1
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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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2
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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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3
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The inner junction protein CFAP20 functions in motile and non-motile cilia and is critical for vision. Nat Commun 2022; 13:6595. [PMID: 36329026 PMCID: PMC9633640 DOI: 10.1038/s41467-022-33820-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/03/2022] [Indexed: 11/06/2022] Open
Abstract
Motile and non-motile cilia are associated with mutually-exclusive genetic disorders. Motile cilia propel sperm or extracellular fluids, and their dysfunction causes primary ciliary dyskinesia. Non-motile cilia serve as sensory/signalling antennae on most cell types, and their disruption causes single-organ ciliopathies such as retinopathies or multi-system syndromes. CFAP20 is a ciliopathy candidate known to modulate motile cilia in unicellular eukaryotes. We demonstrate that in zebrafish, cfap20 is required for motile cilia function, and in C. elegans, CFAP-20 maintains the structural integrity of non-motile cilia inner junctions, influencing sensory-dependent signalling and development. Human patients and zebrafish with CFAP20 mutations both exhibit retinal dystrophy. Hence, CFAP20 functions within a structural/functional hub centered on the inner junction that is shared between motile and non-motile cilia, and is distinct from other ciliopathy-associated domains or macromolecular complexes. Our findings suggest an uncharacterised pathomechanism for retinal dystrophy, and potentially for motile and non-motile ciliopathies in general.
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Lin T, Ma Y, Zhou D, Sun L, Chen K, Xiang Y, Tong K, Jia C, Jiang K, Liu D, Huang G. Case Report: Preimplantation Genetic Testing for Meckel Syndrome Induced by Novel Compound Heterozygous Mutations of MKS1. Front Genet 2022; 13:843931. [PMID: 35360848 PMCID: PMC8963843 DOI: 10.3389/fgene.2022.843931] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/02/2022] [Indexed: 11/13/2022] Open
Abstract
Meckel syndrome (MKS), also known as the Meckel–Gruber syndrome, is a severe pleiotropic autosomal recessive developmental disorder caused by dysfunction of the primary cilia during early embryogenesis. The diagnostic criteria are based on clinical variability and genetic heterogeneity. Mutations in the MKS1 gene constitute approximately 7% of all MKS cases. Herein, we present a non-consanguineous couple with three abnormal pregnancies as the fetuses showed MKS-related phenotypes of the central nervous system malformation and postaxial polydactyly. Whole-exome sequencing identified two novel heterozygous mutations of MKS1: c.350C>A and c.1408-14A>G. The nonsense mutation c.350C>A produced a premature stop codon and induced the truncation of the MKS1 protein (p.S117*). Reverse-transcription polymerase chain reaction (RT-PCR) showed that c.1408-14A>G skipped exon 16 and encoded the mutant MKS1 p.E471Lfs*92. Functional studies showed that these two mutations disrupted the B9–C2 domain of the MKS1 protein and attenuated the interactions with B9D2, the essential component of the ciliary transition zone. The couple finally got a healthy baby through preimplantation genetic testing for monogenic disorder (PGT-M) with haplotype linkage analysis. Thus, this study expanded the mutation spectrum of MKS1 and elucidated the genetic heterogeneity of MKS1 in clinical cases.
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Affiliation(s)
- Tingting Lin
- Chongqing Key Laboratory of Human Embryo Engineering, Chongqing, China
- Chongqing Clinical Research Center for Reproductive Medicine, Chongqing, China
- Reproductive and Genetic Institute, Chongqing Health Center for Women and Children, Chongqing, China
| | - Yongyi Ma
- The Southwest Hospital of Army Medical University, Chongqing, China
| | - Danni Zhou
- Chongqing Key Laboratory of Human Embryo Engineering, Chongqing, China
- Chongqing Clinical Research Center for Reproductive Medicine, Chongqing, China
- Reproductive and Genetic Institute, Chongqing Health Center for Women and Children, Chongqing, China
| | - Liwei Sun
- Chongqing Key Laboratory of Human Embryo Engineering, Chongqing, China
- Chongqing Clinical Research Center for Reproductive Medicine, Chongqing, China
- Reproductive and Genetic Institute, Chongqing Health Center for Women and Children, Chongqing, China
| | - Ke Chen
- Chongqing Key Laboratory of Human Embryo Engineering, Chongqing, China
- Chongqing Clinical Research Center for Reproductive Medicine, Chongqing, China
- Reproductive and Genetic Institute, Chongqing Health Center for Women and Children, Chongqing, China
| | - Yezhou Xiang
- Chongqing Key Laboratory of Human Embryo Engineering, Chongqing, China
- Chongqing Clinical Research Center for Reproductive Medicine, Chongqing, China
- Reproductive and Genetic Institute, Chongqing Health Center for Women and Children, Chongqing, China
| | - Keya Tong
- Chongqing Key Laboratory of Human Embryo Engineering, Chongqing, China
- Chongqing Clinical Research Center for Reproductive Medicine, Chongqing, China
- Reproductive and Genetic Institute, Chongqing Health Center for Women and Children, Chongqing, China
| | - Chaoli Jia
- Chongqing Key Laboratory of Human Embryo Engineering, Chongqing, China
- Chongqing Clinical Research Center for Reproductive Medicine, Chongqing, China
- Reproductive and Genetic Institute, Chongqing Health Center for Women and Children, Chongqing, China
| | - Kean Jiang
- Chongqing Key Laboratory of Human Embryo Engineering, Chongqing, China
- Chongqing Clinical Research Center for Reproductive Medicine, Chongqing, China
- Reproductive and Genetic Institute, Chongqing Health Center for Women and Children, Chongqing, China
| | - Dongyun Liu
- Chongqing Key Laboratory of Human Embryo Engineering, Chongqing, China
- Chongqing Clinical Research Center for Reproductive Medicine, Chongqing, China
- Reproductive and Genetic Institute, Chongqing Health Center for Women and Children, Chongqing, China
- *Correspondence: Dongyun Liu, ; Guoning Huang,
| | - Guoning Huang
- Chongqing Key Laboratory of Human Embryo Engineering, Chongqing, China
- Chongqing Clinical Research Center for Reproductive Medicine, Chongqing, China
- Reproductive and Genetic Institute, Chongqing Health Center for Women and Children, Chongqing, China
- *Correspondence: Dongyun Liu, ; Guoning Huang,
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Szymanska K, Boldt K, Logan CV, Adams M, Robinson PA, Ueffing M, Zeqiraj E, Wheway G, Johnson CA. Regulation of canonical Wnt signalling by the ciliopathy protein MKS1 and the E2 ubiquitin-conjugating enzyme UBE2E1. eLife 2022; 11:57593. [PMID: 35170427 PMCID: PMC8880992 DOI: 10.7554/elife.57593] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 02/10/2022] [Indexed: 11/24/2022] Open
Abstract
Primary ciliary defects cause a group of developmental conditions known as ciliopathies. Here, we provide mechanistic insight into ciliary ubiquitin processing in cells and for mouse model lacking the ciliary protein Mks1. In vivo loss of Mks1 sensitises cells to proteasomal disruption, leading to abnormal accumulation of ubiquitinated proteins. We identified UBE2E1, an E2 ubiquitin-conjugating enzyme that polyubiquitinates β-catenin, and RNF34, an E3 ligase, as novel interactants of MKS1. UBE2E1 and MKS1 colocalised, and loss of UBE2E1 recapitulates the ciliary and Wnt signalling phenotypes observed during loss of MKS1. Levels of UBE2E1 and MKS1 are co-dependent and UBE2E1 mediates both regulatory and degradative ubiquitination of MKS1. We demonstrate that processing of phosphorylated β-catenin occurs at the ciliary base through the functional interaction between UBE2E1 and MKS1. These observations suggest that correct β-catenin levels are tightly regulated at the primary cilium by a ciliary-specific E2 (UBE2E1) and a regulatory substrate-adaptor (MKS1).
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Affiliation(s)
- Katarzyna Szymanska
- Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom
| | - Karsten Boldt
- Institute of Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | | | - Matthew Adams
- Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom
| | | | - Marius Ueffing
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Elton Zeqiraj
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Gabrielle Wheway
- Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Colin A Johnson
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
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6
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Roopasree OJ, Adivitiya, Chakraborty S, Kateriya S, Veleri S. Centriole is the pivot coordinating dynamic signaling for cell proliferation and organization during early development in the vertebrates. Cell Biol Int 2021; 45:2178-2197. [PMID: 34288241 DOI: 10.1002/cbin.11667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 07/12/2021] [Indexed: 11/07/2022]
Abstract
Vertebrates have an elaborate and functionally segmented body. It evolves from a single cell by systematic cell proliferation but attains a complex body structure with exquisite precision. This development requires two cellular events: cell cycle and ciliogenesis. For these events, the dynamic molecular signaling is converged at the centriole. The cell cycle helps in cell proliferation and growth of the body and is a highly regulated and integrated process. Its errors cause malignancies and developmental disorders. The cells newly proliferated are organized during organogenesis. For a cellular organization, dedicated signaling hubs are developed in the cells, and most often cilia are utilized. The cilium is generated from one of the centrioles involved in cell proliferation. The developmental signaling pathways hosted in cilia are essential for the elaboration of the body plan. The cilium's compartmental seclusion is ideal for noise-free molecular signaling and is essential for the precision of the body layout. The dysfunctional centrioles and primary cilia distort the development of body layout that manifest as serious developmental disorders. Thus, centriole has a dual role in the growth and cellular organization. It organizes dynamically expressed molecules of cell cycle and ciliogenesis and plays a balancing act to generate new cells and organize them during development. A putative master molecule may regulate and coordinate the dynamic gene expression at the centrioles. The convergence of many critical signaling components at the centriole reiterates the idea that centriole is a major molecular workstation involved in elaborating the structural design and complexity in vertebrates. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- O J Roopasree
- Agroprocessing Technology Division, CSIR-National Institute of Interdisciplinary Science and Technology, Thiruvananthapuram, Kerala 695019 and Academy of CSIR, Uttar Pradesh - 201002, India
| | - Adivitiya
- Laboratory of Optobiology, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Soura Chakraborty
- Laboratory of Optobiology, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Suneel Kateriya
- Laboratory of Optobiology, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Shobi Veleri
- Drug Safety Division, ICMR-National Institute of Nutrition, Hyderabad, 500007, India
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A complement factor H homolog, heparan sulfation, and syndecan maintain inversin compartment boundaries in C. elegans cilia. Proc Natl Acad Sci U S A 2021; 118:2016698118. [PMID: 33859044 DOI: 10.1073/pnas.2016698118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of blindness among the elderly. Canonical disease models suggest that defective interactions between complement factor H (CFH) and cell surface heparan sulfate (HS) result in increased alternative complement pathway activity, cytolytic damage, and tissue inflammation in the retina. Although these factors are thought to contribute to increased disease risk, multiple studies indicate that noncanonical mechanisms that result from defective CFH and HS interaction may contribute to the progression of AMD as well. A total of 60 ciliated sensory neurons in the nematode Caenorhabditis elegans detect chemical, olfactory, mechanical, and thermal cues in the environment. Here, we find that a C. elegans CFH homolog localizes on CEP mechanosensory neuron cilia where it has noncanonical roles in maintaining inversin/NPHP-2 within its namesake proximal compartment and preventing inversin/NPHP-2 accumulation in distal cilia compartments in aging adults. CFH localization and maintenance of inversin/NPHP-2 compartment integrity depend on the HS 3-O sulfotransferase HST-3.1 and the transmembrane proteoglycan syndecan/SDN-1. Defective inversin/NPHP-2 localization in mouse and human photoreceptors with CFH mutations indicates that these functions and interactions may be conserved in vertebrate sensory neurons, suggesting that previously unappreciated defects in cilia structure may contribute to the progressive photoreceptor dysfunction associated with CFH loss-of-function mutations in some AMD patients.
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8
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Hazime KS, Zhou Z, Joachimiak E, Bulgakova NA, Wloga D, Malicki JJ. STORM imaging reveals the spatial arrangement of transition zone components and IFT particles at the ciliary base in Tetrahymena. Sci Rep 2021; 11:7899. [PMID: 33846423 PMCID: PMC8041816 DOI: 10.1038/s41598-021-86909-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 03/22/2021] [Indexed: 11/17/2022] Open
Abstract
The base of the cilium comprising the transition zone (TZ) and transition fibers (TF) acts as a selecting gate to regulate the intraflagellar transport (IFT)-dependent trafficking of proteins to and from cilia. Before entering the ciliary compartment, IFT complexes and transported cargoes accumulate at or near the base of the cilium. The spatial organization of IFT proteins at the cilia base is key for understanding cilia formation and function. Using stochastic optical reconstruction microscopy (STORM) and computational averaging, we show that seven TZ, nine IFT, three Bardet–Biedl syndrome (BBS), and one centrosomal protein, form 9-clustered rings at the cilium base of a ciliate Tetrahymena thermophila. In the axial dimension, analyzed TZ proteins localize to a narrow region of about 30 nm while IFT proteins dock approximately 80 nm proximal to TZ. Moreover, the IFT-A subcomplex is positioned peripheral to the IFT-B subcomplex and the investigated BBS proteins localize near the ciliary membrane. The positioning of the HA-tagged N- and C-termini of the selected proteins enabled the prediction of the spatial orientation of protein particles and likely cargo interaction sites. Based on the obtained data, we built a comprehensive 3D-model showing the arrangement of the investigated ciliary proteins.
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Affiliation(s)
- Khodor S Hazime
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
| | - Zhu Zhou
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, 3 Pasteur Street, 02-093, Warsaw, Poland
| | - Natalia A Bulgakova
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, 3 Pasteur Street, 02-093, Warsaw, Poland.
| | - Jarema J Malicki
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
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Lange KI, Tsiropoulou S, Kucharska K, Blacque OE. Interpreting the pathogenicity of Joubert syndrome missense variants in Caenorhabditis elegans. Dis Model Mech 2021; 14:dmm.046631. [PMID: 33234550 PMCID: PMC7859701 DOI: 10.1242/dmm.046631] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/13/2020] [Indexed: 12/26/2022] Open
Abstract
Ciliopathies are inherited disorders caused by defects in motile and non-motile (primary) cilia. Ciliopathy syndromes and associated gene variants are often highly pleiotropic and represent exemplars for interrogating genotype-phenotype correlations. Towards understanding disease mechanisms in the context of ciliopathy mutations, we have used a leading model organism for cilia and ciliopathy research, Caenorhabditis elegans, together with gene editing, to characterise two missense variants (P74S and G155S) in mksr-2/B9D2 associated with Joubert syndrome (JBTS). B9D2 functions within the Meckel syndrome (MKS) module at the ciliary base transition zone (TZ) compartment and regulates the molecular composition and sensory/signalling functions of the cilium. Quantitative assays of cilium/TZ structure and function, together with knock-in reporters, confirm that both variant alleles are pathogenic in worms. G155S causes a more severe overall phenotype and disrupts endogenous MKSR-2 organisation at the TZ. Recapitulation of the patient biallelic genotype shows that compound heterozygous worms phenocopy worms homozygous for P74S. The P74S and G155S alleles also reveal evidence of a very close functional association between the B9D2-associated B9 complex and MKS-2/TMEM216. Together, these data establish C. elegans as a model for interpreting JBTS mutations and provide further insight into MKS module organisation. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Karen I Lange
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Sofia Tsiropoulou
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Katarzyna Kucharska
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland
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Okazaki M, Kobayashi T, Chiba S, Takei R, Liang L, Nakayama K, Katoh Y. Formation of the B9-domain protein complex MKS1-B9D2-B9D1 is essential as a diffusion barrier for ciliary membrane proteins. Mol Biol Cell 2020; 31:2259-2268. [PMID: 32726168 PMCID: PMC7550698 DOI: 10.1091/mbc.e20-03-0208] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/13/2020] [Accepted: 07/21/2020] [Indexed: 01/20/2023] Open
Abstract
Cilia are plasma membrane protrusions that act as cellular antennae and propellers in eukaryotes. To achieve their sensory and motile functions, cilia maintain protein and lipid compositions that are distinct from those of the cell body. The transition zone (TZ) is a specialized region located at the ciliary base, which functions as a barrier separating the interior and exterior of cilia. The TZ comprises a number of transmembrane and soluble proteins. Meckel syndrome (MKS)1, B9 domain (B9D)1/MKS9, and B9D2/MKS10 are soluble TZ proteins that are encoded by causative genes of MKS and have a B9D in common. We here demonstrate the interaction mode of these B9D proteins to be MKS1-B9D2-B9D1 and demonstrate their interdependent localization to the TZ. Phenotypic analyses of MKS1-knockout (KO) and B9D2-KO cells show that the B9D proteins are involved in, although not essential for, normal cilia biogenesis. Rescue experiments of these KO cells show that formation of the B9D protein complex is crucial for creating a diffusion barrier for ciliary membrane proteins.
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Affiliation(s)
- Misato Okazaki
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Takuya Kobayashi
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shuhei Chiba
- Department of Genetic Disease Research, Graduate School of Medicine, Osaka City University, Abeno-ku, Osaka 545-8585, Japan
| | - Ryota Takei
- 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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11
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Katiyar D, Anderson N, Bommireddipalli S, Bournazos A, Cooper S, Goel H. Two novel B9D1 variants causing Joubert syndrome: Utility of mRNA and splicing studies. Eur J Med Genet 2020; 63:104000. [PMID: 32622957 DOI: 10.1016/j.ejmg.2020.104000] [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: 04/08/2020] [Revised: 05/28/2020] [Accepted: 06/28/2020] [Indexed: 11/26/2022]
Abstract
The primary cilium is an organelle which plays an important role in the transduction of signals in the Wnt and Sonic hedgehog pathways. Abnormal or absent primary cilia result in various neurodevelopmental, retinal, renal, hepatic and musculoskeletal abnormalities. Joubert syndrome (JS) is a ciliopathy with a prevalence estimated to be between 1:80 000 and 1:100 000. JS occurs due to bi-allelic mutations in one of the 34 identified genes, all of which encode for protein components of the primary cilia. The presentation of JS is highly variable, however a clinical diagnosis can be established by the presence of the molar tooth sign on axial brain MRI, hypotonia in infancy, and developmental delay. JS is less severe than Meckel syndrome (MKS), which is another recessive, and often lethal, ciliopathy. This report outlines an interesting case of JS, in which two novel mutations in B9D1 were identified. This gene is not commonly associated with JS, and is often implicated in MKS. Functional mRNA study was helpful in delineating the pathogenic role of novel variants in this case.
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Affiliation(s)
- Disha Katiyar
- University of New England, Armidale, NSW, 2351, Australia; University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Neil Anderson
- John Hunter Children's Hospital, Hunter New England Local Health District (HNELHD), New Lambton Heights, NSW, Australia
| | | | - Adam Bournazos
- Kids Neuroscience Centre, The Children's Hospital at Westmead Sydney, Australia
| | - Sandra Cooper
- Kids Neuroscience Centre, The Children's Hospital at Westmead Sydney, Australia
| | - Himanshu Goel
- University of Newcastle, Callaghan, NSW, 2308, Australia; Hunter Genetics, Hunter New England Local Health District (HNELHD), Waratah, NSW, 2298, Australia.
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12
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Zhang R, Chen S, Han P, Chen F, Kuang S, Meng Z, Liu J, Sun R, Wang Z, He X, Li Y, Guan Y, Yue Z, Li C, Kumar Dey S, Zhu Y, Banerjee S. Whole exome sequencing identified a homozygous novel variant in CEP290 gene causes Meckel syndrome. J Cell Mol Med 2019; 24:1906-1916. [PMID: 31840411 PMCID: PMC6991682 DOI: 10.1111/jcmm.14887] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 11/15/2019] [Accepted: 11/22/2019] [Indexed: 12/01/2022] Open
Abstract
Meckel syndrome (MKS) is a pre‐ or perinatal multisystemic ciliopathic lethal disorder with an autosomal recessive mode of inheritance. Meckel syndrome is usually manifested with meningo‐occipital encephalocele, polycystic kidney dysplasia, postaxial polydactyly and hepatobiliary ductal plate malformation. Germline variants in CEP290 cause MKS4. In this study, we investigated a 35‐years‐old Chinese female who was 17+1 weeks pregnant. She had a history of adverse pregnancy of having foetus with multiple malformations. We performed ultrasonography and identified the foetus with occipital meningoencephalocele and enlarged cystic dysplastic kidneys. So, she decided to terminate her pregnancy and further genetic molecular analysis was performed. We identified the aborted foetus without postaxial polydactyly. Histological examination of foetal kidney showed cysts in kidney and thinning of the renal cortex with glomerular atrophy. Whole exome sequencing identified a novel homozygous variant (c.2144T>G; p.L715*) in exon 21 of the CEP290 in the foetus. Sanger sequencing confirmed that both the parents of the foetus were carrying this variant in a heterozygous state. This variant was not identified in two elder sisters of the foetus as well as in the 100 healthy individuals. Western blot analysis showed that this variant leads to the formation of truncated CEP290 protein with the molecular weight of 84 KD compared with the wild‐type CEP290 protein of 290 KD. Hence, it is a loss‐of‐function variant. We also found that the mutant cilium appears longer in length than the wild‐type cilium. Our present study reported the first variant of CEP290 associated with MKS4 in Chinese population.
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Affiliation(s)
- Rui Zhang
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Shaoyun Chen
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Peng Han
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Fangfang Chen
- Department of Pathology, Bao'an Maternity and Child Health Hospital, Shenzhen, China
| | - Shan Kuang
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Zhuo Meng
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Junnian Liu
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China.,BGI-Shenzhen, Beishan Industrial Zone, Shenzhen, China
| | - Ruliang Sun
- Department of Pathology, Bao'an Maternity and Child Health Hospital, Shenzhen, China
| | - Zhiwei Wang
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Xiaohong He
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Yong Li
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Yuanning Guan
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | | | - Chen Li
- Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Hangzhou, China
| | - Subrata Kumar Dey
- Department of Biotechnology, Centre for Genetic Studies, School of Biotechnology and Biological Sciences, Maulana Abul Kalam Azad University of Technology (Formerly West Bengal University of Technology), Kolkata, India.,Brainware University, Barasat, India
| | - Yuanfang Zhu
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Santasree Banerjee
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China.,BGI-Shenzhen, Beishan Industrial Zone, Shenzhen, China.,Brainware University, Barasat, India
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13
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Radhakrishnan P, Nayak SS, Shukla A, Lindstrand A, Girisha KM. Meckel syndrome: Clinical and mutation profile in six fetuses. Clin Genet 2019; 96:560-565. [PMID: 31411728 DOI: 10.1111/cge.13623] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 11/30/2022]
Abstract
Meckel syndrome (MKS) is a perinatally lethal, genetically heterogeneous, autosomal recessive condition caused by defective primary cilium formation leading to polydactyly, multiple cysts in kidneys and malformations of nervous system. We performed exome sequencing in six fetuses from six unrelated families with MKS. We identified seven novel variants in B9D2, TNXDC15, CC2D2A, CEP290 and TMEM67. We describe the second family with MKS due to a homozygous variant in B9D2 and fifth family with bi-allelic variant in TXNDC15. Our data validates the causation of MKS by pathogenic variation in B9D2 and TXNDC15 and also adds novel variants in CC2D2A, CEP290 and TMEM67 to the literature.
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Affiliation(s)
- Periyasamy Radhakrishnan
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Shalini S Nayak
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Anna Lindstrand
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Katta M Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
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14
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Hanke-Gogokhia C, Chiodo VA, Hauswirth WW, Frederick JM, Baehr W. Rescue of cone function in cone-only Nphp5 knockout mouse model with Leber congenital amaurosis phenotype. Mol Vis 2018; 24:834-846. [PMID: 30713422 PMCID: PMC6334983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 12/28/2018] [Indexed: 11/09/2022] Open
Abstract
Purpose Recessive mutations in the human IQCB1/NPHP5 gene are associated with Senior-Løken syndrome (SLS), a ciliopathy presenting with nephronophthisis and Leber congenital amaurosis (LCA). Nphp5-knockout mice develop LCA without nephronophthisis. Mutant rods rapidly degenerate while mutant cones survive for months. The purpose of this study was to reinitiate cone ciliogenesis in a Nphp5 -/-; Nrl -/- mouse with viral expression of full-length NPHP5 and rescue function. Methods Nphp5 -/- mice were mated with Nrl -/- mice to generate Nphp5-/-; Nrl-/- double-knockouts. Nphp5-/-; Nrl-/- mice and Nphp5+/-; Nrl-/- controls were phenotyped with confocal microscopy from postnatal day 10 (P10) until 6 months of age. Nphp5-/-; Nrl-/- mice and Nphp5+/-; Nrl-/- controls were injected at P15 with self-complementary adenoassociated virus 8 (Y733F) (AAV8(Y733F)) expressing GRK1-FL-cNPHP5. Expression of mutant NPHP5 was verified with confocal microscopy and electroretinography (ERG). Results In the Nphp5 -/- and cone-only Nphp5 -/-; Nrl -/- mice, cone outer segments did not form, but mutant cones continued to express cone pigments in the inner segments without obvious signs of cone cell death. The mutant cone outer nuclear layer (ONL) and the inner segments were stable for more than 6 months in the cone-only Nphp5 -/-; Nrl -/- retinas. Viral expression of NPHP5 initiated after eye opening showed that connecting cilia and RP1-positive axonemes were formed. Furthermore, cone pigments and other cone outer segment proteins (cone transducin and cone PDE6) were present in the nascent mutant cone outer segments, and rescued mutant cones exhibited a significant photopic b-wave (30% of Nphp5 +/-; Nrl -/- controls). Conclusions Nphp5-/-; Nrl-/- cones persistently express cone pigments in the inner segments without obvious degeneration, providing an extended duration interval for viral gene expression. Viral expression of full-length NPHP5 initiates ciliogenesis between P15 and P60, and mutant cones are, in part, functional, encouraging future retina gene replacement therapy.
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Affiliation(s)
- Christin Hanke-Gogokhia
- Department of Ophthalmology, John A. Moran Eye Center, University of Utah Health Science Center, Salt Lake City, UT
| | - Vince A. Chiodo
- Department of Ophthalmology, University of Florida, Gainesville, FL
| | | | - Jeanne M. Frederick
- Department of Ophthalmology, John A. Moran Eye Center, University of Utah Health Science Center, Salt Lake City, UT
| | - Wolfgang Baehr
- Department of Ophthalmology, John A. Moran Eye Center, University of Utah Health Science Center, Salt Lake City, UT,Department of Neurobiology and Anatomy, University of Utah Health Science Center, Salt Lake City, UT,Department of Biology, University of Utah, Salt Lake City, UT
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15
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Goetz SC, Bangs F, Barrington CL, Katsanis N, Anderson KV. The Meckel syndrome- associated protein MKS1 functionally interacts with components of the BBSome and IFT complexes to mediate ciliary trafficking and hedgehog signaling. PLoS One 2017; 12:e0173399. [PMID: 28291807 PMCID: PMC5349470 DOI: 10.1371/journal.pone.0173399] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/20/2017] [Indexed: 12/04/2022] Open
Abstract
The importance of primary cilia in human health is underscored by the link between ciliary dysfunction and a group of primarily recessive genetic disorders with overlapping clinical features, now known as ciliopathies. Many of the proteins encoded by ciliopathy-associated genes are components of a handful of multi-protein complexes important for the transport of cargo to the basal body and/or into the cilium. A key question is whether different complexes cooperate in cilia formation, and whether they participate in cilium assembly in conjunction with intraflagellar transport (IFT) proteins. To examine how ciliopathy protein complexes might function together, we have analyzed double mutants of an allele of the Meckel syndrome (MKS) complex protein MKS1 and the BBSome protein BBS4. We find that Mks1; Bbs4 double mutant mouse embryos exhibit exacerbated defects in Hedgehog (Hh) dependent patterning compared to either single mutant, and die by E14.5. Cells from double mutant embryos exhibit a defect in the trafficking of ARL13B, a ciliary membrane protein, resulting in disrupted ciliary structure and signaling. We also examined the relationship between the MKS complex and IFT proteins by analyzing double mutant between Mks1 and a hypomorphic allele of the IFTB component Ift172. Despite each single mutant surviving until around birth, Mks1; Ift172avc1 double mutants die at mid-gestation, and exhibit a dramatic failure of cilia formation. We also find that Mks1 interacts genetically with an allele of Dync2h1, the IFT retrograde motor. Thus, we have demonstrated that the MKS transition zone complex cooperates with the BBSome to mediate trafficking of specific trans-membrane receptors to the cilium. Moreover, the genetic interaction of Mks1 with components of IFT machinery suggests that the transition zone complex facilitates IFT to promote cilium assembly and structure.
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Affiliation(s)
- Sarah C. Goetz
- Program in Developmental Biology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Ave. New York, United States of America
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, United States of America
| | - Fiona Bangs
- Program in Developmental Biology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Ave. New York, United States of America
| | - Chloe L. Barrington
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, United States of America
| | - Nicholas Katsanis
- Department of Cell Biology and Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, United States of America
| | - Kathryn V. Anderson
- Program in Developmental Biology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Ave. New York, United States of America
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16
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Vieillard J, Paschaki M, Duteyrat JL, Augière C, Cortier E, Lapart JA, Thomas J, Durand B. Transition zone assembly and its contribution to axoneme formation in Drosophila male germ cells. J Cell Biol 2016; 214:875-89. [PMID: 27646273 PMCID: PMC5037411 DOI: 10.1083/jcb.201603086] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/26/2016] [Indexed: 01/04/2023] Open
Abstract
Ciliary transition zone (TZ) assembly is complex and incompletely understood. Vieillard et al. show that Drosophila Cby and Dila cooperate to assemble the TZ and membrane cap, which, together with microtubule remodeling by kinesin-13, is required for axoneme formation in male germ cells. The ciliary transition zone (TZ) is a complex structure found at the cilia base. Defects in TZ assembly are associated with human ciliopathies. In most eukaryotes, three protein complexes (CEP290, NPHP, and MKS) cooperate to build the TZ. We show that in Drosophila melanogaster, mild TZ defects are observed in the absence of MKS components. In contrast, Cby and Azi1 cooperate to build the TZ by acting upstream of Cep290 and MKS components. Without Cby and Azi1, centrioles fail to form the TZ, precluding sensory cilia assembly, and no ciliary membrane cap associated with sperm ciliogenesis is made. This ciliary cap is critical to recruit the tubulin-depolymerizing kinesin Klp59D, required for regulation of axonemal growth. Our results show that Drosophila TZ assembly in sensory neurons and male germ cells involves cooperative actions of Cby and Dila. They further reveal that temporal control of membrane cap assembly by TZ components and microtubule elongation by kinesin-13 is required for axoneme formation in male germ cells.
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Affiliation(s)
- Jennifer Vieillard
- Université Claude Bernard Lyon 1, Institut National de la Santé et de la Recherche Médicale U1217, Institut NeuroMyoGène, Centre National de la Recherche Scientifique UMR 5310, F-69100 Lyon, France
| | - Marie Paschaki
- Université Claude Bernard Lyon 1, Institut National de la Santé et de la Recherche Médicale U1217, Institut NeuroMyoGène, Centre National de la Recherche Scientifique UMR 5310, F-69100 Lyon, France
| | - Jean-Luc Duteyrat
- Université Claude Bernard Lyon 1, Institut National de la Santé et de la Recherche Médicale U1217, Institut NeuroMyoGène, Centre National de la Recherche Scientifique UMR 5310, F-69100 Lyon, France
| | - Céline Augière
- Université Claude Bernard Lyon 1, Institut National de la Santé et de la Recherche Médicale U1217, Institut NeuroMyoGène, Centre National de la Recherche Scientifique UMR 5310, F-69100 Lyon, France
| | - Elisabeth Cortier
- Université Claude Bernard Lyon 1, Institut National de la Santé et de la Recherche Médicale U1217, Institut NeuroMyoGène, Centre National de la Recherche Scientifique UMR 5310, F-69100 Lyon, France
| | - Jean-André Lapart
- Université Claude Bernard Lyon 1, Institut National de la Santé et de la Recherche Médicale U1217, Institut NeuroMyoGène, Centre National de la Recherche Scientifique UMR 5310, F-69100 Lyon, France
| | - Joëlle Thomas
- Université Claude Bernard Lyon 1, Institut National de la Santé et de la Recherche Médicale U1217, Institut NeuroMyoGène, Centre National de la Recherche Scientifique UMR 5310, F-69100 Lyon, France
| | - Bénédicte Durand
- Université Claude Bernard Lyon 1, Institut National de la Santé et de la Recherche Médicale U1217, Institut NeuroMyoGène, Centre National de la Recherche Scientifique UMR 5310, F-69100 Lyon, France
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17
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Pratt MB, Titlow JS, Davis I, Barker AR, Dawe HR, Raff JW, Roque H. Drosophila sensory cilia lacking MKS proteins exhibit striking defects in development but only subtle defects in adults. J Cell Sci 2016; 129:3732-3743. [PMID: 27577095 PMCID: PMC5087661 DOI: 10.1242/jcs.194621] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 08/19/2016] [Indexed: 01/05/2023] Open
Abstract
Cilia are conserved organelles that have important motility, sensory and signalling roles. The transition zone (TZ) at the base of the cilium is crucial for cilia function, and defects in several TZ proteins are associated with human congenital ciliopathies such as nephronophthisis (NPHP) and Meckel-Gruber syndrome (MKS). In several species, MKS and NPHP proteins form separate complexes that cooperate with Cep290 to assemble the TZ, but flies seem to lack core components of the NPHP module. We show that MKS proteins in flies are spatially separated from Cep290 at the TZ, and that flies mutant for individual MKS genes fail to recruit other MKS proteins to the TZ, whereas Cep290 seems to be recruited normally. Although there are abnormalities in microtubule and membrane organisation in developing MKS mutant cilia, these defects are less apparent in adults, where sensory cilia and sperm flagella seem to function quite normally. Thus, localising MKS proteins to the cilium or flagellum is not essential for viability or fertility in flies.
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Affiliation(s)
- Metta B Pratt
- The Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Joshua S Titlow
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Ilan Davis
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Amy R Barker
- Centre for Microvascular Research, William Harvey Research Institute, Queen Mary University of London, London EC1M 6BQ, UK
| | - Helen R Dawe
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Jordan W Raff
- The Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Helio Roque
- The Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
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18
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Loucks CM, Bialas NJ, Dekkers MPJ, Walker DS, Grundy LJ, Li C, Inglis PN, Kida K, Schafer WR, Blacque OE, Jansen G, Leroux MR. PACRG, a protein linked to ciliary motility, mediates cellular signaling. Mol Biol Cell 2016; 27:2133-44. [PMID: 27193298 PMCID: PMC4927285 DOI: 10.1091/mbc.e15-07-0490] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 05/09/2016] [Indexed: 01/15/2023] Open
Abstract
Cilia are cellular projections that can be motile to generate fluid flow or nonmotile to enable signaling. Both forms are based on shared components, and proteins involved in ciliary motility, like PACRG, may also function in ciliary signaling. Caenorhabditis elegans PACRG acts in a subset of nonmotile cilia to influence a learning behavior and promote longevity. Cilia are microtubule-based organelles that project from nearly all mammalian cell types. Motile cilia generate fluid flow, whereas nonmotile (primary) cilia are required for sensory physiology and modulate various signal transduction pathways. Here we investigate the nonmotile ciliary signaling roles of parkin coregulated gene (PACRG), a protein linked to ciliary motility. PACRG is associated with the protofilament ribbon, a structure believed to dictate the regular arrangement of motility-associated ciliary components. Roles for protofilament ribbon–associated proteins in nonmotile cilia and cellular signaling have not been investigated. We show that PACRG localizes to a small subset of nonmotile cilia in Caenorhabditis elegans, suggesting an evolutionary adaptation for mediating specific sensory/signaling functions. We find that it influences a learning behavior known as gustatory plasticity, in which it is functionally coupled to heterotrimeric G-protein signaling. We also demonstrate that PACRG promotes longevity in C. elegans by acting upstream of the lifespan-promoting FOXO transcription factor DAF-16 and likely upstream of insulin/IGF signaling. Our findings establish previously unrecognized sensory/signaling functions for PACRG and point to a role for this protein in promoting longevity. Furthermore, our work suggests additional ciliary motility-signaling connections, since EFHC1 (EF-hand containing 1), a potential PACRG interaction partner similarly associated with the protofilament ribbon and ciliary motility, also positively regulates lifespan.
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Affiliation(s)
- Catrina M Loucks
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Nathan J Bialas
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | | | - Denise S Walker
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Laura J Grundy
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Chunmei Li
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - P Nick Inglis
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Katarzyna Kida
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Gert Jansen
- Department of Cell Biology, Erasmus MC, 3000 CA, Rotterdam, The Netherlands
| | - Michel R Leroux
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
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19
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Li C, Jensen VL, Park K, Kennedy J, Garcia-Gonzalo FR, Romani M, De Mori R, Bruel AL, Gaillard D, Doray B, Lopez E, Rivière JB, Faivre L, Thauvin-Robinet C, Reiter JF, Blacque OE, Valente EM, Leroux MR. MKS5 and CEP290 Dependent Assembly Pathway of the Ciliary Transition Zone. PLoS Biol 2016; 14:e1002416. [PMID: 26982032 PMCID: PMC4794247 DOI: 10.1371/journal.pbio.1002416] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 02/24/2016] [Indexed: 11/19/2022] Open
Abstract
Cilia have a unique diffusion barrier (“gate”) within their proximal region, termed transition zone (TZ), that compartmentalises signalling proteins within the organelle. The TZ is known to harbour two functional modules/complexes (Meckel syndrome [MKS] and Nephronophthisis [NPHP]) defined by genetic interaction, interdependent protein localisation (hierarchy), and proteomic studies. However, the composition and molecular organisation of these modules and their links to human ciliary disease are not completely understood. Here, we reveal Caenorhabditis elegans CEP-290 (mammalian Cep290/Mks4/Nphp6 orthologue) as a central assembly factor that is specific for established MKS module components and depends on the coiled coil region of MKS-5 (Rpgrip1L/Rpgrip1) for TZ localisation. Consistent with a critical role in ciliary gate function, CEP-290 prevents inappropriate entry of membrane-associated proteins into cilia and keeps ARL-13 (Arl13b) from leaking out of cilia via the TZ. We identify a novel MKS module component, TMEM-218 (Tmem218), that requires CEP-290 and other MKS module components for TZ localisation and functions together with the NPHP module to facilitate ciliogenesis. We show that TZ localisation of TMEM-138 (Tmem138) and CDKL-1 (Cdkl1/Cdkl2/Cdkl3/Cdlk4 related), not previously linked to a specific TZ module, similarly depends on CEP-290; surprisingly, neither TMEM-138 or CDKL-1 exhibit interdependent localisation or genetic interactions with core MKS or NPHP module components, suggesting they are part of a distinct, CEP-290-associated module. Lastly, we show that families presenting with Oral-Facial-Digital syndrome type 6 (OFD6) have likely pathogenic mutations in CEP-290-dependent TZ proteins, namely Tmem17, Tmem138, and Tmem231. Notably, patient fibroblasts harbouring mutated Tmem17, a protein not yet ciliopathy-associated, display ciliogenesis defects. Together, our findings expand the repertoire of MKS module-associated proteins—including the previously uncharacterised mammalian Tmem80—and suggest an MKS-5 and CEP-290-dependent assembly pathway for building a functional TZ. The transition zone is a barrier structure required to maintain the dynamic composition and functional integrity of the cilium. This study describes the pathway by which the transition zone is assembled during cilium formation. The primary cilium is a structure found in most animal cell types. Much like an antenna, it is responsible for sensing extracellular signals, including light and small molecules, and conveying this information to the receiving cell and respective tissue or organ. At the base of the cilium is the transition zone (TZ), which acts as a “gate” to regulate the entry and exit of ciliary proteins required for signal transduction. Here, we use the nematode Caenorhabditis elegans as a model system to dissect how different proteins within the TZ assemble to form a functional barrier. We find that the TZ protein MKS-5 (Rpgrip1/Rpgrip1L orthologue) forms the foundation for two different assembly pathways involving two distinct modules: Nephronophthisis (NPHP) and Meckel syndrome (MKS). We show that at the base of the MKS module is CEP-290, another TZ protein that assembles MKS module proteins, including a novel TZ protein we identify as TMEM-218. CEP-290 also helps assemble a potentially separate submodule containing TMEM-138 and CDKL-1. Notably, we provide evidence that the MKS module protein TMEM-17 facilitates cilium formation and is disrupted in the human disorder (ciliopathy) Oral-Facial-Digital Syndrome type 6 (OFD6). Together, our findings provide essential insights into the assembly pathway of the ciliary TZ and suggest further connections between the transition zone and human health.
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Affiliation(s)
- Chunmei Li
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Victor L. Jensen
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Kwangjin Park
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Julie Kennedy
- School of Biomolecular & Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Francesc R. Garcia-Gonzalo
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Marta Romani
- Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Roberta De Mori
- Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Ange-Line Bruel
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
| | | | - Bérénice Doray
- Service de Génétique clinique, CHRU Strasbourg, Strasbourg, France
| | - Estelle Lopez
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
| | - Jean-Baptiste Rivière
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
- Laboratoire de Génétique moléculaire, Plateau Technique de Biologie, CHU Dijon, Dijon, France
| | - Laurence Faivre
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
- Centre de Génétique, FHU-TRANSLAD, Hôpital d’Enfants, CHU Dijon, Dijon, France
| | - Christel Thauvin-Robinet
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
- Centre de Génétique, FHU-TRANSLAD, Hôpital d’Enfants, CHU Dijon, Dijon, France
| | - Jeremy F. Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Oliver E. Blacque
- School of Biomolecular & Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Enza Maria Valente
- Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
- Department of Medicine and Surgery, University of Salerno, Salerno, Italy
| | - Michel R. Leroux
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
- * E-mail:
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20
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Khan S, Muhammad N, Khan M, Kamal A, Rehman Z, Khan S. Genetics of human Bardet-Biedl syndrome, an updates. Clin Genet 2016; 90:3-15. [DOI: 10.1111/cge.12737] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Revised: 12/21/2015] [Accepted: 01/03/2016] [Indexed: 12/22/2022]
Affiliation(s)
- S.A. Khan
- Department of Biotechnology and Genetic Engineering; Kohat University of Science and Technology; Khyber Pakhtunkhwa Pakistan
| | - N. Muhammad
- Department of Biotechnology and Genetic Engineering; Kohat University of Science and Technology; Khyber Pakhtunkhwa Pakistan
| | - M.A. Khan
- Gomal Centre of Biochemistry and Biotechnology; Gomal University; Khyber Pakhtunkhwa Pakistan
- Genomic Core Facility; Interim Translational Research Institute; Doha Qatar
| | - A. Kamal
- Department of Biotechnology and Genetic Engineering; Kohat University of Science and Technology; Khyber Pakhtunkhwa Pakistan
| | - Z.U. Rehman
- Department of Biotechnology and Genetic Engineering; Kohat University of Science and Technology; Khyber Pakhtunkhwa Pakistan
| | - S. Khan
- Department of Biotechnology and Genetic Engineering; Kohat University of Science and Technology; Khyber Pakhtunkhwa Pakistan
- Genomic Core Facility; Interim Translational Research Institute; Doha Qatar
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21
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Collado-Hilly M, Fisch C, Desforges B, Jerber J, Combettes L, Campillo C, Dupuis-Williams P. Evidence for a role of the ciliopathy protein MKS1 in cell polarity. Cilia 2015. [PMCID: PMC4519118 DOI: 10.1186/2046-2530-4-s1-p42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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22
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Ciliary subcompartments and cysto-proteins. Anat Sci Int 2015; 92:207-214. [DOI: 10.1007/s12565-015-0302-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 09/14/2015] [Indexed: 11/26/2022]
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23
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Roberson EC, Dowdle WE, Ozanturk A, Garcia-Gonzalo FR, Li C, Halbritter J, Elkhartoufi N, Porath JD, Cope H, Ashley-Koch A, Gregory S, Thomas S, Sayer JA, Saunier S, Otto EA, Katsanis N, Davis EE, Attié-Bitach T, Hildebrandt F, Leroux MR, Reiter JF. TMEM231, mutated in orofaciodigital and Meckel syndromes, organizes the ciliary transition zone. ACTA ACUST UNITED AC 2015; 209:129-42. [PMID: 25869670 PMCID: PMC4395494 DOI: 10.1083/jcb.201411087] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
TMEM231, a functional component of the MKS complex at the ciliary transition zone, is mutated in orofaciodigital syndrome type 3 and Meckel syndrome. The Meckel syndrome (MKS) complex functions at the transition zone, located between the basal body and axoneme, to regulate the localization of ciliary membrane proteins. We investigated the role of Tmem231, a two-pass transmembrane protein, in MKS complex formation and function. Consistent with a role in transition zone function, mutation of mouse Tmem231 disrupts the localization of proteins including Arl13b and Inpp5e to cilia, resulting in phenotypes characteristic of MKS such as polydactyly and kidney cysts. Tmem231 and B9d1 are essential for each other and other complex components such as Mks1 to localize to the transition zone. As in mouse, the Caenorhabditis elegans orthologue of Tmem231 localizes to and controls transition zone formation and function, suggesting an evolutionarily conserved role for Tmem231. We identified TMEM231 mutations in orofaciodigital syndrome type 3 (OFD3) and MKS patients that compromise transition zone function. Thus, Tmem231 is critical for organizing the MKS complex and controlling ciliary composition, defects in which cause OFD3 and MKS.
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Affiliation(s)
- Elle C Roberson
- Department of Biochemistry and Biophysics and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158
| | - William E Dowdle
- Department of Biochemistry and Biophysics and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158
| | - Aysegul Ozanturk
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Francesc R Garcia-Gonzalo
- Department of Biochemistry and Biophysics and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158
| | - Chunmei Li
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 Canada
| | - Jan Halbritter
- Division of Nephrology, Department of Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115
| | - Nadia Elkhartoufi
- Département de Génétique, Hôpital Necker-Enfants Malades, Assistance Publique/Hôpitaux de Paris, 75015 Paris, France
| | - Jonathan D Porath
- Division of Nephrology, Department of Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115
| | - Heidi Cope
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Allison Ashley-Koch
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710 Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Simon Gregory
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Sophie Thomas
- Institut National de la Santé et de la Recherche Médicale UMR1163, 75015 Paris, France Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France
| | - John A Sayer
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, England, UK Newcastle Hospitals National Health Service Foundation Trust, Newcastle upon Tyne NE7 7DN, England, UK
| | - Sophie Saunier
- Institut National de la Santé et de la Recherche Médicale UMR1163, 75015 Paris, France Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France
| | - Edgar A Otto
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Erica E Davis
- Center for Human Disease Modeling, Department of Medicine, and Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 22710
| | - Tania Attié-Bitach
- Institut National de la Santé et de la Recherche Médicale UMR1163, 75015 Paris, France Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, 75015 Paris, France Département de Génétique, Hôpital Necker-Enfants Malades, Assistance Publique/Hôpitaux de Paris, 75015 Paris, France
| | - Friedhelm Hildebrandt
- Division of Nephrology, Department of Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115 Howard Hughes Medical Institute, Chevy Chase, MD 20815
| | - Michel R Leroux
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 Canada
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158
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24
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Sanders AAWM, Kennedy J, Blacque OE. Image analysis of Caenorhabditis elegans ciliary transition zone structure, ultrastructure, molecular composition, and function. Methods Cell Biol 2015; 127:323-47. [PMID: 25837399 DOI: 10.1016/bs.mcb.2015.01.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The transition zone (TZ) at the ciliary base has emerged as an important regulator of the composition and functions of cilia, which are microtubule-based structures extending from the surfaces of most eukaryotic cells, serving motility, chemo-/mechano-/photosensation and developmental signaling roles. Possessing distinct ultrastructural features such as microtubule-membrane spanning Y-links, the ∼0.2-1.0-μm long TZ is thought to act as a gated cytosolic (size dependent) and membrane diffusion barrier that drives ciliary compartmentalization by preventing unregulated protein exchange between the cilium and the rest of the cell. Multiple proteins associated with ciliary diseases (ciliopathies) such as Meckel-Gruber syndrome (MKS) and nephronophthisis are specifically found in the TZ, and work from a number of model systems, including Chlamydomonas reinharditii, Caenorhabditis elegans and the mouse indicates TZ-gating and associated ciliogenic functions for a number of these proteins. Here we present a suite of assays for probing the structure, function, and molecular composition of the C. elegans TZ, with emphasis on TZ ultrastructure, diffusion barrier kinetics, MKS module assembly hierarchy, and TZ-dependent behaviors.
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Affiliation(s)
- Anna A W M Sanders
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
| | - Julie Kennedy
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
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25
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Ciliary dysfunction impairs beta-cell insulin secretion and promotes development of type 2 diabetes in rodents. Nat Commun 2014; 5:5308. [PMID: 25374274 DOI: 10.1038/ncomms6308] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 09/18/2014] [Indexed: 11/08/2022] Open
Abstract
Type 2 diabetes mellitus is affecting more than 382 million people worldwide. Although much progress has been made, a comprehensive understanding of the underlying disease mechanism is still lacking. Here we report a role for the β-cell primary cilium in type 2 diabetes susceptibility. We find impaired glucose handling in young Bbs4(-/-) mice before the onset of obesity. Basal body/ciliary perturbation in murine pancreatic islets leads to impaired first phase insulin release ex and in vivo. Insulin receptor is recruited to the cilium of stimulated β-cells and ciliary/basal body integrity is required for activation of downstream targets of insulin signalling. We also observe a reduction in the number of ciliated β-cells along with misregulated ciliary/basal body gene expression in pancreatic islets in a diabetic rat model. We suggest that ciliary function is implicated in insulin secretion and insulin signalling in the β-cell and that ciliary dysfunction could contribute to type 2 diabetes susceptibility.
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26
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Madhivanan K, Aguilar RC. Ciliopathies: the trafficking connection. Traffic 2014; 15:1031-56. [PMID: 25040720 DOI: 10.1111/tra.12195] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 06/28/2014] [Accepted: 07/08/2014] [Indexed: 12/15/2022]
Abstract
The primary cilium (PC) is a very dynamic hair-like membrane structure that assembles/disassembles in a cell-cycle-dependent manner and is present in almost every cell type. Despite being continuous with the plasma membrane, a diffusion barrier located at the ciliary base confers the PC properties of a separate organelle with very specific characteristics and membrane composition. Therefore, vesicle trafficking is the major process by which components are acquired for cilium formation and maintenance. In fact, a system of specific sorting signals controls the right of cargo admission into the cilia. Disruption to the ciliary structure or its function leads to multiorgan diseases known as ciliopathies. These illnesses arise from a spectrum of mutations in any of the more than 50 loci linked to these conditions. Therefore, it is not surprising that symptom variability (specific manifestations and severity) among and within ciliopathies appears to be an emerging characteristic. Nevertheless, one can speculate that mutations occurring in genes whose products contribute to the overall vesicle trafficking to the PC (i.e. affecting cilia assembly) will lead to more severe symptoms, whereas those involved in the transport of specific cargoes will result in milder phenotypes. In this review, we summarize the trafficking mechanisms to the cilia and also provide a description of the trafficking defects observed in some ciliopathies which can be correlated to the severity of the pathology.
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27
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Remans K, Bürger M, Vetter IR, Wittinghofer A. C2 domains as protein-protein interaction modules in the ciliary transition zone. Cell Rep 2014; 8:1-9. [PMID: 24981858 DOI: 10.1016/j.celrep.2014.05.049] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/22/2014] [Accepted: 05/27/2014] [Indexed: 11/16/2022] Open
Abstract
RPGR-interacting protein 1 (RPGRIP1) is mutated in the eye disease Leber congenital amaurosis (LCA) and its structural homolog, RPGRIP1-like (RPGRIP1L), is mutated in many different ciliopathies. Both are multidomain proteins that are predicted to interact with retinitis pigmentosa G-protein regulator (RPGR). RPGR is mutated in X-linked retinitis pigmentosa and is located in photoreceptors and primary cilia. We solved the crystal structure of the complex between the RPGR-interacting domain (RID) of RPGRIP1 and RPGR and demonstrate that RPGRIP1L binds to RPGR similarly. RPGRIP1 binding to RPGR affects the interaction with PDEδ, the cargo shuttling factor for prenylated ciliary proteins. RPGRIP1-RID is a C2 domain with a canonical β sandwich structure that does not bind Ca(2+) and/or phospholipids and thus constitutes a unique type of protein-protein interaction module. Judging from the large number of C2 domains in most of the ciliary transition zone proteins identified thus far, the structure presented here seems to constitute a cilia-specific module that is present in multiprotein transition zone complexes.
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Affiliation(s)
- Kim Remans
- Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Marco Bürger
- Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Ingrid R Vetter
- Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Alfred Wittinghofer
- Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.
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28
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Abstract
The primary cilium compartmentalizes a tiny fraction of the cell surface and volume, yet many proteins are highly enriched in this area and so efficient mechanisms are necessary to concentrate them in the ciliary compartment. Here we review mechanisms that are thought to deliver protein cargo to the base of cilia and are likely to interact with ciliary gating mechanisms. Given the immense variety of ciliary cytosolic and transmembrane proteins, it is almost certain that multiple, albeit frequently interconnected, pathways mediate this process. It is also clear that none of these pathways is fully understood at the present time. Mechanisms that are discussed below facilitate ciliary localization of structural and signaling molecules, which include receptors, G-proteins, ion channels, and enzymes. These mechanisms form a basis for every aspect of cilia function in early embryonic patterning, organ morphogenesis, sensory perception and elsewhere.
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Affiliation(s)
- Jarema Malicki
- MRC Centre for Developmental and Biomedical Genetics; Department of Biomedical Science; The University of Sheffield; Sheffield, UK
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29
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Blacque OE, Sanders AAWM. Compartments within a compartment: what C. elegans can tell us about ciliary subdomain composition, biogenesis, function, and disease. Organogenesis 2014; 10:126-37. [PMID: 24732235 DOI: 10.4161/org.28830] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The primary cilium has emerged as a hotbed of sensory and developmental signaling, serving as a privileged domain to concentrate the functions of a wide number of channels, receptors and downstream signal transducers. This realization has provided important insight into the pathophysiological mechanisms underlying the ciliopathies, an ever expanding spectrum of multi-symptomatic disorders affecting the development and maintenance of multiple tissues and organs. One emerging research focus is the subcompartmentalised nature of the organelle, consisting of discrete structural and functional subdomains such as the periciliary membrane/basal body compartment, the transition zone, the Inv compartment and the distal segment/ciliary tip region. Numerous ciliopathy, transport-related and signaling molecules localize at these compartments, indicating specific roles at these subciliary sites. Here, by focusing predominantly on research from the genetically tractable nematode C. elegans, we review ciliary subcompartments in terms of their structure, function, composition, biogenesis and relationship to human disease.
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Affiliation(s)
- Oliver E Blacque
- School of Biomolecular and Biomedical Science; University College Dublin; Dublin, Ireland
| | - Anna A W M Sanders
- School of Biomolecular and Biomedical Science; University College Dublin; Dublin, Ireland
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30
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Diverse cell type-specific mechanisms localize G protein-coupled receptors to Caenorhabditis elegans sensory cilia. Genetics 2014; 197:667-84. [PMID: 24646679 DOI: 10.1534/genetics.114.161349] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The localization of signaling molecules such as G protein-coupled receptors (GPCRs) to primary cilia is essential for correct signal transduction. Detailed studies over the past decade have begun to elucidate the diverse sequences and trafficking mechanisms that sort and transport GPCRs to the ciliary compartment. However, a systematic analysis of the pathways required for ciliary targeting of multiple GPCRs in different cell types in vivo has not been reported. Here we describe the sequences and proteins required to localize GPCRs to the cilia of the AWB and ASK sensory neuron types in Caenorhabditis elegans. We find that GPCRs expressed in AWB or ASK utilize conserved and novel sequences for ciliary localization, and that the requirement for a ciliary targeting sequence in a given GPCR is different in different neuron types. Consistent with the presence of multiple ciliary targeting sequences, we identify diverse proteins required for ciliary localization of individual GPCRs in AWB and ASK. In particular, we show that the TUB-1 Tubby protein is required for ciliary localization of a subset of GPCRs, implying that defects in GPCR localization may be causal to the metabolic phenotypes of tub-1 mutants. Together, our results describe a remarkable complexity of mechanisms that act in a protein- and cell-specific manner to localize GPCRs to cilia, and suggest that this diversity allows for precise regulation of GPCR-mediated signaling as a function of external and internal context.
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31
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Barker AR, Thomas R, Dawe HR. Meckel-Gruber syndrome and the role of primary cilia in kidney, skeleton, and central nervous system development. Organogenesis 2013; 10:96-107. [PMID: 24322779 DOI: 10.4161/org.27375] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The ciliopathies are a group of related inherited diseases characterized by malformations in organ development. The diseases affect multiple organ systems, with kidney, skeleton, and brain malformations frequently observed. Research over the last decade has revealed that these diseases are due to defects in primary cilia, essential sensory organelles found on most cells in the human body. Here we discuss the genetic and cell biological basis of one of the most severe ciliopathies, Meckel-Gruber syndrome, and explain how primary cilia contribute to the development of the affected organ systems.
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Affiliation(s)
- Amy R Barker
- College of Life and Environmental Sciences; University of Exeter; Exeter, UK
| | - Rhys Thomas
- College of Life and Environmental Sciences; University of Exeter; Exeter, UK
| | - Helen R Dawe
- College of Life and Environmental Sciences; University of Exeter; Exeter, UK
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32
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Wojtyniak M, Brear AG, O'Halloran DM, Sengupta P. Cell- and subunit-specific mechanisms of CNG channel ciliary trafficking and localization in C. elegans. J Cell Sci 2013; 126:4381-95. [PMID: 23886944 DOI: 10.1242/jcs.127274] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Primary cilia are ubiquitous sensory organelles that concentrate transmembrane signaling proteins essential for sensing environmental cues. Mislocalization of crucial ciliary signaling proteins, such as the tetrameric cyclic nucleotide-gated (CNG) channels, can lead to cellular dysfunction and disease. Although several cis- and trans-acting factors required for ciliary protein trafficking and localization have been identified, whether these mechanisms act in a protein- and cell-specific manner is largely unknown. Here, we show that CNG channel subunits can be localized to discrete ciliary compartments in individual sensory neurons in C. elegans, suggesting that channel composition is heterogeneous across the cilium. We demonstrate that ciliary localization of CNG channel subunits is interdependent on different channel subunits in specific cells, and identify sequences required for efficient ciliary targeting and localization of the TAX-2 CNGB and TAX-4 CNGA subunits. Using a candidate gene approach, we show that Inversin, transition zone proteins, intraflagellar transport motors and a MYND-domain protein are required to traffic and/or localize CNG channel subunits in both a cell- and channel subunit-specific manner. We further find that TAX-2 and TAX-4 are relatively immobile in specific sensory cilia subcompartments, suggesting that these proteins undergo minimal turnover in these domains in mature cilia. Our results uncover unexpected diversity in the mechanisms that traffic and localize CNG channel subunits to cilia both within and across cell types, highlighting the essential contribution of this process to cellular functions.
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Affiliation(s)
- Martin Wojtyniak
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02454, USA
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33
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Olivier-Mason A, Wojtyniak M, Bowie RV, Nechipurenko IV, Blacque OE, Sengupta P. Transmembrane protein OSTA-1 shapes sensory cilia morphology via regulation of intracellular membrane trafficking in C. elegans. Development 2013; 140:1560-72. [PMID: 23482491 DOI: 10.1242/dev.086249] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The structure and function of primary cilia are critically dependent on intracellular trafficking pathways that transport ciliary membrane and protein components. The mechanisms by which these trafficking pathways are regulated are not fully characterized. Here we identify the transmembrane protein OSTA-1 as a new regulator of the trafficking pathways that shape the morphology and protein composition of sensory cilia in C. elegans. osta-1 encodes an organic solute transporter alpha-like protein, mammalian homologs of which have been implicated in membrane trafficking and solute transport, although a role in regulating cilia structure has not previously been demonstrated. We show that mutations in osta-1 result in altered ciliary membrane volume, branch length and complexity, as well as defects in localization of a subset of ciliary transmembrane proteins in different sensory cilia types. OSTA-1 is associated with transport vesicles, localizes to a ciliary compartment shown to house trafficking proteins, and regulates both retrograde and anterograde flux of the endosome-associated RAB-5 small GTPase. Genetic epistasis experiments with sensory signaling, exocytic and endocytic proteins further implicate OSTA-1 as a crucial regulator of ciliary architecture via regulation of cilia-destined trafficking. Our findings suggest that regulation of transport pathways in a cell type-specific manner contributes to diversity in sensory cilia structure and might allow dynamic remodeling of ciliary architecture via multiple inputs.
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Affiliation(s)
- Anique Olivier-Mason
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02454, USA
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34
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Jerber J, Thomas J, Durand B. [Transcriptional control of ciliogenesis in animal development]. Biol Aujourdhui 2012; 206:205-18. [PMID: 23171843 DOI: 10.1051/jbio/2012023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Indexed: 12/20/2022]
Abstract
Cilia and flagella are eukaryotic organelles with a conserved structure and function from unicellular organisms to human. In animals, different types of cilia can be found and cilia assembly during development is a highly dynamic process. Ciliary defects in human lead to a wide spectrum of diseases called ciliopathies. Understanding the molecular mechanisms that govern dynamic cilia assembly during development and in different tissues in metazoans is an important biological challenge. The FOXJ1 (Forkhead Box J1) and RFX (Regulatory Factor X) family of transcription factors have been shown to be important factors in ciliogenesis control. FOXJ1 proteins are required for motile ciliogenesis in vertebrates. By contrast, RFX proteins are essential to assemble both primary and motile cilia through the regulation of specific sets of genes such as those encoding intraflagellar transport components. Recently, new actors with more specific roles in cilia biogenesis and physiology have also been discovered. All these factors are subject to complex regulation, allowing for the dynamic and specific regulation of ciliogenesis in metazoans.
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Affiliation(s)
- Julie Jerber
- Centre de Genetique et de Physiologie Moleculare et Cellulaire, Universite Lyon, Villeurbanne, Lyon, France
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35
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The base of the cilium: roles for transition fibres and the transition zone in ciliary formation, maintenance and compartmentalization. EMBO Rep 2012; 13:608-18. [PMID: 22653444 DOI: 10.1038/embor.2012.73] [Citation(s) in RCA: 354] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/11/2012] [Indexed: 12/13/2022] Open
Abstract
Both the basal body and the microtubule-based axoneme it nucleates have evolutionarily conserved subdomains crucial for cilium biogenesis, function and maintenance. Here, we focus on two conspicuous but underappreciated regions of these structures that make membrane connections. One is the basal body distal end, which includes transition fibres of largely undefined composition that link to the base of the ciliary membrane. Transition fibres seem to serve as docking sites for intraflagellar transport particles, which move proteins within the ciliary compartment and are required for cilium biogenesis and sustained function. The other is the proximal-most region of the axoneme, termed the transition zone, which is characterized by Y-shaped linkers that span from the axoneme to the ciliary necklace on the membrane surface. The transition zone comprises a growing number of ciliopathy proteins that function as modular components of a ciliary gate. This gate, which forms early during ciliogenesis, might function in part by regulating intraflagellar transport. Together with a recently described septin ring diffusion barrier at the ciliary base, the transition fibres and transition zone deserve attention for their varied roles in forming functional ciliary compartments.
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Enjolras C, Thomas J, Chhin B, Cortier E, Duteyrat JL, Soulavie F, Kernan MJ, Laurençon A, Durand B. Drosophila chibby is required for basal body formation and ciliogenesis but not for Wg signaling. ACTA ACUST UNITED AC 2012; 197:313-25. [PMID: 22508513 PMCID: PMC3328381 DOI: 10.1083/jcb.201109148] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In contrast to vertebrate CBY, which functions in WNT signaling, Drosophila CBY is essential for normal basal body structure and function but dispensable for Wg signaling. Centriole-to–basal body conversion, a complex process essential for ciliogenesis, involves the progressive addition of specific proteins to centrioles. CHIBBY (CBY) is a coiled-coil domain protein first described as interacting with β-catenin and involved in Wg-Int (WNT) signaling. We found that, in Drosophila melanogaster, CBY was exclusively expressed in cells that require functional basal bodies, i.e., sensory neurons and male germ cells. CBY was associated with the basal body transition zone (TZ) in these two cell types. Inactivation of cby led to defects in sensory transduction and in spermatogenesis. Loss of CBY resulted in altered ciliary trafficking into neuronal cilia, irregular deposition of proteins on spermatocyte basal bodies, and, consequently, distorted axonemal assembly. Importantly, cby1/1 flies did not show Wingless signaling defects. Hence, CBY is essential for normal basal body structure and function in Drosophila, potentially through effects on the TZ. The function of CBY in WNT signaling in vertebrates has either been acquired during vertebrate evolution or lost in Drosophila.
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Affiliation(s)
- Camille Enjolras
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique UMR 5534, Université Claude Bernard Lyon 1, Villeurbanne, Lyon F69622, France
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Warburton-Pitt SRF, Jauregui AR, Li C, Wang J, Leroux MR, Barr MM. Ciliogenesis in Caenorhabditis elegans requires genetic interactions between ciliary middle segment localized NPHP-2 (inversin) and transition zone-associated proteins. J Cell Sci 2012; 125:2592-603. [PMID: 22393243 DOI: 10.1242/jcs.095539] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The cystic kidney diseases nephronophthisis (NPHP), Meckel-Gruber syndrome (MKS) and Joubert syndrome (JBTS) share an underlying etiology of dysfunctional cilia. Patients diagnosed with NPHP type II have mutations in the gene INVS (also known as NPHP2), which encodes inversin, a cilia localizing protein. Here, we show that the C. elegans inversin ortholog, NPHP-2, localizes to the middle segment of sensory cilia and that nphp-2 is partially redundant with nphp-1 and nphp-4 (orthologs of human NPHP1 and NPHP4, respectively) for cilia placement within the head and tail sensilla. nphp-2 also genetically interacts with MKS ciliopathy gene orthologs, including mks-1, mks-3, mks-6, mksr-1 and mksr-2, in a sensilla-dependent manner to control cilia formation and placement. However, nphp-2 is not required for correct localization of the NPHP- and MKS-encoded ciliary transition zone proteins or for intraflagellar transport (IFT). We conclude that INVS/NPHP2 is conserved in C. elegans and that nphp-2 plays an important role in C. elegans cilia by acting as a modifier of the NPHP and MKS pathways to control cilia formation and development.
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A ciliopathy complex at the transition zone protects the cilia as a privileged membrane domain. Nat Cell Biol 2011; 14:61-72. [PMID: 22179047 DOI: 10.1038/ncb2410] [Citation(s) in RCA: 262] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 11/23/2011] [Indexed: 12/21/2022]
Abstract
Using RNAi screening, proteomics, cell biological and mouse genetics approaches, we have identified a complex of nine proteins, seven of which are disrupted in human ciliopathies. A transmembrane component, TMEM231, localizes to the basal body before and independently of intraflagellar transport in a Septin 2 (Sept2)-regulated fashion. The localizations of TMEM231, B9D1 (B9 domain-containing protein 1) and CC2D2A (coiled-coil and C2 domain-containing protein 2A) at the transition zone are dependent on one another and on Sept2. Disruption of the complex in vitro causes a reduction in cilia formation and a loss of signalling receptors from the remaining cilia. Mouse knockouts of B9D1 and TMEM231 have identical defects in Sonic hedgehog (Shh) signalling and ciliogenesis. Strikingly, disruption of the complex increases the rate of diffusion into the ciliary membrane and the amount of plasma-membrane protein in the cilia. The complex that we have described is essential for normal cilia function and acts as a diffusion barrier to maintain the cilia membrane as a compartmentalized signalling organelle.
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Huang L, Szymanska K, Jensen V, Janecke A, Innes A, Davis E, Frosk P, Li C, Willer J, Chodirker B, Greenberg C, McLeod D, Bernier F, Chudley A, Müller T, Shboul M, Logan C, Loucks C, Beaulieu C, Bowie R, Bell S, Adkins J, Zuniga F, Ross K, Wang J, Ban M, Becker C, Nürnberg P, Douglas S, Craft C, Akimenko MA, Hegele R, Ober C, Utermann G, Bolz H, Bulman D, Katsanis N, Blacque O, Doherty D, Parboosingh J, Leroux M, Johnson C, Boycott K. TMEM237 is mutated in individuals with a Joubert syndrome related disorder and expands the role of the TMEM family at the ciliary transition zone. Am J Hum Genet 2011; 89:713-30. [PMID: 22152675 PMCID: PMC3234373 DOI: 10.1016/j.ajhg.2011.11.005] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 10/25/2011] [Accepted: 11/08/2011] [Indexed: 12/23/2022] Open
Abstract
Joubert syndrome related disorders (JSRDs) have broad but variable phenotypic overlap with other ciliopathies. The molecular etiology of this overlap is unclear but probably arises from disrupting common functional module components within primary cilia. To identify additional module elements associated with JSRDs, we performed homozygosity mapping followed by next-generation sequencing (NGS) and uncovered mutations in TMEM237 (previously known as ALS2CR4). We show that loss of the mammalian TMEM237, which localizes to the ciliary transition zone (TZ), results in defective ciliogenesis and deregulation of Wnt signaling. Furthermore, disruption of Danio rerio (zebrafish) tmem237 expression produces gastrulation defects consistent with ciliary dysfunction, and Caenorhabditis elegans jbts-14 genetically interacts with nphp-4, encoding another TZ protein, to control basal body-TZ anchoring to the membrane and ciliogenesis. Both mammalian and C. elegans TMEM237/JBTS-14 require RPGRIP1L/MKS5 for proper TZ localization, and we demonstrate additional functional interactions between C. elegans JBTS-14 and MKS-2/TMEM216, MKSR-1/B9D1, and MKSR-2/B9D2. Collectively, our findings integrate TMEM237/JBTS-14 in a complex interaction network of TZ-associated proteins and reveal a growing contribution of a TZ functional module to the spectrum of ciliopathy phenotypes.
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Affiliation(s)
- Lijia Huang
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Katarzyna Szymanska
- Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, St. James's University Hospital, Leeds LS9 7TF, UK
| | - Victor L. Jensen
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Andreas R. Janecke
- Department of Pediatrics II, Innsbruck Medical University, Innsbruck 6020, Austria
- Division of Human Genetics, Innsbruck Medical University, Innsbruck 6020, Austria
| | - A. Micheil Innes
- Department of Medical Genetics, University of Calgary, Calgary, AB T3B 6A8, Canada
| | - Erica E. Davis
- Center for Human Disease Modeling, Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Patrick Frosk
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3R 0J9, Canada
| | - Chunmei Li
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Jason R. Willer
- Center for Human Disease Modeling, Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Bernard N. Chodirker
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3R 0J9, Canada
| | - Cheryl R. Greenberg
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3R 0J9, Canada
| | - D. Ross McLeod
- Department of Medical Genetics, University of Calgary, Calgary, AB T3B 6A8, Canada
| | - Francois P. Bernier
- Department of Medical Genetics, University of Calgary, Calgary, AB T3B 6A8, Canada
| | - Albert E. Chudley
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB R3R 0J9, Canada
| | - Thomas Müller
- Department of Pediatrics II, Innsbruck Medical University, Innsbruck 6020, Austria
| | - Mohammad Shboul
- Institute of Medical Biology: Human Embryology, 8A Biomedical Grove, #05-40 Immunos, Singapore 138648, Singapore
| | - Clare V. Logan
- Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, St. James's University Hospital, Leeds LS9 7TF, UK
| | - Catrina M. Loucks
- Department of Medical Genetics, University of Calgary, Calgary, AB T3B 6A8, Canada
| | - Chandree L. Beaulieu
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Rachel V. Bowie
- School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Sandra M. Bell
- Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, St. James's University Hospital, Leeds LS9 7TF, UK
| | - Jonathan Adkins
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Freddi I. Zuniga
- Mary D. Allen Laboratory in Vision Research, Doheny Eye Institute, Departments of Ophthalmology and Cell and Neurobiology, Los Angeles, CA 90033-9224, USA
| | - Kevin D. Ross
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Jian Wang
- Robarts Research Institute and University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Matthew R. Ban
- Robarts Research Institute and University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Christian Becker
- Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Stuart Douglas
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Cheryl M. Craft
- Mary D. Allen Laboratory in Vision Research, Doheny Eye Institute, Departments of Ophthalmology and Cell and Neurobiology, Los Angeles, CA 90033-9224, USA
| | | | - Robert A. Hegele
- Robarts Research Institute and University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Carole Ober
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Gerd Utermann
- Division of Human Genetics, Innsbruck Medical University, Innsbruck 6020, Austria
| | - Hanno J. Bolz
- Center for Human Genetics, Bioscientia, 55218 Ingelheim, Germany
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
| | - Dennis E. Bulman
- Ottawa Hospital Research Institute and University of Ottawa, Ottawa, ON K1H 8L6, Canada
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Oliver E. Blacque
- School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Dan Doherty
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | | | - Michel R. Leroux
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Colin A. Johnson
- Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, St. James's University Hospital, Leeds LS9 7TF, UK
| | - Kym M. Boycott
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
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Caenorhabditis elegans, a model organism for kidney research: from cilia to mechanosensation and longevity. Curr Opin Nephrol Hypertens 2011; 20:400-8. [PMID: 21537177 DOI: 10.1097/mnh.0b013e3283471a22] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The introduction of Caenorhabditis elegans by Sydney Brenner to study 'how genes might specify the complex structures found in higher organisms' revolutionized molecular and developmental biology and pioneered a new research area to study organ development and cellular differentiation with this model organism. Here, we review the role of the nematode in renal research and discuss future perspectives for its use in molecular nephrology. RECENT FINDINGS Although C. elegans does not possess an excretory system comparable with the mammalian kidney, various studies have demonstrated the conserved functional role of kidney disease genes in C. elegans. The finding that cystic kidney diseases can be considered ciliopathies is based to a great extent on research studying their homologues in the nematode's ciliated neurons. Moreover, proteins of the kidney filtration barrier play important roles in both correct synapse formation, mechanosensation and signal transduction in the nematode. Intriguingly, the renal cell carcinoma disease gene product von-Hippel-Lindau protein was shown to regulate lifespan in the nematode. Last but not least, the worm's excretory system itself expresses genes involved in electrolyte and osmotic homeostasis and may serve as a valuable tool to study these processes on a molecular level. SUMMARY C. elegans has proven to be an incredibly powerful tool in studying various aspects of renal function, development and disease and will certainly continue to do so in the future.
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Sang L, Miller JJ, Corbit KC, Giles RH, Brauer MJ, Otto EA, Baye LM, Wen X, Scales SJ, Kwong M, Huntzicker EG, Sfakianos MK, Sandoval W, Bazan JF, Kulkarni P, Garcia-Gonzalo FR, Seol AD, O'Toole JF, Held S, Reutter HM, Lane WS, Rafiq MA, Noor A, Ansar M, Devi ARR, Sheffield VC, Slusarski DC, Vincent JB, Doherty DA, Hildebrandt F, Reiter JF, Jackson PK. Mapping the NPHP-JBTS-MKS protein network reveals ciliopathy disease genes and pathways. Cell 2011; 145:513-28. [PMID: 21565611 DOI: 10.1016/j.cell.2011.04.019] [Citation(s) in RCA: 455] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 03/16/2011] [Accepted: 04/27/2011] [Indexed: 12/18/2022]
Abstract
Nephronophthisis (NPHP), Joubert (JBTS), and Meckel-Gruber (MKS) syndromes are autosomal-recessive ciliopathies presenting with cystic kidneys, retinal degeneration, and cerebellar/neural tube malformation. Whether defects in kidney, retinal, or neural disease primarily involve ciliary, Hedgehog, or cell polarity pathways remains unclear. Using high-confidence proteomics, we identified 850 interactors copurifying with nine NPHP/JBTS/MKS proteins and discovered three connected modules: "NPHP1-4-8" functioning at the apical surface, "NPHP5-6" at centrosomes, and "MKS" linked to Hedgehog signaling. Assays for ciliogenesis and epithelial morphogenesis in 3D renal cultures link renal cystic disease to apical organization defects, whereas ciliary and Hedgehog pathway defects lead to retinal or neural deficits. Using 38 interactors as candidates, linkage and sequencing analysis of 250 patients identified ATXN10 and TCTN2 as new NPHP-JBTS genes, and our Tctn2 mouse knockout shows neural tube and Hedgehog signaling defects. Our study further illustrates the power of linking proteomic networks and human genetics to uncover critical disease pathways.
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Affiliation(s)
- Liyun Sang
- Genentech Inc., South San Francisco, CA 94080, USA
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Dowdle WE, Robinson JF, Kneist A, Sirerol-Piquer MS, Frints SGM, Corbit KC, Zaghloul NA, van Lijnschoten G, Mulders L, Verver DE, Zerres K, Reed RR, Attié-Bitach T, Johnson CA, García-Verdugo JM, Katsanis N, Bergmann C, Reiter JF. Disruption of a ciliary B9 protein complex causes Meckel syndrome. Am J Hum Genet 2011; 89:94-110. [PMID: 21763481 DOI: 10.1016/j.ajhg.2011.06.003] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 05/24/2011] [Accepted: 06/03/2011] [Indexed: 02/06/2023] Open
Abstract
Nearly every ciliated organism possesses three B9 domain-containing proteins: MKS1, B9D1, and B9D2. Mutations in human MKS1 cause Meckel syndrome (MKS), a severe ciliopathy characterized by occipital encephalocele, liver ductal plate malformations, polydactyly, and kidney cysts. Mouse mutations in either Mks1 or B9d2 compromise ciliogenesis and result in phenotypes similar to those of MKS. Given the importance of these two B9 proteins to ciliogenesis, we examined the role of the third B9 protein, B9d1. Mice lacking B9d1 displayed polydactyly, kidney cysts, ductal plate malformations, and abnormal patterning of the neural tube, concomitant with compromised ciliogenesis, ciliary protein localization, and Hedgehog (Hh) signal transduction. These data prompted us to screen MKS patients for mutations in B9D1 and B9D2. We identified a homozygous c.301A>C (p.Ser101Arg) B9D2 mutation that segregates with MKS, affects an evolutionarily conserved residue, and is absent from controls. Unlike wild-type B9D2 mRNA, the p.Ser101Arg mutation failed to rescue zebrafish phenotypes induced by the suppression of b9d2. With coimmunoprecipitation and mass spectrometric analyses, we found that Mks1, B9d1, and B9d2 interact physically, but that the p.Ser101Arg mutation abrogates the ability of B9d2 to interact with Mks1, further suggesting that the mutation compromises B9d2 function. Our data indicate that B9d1 is required for normal Hh signaling, ciliogenesis, and ciliary protein localization and that B9d1 and B9d2 are essential components of a B9 protein complex, disruption of which causes MKS.
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Affiliation(s)
- William E Dowdle
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, 94158, USA
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Linford NJ, Kuo TH, Chan TP, Pletcher SD. Sensory perception and aging in model systems: from the outside in. Annu Rev Cell Dev Biol 2011; 27:759-85. [PMID: 21756108 DOI: 10.1146/annurev-cellbio-092910-154240] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sensory systems provide organisms from bacteria to humans with the ability to interact with the world. Numerous senses have evolved that allow animals to detect and decode cues from sources in both their external and internal environments. Recent advances in understanding the central mechanisms by which the brains of simple organisms evaluate different cues and initiate behavioral decisions, coupled with observations that sensory manipulations are capable of altering organismal lifespan, have opened the door for powerful new research into aging. Although direct links between sensory perception and aging have been established only recently, here we discuss these initial discoveries and evaluate the potential for different forms of sensory processing to modulate lifespan across taxa. Harnessing the neurobiology of simple model systems to study the biological impact of sensory experiences will yield insights into the broad influence of sensory perception in mammals and may help uncover new mechanisms of healthy aging.
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Affiliation(s)
- Nancy J Linford
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA.
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Transcriptional profiling of C. elegans DAF-19 uncovers a ciliary base-associated protein and a CDK/CCRK/LF2p-related kinase required for intraflagellar transport. Dev Biol 2011; 357:235-47. [PMID: 21740898 DOI: 10.1016/j.ydbio.2011.06.028] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 06/19/2011] [Accepted: 06/20/2011] [Indexed: 11/23/2022]
Abstract
Cilia are ubiquitous cell surface projections that mediate various sensory- and motility-based processes and are implicated in a growing number of multi-organ genetic disorders termed ciliopathies. To identify new components required for cilium biogenesis and function, we sought to further define and validate the transcriptional targets of DAF-19, the ciliogenic C. elegans RFX transcription factor. Transcriptional profiling of daf-19 mutants (which do not form cilia) and wild-type animals was performed using embryos staged to when the cell types developing cilia in the worm, the ciliated sensory neurons (CSNs), still differentiate. Comparisons between the two populations revealed 881 differentially regulated genes with greater than a 1.5-fold increase or decrease in expression. A subset of these was confirmed by quantitative RT-PCR. Transgenic worms expressing transcriptional GFP fusions revealed CSN-specific expression patterns for 11 of 14 candidate genes. We show that two uncharacterized candidate genes, termed dyf-17 and dyf-18 because their corresponding mutants display dye-filling (Dyf) defects, are important for ciliogenesis. DYF-17 localizes at the base of cilia and is specifically required for building the distal segment of sensory cilia. DYF-18 is an evolutionarily conserved CDK7/CCRK/LF2p-related serine/threonine kinase that is necessary for the proper function of intraflagellar transport, a process critical for cilium biogenesis. Together, our microarray study identifies targets of the evolutionarily conserved RFX transcription factor, DAF-19, providing a rich dataset from which to uncover-in addition to DYF-17 and DYF-18-cellular components important for cilium formation and function.
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Liu L, Zhang M, Xia Z, Xu P, Chen L, Xu T. Caenorhabditis elegans ciliary protein NPHP-8, the homologue of human RPGRIP1L, is required for ciliogenesis and chemosensation. Biochem Biophys Res Commun 2011; 410:626-31. [PMID: 21689635 DOI: 10.1016/j.bbrc.2011.06.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 06/06/2011] [Indexed: 11/17/2022]
Abstract
Nephronophthisis (NPHP) is the most frequent genetic cause of end-stage renal failure in children and young adults. NPHP8/RPGRIP1L is a novel ciliary gene that, when mutated, in addition to causing NPHP, also causes Joubert syndrome (JBTS) and Meckel syndrome (MKS). The exact function of NPHP8 and how defects in NPHP8 lead to human diseases are poorly understood. Here, we studied the Caenorhabditis elegans homolog nphp-8 (C09G5.8) and explored the possible function of NPHP-8 in ciliated sensory neurons. We determined the gene structure of nphp-8 through rapid amplification of cDNA ends (RACE) analysis and discovered an X-box motif that had been previously overlooked. Moreover, NPHP-8 co-localized with NPHP-4 at the transition zone at the base of cilia. Mutation of nphp-8 led to abnormal dye filling (Dyf) and shorter cilia lengths in a subset of ciliary neurons. In addition, chemotaxis to several volatile attractants was significantly impaired in nphp-8 mutants. Our data suggest that NPHP-8/RPGRIP1L plays an important role in cilia formation and cilia-mediated chemosensation in a cell type-specific manner.
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Affiliation(s)
- Lin Liu
- Joint Laboratory of the Institute of Biophysics & Huazhong University of Science and Technology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, PR China
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Hu Q, Nelson WJ. Ciliary diffusion barrier: the gatekeeper for the primary cilium compartment. Cytoskeleton (Hoboken) 2011; 68:313-24. [PMID: 21634025 DOI: 10.1002/cm.20514] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 05/04/2011] [Indexed: 11/08/2022]
Abstract
The primary cilium is a cellular antenna that detects and transmits chemical and mechanical cues in the environment through receptors and downstream signal proteins enriched along the ciliary membrane. While it is known that ciliary membrane proteins enter the cilium by way of vesicular and intraflagellar transport, less is known about how ciliary membrane proteins are retained in, and how apical membrane proteins are excluded from the cilium. Here, we review evidence for a membrane diffusion barrier at the base of the primary cilium, and highlight the recent finding of a septin cytoskeleton diffusion barrier. We also discuss candidate ciliopathy genes that may be involved in formation of the barrier, and the role of a diffusion barrier as a common mechanism for compartmentalizing membranes and lipid domains.
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Affiliation(s)
- Qicong Hu
- Department of Biology, Stanford University, Stanford, California 94305., USA
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47
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Zhao C, Malicki J. Nephrocystins and MKS proteins interact with IFT particle and facilitate transport of selected ciliary cargos. EMBO J 2011; 30:2532-44. [PMID: 21602787 DOI: 10.1038/emboj.2011.165] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 04/19/2011] [Indexed: 01/16/2023] Open
Abstract
Cilia are required for the development and function of many organs. Efficient transport of protein cargo along ciliary axoneme is necessary to sustain these processes. Despite its importance, the mode of interaction between the intraflagellar ciliary transport (IFT) mechanism and its cargo proteins remains poorly understood. Our studies demonstrate that IFT particle components, and a Meckel-Gruber syndrome 1 (MKS1)-related, B9 domain protein, B9d2, bind each other and contribute to the ciliary localization of Inversin (Nephrocystin 2). B9d2, Inversin, and Nephrocystin 5 support, in turn, the transport of a cargo protein, Opsin, but not another photoreceptor ciliary transmembrane protein, Peripherin. Interestingly, the components of this mechanism also contribute to the formation of planar cell polarity in mechanosensory epithelia. These studies reveal a molecular mechanism that mediates the transport of selected ciliary cargos and is of fundamental importance for the differentiation and survival of sensory cells.
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Affiliation(s)
- Chengtian Zhao
- Division of Craniofacial and Molecular Genetics, and Program in Genetics, Sackler School of Graduate Biomedical Studies, Tufts University, Boston, MA, USA
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48
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Williams CL, Li C, Kida K, Inglis PN, Mohan S, Semenec L, Bialas NJ, Stupay RM, Chen N, Blacque OE, Yoder BK, Leroux MR. MKS and NPHP modules cooperate to establish basal body/transition zone membrane associations and ciliary gate function during ciliogenesis. ACTA ACUST UNITED AC 2011; 192:1023-41. [PMID: 21422230 PMCID: PMC3063147 DOI: 10.1083/jcb.201012116] [Citation(s) in RCA: 360] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Eight proteins, defects in which are associated with Meckel-Gruber syndrome and nephronophthisis ciliopathies, work together as two functional modules at the transition zone to establish basal body/transition zone connections with the membrane and barricade entry of non-ciliary components into this organelle. Meckel-Gruber syndrome (MKS), nephronophthisis (NPHP), and related ciliopathies present with overlapping phenotypes and display considerable allelism between at least twelve different genes of largely unexplained function. We demonstrate that the conserved C. elegans B9 domain (MKS-1, MKSR-1, and MKSR-2), MKS-3/TMEM67, MKS-5/RPGRIP1L, MKS-6/CC2D2A, NPHP-1, and NPHP-4 proteins exhibit essential, collective functions at the transition zone (TZ), an underappreciated region at the base of all cilia characterized by Y-shaped assemblages that link axoneme microtubules to surrounding membrane. These TZ proteins functionally interact as members of two distinct modules, which together contribute to an early ciliogenic event. Specifically, MKS/MKSR/NPHP proteins establish basal body/TZ membrane attachments before or coinciding with intraflagellar transport–dependent axoneme extension and subsequently restrict accumulation of nonciliary components within the ciliary compartment. Together, our findings uncover a unified role for eight TZ-localized proteins in basal body anchoring and establishing a ciliary gate during ciliogenesis, and suggest that disrupting ciliary gate function contributes to phenotypic features of the MKS/NPHP disease spectrum.
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Affiliation(s)
- Corey L Williams
- Department of Cell Biology, University of Alabama, Birmingham, AL 35294, USA
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Hopp K, Heyer CM, Hommerding CJ, Henke SA, Sundsbak JL, Patel S, Patel P, Consugar MB, Czarnecki PG, Gliem TJ, Torres VE, Rossetti S, Harris PC. B9D1 is revealed as a novel Meckel syndrome (MKS) gene by targeted exon-enriched next-generation sequencing and deletion analysis. Hum Mol Genet 2011; 20:2524-34. [PMID: 21493627 DOI: 10.1093/hmg/ddr151] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Meckel syndrome (MKS) is an embryonic lethal, autosomal recessive disorder characterized by polycystic kidney disease, central nervous system defects, polydactyly and liver fibrosis. This disorder is thought to be associated with defects in primary cilia; therefore, it is classed as a ciliopathy. To date, six genes have been commonly associated with MKS (MKS1, TMEM67, TMEM216, CEP290, CC2D2A and RPGRIP1L). However, mutation screening of these genes revealed two mutated alleles in only just over half of our MKS cohort (46 families), suggesting an even greater level of genetic heterogeneity. To explore the full genetic complexity of MKS, we performed exon-enriched next-generation sequencing of 31 ciliopathy genes in 12 MKS pedigrees using RainDance microdroplet-PCR enrichment and IlluminaGAIIx next-generation sequencing. In family M456, we detected a splice-donor site change in a novel MKS gene, B9D1. The B9D1 protein is structurally similar to MKS1 and has been shown to be of importance for ciliogenesis in Caenorhabditis elegans. Reverse transcriptase-PCR analysis of fetal RNA revealed, hemizygously, a single smaller mRNA product with a frameshifting exclusion of B9D1 exon 4. ArrayCGH showed that the second mutation was a 1.713 Mb de novo deletion completely deleting the B9D1 allele. Immunofluorescence analysis highlighted a significantly lower level of ciliated patient cells compared to controls, confirming a role for B9D1 in ciliogenesis. The fetus inherited an additional likely pathogenic novel missense change to a second MKS gene, CEP290; p.R2210C, suggesting oligogenic inheritance in this disorder.
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Affiliation(s)
- Katharina Hopp
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street SW,Rochester, MN 55905, USA
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Abstract
Small GTPases are key molecular switches that bind and hydrolyze GTP in diverse membrane- and cytoskeleton-related cellular processes. Recently, mounting evidences have highlighted the role of various small GTPases, including the members in Arf/Arl, Rab, and Ran subfamilies, in cilia formation and function. Once overlooked as an evolutionary vestige, the primary cilium has attracted more and more attention in last decade because of its role in sensing various extracellular signals and the association between cilia dysfunction and a wide spectrum of human diseases, now called ciliopathies. Here we review recent advances about the function of small GTPases in the context of cilia, and the correlation between the functional impairment of small GTPases and ciliopathies. Understanding of these cellular processes is of fundamental importance for broadening our view of cilia development and function in normal and pathological states and for providing valuable insights into the role of various small GTPases in disease processes, and their potential as therapeutic targets.
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Affiliation(s)
- Yujie Li
- Department of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
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