dysfunction classified into first-order and second-order ciliopathy. With the advancement of clinical diagnosis and radiography, numerous skeletal phenotypes, including polydactyly, short limbs, short ribs, scoliosis, a narrow thorax, and numerous anomalies in bone and cartilage, have been discovered in ciliopathies. Mutation in genes encoding cilia core components or other cilia-related molecules have been found in skeletal ciliopathies. Meanwhile, various signaling pathways associated with cilia and skeleton development have been deemed to be significant for the occurrence and progression of diseases. Herein, we review the structure and key components of the cilium and summarize several skeletal ciliopathies with their presumable pathology. We also emphasize the signaling pathways involved in skeletal ciliopathies, which may assist in developing potential therapies for these diseases.
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Affiliation(s)
- Bowen Lai
- Department of Orthopedics, Changzheng Hospital, Second Military Medical University, Fengyang Road 415, Shanghai, 200003, China
| | - Heng Jiang
- Department of Orthopedics, Changzheng Hospital, Second Military Medical University, Fengyang Road 415, Shanghai, 200003, China
| | - Yuan Gao
- Department of Orthopedics, Changzheng Hospital, Second Military Medical University, Fengyang Road 415, Shanghai, 200003, China
| | - Xuhui Zhou
- Department of Orthopedics, Changzheng Hospital, Second Military Medical University, Fengyang Road 415, Shanghai, 200003, China.
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10
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Jayarajan RO, Chakraborty S, Raghu KG, Purushothaman J, Veleri S. Joubert syndrome causing mutation in C2 domain of CC2D2A affects structural integrity of cilia and cellular signaling molecules. Exp Brain Res 2024; 242:619-637. [PMID: 38231387 DOI: 10.1007/s00221-023-06762-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 12/08/2023] [Indexed: 01/18/2024]
Abstract
Cilia are organelles extend from cells to sense external signals for tuning intracellular signaling for optimal cellular functioning. They have evolved sensory and motor roles in various cells for tissue organization and homeostasis in development and post-development. More than a thousand genes are required for cilia function. Mutations in them cause multisystem disorders termed ciliopathies. The null mutations in CC2D2A result in Meckel syndrome (MKS), which is embryonic lethal, whereas patients who have missense mutations in the C2 domain of CC2D2A display Joubert syndrome (JBTS). They survive with blindness and mental retardation. How C2 domain defects cause disease conditions is not understood. To answer this question, C2 domain of Cc2d2a (mice gene) was knocked down (KD) in IMCD-3 cells by shRNA. This resulted in defective cilia morphology observed by immunofluorescence analysis. To further probe the cellular signaling alteration in affected cells, gene expression profiling was done by RNAseq and compared with the controls. Bioinformatics analysis revealed that the differentially expressed genes (DEGs) have functions in cilia. Among the 61 cilia DEGs identified, 50 genes were downregulated and 11 genes were upregulated. These cilia genes are involved in cilium assembly, protein trafficking to the cilium, intraflagellar transport (IFT), cellular signaling like polarity patterning, and Hedgehog signaling pathway. This suggests that the C2 domain of CC2D2A plays a critical role in cilia assembly and molecular signaling hosted in cilia for cellular homeostasis. Taken together, the missense mutations in the C2 domain of CC2D2A seen in JBTS might have affected cilia-mediated signaling in neurons of the retina and brain.
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Affiliation(s)
- Roopasree O Jayarajan
- Agro-processing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram, Kerala, 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Soura Chakraborty
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Kozhiparambil Gopalan Raghu
- Agro-processing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram, Kerala, 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Jayamurthy Purushothaman
- Agro-processing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram, Kerala, 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Shobi Veleri
- Drug Safety Division, National Institute of Nutrition, Indian Council of Medical Research, Department of Health Research, Ministry of Health and Family Welfare, Govt. of India, Hyderabad, 500007, India.
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11
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Xie S, Naslavsky N, Caplan S. Emerging insights into CP110 removal during early steps of ciliogenesis. J Cell Sci 2024; 137:jcs261579. [PMID: 38415788 PMCID: PMC10941660 DOI: 10.1242/jcs.261579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024] Open
Abstract
The primary cilium is an antenna-like projection from the plasma membrane that serves as a sensor of the extracellular environment and a crucial signaling hub. Primary cilia are generated in most mammalian cells, and their physiological significance is highlighted by the large number of severe developmental disorders or ciliopathies that occur when primary ciliogenesis is impaired. Primary ciliogenesis is a tightly regulated process, and a central early regulatory step is the removal of a key mother centriole capping protein, CP110 (also known as CCP110). This uncapping allows vesicles docked on the distal appendages of the mother centriole to fuse to form a ciliary vesicle, which is bent into a ciliary sheath as the microtubule-based axoneme grows and extends from the mother centriole. When the mother centriole migrates toward the plasma membrane, the ciliary sheath fuses with the plasma membrane to form the primary cilium. In this Review, we outline key early steps of primary ciliogenesis, focusing on several novel mechanisms for removal of CP110. We also highlight examples of ciliopathies caused by genetic variants that encode key proteins involved in the early steps of ciliogenesis.
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Affiliation(s)
- Shuwei Xie
- Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Naava Naslavsky
- Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Steve Caplan
- Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
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12
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Moran AL, Louzao-Martinez L, Norris DP, Peters DJM, Blacque OE. Transport and barrier mechanisms that regulate ciliary compartmentalization and ciliopathies. Nat Rev Nephrol 2024; 20:83-100. [PMID: 37872350 DOI: 10.1038/s41581-023-00773-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2023] [Indexed: 10/25/2023]
Abstract
Primary cilia act as cell surface antennae, coordinating cellular responses to sensory inputs and signalling molecules that regulate developmental and homeostatic pathways. Cilia are therefore critical to physiological processes, and defects in ciliary components are associated with a large group of inherited pleiotropic disorders - known collectively as ciliopathies - that have a broad spectrum of phenotypes and affect many or most tissues, including the kidney. A central feature of the cilium is its compartmentalized structure, which imparts its unique molecular composition and signalling environment despite its membrane and cytosol being contiguous with those of the cell. Such compartmentalization is achieved via active transport pathways that bring protein cargoes to and from the cilium, as well as gating pathways at the ciliary base that establish diffusion barriers to protein exchange into and out of the organelle. Many ciliopathy-linked proteins, including those involved in kidney development and homeostasis, are components of the compartmentalizing machinery. New insights into the major compartmentalizing pathways at the cilium, namely, ciliary gating, intraflagellar transport, lipidated protein flagellar transport and ciliary extracellular vesicle release pathways, have improved our understanding of the mechanisms that underpin ciliary disease and associated renal disorders.
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Affiliation(s)
- Ailis L Moran
- School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Laura Louzao-Martinez
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Dorien J M Peters
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland.
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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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14
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Bhat S, Dietz A, Senf K, Nietzsche S, Hirabayashi Y, Westermann M, Neuhaus EM. GPRC5C regulates the composition of cilia in the olfactory system. BMC Biol 2023; 21:292. [PMID: 38110903 PMCID: PMC10729543 DOI: 10.1186/s12915-023-01790-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 11/30/2023] [Indexed: 12/20/2023] Open
Abstract
BACKGROUND Olfactory sensory neurons detect odourants via multiple long cilia that protrude from their dendritic endings. The G protein-coupled receptor GPRC5C was identified as part of the olfactory ciliary membrane proteome, but its function and localization is unknown. RESULTS High-resolution confocal and electron microscopy revealed that GPRC5C is located at the base of sensory cilia in olfactory neurons, but not in primary cilia of immature neurons or stem cells. Additionally, GPRC5C localization in sensory cilia parallels cilia formation and follows the formation of the basal body. In closer examination, GPRC5C was found in the ciliary transition zone. GPRC5C deficiency altered the structure of sensory cilia and increased ciliary layer thickness. However, primary cilia were unaffected. Olfactory sensory neurons from Gprc5c-deficient mice exhibited altered localization of olfactory signalling cascade proteins, and of ciliary phosphatidylinositol-4,5-bisphosphat. Sensory neurons also exhibited increased neuronal activity as well as altered mitochondrial morphology, and knockout mice had an improved ability to detect food pellets based on smell. CONCLUSIONS Our study shows that GPRC5C regulates olfactory cilia composition and length, thereby controlling odour perception.
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Affiliation(s)
- Sneha Bhat
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, 07747, Jena, Germany
| | - André Dietz
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, 07747, Jena, Germany
| | - Katja Senf
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, 07747, Jena, Germany
| | - Sandor Nietzsche
- Centre for Electron Microscopy, Jena University Hospital, Friedrich Schiller University Jena, Ziegelmühlenweg 1, 07743, Jena, Germany
| | - Yoshio Hirabayashi
- Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Chiba, 279-0021, Japan
- RIKEN Cluster for Pioneering Research, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Martin Westermann
- Centre for Electron Microscopy, Jena University Hospital, Friedrich Schiller University Jena, Ziegelmühlenweg 1, 07743, Jena, Germany
| | - Eva Maria Neuhaus
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, 07747, Jena, Germany.
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15
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Syu JJ, Chang CH, Chang PY, Liu CH, Yu CJ, Jou TS. Lipid raft interacting galectin 8 regulates primary ciliogenesis. FASEB J 2023; 37:e23300. [PMID: 37997673 DOI: 10.1096/fj.202301943r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 10/23/2023] [Accepted: 10/26/2023] [Indexed: 11/25/2023]
Abstract
Primary cilium is a specialized sensory organelle that transmits environmental information into cells. Its length is tightly controlled by various mechanisms such as the frequency or the cargo size of the intraflagellar transport trains which deliver the building materials such as tubulin subunits essential for the growing cilia. Here, we show the sialoglycan interacting galectin 8 regulates the process of primary ciliogenesis. As the epithelia become polarized, there are more galectin 8 being apically secreted and these extracellular galectin 8 molecules apparently bind to a lipid raft enriched domain at the base of the primary cilia through interacting with lipid raft components, such as GD3 ganglioside and scaffold protein caveolin 1. Furthermore, the binding of galectin 8 at this critical region triggers rapid growth of primary cilia by perturbing the barrier function of the transition zone (TZ). Our study also demonstrates the functionality of this barrier depends on intact organization of lipid rafts at the cilia as genetically knockout of Cav1 and pharmacologically inhibition of lipid raft both phenocopy the effect of apical addition of recombinant galectin 8; that is, rapid elongation of primary cilia and redistribution of cilia proteins from TZ to the growing axoneme. Indeed, as cilia elongated, endogenous galectin 8, caveolin 1, and TZ component, TMEM231, also transited from the TZ to the growing axoneme. We also noted that the interaction between caveolin 1 and TMEM231 could be perturbed by exogenous galectin 8. Taken together, we proposed that galectin 8 promoted primary cilia elongation through impeding the barrier function of the TZ by interfering with the interaction between caveolin 1 and TMEM231.
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Affiliation(s)
- Jhan-Jhang Syu
- Graduate Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chieh-Hsiang Chang
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Pei-Yu Chang
- Graduate Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chia-Hsiung Liu
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Surgery, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chia-Jung Yu
- Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Tzuu-Shuh Jou
- Graduate Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
- Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
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16
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Chatzifrangkeskou M, Kouis P, Skourides PA. JNK regulates ciliogenesis through the interflagellar transport complex and actin networks. J Cell Biol 2023; 222:e202303052. [PMID: 37851005 PMCID: PMC10585068 DOI: 10.1083/jcb.202303052] [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: 03/13/2023] [Revised: 06/16/2023] [Accepted: 08/29/2023] [Indexed: 10/19/2023] Open
Abstract
The c-Jun N-terminal kinase (JNK) regulates various important physiological processes. Although the JNK pathway has been under intense investigation for over 20 yr, its complexity is still perplexing, with multiple protein partners underlying the diversity of its activity. We show that JNK is associated with the basal bodies in both primary and motile cilia. Loss of JNK disrupts basal body migration and docking and leads to severe ciliogenesis defects. JNK's involvement in ciliogenesis stems from a dual role in the regulation of the actin networks of multiciliated cells (MCCs) and the establishment of the intraflagellar transport-B core complex. JNK signaling is also critical for the maintenance of the actin networks and ciliary function in mature MCCs. JNK is implicated in the development of diabetes, neurodegeneration, and liver disease, all of which have been linked to ciliary dysfunction. Our work uncovers a novel role of JNK in ciliogenesis and ciliary function that could have important implications for JNK's role in the disease.
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Affiliation(s)
| | - Panayiotis Kouis
- Respiratory Physiology Laboratory, Medical School, University of Cyprus, Nicosia, Cyprus
| | - Paris A. Skourides
- Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
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17
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Kruczek K, Swaroop A. Patient stem cell-derived in vitro disease models for developing novel therapies of retinal ciliopathies. Curr Top Dev Biol 2023; 155:127-163. [PMID: 38043950 DOI: 10.1016/bs.ctdb.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Primary cilia are specialized organelles on the surface of almost all cells in vertebrate tissues and are primarily involved in the detection of extracellular stimuli. In retinal photoreceptors, cilia are uniquely modified to form outer segments containing components required for the detection of light in stacks of membrane discs. Not surprisingly, vision impairment is a frequent phenotype associated with ciliopathies, a heterogeneous class of conditions caused by mutations in proteins required for formation, maintenance and/or function of primary cilia. Traditionally, immortalized cell lines and model organisms have been used to provide insights into the biology of ciliopathies. The advent of methods for reprogramming human somatic cells into pluripotent stem cells has enabled the generation of in vitro disease models directly from patients suffering from ciliopathies. Such models help us in investigating pathological mechanisms specific to human physiology and in developing novel therapeutic approaches. In this article, we review current protocols to differentiate human pluripotent stem cells into retinal cell types, and discuss how these cellular and/or organoid models can be utilized to interrogate pathobiology of ciliopathies affecting the retina and for testing prospective treatments.
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Affiliation(s)
- Kamil Kruczek
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, United States.
| | - Anand Swaroop
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, United States.
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18
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Huang C, Chen W, Wang X. Studies on the fat mass and obesity-associated (FTO) gene and its impact on obesity-associated diseases. Genes Dis 2023; 10:2351-2365. [PMID: 37554175 PMCID: PMC10404889 DOI: 10.1016/j.gendis.2022.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/29/2022] [Accepted: 04/01/2022] [Indexed: 10/18/2022] Open
Abstract
Obesity has become a major health crisis in the past ∼50 years. The fat mass and obesity-associated (FTO) gene, identified by genome-wide association studies (GWAS), was first reported to be positively associated with obesity in humans. Mice with more copies of the FTO gene were observed to be obese, while loss of the gene in mice was found to protect from obesity. Later, FTO was found to encode an m6A RNA demethylase and has a profound effect on many biological and metabolic processes. In this review, we first summarize recent studies that demonstrate the critical roles and regulatory mechanisms of FTO in obesity and metabolic disease. Second, we discuss the ongoing debates concerning the association between FTO polymorphisms and obesity. Third, since several small molecule drugs and micronutrients have been found to regulate metabolic homeostasis through controlling the expression or activity of FTO, we highlight the broad potential of targeting FTO for obesity treatment. Improving our understanding of FTO and the underlying mechanisms may provide new approaches for treating obesity and metabolic diseases.
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Affiliation(s)
- Chaoqun Huang
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou, Zhejiang 310058, China
| | - Wei Chen
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou, Zhejiang 310058, China
| | - Xinxia Wang
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou, Zhejiang 310058, China
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19
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Campagna CM, McMahon H, Nechipurenko I. The G protein alpha chaperone and guanine-nucleotide exchange factor RIC-8 regulates cilia morphogenesis in Caenorhabditis elegans sensory neurons. PLoS Genet 2023; 19:e1011015. [PMID: 37910589 PMCID: PMC10642896 DOI: 10.1371/journal.pgen.1011015] [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: 08/27/2023] [Revised: 11/13/2023] [Accepted: 10/12/2023] [Indexed: 11/03/2023] Open
Abstract
Heterotrimeric G (αβγ) proteins are canonical transducers of G-protein-coupled receptor (GPCR) signaling and play critical roles in communication between cells and their environment. Many GPCRs and heterotrimeric G proteins localize to primary cilia and modulate cilia morphology via mechanisms that are not well understood. Here, we show that RIC-8, a cytosolic guanine nucleotide exchange factor (GEF) and chaperone for Gα protein subunits, shapes cilia membrane morphology in a subset of Caenorhabditis elegans sensory neurons. Consistent with its role in ciliogenesis, C. elegans RIC-8 localizes to cilia in different sensory neuron types. Using domain mutagenesis, we demonstrate that while the GEF function alone is not sufficient, both the GEF and Gα-interacting chaperone motifs of RIC-8 are required for its role in cilia morphogenesis. We identify ODR-3 as the RIC-8 Gα client and demonstrate that RIC-8 functions in the same genetic pathway with another component of the non-canonical G protein signaling AGS-3 to shape cilia morphology. Notably, despite defects in AWC cilia morphology, ags-3 null mutants exhibit normal chemotaxis toward benzaldehyde unlike odr-3 mutant animals. Collectively, our findings describe a novel function for the evolutionarily conserved protein RIC-8 and non-canonical RIC-8-AGS-3-ODR-3 signaling in cilia morphogenesis and uncouple Gα ODR-3 functions in ciliogenesis and olfaction.
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Affiliation(s)
- Christina M. Campagna
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| | - Hayley McMahon
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| | - Inna Nechipurenko
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
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20
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Chen Y, Zhang Y, Zhou X. Non-classical functions of nuclear pore proteins in ciliopathy. Front Mol Biosci 2023; 10:1278976. [PMID: 37908226 PMCID: PMC10614291 DOI: 10.3389/fmolb.2023.1278976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/02/2023] [Indexed: 11/02/2023] Open
Abstract
Nucleoporins (NUPs) constitute integral nuclear pore protein (NPC) elements. Although traditional NUP functions have been extensively researched, evidence of additional vital non-NPC roles, referred to herein as non-classical NUP functions, is also emerging. Several NUPs localise at the ciliary base. Indeed, Nup188, Nup93 or Nup205 knockdown results in cilia loss, impacting cardiac left-right patterning in models and cell lines. Genetic variants of Nup205 and Nup188 have been identified in patients with congenital heart disease and situs inversus totalis or heterotaxy, a prevalent human ciliopathy. These findings link non-classical NUP functions to human diseases. This mini-review summarises pivotal NUP interactions with NIMA-related kinases or nephronophthisis proteins that regulate ciliary function and explores other NUPs potentially implicated in cilia-related disorders. Overall, elucidating the non-classical roles of NUPs will enhance comprehension of ciliopathy aetiology.
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Affiliation(s)
- Yan Chen
- Obstetrics and Gynecology Hospital of Fudan University, Fudan University Shanghai Medical College, Shanghai, China
| | - Yuan Zhang
- Department of Assisted Reproduction, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xiangyu Zhou
- Obstetrics and Gynecology Hospital of Fudan University, Fudan University Shanghai Medical College, Shanghai, China
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21
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Masek M, Bachmann-Gagescu R. Control of protein and lipid composition of photoreceptor outer segments-Implications for retinal disease. Curr Top Dev Biol 2023; 155:165-225. [PMID: 38043951 DOI: 10.1016/bs.ctdb.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Vision is arguably our most important sense, and its loss brings substantial limitations to daily life for affected individuals. Light is perceived in retinal photoreceptors (PRs), which are highly specialized neurons subdivided into several compartments with distinct functions. The outer segments (OSs) of photoreceptors represent highly specialized primary ciliary compartments hosting the phototransduction cascade, which transforms incoming light into a neuronal signal. Retinal disease can result from various pathomechanisms originating in distinct subcompartments of the PR cell, or in the retinal pigment epithelium which supports the PRs. Dysfunction of primary cilia causes human disorders known as "ciliopathies", in which retinal disease is a common feature. This chapter focuses on PR OSs, discussing the mechanisms controlling their complex structure and composition. A sequence of tightly regulated sorting and trafficking events, both upstream of and within this ciliary compartment, ensures the establishment and maintenance of the adequate proteome and lipidome required for signaling in response to light. We discuss in particular our current understanding of the role of ciliopathy proteins involved in multi-protein complexes at the ciliary transition zone (CC2D2A) or BBSome (BBS1) and how their dysfunction causes retinal disease. While the loss of CC2D2A prevents the fusion of vesicles and delivery of the photopigment rhodopsin to the ciliary base, leading to early OS ultrastructural defects, BBS1 deficiency results in precocious accumulation of cholesterol in mutant OSs and decreased visual function preceding morphological changes. These distinct pathomechanisms underscore the central role of ciliary proteins involved in multiple processes controlling OS protein and lipid composition.
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Affiliation(s)
- Markus Masek
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland; Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Ruxandra Bachmann-Gagescu
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland; Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland; University Research Priority Program AdaBD, University of Zurich, Zurich, Switzerland.
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22
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Kozina AA, Kanaeva GK, Baryshnikova NV, Ilinskaya AY, Kim AA, Erofeeva AV, Pogodina NA, Gadzhiyeva JP, Surkova EI, Ilinsky VV. A case of Joubert syndrome caused by novel compound heterozygous variants in the TMEM67 gene. J Int Med Res 2023; 51:3000605231206294. [PMID: 37910852 PMCID: PMC10621312 DOI: 10.1177/03000605231206294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 09/21/2023] [Indexed: 11/03/2023] Open
Abstract
Joubert syndrome (JS) is a recessive disorder that is characterized by midbrain-hindbrain malformation and shows the "molar tooth sign" on magnetic resonance imaging. Mutations in 40 genes, including Abelson helper integration site 1 (AHI1), inositol polyphosphate-5-phosphatase (INPP5E), coiled-coil and c2 domain-containing protein 2A (CC2D2A), and ARL2-like protein 1 (ARL13B), can cause JS. Classic JS is a part of a group of diseases associated with JS, and its manifestations include various neurological signs such as skeletal abnormalities, ocular coloboma, renal disease, and hepatic fibrosis. Here, we present a proband with the molar tooth sign, ataxia, and developmental and psychomotor delays in a Dagestan family from Russia. Molecular genetic testing revealed two novel heterozygous variants, c.2924G>A (p.Arg975His) in exon 28 and c.1241C>G (p.Pro414Arg) in exon 12 of the transmembrane protein 67 (TMEM67) gene. These TMEM67 gene variants significantly affected the development of JS type 6. This case highlights the importance of whole exome sequencing for a proper clinical diagnosis of children with complex motor and psycho-language delays. This case also expands the clinical phenotype and genotype of TMEM67-associated diseases.
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Affiliation(s)
- Anastasiya Aleksandrovna Kozina
- Department of Medical Genomics Group, Institute of Biomedical Chemistry, Moscow, Russia
- Department of Science, Genotek Ltd., Moscow, Russia
| | | | - Natalia Vladimirovna Baryshnikova
- Department of General and Medical Genetics, Pirogov Russian National Research Medical University, Moscow, Russia
- Department of Science, Genotek Ltd., Moscow, Russia
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23
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Truong HM, Cruz-Colón KO, Martínez-Márquez JY, Willer JR, Travis AM, Biswas SK, Lo WK, Bolz HJ, Pearring JN. The tectonic complex regulates membrane protein composition in the photoreceptor cilium. Nat Commun 2023; 14:5671. [PMID: 37704658 PMCID: PMC10500017 DOI: 10.1038/s41467-023-41450-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 08/30/2023] [Indexed: 09/15/2023] Open
Abstract
The primary cilium is a signaling organelle with a unique membrane composition maintained by a diffusional barrier residing at the transition zone. Many transition zone proteins, such as the tectonic complex, are linked to preserving ciliary composition but the mechanism remains unknown. To understand tectonic's role, we generate a photoreceptor-specific Tctn1 knockout mouse. Loss of Tctn1 results in the absence of the entire tectonic complex and associated MKS proteins yet has minimal effects on the transition zone structure of rod photoreceptors. We find that the protein composition of the photoreceptor cilium is disrupted as non-resident membrane proteins accumulate in the cilium over time, ultimately resulting in photoreceptor degeneration. We further show that fluorescent rhodopsin moves faster through the transition zone in photoreceptors lacking tectonic, which suggests that the tectonic complex acts as a physical barrier to slow down membrane protein diffusion in the photoreceptor transition zone to ensure proper removal of non-resident membrane proteins.
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Affiliation(s)
- Hanh M Truong
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Kevin O Cruz-Colón
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | | | - Jason R Willer
- Department of Ophthalmology and Visual Science, University of Michigan, Ann Arbor, MI, USA
| | - Amanda M Travis
- Department of Ophthalmology and Visual Science, University of Michigan, Ann Arbor, MI, USA
| | - Sondip K Biswas
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA, USA
| | - Woo-Kuen Lo
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA, USA
| | - Hanno J Bolz
- Senckenberg Centre for Human Genetics, Frankfurt am Main, Germany
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
| | - Jillian N Pearring
- Department of Ophthalmology and Visual Science, University of Michigan, Ann Arbor, MI, USA.
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
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24
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Campagna CM, McMahon H, Nechipurenko I. The G protein alpha Chaperone and Guanine-Nucleotide Exchange Factor RIC-8 Regulates Cilia Morphogenesis in Caenorhabditis elegans Sensory Neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.25.554856. [PMID: 37662329 PMCID: PMC10473713 DOI: 10.1101/2023.08.25.554856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Heterotrimeric G (αβγ) proteins are canonical transducers of G-protein-coupled receptor (GPCR) signaling and play critical roles in communication between cells and their environment. Many GPCRs and heterotrimeric G proteins localize to primary cilia and modulate cilia morphology via mechanisms that are not well understood. Here, we show that RIC-8, a cytosolic guanine nucleotide exchange factor (GEF) and chaperone for Gα protein subunits, shapes cilia membrane morphology in a subset of Caenorhabditis elegans sensory neurons. Consistent with its role in ciliogenesis, C. elegans RIC-8 localizes to cilia in different sensory neuron types. Using domain mutagenesis, we demonstrate that while the GEF function alone is not sufficient, both the GEF and Gα-interacting chaperone motifs of RIC-8 are required for its role in cilia morphogenesis. We identify ODR-3 as the RIC-8 Gα client and demonstrate that RIC-8 functions in the same genetic pathway with another component of the non-canonical G protein signaling AGS-3 to shape cilia morphology. Notably, despite severe defects in AWC cilia morphology, ags-3 null mutants exhibit normal chemotaxis toward benzaldehyde unlike odr-3 mutant animals. Collectively, our findings describe a novel function for the evolutionarily conserved protein RIC-8 and non-canonical RIC-8-AGS-3-ODR-3 signaling in cilia morphogenesis and uncouple Gα ODR-3 functions in ciliogenesis and olfaction.
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Affiliation(s)
- Christina M. Campagna
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| | - Hayley McMahon
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| | - Inna Nechipurenko
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
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25
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Clearman KR, Haycraft CJ, Croyle MJ, Collawn JF, Yoder BK. Functions of the primary cilium in the kidney and its connection with renal diseases. Curr Top Dev Biol 2023; 155:39-94. [PMID: 38043952 DOI: 10.1016/bs.ctdb.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
The nonmotile primary cilium is a sensory structure found on most mammalian cell types that integrates multiple signaling pathways involved in tissue development and postnatal function. As such, mutations disrupting cilia activities cause a group of disorders referred to as ciliopathies. These disorders exhibit a wide spectrum of phenotypes impacting nearly every tissue. In the kidney, primary cilia dysfunction caused by mutations in polycystin 1 (Pkd1), polycystin 2 (Pkd2), or polycystic kidney and hepatic disease 1 (Pkhd1), result in polycystic kidney disease (PKD), a progressive disorder causing renal functional decline and end-stage renal disease. PKD affects nearly 1 in 1000 individuals and as there is no cure for PKD, patients frequently require dialysis or renal transplantation. Pkd1, Pkd2, and Pkhd1 encode membrane proteins that all localize in the cilium. Pkd1 and Pkd2 function as a nonselective cation channel complex while Pkhd1 protein function remains uncertain. Data indicate that the cilium may act as a mechanosensor to detect fluid movement through renal tubules. Other functions proposed for the cilium and PKD proteins in cyst development involve regulation of cell cycle and oriented division, regulation of renal inflammation and repair processes, maintenance of epithelial cell differentiation, and regulation of mitochondrial structure and metabolism. However, how loss of cilia or cilia function leads to cyst development remains elusive. Studies directed at understanding the roles of Pkd1, Pkd2, and Pkhd1 in the cilium and other locations within the cell will be important for developing therapeutic strategies to slow cyst progression.
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Affiliation(s)
- Kelsey R Clearman
- Department of Cell, Developmental, and Integrative Biology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Courtney J Haycraft
- Department of Cell, Developmental, and Integrative Biology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mandy J Croyle
- Department of Cell, Developmental, and Integrative Biology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - James F Collawn
- Department of Cell, Developmental, and Integrative Biology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Bradley K Yoder
- Department of Cell, Developmental, and Integrative Biology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States.
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26
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Cevik S, Peng X, Beyer T, Pir MS, Yenisert F, Woerz F, Hoffmann F, Altunkaynak B, Pir B, Boldt K, Karaman A, Cakiroglu M, Oner SS, Cao Y, Ueffing M, Kaplan OI. WDR31 displays functional redundancy with GTPase-activating proteins (GAPs) ELMOD and RP2 in regulating IFT complex and recruiting the BBSome to cilium. Life Sci Alliance 2023; 6:e202201844. [PMID: 37208194 PMCID: PMC10200814 DOI: 10.26508/lsa.202201844] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 05/21/2023] Open
Abstract
The correct intraflagellar transport (IFT) assembly at the ciliary base and the IFT turnaround at the ciliary tip are key for the IFT to perform its function, but we still have poor understanding about how these processes are regulated. Here, we identify WDR31 as a new ciliary protein, and analysis from zebrafish and Caenorhabditis elegans reveals the role of WDR31 in regulating the cilia morphology. We find that loss of WDR-31 together with RP-2 and ELMD-1 (the sole ortholog ELMOD1-3) results in ciliary accumulations of IFT Complex B components and KIF17 kinesin, with fewer IFT/BBSome particles traveling along cilia in both anterograde and retrograde directions, suggesting that the IFT/BBSome entry into the cilia and exit from the cilia are impacted. Furthermore, anterograde IFT in the middle segment travels at increased speed in wdr-31;rpi-2;elmd-1 Remarkably, a non-ciliary protein leaks into the cilia of wdr-31;rpi-2;elmd-1, possibly because of IFT defects. This work reveals WDR31-RP-2-ELMD-1 as IFT and BBSome trafficking regulators.
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Affiliation(s)
- Sebiha Cevik
- Rare Disease Laboratory, School of Life and Natural Sciences, Abdullah Gul University, Kayseri, Turkey
| | - Xiaoyu Peng
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Tina Beyer
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Mustafa S Pir
- Rare Disease Laboratory, School of Life and Natural Sciences, Abdullah Gul University, Kayseri, Turkey
| | - Ferhan Yenisert
- Rare Disease Laboratory, School of Life and Natural Sciences, Abdullah Gul University, Kayseri, Turkey
| | - Franziska Woerz
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Felix Hoffmann
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Betul Altunkaynak
- Rare Disease Laboratory, School of Life and Natural Sciences, Abdullah Gul University, Kayseri, Turkey
| | - Betul Pir
- Rare Disease Laboratory, School of Life and Natural Sciences, Abdullah Gul University, Kayseri, Turkey
| | - Karsten Boldt
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Asli Karaman
- Science and Advanced Technology Application and Research Center, Istanbul Medeniyet University, Istanbul, Turkey
| | - Miray Cakiroglu
- Science and Advanced Technology Application and Research Center, Istanbul Medeniyet University, Istanbul, Turkey
| | - S Sadik Oner
- Goztepe Prof. Dr. Suleyman Yalcin City Hospital, Istanbul, Turkey
- Science and Advanced Technology Application and Research Center, Istanbul Medeniyet University, Istanbul, Turkey
| | - Ying Cao
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Marius Ueffing
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Oktay I Kaplan
- Rare Disease Laboratory, School of Life and Natural Sciences, Abdullah Gul University, Kayseri, Turkey
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27
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Hanna C, Iliuta IA, Besse W, Mekahli D, Chebib FT. Cystic Kidney Diseases in Children and Adults: Differences and Gaps in Clinical Management. Semin Nephrol 2023; 43:151434. [PMID: 37996359 DOI: 10.1016/j.semnephrol.2023.151434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
Cystic kidney diseases, when broadly defined, have a wide differential diagnosis extending from recessive diseases with a prenatal or pediatric diagnosis, to the most common autosomal-dominant polycystic kidney disease primarily affecting adults, and several other genetic or acquired etiologies that can manifest with kidney cysts. The most likely diagnoses to consider when assessing a patient with cystic kidney disease differ depending on family history, age stratum, radiologic characteristics, and extrarenal features. Accurate identification of the underlying condition is crucial to estimate the prognosis and initiate the appropriate management, identification of extrarenal manifestations, and counseling on recurrence risk in future pregnancies. There are significant differences in the clinical approach to investigating and managing kidney cysts in children compared with adults. Next-generation sequencing has revolutionized the diagnosis of inherited disorders of the kidney, despite limitations in access and challenges in interpreting the data. Disease-modifying treatments are lacking in the majority of kidney cystic diseases. For adults with rapid progressive autosomal-dominant polycystic kidney disease, tolvaptan (V2-receptor antagonist) has been approved to slow the rate of decline in kidney function. In this article, we examine the differences in the differential diagnosis and clinical management of cystic kidney disease in children versus adults, and we highlight the progress in molecular diagnostics and therapeutics, as well as some of the gaps meriting further attention.
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Affiliation(s)
- Christian Hanna
- Division of Pediatric Nephrology and Hypertension, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN; Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, MN.
| | - Ioan-Andrei Iliuta
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Jacksonville, FL
| | - Whitney Besse
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, CT
| | - Djalila Mekahli
- PKD Research Group, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium; Department of Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium
| | - Fouad T Chebib
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Jacksonville, FL.
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28
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Reed R, Park K, Waddell B, Timbers TA, Li C, Baxi K, Giacomin RM, Leroux MR, Carvalho CE. The Caenorhabditis elegans Shugoshin regulates TAC-1 in cilia. Sci Rep 2023; 13:9410. [PMID: 37296204 PMCID: PMC10256747 DOI: 10.1038/s41598-023-36430-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 06/03/2023] [Indexed: 06/12/2023] Open
Abstract
The conserved Shugoshin (SGO) protein family is essential for mediating proper chromosome segregation from yeast to humans but has also been implicated in diverse roles outside of the nucleus. SGO's roles include inhibiting incorrect spindle attachment in the kinetochore, regulating the spindle assembly checkpoint (SAC), and ensuring centriole cohesion in the centrosome, all functions that involve different microtubule scaffolding structures in the cell. In Caenorhabditis elegans, a species with holocentric chromosomes, SGO-1 is not required for cohesin protection or spindle attachment but appears important for licensing meiotic recombination. Here we provide the first functional evidence that in C. elegans, Shugoshin functions in another extranuclear, microtubule-based structure, the primary cilium. We identify the centrosomal and microtubule-regulating transforming acidic coiled-coil protein, TACC/TAC-1, which also localizes to the basal body, as an SGO-1 binding protein. Genetic analyses indicate that TAC-1 activity must be maintained below a threshold at the ciliary base for correct cilia function, and that SGO-1 likely participates in constraining TAC-1 to the basal body by influencing the function of the transition zone 'ciliary gate'. This research expands our understanding of cellular functions of Shugoshin proteins and contributes to the growing examples of overlap between kinetochore, centrosome and cilia proteomes.
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Affiliation(s)
- R Reed
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - K Park
- Department of Molecular Biology & Biochemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
- Terry Fox Laboratory, BC Cancer, Vancouver, BC, V5Z 1L3, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - B Waddell
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - T A Timbers
- Department of Molecular Biology & Biochemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - C Li
- Department of Molecular Biology & Biochemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - K Baxi
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - R M Giacomin
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - M R Leroux
- Department of Molecular Biology & Biochemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada.
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
| | - C E Carvalho
- Department of Biology, University of Saskatchewan, Saskatoon, Canada.
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29
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Polino AJ, Sviben S, Melena I, Piston DW, Hughes JW. Scanning electron microscopy of human islet cilia. Proc Natl Acad Sci U S A 2023; 120:e2302624120. [PMID: 37205712 PMCID: PMC10235940 DOI: 10.1073/pnas.2302624120] [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: 02/14/2023] [Accepted: 04/12/2023] [Indexed: 05/21/2023] Open
Abstract
Human islet primary cilia are vital glucose-regulating organelles whose structure remains uncharacterized. Scanning electron microscopy (SEM) is a useful technique for studying the surface morphology of membrane projections like cilia, but conventional sample preparation does not reveal the submembrane axonemal structure, which holds key implications for ciliary function. To overcome this challenge, we combined SEM with membrane-extraction techniques to examine primary cilia in native human islets. Our data show well-preserved cilia subdomains which demonstrate both expected and unexpected ultrastructural motifs. Morphometric features were quantified when possible, including axonemal length and diameter, microtubule conformations, and chirality. We further describe a ciliary ring, a structure that may be a specialization in human islets. Key findings are correlated with fluorescence microscopy and interpreted in the context of cilia function as a cellular sensor and communications locus in pancreatic islets.
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Affiliation(s)
- Alexander J. Polino
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO63110
| | - Sanja Sviben
- Washington University Center for Cellular Imaging, Washington University School of Medicine, Saint Louis, MO63110
| | - Isabella Melena
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO63110
| | - David W. Piston
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO63110
| | - Jing W. Hughes
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO63110
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO63110
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30
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Fisher WW, Hammonds AS, Weiszmann R, Booth BW, Gevirtzman L, Patton JEJ, Kubo CA, Waterston RH, Celniker SE. A modERN resource: identification of Drosophila transcription factor candidate target genes using RNAi. Genetics 2023; 223:iyad004. [PMID: 36652461 PMCID: PMC10078917 DOI: 10.1093/genetics/iyad004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 11/18/2022] [Accepted: 12/22/2022] [Indexed: 01/19/2023] Open
Abstract
Transcription factors (TFs) play a key role in development and in cellular responses to the environment by activating or repressing the transcription of target genes in precise spatial and temporal patterns. In order to develop a catalog of target genes of Drosophila melanogaster TFs, the modERN consortium systematically knocked down the expression of TFs using RNAi in whole embryos followed by RNA-seq. We generated data for 45 TFs which have 18 different DNA-binding domains and are expressed in 15 of the 16 organ systems. The range of inactivation of the targeted TFs by RNAi ranged from log2fold change -3.52 to +0.49. The TFs also showed remarkable heterogeneity in the numbers of candidate target genes identified, with some generating thousands of candidates and others only tens. We present detailed analysis from five experiments, including those for three TFs that have been the focus of previous functional studies (ERR, sens, and zfh2) and two previously uncharacterized TFs (sens-2 and CG32006), as well as short vignettes for selected additional experiments to illustrate the utility of this resource. The RNA-seq datasets are available through the ENCODE DCC (http://encodeproject.org) and the Sequence Read Archive (SRA). TF and target gene expression patterns can be found here: https://insitu.fruitfly.org. These studies provide data that facilitate scientific inquiries into the functions of individual TFs in key developmental, metabolic, defensive, and homeostatic regulatory pathways, as well as provide a broader perspective on how individual TFs work together in local networks during embryogenesis.
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Affiliation(s)
- William W Fisher
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Ann S Hammonds
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Richard Weiszmann
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Benjamin W Booth
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Louis Gevirtzman
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Jaeda E J Patton
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Connor A Kubo
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Robert H Waterston
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Susan E Celniker
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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31
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Safavian D, Kim MS, Xie H, El-Zeiry M, Palander O, Dai L, Collins RF, Froese C, Shannon R, Nagata KI, Trimble WS. Septin-mediated RhoA activation engages the exocyst complex to recruit the cilium transition zone. J Cell Biol 2023; 222:e201911062. [PMID: 36912772 PMCID: PMC10039714 DOI: 10.1083/jcb.201911062] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/25/2022] [Accepted: 01/05/2023] [Indexed: 03/14/2023] Open
Abstract
Septins are filamentous GTPases that play important but poorly characterized roles in ciliogenesis. Here, we show that SEPTIN9 regulates RhoA signaling at the base of cilia by binding and activating the RhoA guanine nucleotide exchange factor, ARHGEF18. GTP-RhoA is known to activate the membrane targeting exocyst complex, and suppression of SEPTIN9 causes disruption of ciliogenesis and mislocalization of an exocyst subunit, SEC8. Using basal body-targeted proteins, we show that upregulating RhoA signaling at the cilium can rescue ciliary defects and mislocalization of SEC8 caused by global SEPTIN9 depletion. Moreover, we demonstrate that the transition zone components, RPGRIP1L and TCTN2, fail to accumulate at the transition zone in cells lacking SEPTIN9 or depleted of the exocyst complex. Thus, SEPTIN9 regulates the recruitment of transition zone proteins on Golgi-derived vesicles by activating the exocyst via RhoA to allow the formation of primary cilia.
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Affiliation(s)
- Darya Safavian
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Moshe S. Kim
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Hong Xie
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Maha El-Zeiry
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Oliva Palander
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Lu Dai
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Richard F. Collins
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Carol Froese
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Rachel Shannon
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Koh-ichi Nagata
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - William S. Trimble
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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32
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Structure of the N-terminal coiled-coil domains of the ciliary protein Rpgrip1l. iScience 2023; 26:106249. [PMID: 36915689 PMCID: PMC10006689 DOI: 10.1016/j.isci.2023.106249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 12/30/2022] [Accepted: 02/16/2023] [Indexed: 02/25/2023] Open
Abstract
Rpgrip1l is one of the key ciliary proteins located at the transition zone of the primary cilium, an important organelle for cells to sense the outer environment. Mutations in the RPGRIP1L gene are associated with various ciliopathies. Here, we focused on the N-terminal coiled-coil of Rpgrip1l. By comprehensive biochemical and structural characterizations, we demonstrated that the two predicted coiled-coil regions (CC12) located at Rpgrip1l N-terminus each can form a stable parallel dimer. We further showed that overexpression of Rpgrip1l CC12 in NIH/3T3 cells significantly shortened the length of primary cilia, and this effect depended on the dimer formation. In addition, we found that CC12 of the homolog protein Rpgrip1 in mouse and human were significantly different from Rpgrip1l. Finally, we confirmed that some disease-related mutations can alter the dimeric states of CC12 of Rpgrip1l or Rpgrip1, which might explain the pathogenic mechanisms.
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Hou Y, Zheng S, Wu Z, Augière C, Morel V, Cortier E, Duteyrat JL, Zhang Y, Chen H, Peng Y, Durand B, Wei Q. Drosophila transition fibers are essential for IFT-dependent ciliary elongation but not basal body docking and ciliary budding. Curr Biol 2023; 33:727-736.e6. [PMID: 36669498 DOI: 10.1016/j.cub.2022.12.046] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 09/22/2022] [Accepted: 12/19/2022] [Indexed: 01/20/2023]
Abstract
Cilia are highly conserved organelles critical for animal development and perception. Dysfunction of cilia has been linked to a wide spectrum of human genetic diseases, termed ciliopathies.1,2 Transition fibers (TFs) are striking ciliary base structures essential for cilia assembly. Vertebrates' TFs that originate from centriole distal appendages (DAs) mediate basal body docking to ciliary vesicles to initiate ciliogenesis and regulate the entry of ciliary proteins for axoneme assembly via intraflagellar transport (IFT) machinery.3 Although no distal appendages can be observed on Drosophila centrioles,4,5 three key TF proteins, FBF1, CEP164, and CEP89, have obvious homologs in Drosophila. We aimed to compare their functions with their mammalian counterparts in Drosophila ciliogenesis. Here, we show that all three proteins are localized like TF proteins at the ciliary base in both sensory neurons and spermatocytes, the only two types of ciliated cells in flies. Fbf1 and Cep89 are essential for the formation of IFT-dependent neuronal cilia, but Cep164 is dispensable for ciliogenesis in flies. Strikingly, none are required for basal body docking and transition zone (TZ) assembly in IFT-dependent neuronal cilia or IFT-independent spermatocyte cilia. Furthermore, we demonstrate that Unc is essential to recruit all three TF proteins and establish a hierarchical order, with Cep89 acting on Fbf1. Collectively, our results not only demonstrate that TF proteins are required for IFT-dependent ciliogenesis in Drosophila, in agreement with an evolutionarily conserved function of these proteins in regulating ciliary protein entry, but also that the basal body docking function of TFs has diverged during evolution.
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Affiliation(s)
- Yanan Hou
- Center for Energy Metabolism and Reproduction, Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences (CAS), Shenzhen 518055, China
| | - Shirui Zheng
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Zhimao Wu
- Center for Energy Metabolism and Reproduction, Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences (CAS), Shenzhen 518055, China
| | - Céline Augière
- University of Lyon, Université Claude Bernard Lyon 1, MeLiS - UCBL-CNRS UMR 5284 - INSERM U1314, Institut NeuroMyoGène, Lyon 69008, France
| | - Véronique Morel
- University of Lyon, Université Claude Bernard Lyon 1, MeLiS - UCBL-CNRS UMR 5284 - INSERM U1314, Institut NeuroMyoGène, Lyon 69008, France
| | - Elisabeth Cortier
- University of Lyon, Université Claude Bernard Lyon 1, MeLiS - UCBL-CNRS UMR 5284 - INSERM U1314, Institut NeuroMyoGène, Lyon 69008, France
| | - Jean-Luc Duteyrat
- University of Lyon, Université Claude Bernard Lyon 1, MeLiS - UCBL-CNRS UMR 5284 - INSERM U1314, Institut NeuroMyoGène, Lyon 69008, France
| | - Yingying Zhang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Huicheng Chen
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Ying Peng
- Institute of Medicine and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 430000, China
| | - Bénédicte Durand
- University of Lyon, Université Claude Bernard Lyon 1, MeLiS - UCBL-CNRS UMR 5284 - INSERM U1314, Institut NeuroMyoGène, Lyon 69008, France.
| | - Qing Wei
- Center for Energy Metabolism and Reproduction, Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences (CAS), Shenzhen 518055, China; Shenzhen Key Laboratory of Metabolic Health, Shenzhen 518055, China.
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Polino AJ, Sviben S, Melena I, Piston DW, Hughes J. Scanning electron microscopy of human islet cilia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.15.528685. [PMID: 36824775 PMCID: PMC9949088 DOI: 10.1101/2023.02.15.528685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Human islet primary cilia are vital glucose-regulating organelles whose structure remains uncharacterized. Scanning electron microscopy (SEM) is a useful technique for studying the surface morphology of membrane projections like primary cilia, but conventional sample preparation does not reveal the sub-membrane axonemal structure which holds key implications for cilia function. To overcome this challenge, we combined SEM with membrane-extraction techniques to examine cilia in native human islets. Our data show well-preserved cilia subdomains which demonstrate both expected and unexpected ultrastructural motifs. Morphometric features were quantified when possible, including axonemal length and diameter, microtubule conformations and chirality. We further describe a novel ciliary ring, a structure that may be a specialization in human islets. Key findings are correlated with fluorescence microscopy and interpreted in the context of cilia function as a cellular sensor and communications locus in pancreatic islets.
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35
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Jewett CE, McCurdy BL, O'Toole ET, Stemm-Wolf AJ, Given KS, Lin CH, Olsen V, Martin W, Reinholdt L, Espinosa JM, Sullivan KD, Macklin WB, Prekeris R, Pearson CG. Trisomy 21 induces pericentrosomal crowding delaying primary ciliogenesis and mouse cerebellar development. eLife 2023; 12:e78202. [PMID: 36656118 PMCID: PMC9851619 DOI: 10.7554/elife.78202] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 12/06/2022] [Indexed: 01/20/2023] Open
Abstract
Trisomy 21, the genetic cause of Down syndrome, disrupts primary cilia formation and function, in part through elevated Pericentrin, a centrosome protein encoded on chromosome 21. Yet how trisomy 21 and elevated Pericentrin disrupt cilia-related molecules and pathways, and the in vivo phenotypic relevance remain unclear. Utilizing ciliogenesis time course experiments combined with light microscopy and electron tomography, we reveal that chromosome 21 polyploidy elevates Pericentrin and microtubules away from the centrosome that corral MyosinVA and EHD1, delaying ciliary membrane delivery and mother centriole uncapping essential for ciliogenesis. If given enough time, trisomy 21 cells eventually ciliate, but these ciliated cells demonstrate persistent trafficking defects that reduce transition zone protein localization and decrease sonic hedgehog signaling in direct anticorrelation with Pericentrin levels. Consistent with cultured trisomy 21 cells, a mouse model of Down syndrome with elevated Pericentrin has fewer primary cilia in cerebellar granule neuron progenitors and thinner external granular layers at P4. Our work reveals that elevated Pericentrin from trisomy 21 disrupts multiple early steps of ciliogenesis and creates persistent trafficking defects in ciliated cells. This pericentrosomal crowding mechanism results in signaling deficiencies consistent with the neurological phenotypes found in individuals with Down syndrome.
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Affiliation(s)
- Cayla E Jewett
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Bailey L McCurdy
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Eileen T O'Toole
- Molecular, Cellular, and Developmental Biology, University of Colorado BoulderBoulderUnited States
| | - Alexander J Stemm-Wolf
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Katherine S Given
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Carrie H Lin
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Valerie Olsen
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | | | | | - Joaquín M Espinosa
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical CampusAuroraUnited States
- Department of Pharmacology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Kelly D Sullivan
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical CampusAuroraUnited States
- Department of Pediatrics, Section of Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Wendy B Macklin
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Rytis Prekeris
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Chad G Pearson
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical CampusAuroraUnited States
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical CampusAuroraUnited States
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36
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Morleo M, Vieira HL, Pennekamp P, Palma A, Bento-Lopes L, Omran H, Lopes SS, Barral DC, Franco B. Crosstalk between cilia and autophagy: implication for human diseases. Autophagy 2023; 19:24-43. [PMID: 35613303 PMCID: PMC9809938 DOI: 10.1080/15548627.2022.2067383] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Macroautophagy/autophagy is a self-degradative process necessary for cells to maintain their energy balance during development and in response to nutrient deprivation. Autophagic processes are tightly regulated and have been found to be dysfunctional in several pathologies. Increasing experimental evidence points to the existence of an interplay between autophagy and cilia. Cilia are microtubule-based organelles protruding from the cell surface of mammalian cells that perform a variety of motile and sensory functions and, when dysfunctional, result in disorders known as ciliopathies. Indeed, selective autophagic degradation of ciliary proteins has been shown to control ciliogenesis and, conversely, cilia have been reported to control autophagy. Moreover, a growing number of players such as lysosomal and mitochondrial proteins are emerging as actors of the cilia-autophagy interplay. However, some of the published data on the cilia-autophagy axis are contradictory and indicate that we are just starting to understand the underlying molecular mechanisms. In this review, the current knowledge about this axis and challenges are discussed, as well as the implication for ciliopathies and autophagy-associated disorders.
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Affiliation(s)
- Manuela Morleo
- Telethon Institute of Genetics and Medicine (TIGEM), 80078, Pozzuoli, Italy,Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Helena L.A. Vieira
- CEDOC, NOVA Medical School, NMS, Universidade NOVA de Lisboa, Lisboa1169-056, Portugal,UCIBIO, Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal,Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Petra Pennekamp
- Department of General Pediatrics, University Hospital Münster, University of Münster, Münster48149, Germany,Member of the European Reference Networks ERN-LUNG, Lisbon, Portugal
| | - Alessandro Palma
- Department of Onco-hematology, Gene and Cell Therapy, Bambino Gesù Children’s Hospital - IRCCS, Rome, Italy
| | - Liliana Bento-Lopes
- CEDOC, NOVA Medical School, NMS, Universidade NOVA de Lisboa, Lisboa1169-056, Portugal
| | - Heymut Omran
- Department of General Pediatrics, University Hospital Münster, University of Münster, Münster48149, Germany,Member of the European Reference Networks ERN-LUNG, Lisbon, Portugal
| | - Susana S. Lopes
- CEDOC, NOVA Medical School, NMS, Universidade NOVA de Lisboa, Lisboa1169-056, Portugal,Member of the European Reference Networks ERN-LUNG, Lisbon, Portugal
| | - Duarte C. Barral
- CEDOC, NOVA Medical School, NMS, Universidade NOVA de Lisboa, Lisboa1169-056, Portugal
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine (TIGEM), 80078, Pozzuoli, Italy,Medical Genetics, Department of Translational Medical Science, University of Naples “Federico II”, Naples, Italy,Scuola Superiore Meridionale, School for Advanced Studies, Naples, Italy,CONTACT Brunella Franco CEDOC, NOVA Medical School, NMS, Universidade NOVA de Lisboa, Lisboa1169-056, Portugal
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37
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Life-Saver or Undertaker: The Relationship between Primary Cilia and Cell Death in Vertebrate Embryonic Development. J Dev Biol 2022; 10:jdb10040052. [PMID: 36547474 PMCID: PMC9783631 DOI: 10.3390/jdb10040052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/02/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
The development of multicellular organisms requires a tightly coordinated network of cellular processes and intercellular signalling. For more than 20 years, it has been known that primary cilia are deeply involved in the mediation of intercellular signalling and that ciliary dysfunction results in severe developmental defects. Cilia-mediated signalling regulates cellular processes such as proliferation, differentiation, migration, etc. Another cellular process ensuring proper embryonic development is cell death. While the effect of cilia-mediated signalling on many cellular processes has been extensively studied, the relationship between primary cilia and cell death remains largely unknown. This article provides a short review on the current knowledge about this relationship.
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38
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Park K, Leroux MR. Composition, organization and mechanisms of the transition zone, a gate for the cilium. EMBO Rep 2022; 23:e55420. [PMID: 36408840 PMCID: PMC9724682 DOI: 10.15252/embr.202255420] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/08/2022] [Accepted: 10/31/2022] [Indexed: 11/22/2022] Open
Abstract
The cilium evolved to provide the ancestral eukaryote with the ability to move and sense its environment. Acquiring these functions required the compartmentalization of a dynein-based motility apparatus and signaling proteins within a discrete subcellular organelle contiguous with the cytosol. Here, we explore the potential molecular mechanisms for how the proximal-most region of the cilium, termed transition zone (TZ), acts as a diffusion barrier for both membrane and soluble proteins and helps to ensure ciliary autonomy and homeostasis. These include a unique complement and spatial organization of proteins that span from the microtubule-based axoneme to the ciliary membrane; a protein picket fence; a specialized lipid microdomain; differential membrane curvature and thickness; and lastly, a size-selective molecular sieve. In addition, the TZ must be permissive for, and functionally integrates with, ciliary trafficking systems (including intraflagellar transport) that cross the barrier and make the ciliary compartment dynamic. The quest to understand the TZ continues and promises to not only illuminate essential aspects of human cell signaling, physiology, and development, but also to unravel how TZ dysfunction contributes to ciliopathies that affect multiple organ systems, including eyes, kidney, and brain.
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Affiliation(s)
- Kwangjin Park
- Department of Molecular Biology and BiochemistrySimon Fraser UniversityBurnabyBCCanada
- Centre for Cell Biology, Development, and DiseaseSimon Fraser UniversityBurnabyBCCanada
- Present address:
Terry Fox LaboratoryBC CancerVancouverBCCanada
- Present address:
Department of Medical GeneticsUniversity of British ColumbiaVancouverBCCanada
| | - Michel R Leroux
- Department of Molecular Biology and BiochemistrySimon Fraser UniversityBurnabyBCCanada
- Centre for Cell Biology, Development, and DiseaseSimon Fraser UniversityBurnabyBCCanada
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39
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Valentini G, Saia M, Farello G, Salpietro V, Mancuso A, Ceravolo I, Colucci PV, Torre M, Iapadre G, Rosa GD, Cucinotta F. Meckel Syndrome: A Clinical and Molecular Overview. JOURNAL OF PEDIATRIC NEUROLOGY 2022. [DOI: 10.1055/s-0042-1759531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AbstractMeckel syndrome (MKS) is a lethal, autosomal recessive, congenital syndrome caused by mutations in genes that encode proteins structurally or functionally related to the primary cilium. MKS is a malformative syndrome, most commonly characterized by occipital meningoencephalocele, polycystic kidney disease, liver fibrosis, and post- and (occasionally) preaxial polydactyly. To date, more than 10 genes are known to constitute the molecular background of MKS, displaying genetic heterogeneity. Individuals with MKS may resemble some phenotypic features of Joubert syndrome and related disorders, thus making diagnostic setting quite challenging. Here, we systematically reviewed the main clinical and genetic characteristics of MKS and its role among ciliopathies.
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Affiliation(s)
- Giulia Valentini
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “G. Barresi,” University Hospital of Messina, Messina, Italy
| | - Maria Saia
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “G. Barresi,” University Hospital of Messina, Messina, Italy
| | - Giovanni Farello
- Pediatric Clinic–Department of Life, Health and Environmental Sciences–Piazzale Salvatore Tommasi 1, Coppito (AQ), Italy
| | | | - Alessio Mancuso
- Unit of Pediatric Emergency, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| | - Ida Ceravolo
- Department of Clinical and Experimental Medicine, University of Messina, Via C. Valeria, Messina, Italy
| | - Pia V. Colucci
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “G. Barresi,” University Hospital of Messina, Messina, Italy
| | - Manuela Torre
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “G. Barresi,” University Hospital of Messina, Messina, Italy
| | - Giulia Iapadre
- Department of Pediatrics, University of L'Aquila, L'Aquila, Italy
| | - Gabriella Di Rosa
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “G. Barresi,” University Hospital of Messina, Messina, Italy
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40
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Amack JD. Structures and functions of cilia during vertebrate embryo development. Mol Reprod Dev 2022; 89:579-596. [PMID: 36367893 PMCID: PMC9805515 DOI: 10.1002/mrd.23650] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/05/2022] [Accepted: 10/28/2022] [Indexed: 11/13/2022]
Abstract
Cilia are hair-like structures that project from the surface of cells. In vertebrates, most cells have an immotile primary cilium that mediates cell signaling, and some specialized cells assemble one or multiple cilia that are motile and beat synchronously to move fluids in one direction. Gene mutations that alter cilia structure or function cause a broad spectrum of disorders termed ciliopathies that impact virtually every system in the body. A wide range of birth defects associated with ciliopathies underscores critical functions for cilia during embryonic development. In many cases, the mechanisms underlying cilia functions during development and disease remain poorly understood. This review describes different types of cilia in vertebrate embryos and discusses recent research results from diverse model systems that provide novel insights into how cilia form and function during embryo development. The work discussed here not only expands our understanding of in vivo cilia biology, but also opens new questions about cilia and their roles in establishing healthy embryos.
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Affiliation(s)
- Jeffrey D. Amack
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, USA,,BioInspired Syracuse: Institute for Material and Living Systems, Syracuse, New York, USA
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41
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Wang J, Thomas HR, Thompson RG, Waldrep SC, Fogerty J, Song P, Li Z, Ma Y, Santra P, Hoover JD, Yeo NC, Drummond IA, Yoder BK, Amack JD, Perkins B, Parant JM. Variable phenotypes and penetrance between and within different zebrafish ciliary transition zone mutants. Dis Model Mech 2022; 15:dmm049568. [PMID: 36533556 PMCID: PMC9844136 DOI: 10.1242/dmm.049568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 11/04/2022] [Indexed: 12/23/2022] Open
Abstract
Meckel syndrome, nephronophthisis, Joubert syndrome and Bardet-Biedl syndrome are caused by mutations in proteins that localize to the ciliary transition zone (TZ). The phenotypically distinct syndromes suggest that these TZ proteins have differing functions. However, mutations in a single TZ gene can result in multiple syndromes, suggesting that the phenotype is influenced by modifier genes. We performed a comprehensive analysis of ten zebrafish TZ mutants, including mks1, tmem216, tmem67, rpgrip1l, cc2d2a, b9d2, cep290, tctn1, nphp1 and nphp4, as well as mutants in ift88 and ift172. Our data indicate that variations in phenotypes exist between different TZ mutants, supporting different tissue-specific functions of these TZ genes. Further, we observed phenotypic variations within progeny of a single TZ mutant, reminiscent of multiple disease syndromes being associated with mutations in one gene. In some mutants, the dynamics of the phenotype became complex with transitory phenotypes that are corrected over time. We also demonstrated that multiple-guide-derived CRISPR/Cas9 F0 'crispant' embryos recapitulate zygotic null phenotypes, and rapidly identified ciliary phenotypes in 11 cilia-associated gene candidates (ankfn1, ccdc65, cfap57, fhad1, nme7, pacrg, saxo2, c1orf194, ttc26, zmynd12 and cfap52).
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Affiliation(s)
- Jun Wang
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Holly R. Thomas
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Robert G. Thompson
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Stephanie C. Waldrep
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Joseph Fogerty
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Ping Song
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Zhang Li
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, AL 35294, USA
| | - Yongjie Ma
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Peu Santra
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Jonathan D. Hoover
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Nan Cher Yeo
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
| | - Iain A. Drummond
- Davis Center for Aging and Regeneration, Mount Desert Island Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609, USA
| | - Bradley K. Yoder
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, AL 35294, USA
| | - Jeffrey D. Amack
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Brian Perkins
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - John M. Parant
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA
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42
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van den Hoek H, Klena N, Jordan MA, Alvarez Viar G, Righetto RD, Schaffer M, Erdmann PS, Wan W, Geimer S, Plitzko JM, Baumeister W, Pigino G, Hamel V, Guichard P, Engel BD. In situ architecture of the ciliary base reveals the stepwise assembly of intraflagellar transport trains. Science 2022; 377:543-548. [PMID: 35901159 DOI: 10.1126/science.abm6704] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The cilium is an antenna-like organelle that performs numerous cellular functions, including motility, sensing, and signaling. The base of the cilium contains a selective barrier that regulates the entry of large intraflagellar transport (IFT) trains, which carry cargo proteins required for ciliary assembly and maintenance. However, the native architecture of the ciliary base and the process of IFT train assembly remain unresolved. In this work, we used in situ cryo-electron tomography to reveal native structures of the transition zone region and assembling IFT trains at the ciliary base in Chlamydomonas. We combined this direct cellular visualization with ultrastructure expansion microscopy to describe the front-to-back stepwise assembly of IFT trains: IFT-B forms the backbone, onto which bind IFT-A, dynein-1b, and finally kinesin-2 before entry into the cilium.
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Affiliation(s)
- Hugo van den Hoek
- Biozentrum, University of Basel, 4056 Basel, Switzerland.,Helmholtz Pioneer Campus, Helmholtz Munich, 85764 Neuherberg, Germany.,Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Nikolai Klena
- Department of Molecular and Cellular Biology, Section of Biology, University of Geneva, 1211 Geneva, Switzerland.,Human Technopole, 20157 Milan, Italy
| | - Mareike A Jordan
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Gonzalo Alvarez Viar
- Human Technopole, 20157 Milan, Italy.,Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Ricardo D Righetto
- Biozentrum, University of Basel, 4056 Basel, Switzerland.,Helmholtz Pioneer Campus, Helmholtz Munich, 85764 Neuherberg, Germany
| | - Miroslava Schaffer
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | | | - William Wan
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Stefan Geimer
- Cell Biology and Electron Microscopy, University of Bayreuth, 95447 Bayreuth, Germany
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Wolfgang Baumeister
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Gaia Pigino
- Human Technopole, 20157 Milan, Italy.,Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Virginie Hamel
- Department of Molecular and Cellular Biology, Section of Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Paul Guichard
- Department of Molecular and Cellular Biology, Section of Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Benjamin D Engel
- Biozentrum, University of Basel, 4056 Basel, Switzerland.,Helmholtz Pioneer Campus, Helmholtz Munich, 85764 Neuherberg, Germany
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43
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Kayser N, Zaiser F, Veenstra AC, Wang H, Göcmen B, Eckert P, Franz H, Köttgen A, Walz G, Yakulov TA. Clock genes rescue nphp mutations in zebrafish. Hum Mol Genet 2022; 31:4143-4158. [PMID: 35861640 PMCID: PMC9759334 DOI: 10.1093/hmg/ddac160] [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: 05/16/2022] [Revised: 07/06/2022] [Accepted: 07/08/2022] [Indexed: 01/21/2023] Open
Abstract
The zebrafish pronephros model, using morpholino oligonucleotides (MO) to deplete target genes, has been extensively used to characterize human ciliopathy phenotypes. Recently, discrepancies between MO and genetically defined mutants have questioned this approach. We analyzed zebrafish with mutations in the nphp1-4-8 module to determine the validity of MO-based results. While MO-mediated depletion resulted in glomerular cyst and cloaca malformation, these ciliopathy-typical manifestations were observed at a much lower frequency in zebrafish embryos with defined nphp mutations. All nphp1-4-8 mutant zebrafish were viable and displayed decreased manifestations in the next (F2) generation, lacking maternal RNA contribution. While genetic compensation was further supported by the observation that nphp4-deficient mutants became partially refractory to MO-based nphp4 depletion, zebrafish embryos, lacking one nphp gene, became more sensitive to MO-based depletion of additional nphp genes. Transcriptome analysis of nphp8 mutant embryos revealed an upregulation of the circadian clock genes cry1a and cry5. MO-mediated depletion of cry1a and cry5 caused ciliopathy phenotypes in wild-type embryos, while cry1a and cry5 depletion in maternal zygotic nphp8 mutant embryos increased the frequency of glomerular cysts compared to controls. Importantly, cry1a and cry5 rescued the nephropathy-related phenotypes in nphp1, nphp4 or nphp8-depleted zebrafish embryos. Our results reveal that nphp mutant zebrafish resemble the MO-based phenotypes, albeit at a much lower frequency. Rapid adaption through upregulation of circadian clock genes seems to ameliorate the loss of nphp genes, contributing to phenotypic differences.
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Affiliation(s)
| | | | | | | | - Burulca Göcmen
- Institute of Genetic Epidemiology, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg 79106, Germany
| | - Priska Eckert
- Renal Division, University Freiburg Medical Center, Faculty of Medicine, Hugstetter Str. 55, Freiburg 79106, Germany
| | - Henriette Franz
- Department of Biomedicine, University of Basel, Pestalozzistr. 20, Basel CH-4056, Switzerland
| | - Anna Köttgen
- Institute of Genetic Epidemiology, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg 79106, Germany
| | - Gerd Walz
- Renal Division, University Freiburg Medical Center, Faculty of Medicine, Hugstetter Str. 55, Freiburg 79106, Germany,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Albertstrasse 19, Freiburg 79104, Germany
| | - Toma A Yakulov
- To whom correspondence should be addressed. Tel: +49 76127063036;
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44
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Wang L, Wen X, Wang Z, Lin Z, Li C, Zhou H, Yu H, Li Y, Cheng Y, Chen Y, Lou G, Pan J, Cao M. Ciliary transition zone proteins coordinate ciliary protein composition and ectosome shedding. Nat Commun 2022; 13:3997. [PMID: 35810181 PMCID: PMC9271036 DOI: 10.1038/s41467-022-31751-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 06/30/2022] [Indexed: 11/09/2022] Open
Abstract
The transition zone (TZ) of the cilium/flagellum serves as a diffusion barrier that controls the entry/exit of ciliary proteins. Mutations of the TZ proteins disrupt barrier function and lead to multiple human diseases. However, the systematic regulation of ciliary composition and signaling-related processes by different TZ proteins is not completely understood. Here, we reveal that loss of TCTN1 in Chlamydomonas reinhardtii disrupts the assembly of wedge-shaped structures in the TZ. Proteomic analysis of cilia from WT and three TZ mutants, tctn1, cep290, and nphp4, shows a unique role of each TZ subunit in the regulation of ciliary composition, explaining the phenotypic diversity of different TZ mutants. Interestingly, we find that defects in the TZ impair the formation and biological activity of ciliary ectosomes. Collectively, our findings provide systematic insights into the regulation of ciliary composition by TZ proteins and reveal a link between the TZ and ciliary ectosomes. Cilia project from cells to serve sensory functions, and ciliary disruption can result in multiple disorders known as ciliopathies. Here the authors show that the ciliopathy gene TCTN1 functions to regulate the ciliary transition zone and ectosome formation.
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Affiliation(s)
- Liang Wang
- School of Life Sciences, Jiangsu Normal University, 221116, Xuzhou, China.
| | - Xin Wen
- School of Life Sciences, Jiangsu Normal University, 221116, Xuzhou, China
| | - Zhengmao Wang
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266071, Qingdao, China.,MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Zaisheng Lin
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China
| | - Chunhong Li
- School of Life Sciences, Jiangsu Normal University, 221116, Xuzhou, China
| | - Huilin Zhou
- School of Life Sciences, Jiangsu Normal University, 221116, Xuzhou, China
| | - Huimin Yu
- School of Life Sciences, Jiangsu Normal University, 221116, Xuzhou, China
| | - Yuhan Li
- School of Life Sciences, Jiangsu Normal University, 221116, Xuzhou, China
| | - Yifei Cheng
- School of Life Sciences, Jiangsu Normal University, 221116, Xuzhou, China
| | - Yuling Chen
- School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Geer Lou
- Shanghai Biotree Biotech Co. Ltd, 201815, Shanghai, China
| | - Junmin Pan
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266071, Qingdao, China.,MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Muqing Cao
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China.
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45
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Rusterholz TDS, Hofmann C, Bachmann-Gagescu R. Insights Gained From Zebrafish Models for the Ciliopathy Joubert Syndrome. Front Genet 2022; 13:939527. [PMID: 35846153 PMCID: PMC9280682 DOI: 10.3389/fgene.2022.939527] [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: 05/09/2022] [Accepted: 05/26/2022] [Indexed: 12/04/2022] Open
Abstract
Cilia are quasi-ubiquitous microtubule-based sensory organelles, which play vital roles in signal transduction during development and cell homeostasis. Dysfunction of cilia leads to a group of Mendelian disorders called ciliopathies, divided into different diagnoses according to clinical phenotype constellation and genetic causes. Joubert syndrome (JBTS) is a prototypical ciliopathy defined by a diagnostic cerebellar and brain stem malformation termed the “Molar Tooth Sign” (MTS), in addition to which patients display variable combinations of typical ciliopathy phenotypes such as retinal dystrophy, fibrocystic renal disease, polydactyly or skeletal dystrophy. Like most ciliopathies, JBTS is genetically highly heterogeneous with ∼40 associated genes. Zebrafish are widely used to model ciliopathies given the high conservation of ciliary genes and the variety of specialized cilia types similar to humans. In this review, we compare different existing JBTS zebrafish models with each other and describe their contributions to our understanding of JBTS pathomechanism. We find that retinal dystrophy, which is the most investigated ciliopathy phenotype in zebrafish ciliopathy models, is caused by distinct mechanisms according to the affected gene. Beyond this, differences in phenotypes in other organs observed between different JBTS-mutant models suggest tissue-specific roles for proteins implicated in JBTS. Unfortunately, the lack of systematic assessment of ciliopathy phenotypes in the mutants described in the literature currently limits the conclusions that can be drawn from these comparisons. In the future, the numerous existing JBTS zebrafish models represent a valuable resource that can be leveraged in order to gain further insights into ciliary function, pathomechanisms underlying ciliopathy phenotypes and to develop treatment strategies using small molecules.
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Affiliation(s)
- Tamara D. S. Rusterholz
- Institute of Medical Genetics, University of Zurich, Schlieren, Switzerland
- Department of Molecular Life Sciences, University of Zurich, Zürich, Switzerland
| | - Claudia Hofmann
- Institute of Medical Genetics, University of Zurich, Schlieren, Switzerland
- Department of Molecular Life Sciences, University of Zurich, Zürich, Switzerland
| | - Ruxandra Bachmann-Gagescu
- Institute of Medical Genetics, University of Zurich, Schlieren, Switzerland
- Department of Molecular Life Sciences, University of Zurich, Zürich, Switzerland
- *Correspondence: Ruxandra Bachmann-Gagescu,
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46
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Dutta P, Ray K. Ciliary membrane, localised lipid modification and cilia function. J Cell Physiol 2022; 237:2613-2631. [PMID: 35661356 DOI: 10.1002/jcp.30787] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 05/06/2022] [Accepted: 05/11/2022] [Indexed: 11/08/2022]
Abstract
Cilium, a tiny microtubule-based cellular appendage critical for cell signalling and physiology, displays a large variety of receptors. The composition and turnover of ciliary lipids and receptors determine cell behaviour. Due to the exclusion of ribosomal machinery and limited membrane area, a cilium needs adaptive logistics to actively reconstitute the lipid and receptor compositions during development and differentiation. How is this dynamicity generated? Here, we examine whether, along with the Intraflagellar-Transport, targeted changes in sector-wise lipid composition could control the receptor localisation and functions in the cilia. We discuss how an interplay between ciliary lipid composition, localised lipid modification, and receptor function could contribute to cilia growth and signalling. We argue that lipid modification at the cell-cilium interface could generate an added thrust for a selective exchange of membrane lipids and the transmembrane and membrane-associated proteins.
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Affiliation(s)
- Priya Dutta
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Krishanu Ray
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
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Qiu YL, Wang L, Huang M, Lian M, Wang F, Gong Y, Ma X, Hao CZ, Zhang J, Li ZD, Xing QH, Cao M, Wang JS. Association of novel TMEM67 variants with mild phenotypes of high gamma-glutamyl transpeptidase cholestasis and congenital hepatic fibrosis. J Cell Physiol 2022; 237:2713-2723. [PMID: 35621037 DOI: 10.1002/jcp.30788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 11/11/2022]
Abstract
TMEM67 (mecklin or MKS3) locates in the transition zone of cilia. Dysfunction of TMEM67 disrupts cilia-related signaling and leads to developmental defects of multiple organs in humans. Typical autosomal recessive TMEM67 defects cause partial overlapping phenotypes, including abnormalities in the brain, eyes, liver, kidneys, bones, and so forth. However, emerging reports of isolated nephronophthisis suggest the possibility of a broader phenotype spectrum. In this study, we analyzed the genetic data of cholestasis patients with no obvious extrahepatic involvement but with an unexplained high level of gamma-glutamyl transpeptidase (GGT). We identified five Han Chinese patients from three unrelated families with biallelic nonnull low-frequency TMEM67 variants. All variants were predicted pathogenic in silico, of which p. Arg820Ile and p. Leu144del were previously unreported. In vitro studies revealed that the protein levels of the TMEM67 variants were significantly decreased; however, their interaction with MKS1 remained unaffected. All the patients, aged 7-39 years old, had silently progressive cholestasis with elevated GGT but had normal bilirubin levels. Histological studies of liver biopsy of patients 1, 3, and 5 showed the presence of congenital hepatic fibrosis. We conclude that variants in TMEM67 are associated with a mild phenotype of unexplained, persistent, anicteric, and high GGT cholestasis without typical symptoms of TMEM67 defects; this possibility should be considered by physicians in gastroenterology and hepatology.
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Affiliation(s)
- Yi-Ling Qiu
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Li Wang
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Min Huang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Min Lian
- Division of Gastroenterology and Hepatology, Shanghai Institute of Digestive Disease, Shanghai Jiao Tong University School of Medicine Affiliated Renji Hospital, Shanghai, China
| | - Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Ying Gong
- Department of Radiology, Children's Hospital of Fudan University, Shanghai, China
| | - Xiong Ma
- Division of Gastroenterology and Hepatology, Shanghai Institute of Digestive Disease, Shanghai Jiao Tong University School of Medicine Affiliated Renji Hospital, Shanghai, China
| | - Chen-Zhi Hao
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Jing Zhang
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Zhong-Die Li
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Qing-He Xing
- Institutes of Biomedical Sciences of Fudan University, Shanghai, China
| | - Muqing Cao
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jian-She Wang
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
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Lange KI, Best S, Tsiropoulou S, Berry I, Johnson CA, Blacque OE. Interpreting ciliopathy-associated missense variants of uncertain significance (VUS) in Caenorhabditis elegans. Hum Mol Genet 2022; 31:1574-1587. [PMID: 34964473 PMCID: PMC9122650 DOI: 10.1093/hmg/ddab344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 12/26/2022] Open
Abstract
Better methods are required to interpret the pathogenicity of disease-associated variants of uncertain significance (VUS), which cannot be actioned clinically. In this study, we explore the use of an animal model (Caenorhabditis elegans) for in vivo interpretation of missense VUS alleles of TMEM67, a cilia gene associated with ciliopathies. CRISPR/Cas9 gene editing was used to generate homozygous knock-in C. elegans worm strains carrying TMEM67 patient variants engineered into the orthologous gene (mks-3). Quantitative phenotypic assays of sensory cilia structure and function (neuronal dye filling, roaming and chemotaxis assays) measured how the variants impacted mks-3 gene function. Effects of the variants on mks-3 function were further investigated by looking at MKS-3::GFP localization and cilia ultrastructure. The quantitative assays in C. elegans accurately distinguished between known benign (Asp359Glu, Thr360Ala) and known pathogenic (Glu361Ter, Gln376Pro) variants. Analysis of eight missense VUS generated evidence that three are benign (Cys173Arg, Thr176Ile and Gly979Arg) and five are pathogenic (Cys170Tyr, His782Arg, Gly786Glu, His790Arg and Ser961Tyr). Results from worms were validated by a genetic complementation assay in a human TMEM67 knock-out hTERT-RPE1 cell line that tests a TMEM67 signalling function. We conclude that efficient genome editing and quantitative functional assays in C. elegans make it a tractable in vivo animal model for rapid, cost-effective interpretation of ciliopathy-associated missense VUS alleles.
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Affiliation(s)
- Karen I Lange
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Sunayna Best
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, West Yorkshire, UK
| | - Sofia Tsiropoulou
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Ian Berry
- Bristol Genetics Laboratory, Pathology Sciences, Southmead Hospital, Bristol BS10 5NB, UK
| | - Colin A Johnson
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, West Yorkshire, UK
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
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Song T, Yang Y, Zhou P, Ran J, Zhang L, Wu X, Xie W, Zhong T, Liu H, Liu M, Li D, Zhao H, Zhou J. ENKD1 promotes CP110 removal through competing with CEP97 to initiate ciliogenesis. EMBO Rep 2022; 23:e54090. [PMID: 35301795 PMCID: PMC9066061 DOI: 10.15252/embr.202154090] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 02/23/2022] [Accepted: 03/03/2022] [Indexed: 02/04/2023] Open
Abstract
Despite the importance of cilia in cell signaling and motility, the molecular mechanisms regulating cilium formation remain incompletely understood. Herein, we characterize enkurin domain-containing protein 1 (ENKD1) as a novel centrosomal protein that mediates the removal of centriolar coiled-coil protein 110 (CP110) from the mother centriole to promote ciliogenesis. We show that Enkd1 knockout mice possess ciliogenesis defects in multiple organs. Super-resolution microscopy reveals that ENKD1 is a stable component of the centrosome throughout the ciliogenesis process. Simultaneous knockdown of ENKD1 and CP110 significantly reverses the ciliogenesis defects induced by ENKD1 depletion. Protein interaction analysis shows that ENKD1 competes with centrosomal protein 97 (CEP97) in binding to CP110. Depletion of ENKD1 enhances the CP110-CEP97 interaction and detains CP110 at the mother centriole. These findings thus identify ENKD1 as a centrosomal protein and uncover a novel mechanism controlling CP110 removal from the mother centriole for the initiation of ciliogenesis.
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Affiliation(s)
- Ting Song
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Institute of Biomedical Sciences, College of Life Sciences, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Yunfan Yang
- Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Peng Zhou
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Institute of Biomedical Sciences, College of Life Sciences, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Jie Ran
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Institute of Biomedical Sciences, College of Life Sciences, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Liang Zhang
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Institute of Biomedical Sciences, College of Life Sciences, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Xiaofan Wu
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecology, Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Wei Xie
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Institute of Biomedical Sciences, College of Life Sciences, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Tao Zhong
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Institute of Biomedical Sciences, College of Life Sciences, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Hongbin Liu
- Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Min Liu
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Institute of Biomedical Sciences, College of Life Sciences, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Dengwen Li
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecology, Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Huijie Zhao
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Institute of Biomedical Sciences, College of Life Sciences, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Jun Zhou
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Institute of Biomedical Sciences, College of Life Sciences, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China.,State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecology, Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, China
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50
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Tmem138 is localized to the connecting cilium essential for rhodopsin localization and outer segment biogenesis. Proc Natl Acad Sci U S A 2022; 119:e2109934119. [PMID: 35394880 PMCID: PMC9169668 DOI: 10.1073/pnas.2109934119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The connecting cilium (CC) of the photoreceptor provides the only route for the trafficking of the outer segment (OS) proteins. Failure of OS protein transport causes degenerative photoreceptor diseases, including retinitis pigmentosa. We demonstrate that Tmem138, a protein linked to ciliopathy, is localized to the photoreceptor CC. Germline deletion of Tmem138 abolished OS morphogenesis, followed by rapid photoreceptor degeneration. Tmem138 interacts with rhodopsin and two additional CC compartment proteins, Ahi1 and Tmem231, likely forming a membrane complex to facilitate trafficking of rhodopsin and other OS-bound proteins across the CC. The study thus implicates a new line of regulation on the delivery of OS proteins through interactions with CC membrane complex(es) and provides insights into photoreceptor ciliopathy diseases. Photoreceptor connecting cilium (CC) is structurally analogous to the transition zone (TZ) of primary cilia and gates the molecular trafficking between the inner and the outer segment (OS). Retinal dystrophies with underlying CC defects are manifested in a broad array of syndromic conditions known as ciliopathies as well as nonsyndromic retinal degenerations. Despite extensive studies, many questions remain in the mechanism of protein trafficking across the photoreceptor CC. Here, we genetically inactivated mouse Tmem138, a gene encoding a putative transmembrane protein localized to the ciliary TZ and linked to ciliopathies. Germline deletion of Tmem138 abolished OS morphogenesis, followed by rapid photoreceptor degeneration. Tmem138 was found localized to the photoreceptor CC and was required for localization of Ahi1 to the distal subdomain of the CC. Among the examined set of OS proteins, rhodopsin was mislocalized throughout the mutant cell body prior to OS morphogenesis. Ablation of Tmem138 in mature rods recapitulated the molecular changes in the germline mutants, causing failure of disc renewal and disintegration of the OS. Furthermore, Tmem138 interacts reciprocally with rhodopsin and a related protein Tmem231, and the ciliary localization of the latter was also altered in the mutant photoreceptors. Taken together, these results suggest a crucial role of Tmem138 in the functional organization of the CC, which is essential for rhodopsin localization and OS biogenesis.
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