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Zhang Q, Huang Y, Gao S, Ding Y, Zhang H, Chang G, Wang X. Obesity-Related Ciliopathies: Focus on Advances of Biomarkers. Int J Mol Sci 2024; 25:8484. [PMID: 39126056 PMCID: PMC11312664 DOI: 10.3390/ijms25158484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2024] [Revised: 07/27/2024] [Accepted: 08/01/2024] [Indexed: 08/12/2024] Open
Abstract
Obesity-related ciliopathies, as a group of ciliopathies including Alström Syndrome and Bardet-Biedl Syndrome, exhibit distinct genetic and phenotypic variability. The understanding of these diseases is highly significant for understanding the functions of primary cilia in the human body, particularly regarding the relationship between obesity and primary cilia. The diagnosis of these diseases primarily relies on clinical presentation and genetic testing. However, there is a significant lack of research on biomarkers to elucidate the variability in clinical manifestations, disease progression, prognosis, and treatment responses. Through an extensive literature review, the paper focuses on obesity-related ciliopathies, reviewing the advancements in the field and highlighting the potential roles of biomarkers in the clinical presentation, diagnosis, and prognosis of these diseases.
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Affiliation(s)
- Qianwen Zhang
- Department of Endocrinology and Metabolism, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China; (Q.Z.); (Y.H.); (S.G.); (Y.D.)
| | - Yiguo Huang
- Department of Endocrinology and Metabolism, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China; (Q.Z.); (Y.H.); (S.G.); (Y.D.)
| | - Shiyang Gao
- Department of Endocrinology and Metabolism, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China; (Q.Z.); (Y.H.); (S.G.); (Y.D.)
| | - Yu Ding
- Department of Endocrinology and Metabolism, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China; (Q.Z.); (Y.H.); (S.G.); (Y.D.)
| | - Hao Zhang
- Heart Center and Shanghai Institute of Pediatric Congenital Heart Disease, Shanghai Children’s Medical Center, National Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China;
| | - Guoying Chang
- Department of Endocrinology and Metabolism, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China; (Q.Z.); (Y.H.); (S.G.); (Y.D.)
| | - Xiumin Wang
- Department of Endocrinology and Metabolism, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China; (Q.Z.); (Y.H.); (S.G.); (Y.D.)
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2
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Caiaffa CD, Ambekar YS, Singh M, Lin YL, Wlodarczyk B, Aglyamov SR, Scarcelli G, Larin KV, Finnell RH. Disruption of Fuz in mouse embryos generates hypoplastic hindbrain development and reduced cranial nerve ganglia. Dev Dyn 2024; 253:846-858. [PMID: 38501709 PMCID: PMC11411014 DOI: 10.1002/dvdy.702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/07/2024] [Accepted: 02/20/2024] [Indexed: 03/20/2024] Open
Abstract
BACKGROUND The brain and spinal cord formation is initiated in the earliest stages of mammalian pregnancy in a highly organized process known as neurulation. Environmental or genetic interferences can impair neurulation, resulting in clinically significant birth defects known collectively as neural tube defects. The Fuz gene encodes a subunit of the CPLANE complex, a macromolecular planar polarity effector required for ciliogenesis. Ablation of Fuz in mouse embryos results in exencephaly and spina bifida, including dysmorphic craniofacial structures due to defective cilia formation and impaired Sonic Hedgehog signaling. RESULTS We demonstrate that knocking Fuz out during embryonic mouse development results in a hypoplastic hindbrain phenotype, displaying abnormal rhombomeres with reduced length and width. This phenotype is associated with persistent reduction of ventral neuroepithelial stiffness in a notochord adjacent area at the level of the rhombomere 5. The formation of cranial and paravertebral ganglia is also impaired in these embryos. CONCLUSIONS This study reveals that hypoplastic hindbrain development, identified by abnormal rhombomere morphology and persistent loss of ventral neuroepithelial stiffness, precedes exencephaly in Fuz ablated murine mutants, indicating that the gene Fuz has a critical function sustaining normal neural tube development and neuronal differentiation.
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Affiliation(s)
- Carlo Donato Caiaffa
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas, USA
- Department of Pediatrics, Dell Pediatric Research Institute, University of Texas at Austin Dell Medical School, Austin, Texas, USA
| | - Yogeshwari S Ambekar
- Department of Biomedical Engineering, University of Houston, Houston, Texas, USA
| | - Manmohan Singh
- Department of Biomedical Engineering, University of Houston, Houston, Texas, USA
| | - Ying Linda Lin
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas, USA
| | - Bogdan Wlodarczyk
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas, USA
| | - Salavat R Aglyamov
- Department of Biomedical Engineering, University of Houston, Houston, Texas, USA
| | - Giuliano Scarcelli
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland, USA
| | - Kirill V Larin
- Department of Biomedical Engineering, University of Houston, Houston, Texas, USA
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
| | - Richard H Finnell
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas, USA
- Department of Molecular and Cellular Biology, Molecular and Human Genetics and Medicine, Baylor College of Medicine, Houston, Texas, USA
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3
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Sharma R, Kalot R, Levin Y, Babayeva S, Kachurina N, Chung CF, Liu KJ, Bouchard M, Torban E. The CPLANE protein Fuzzy regulates ciliogenesis by suppressing actin polymerization at the base of the primary cilium via p190A RhoGAP. Development 2024; 151:dev202322. [PMID: 38546045 PMCID: PMC11006408 DOI: 10.1242/dev.202322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 02/14/2024] [Indexed: 04/12/2024]
Abstract
The primary cilium decorates most eukaryotic cells and regulates tissue morphogenesis and maintenance. Structural or functional defects of primary cilium result in ciliopathies, congenital human disorders affecting multiple organs. Pathogenic variants in the ciliogenesis and planar cell polarity effectors (CPLANE) genes FUZZY, INTU and WDPCP disturb ciliogenesis, causing severe ciliopathies in humans and mice. Here, we show that the loss of Fuzzy in mice results in defects of primary cilia, accompanied by increased RhoA activity and excessive actin polymerization at the basal body. We discovered that, mechanistically, Fuzzy interacts with and recruits the negative actin regulator ARHGAP35 (also known as p190A RhoGAP) to the basal body. We identified genetic interactions between the two genes and found that a mutant ArhGAP35 allele increases the severity of phenotypic defects observed in Fuzzy-/- mice. Based on our findings, we propose that Fuzzy regulates ciliogenesis by recruiting ARHGAP35 to the basal body, where the latter likely restricts actin polymerization and modifies the actin network. Our study identifies a mechanism whereby CPLANE proteins control both actin polymerization and primary cilium formation.
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Affiliation(s)
- Rhythm Sharma
- Department of Medicine and Department of Physiology, McGill University, Montreal H4A 3J1, QC, Canada
| | - Rita Kalot
- Department of Medicine and Department of Physiology, McGill University, Montreal H4A 3J1, QC, Canada
| | - Yossef Levin
- Department of Medicine and Department of Physiology, McGill University, Montreal H4A 3J1, QC, Canada
| | - Sima Babayeva
- Metabolic Disorders and Complications Program, Research Institute of the McGill University Health Centre, McGill University, Montreal H4A 3J1, QC, Canada
| | - Nadezda Kachurina
- Metabolic Disorders and Complications Program, Research Institute of the McGill University Health Centre, McGill University, Montreal H4A 3J1, QC, Canada
| | - Chen-Feng Chung
- Department of Medicine and Department of Physiology, McGill University, Montreal H4A 3J1, QC, Canada
| | - Karen J. Liu
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Maxime Bouchard
- Rosalind and Morris Goodman Cancer Institute, Department of Medicine of the McGill University,McGill University, Montreal H3A 1A3, QC, Canada
| | - Elena Torban
- Department of Medicine and Department of Physiology, McGill University, Montreal H4A 3J1, QC, Canada
- Metabolic Disorders and Complications Program, Research Institute of the McGill University Health Centre, McGill University, Montreal H4A 3J1, QC, Canada
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4
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Wilmes S, Kümmel D. Insights into the role of the membranes in Rab GTPase regulation. Curr Opin Cell Biol 2023; 83:102177. [PMID: 37327649 DOI: 10.1016/j.ceb.2023.102177] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/15/2023] [Accepted: 05/19/2023] [Indexed: 06/18/2023]
Abstract
Rab GTPases are molecular switches with essential roles in mediating vesicular trafficking and establishing organelle identity. The conversion from the inactive, cytosolic to the membrane-bound, active species and back is tightly controlled by regulatory proteins. Recently, the roles of membrane properties and lipid composition of different target organelles in determining the activity state of Rabs have come to light. The investigation of several Rab guanine nucleotide exchange factors (GEFs) has revealed principles of how the recruitment via lipid interactions and the spatial confinement on the membrane surface contribute to spatiotemporal specificity in the Rab GTPase network. This paints an intricate picture of the control mechanisms in Rab activation and highlights the importance of the membrane lipid code in the organization of the endomembrane system.
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Affiliation(s)
- Stephan Wilmes
- University of Münster, Institute of Biochemistry, Corrensstraße 36, 48149 Münster, Germany
| | - Daniel Kümmel
- University of Münster, Institute of Biochemistry, Corrensstraße 36, 48149 Münster, Germany.
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5
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Yong X, Jia G, Liu Z, Zhou C, Yi J, Tang Y, Chen L, Chen L, Wang Y, Sun Q, Billadeau D, Su Z, Jia D. Cryo-EM structure of the Mon1-Ccz1-RMC1 complex reveals molecular basis of metazoan RAB7A activation. Proc Natl Acad Sci U S A 2023; 120:e2301725120. [PMID: 37216550 PMCID: PMC10235969 DOI: 10.1073/pnas.2301725120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 04/18/2023] [Indexed: 05/24/2023] Open
Abstract
Understanding of the evolution of metazoans from their unicellular ancestors is a fundamental question in biology. In contrast to fungi which utilize the Mon1-Ccz1 dimeric complex to activate the small GTPase RAB7A, metazoans rely on the Mon1-Ccz1-RMC1 trimeric complex. Here, we report a near-atomic resolution cryogenic-electron microscopy structure of the Drosophila Mon1-Ccz1-RMC1 complex. RMC1 acts as a scaffolding subunit and binds to both Mon1 and Ccz1 on the surface opposite to the RAB7A-binding site, with many of the RMC1-contacting residues from Mon1 and Ccz1 unique to metazoans, explaining the binding specificity. Significantly, the assembly of RMC1 with Mon1-Ccz1 is required for cellular RAB7A activation, autophagic functions and organismal development in zebrafish. Our studies offer a molecular explanation for the different degree of subunit conservation across species, and provide an excellent example of how metazoan-specific proteins take over existing functions in unicellular organisms.
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Affiliation(s)
- Xin Yong
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Guowen Jia
- Department of Geriatrics and National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University610044Chengdu, China
| | - Zhe Liu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Chunzhuang Zhou
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Jiamin Yi
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Yingying Tang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Li Chen
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Lu Chen
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Yuan Wang
- Department of Geriatrics and National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University610044Chengdu, China
| | - Qingxiang Sun
- Department of Geriatrics and National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University610044Chengdu, China
| | - Daniel D. Billadeau
- Division of Oncology Research and Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN55905
| | - Zhaoming Su
- Department of Geriatrics and National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University610044Chengdu, China
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
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6
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Herrmann E, Schäfer JH, Wilmes S, Ungermann C, Moeller A, Kümmel D. Structure of the metazoan Rab7 GEF complex Mon1-Ccz1-Bulli. Proc Natl Acad Sci U S A 2023; 120:e2301908120. [PMID: 37155863 PMCID: PMC10193976 DOI: 10.1073/pnas.2301908120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/14/2023] [Indexed: 05/10/2023] Open
Abstract
The endosomal system of eukaryotic cells represents a central sorting and recycling compartment linked to metabolic signaling and the regulation of cell growth. Tightly controlled activation of Rab GTPases is required to establish the different domains of endosomes and lysosomes. In metazoans, Rab7 controls endosomal maturation, autophagy, and lysosomal function. It is activated by the guanine nucleotide exchange factor (GEF) complex Mon1-Ccz1-Bulli (MCBulli) of the tri-longin domain (TLD) family. While the Mon1 and Ccz1 subunits have been shown to constitute the active site of the complex, the role of Bulli remains elusive. We here present the cryo-electron microscopy (cryo-EM) structure of MCBulli at 3.2 Å resolution. Bulli associates as a leg-like extension at the periphery of the Mon1 and Ccz1 heterodimers, consistent with earlier reports that Bulli does not impact the activity of the complex or the interactions with recruiter and substrate GTPases. While MCBulli shows structural homology to the related ciliogenesis and planar cell polarity effector (Fuzzy-Inturned-Wdpcp) complex, the interaction of the TLD core subunits Mon1-Ccz1 and Fuzzy-Inturned with Bulli and Wdpcp, respectively, is remarkably different. The variations in the overall architecture suggest divergent functions of the Bulli and Wdpcp subunits. Based on our structural analysis, Bulli likely serves as a recruitment platform for additional regulators of endolysosomal trafficking to sites of Rab7 activation.
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Affiliation(s)
- Eric Herrmann
- Department of Chemistry and Pharmacy, Institute of Biochemistry, University of Münster, 48149Münster, Germany
| | - Jan-Hannes Schäfer
- Department of Biology/Chemistry, Structural Biology section, Osnabrück University, 49076Osnabrück, Germany
| | - Stephan Wilmes
- Department of Chemistry and Pharmacy, Institute of Biochemistry, University of Münster, 48149Münster, Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry section, Osnabrück University, 49076Osnabrück, Germany
- Center of Cellular Nanoanalytic Osnabrück, Osnabrück University, 49076Osnabrück, Germany
| | - Arne Moeller
- Department of Biology/Chemistry, Structural Biology section, Osnabrück University, 49076Osnabrück, Germany
- Center of Cellular Nanoanalytic Osnabrück, Osnabrück University, 49076Osnabrück, Germany
| | - Daniel Kümmel
- Department of Chemistry and Pharmacy, Institute of Biochemistry, University of Münster, 48149Münster, Germany
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7
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Zhao H, Khan Z, Westlake CJ. Ciliogenesis membrane dynamics and organization. Semin Cell Dev Biol 2023; 133:20-31. [PMID: 35351373 PMCID: PMC9510604 DOI: 10.1016/j.semcdb.2022.03.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 12/28/2022]
Abstract
Ciliogenesis is a complex multistep process used to describe assembly of cilia and flagella. These organelles play essential roles in motility and signaling on the surface of cells. Cilia are built at the distal ends of centrioles through the formation of an axoneme that is surrounded by the ciliary membrane. As is the case in the biogenesis of other cellular organelles, regulators of membrane trafficking play essential roles in ciliogenesis, albeit with a unique feature that membranes are organized around microtubule-based structures. Membrane association with the distal end of the centriole is a critical initiating step for ciliogenesis. Studies of this process in different cell types suggests that a singular mechanism may not be utilized to initiate cilium assembly. In this review, we focus on recent insights into cilium biogenesis and the roles membrane trafficking regulators play in described ciliogenesis mechanisms with relevance to human disease.
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Affiliation(s)
- Huijie Zhao
- Center for Cancer Research, NCI Frederick, Laboratory of Cellular and Developmental, Signaling, Frederick, MD 21702, USA
| | - Ziam Khan
- Center for Cancer Research, NCI Frederick, Laboratory of Cellular and Developmental, Signaling, Frederick, MD 21702, USA
| | - Christopher J Westlake
- Center for Cancer Research, NCI Frederick, Laboratory of Cellular and Developmental, Signaling, Frederick, MD 21702, USA.
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8
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Herrmann E, Langemeyer L, Auffarth K, Ungermann C, Kümmel D. Targeting of the Mon1-Ccz1 Rab guanine nucleotide exchange factor to distinct organelles by a synergistic protein and lipid code. J Biol Chem 2023; 299:102915. [PMID: 36649906 PMCID: PMC10124900 DOI: 10.1016/j.jbc.2023.102915] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 01/01/2023] [Accepted: 01/05/2023] [Indexed: 01/16/2023] Open
Abstract
Activation of the small GTPase Rab7 by its cognate guanine nucleotide exchange factor Mon1-Ccz1 (MC1) is a key step in the maturation of endosomes and autophagosomes. This process is tightly regulated and subject to precise spatiotemporal control of MC1 localization, but the mechanisms that underly MC1 localization have not been fully elucidated. We here identify and characterize an amphipathic helix in Ccz1, which is required for the function of Mon-Ccz1 in autophagy, but not endosomal maturation. Furthermore, our data show that the interaction of the Ccz1 amphipathic helix with lipid packing defects, binding of Mon1 basic patches to positively charged lipids, and association of MC1 with recruiter proteins collectively govern membrane recruitment of the complex in a synergistic and redundant manner. Membrane binding enhances MC1 activity predominantly by increasing enzyme and substrate concentration on the membrane, but interaction with recruiter proteins can further stimulate the guanine nucleotide exchange factor. Our data demonstrate that specific protein and lipid cues convey the differential targeting of MC1 to endosomes and autophagosomes. In conclusion, we reveal the molecular basis for how MC1 is adapted to recognize distinct target compartments by exploiting the unique biophysical properties of organelle membranes and thus provide a model for how the complex is regulated and activated independently in different functional contexts.
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Affiliation(s)
- Eric Herrmann
- Institute of Biochemistry, University of Münster, Münster, Germany
| | - Lars Langemeyer
- Department of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Kathrin Auffarth
- Department of Biology/Chemistry, Osnabrück University, Osnabrück, Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, Osnabrück University, Osnabrück, Germany; Center of Cellular Nanoanalytics (CellNanOs), Osnabrück University, Osnabrück, Germany
| | - Daniel Kümmel
- Institute of Biochemistry, University of Münster, Münster, Germany.
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9
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Kümmel D, Herrmann E, Langemeyer L, Ungermann C. Molecular insights into endolysosomal microcompartment formation and maintenance. Biol Chem 2022; 404:441-454. [PMID: 36503831 DOI: 10.1515/hsz-2022-0294] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 11/22/2022] [Indexed: 12/14/2022]
Abstract
Abstract
The endolysosomal system of eukaryotic cells has a key role in the homeostasis of the plasma membrane, in signaling and nutrient uptake, and is abused by viruses and pathogens for entry. Endocytosis of plasma membrane proteins results in vesicles, which fuse with the early endosome. If destined for lysosomal degradation, these proteins are packaged into intraluminal vesicles, converting an early endosome to a late endosome, which finally fuses with the lysosome. Each of these organelles has a unique membrane surface composition, which can form segmented membrane microcompartments by membrane contact sites or fission proteins. Furthermore, these organelles are in continuous exchange due to fission and fusion events. The underlying machinery, which maintains organelle identity along the pathway, is regulated by signaling processes. Here, we will focus on the Rab5 and Rab7 GTPases of early and late endosomes. As molecular switches, Rabs depend on activating guanine nucleotide exchange factors (GEFs). Over the last years, we characterized the Rab7 GEF, the Mon1-Ccz1 (MC1) complex, and key Rab7 effectors, the HOPS complex and retromer. Structural and functional analyses of these complexes lead to a molecular understanding of their function in the context of organelle biogenesis.
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Affiliation(s)
- Daniel Kümmel
- Institute of Biochemistry, University of Münster , Corrensstraße 36 , D-48149 Münster , Germany
| | - Eric Herrmann
- Institute of Biochemistry, University of Münster , Corrensstraße 36 , D-48149 Münster , Germany
| | - Lars Langemeyer
- Department of Biology/Chemistry, Biochemistry section , Osnabrück University , Barbarastraße 13 , D-49076 Osnabrück , Germany
- Center of Cellular Nanoanalytics (CellNanOs) , Osnabrück University , Barbarastraße 11 , D-49076 Osnabrück , Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry section , Osnabrück University , Barbarastraße 13 , D-49076 Osnabrück , Germany
- Center of Cellular Nanoanalytics (CellNanOs) , Osnabrück University , Barbarastraße 11 , D-49076 Osnabrück , Germany
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10
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Martín-Salazar JE, Valverde D. CPLANE Complex and Ciliopathies. Biomolecules 2022; 12:biom12060847. [PMID: 35740972 PMCID: PMC9221175 DOI: 10.3390/biom12060847] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/10/2022] [Accepted: 06/16/2022] [Indexed: 02/04/2023] Open
Abstract
Primary cilia are non-motile organelles associated with the cell cycle, which can be found in most vertebrate cell types. Cilia formation occurs through a process called ciliogenesis, which involves several mechanisms including planar cell polarity (PCP) and the Hedgehog (Hh) signaling pathway. Some gene complexes, such as BBSome or CPLANE (ciliogenesis and planar polarity effector), have been linked to ciliogenesis. CPLANE complex is composed of INTU, FUZ and WDPCP, which bind to JBTS17 and RSG1 for cilia formation. Defects in these genes have been linked to a malfunction of intraflagellar transport and defects in the planar cell polarity, as well as defective activation of the Hedgehog signalling pathway. These faults lead to defective cilium formation, resulting in ciliopathies, including orofacial-digital syndrome (OFDS) and Bardet-Biedl syndrome (BBS). Considering the close relationship, between the CPLANE complex and cilium formation, it can be expected that defects in the genes that encode subunits of the CPLANE complex may be related to other ciliopathies.
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Affiliation(s)
| | - Diana Valverde
- CINBIO, Biomedical Research Centre, University of Vigo, 36310 Vigo, Spain;
- Galicia Sur Health Research Institute (IIS-GS), 36310 Vigo, Spain
- Correspondence:
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11
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Abstract
Primary cilia play a key role in the ability of cells to respond to extracellular stimuli, such as signaling molecules and environmental cues. These sensory organelles are crucial to the development of many organ systems, and defects in primary ciliogenesis lead to multisystemic genetic disorders, known as ciliopathies. Here, we review recent advances in the understanding of several key aspects of the regulation of ciliogenesis. Primary ciliogenesis is thought to take different pathways depending on cell type, and some recent studies shed new light on the cell-type-specific mechanisms regulating ciliogenesis at the apical surface in polarized epithelial cells, which are particularly relevant for many ciliopathies. Furthermore, recent findings have demonstrated the importance of actin cytoskeleton dynamics in positively and negatively regulating multiple stages of ciliogenesis, including the vesicular trafficking of ciliary components and the positioning and docking of the basal body. Finally, studies on the formation of motile cilia in multiciliated epithelial cells have revealed requirements for actin remodeling in this process too, as well as showing evidence of an additional alternative ciliogenesis pathway.
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Affiliation(s)
| | - Rytis Prekeris
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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12
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Langousis G, Cavadini S, Boegholm N, Lorentzen E, Kempf G, Matthias P. Structure of the ciliogenesis-associated CPLANE complex. SCIENCE ADVANCES 2022; 8:eabn0832. [PMID: 35427153 PMCID: PMC9012472 DOI: 10.1126/sciadv.abn0832] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
Dysfunctional cilia cause pleiotropic human diseases termed ciliopathies. These hereditary maladies are often caused by defects in cilia assembly, a complex event that is regulated by the ciliogenesis and planar polarity effector (CPLANE) proteins Wdpcp, Inturned, and Fuzzy. CPLANE proteins are essential for building the cilium and are mutated in multiple ciliopathies, yet their structure and molecular functions remain elusive. Here, we show that mammalian CPLANE proteins comprise a bona fide complex and report the near-atomic resolution structures of the human Wdpcp-Inturned-Fuzzy complex and of the mouse Wdpcp-Inturned-Fuzzy complex bound to the small guanosine triphosphatase Rsg1. Notably, the crescent-shaped CPLANE complex binds phospholipids such as phosphatidylinositol 3-phosphate via multiple modules and a CPLANE ciliopathy mutant exhibits aberrant lipid binding. Our study provides critical structural and functional insights into an enigmatic ciliogenesis-associated complex as well as unexpected molecular rationales for ciliopathies.
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Affiliation(s)
- Gerasimos Langousis
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Simone Cavadini
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Niels Boegholm
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark
| | - Georg Kempf
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Patrick Matthias
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
- Faculty of Sciences, University of Basel, 4031 Basel, Switzerland
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13
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Barrell WB, Adel Al-Lami H, Goos JAC, Swagemakers SMA, van Dooren M, Torban E, van der Spek PJ, Mathijssen IMJ, Liu KJ. Identification of a novel variant of the ciliopathic gene FUZZY associated with craniosynostosis. Eur J Hum Genet 2022; 30:282-290. [PMID: 34719684 PMCID: PMC8904458 DOI: 10.1038/s41431-021-00988-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 10/04/2021] [Accepted: 10/14/2021] [Indexed: 11/08/2022] Open
Abstract
Craniosynostosis is a birth defect occurring in approximately one in 2000 live births, where premature fusion of the cranial bones inhibits growth of the skull during critical periods of brain development. The resulting changes in skull shape can lead to compression of the brain, causing severe complications. While we have some understanding of the molecular pathology of craniosynostosis, a large proportion of cases are of unknown genetic aetiology. Based on studies in mouse, we previously proposed that the ciliopathy gene Fuz should be considered a candidate craniosynostosis gene. Here, we report a novel variant of FUZ (c.851 G > C, p.(Arg284Pro)) found in monozygotic twins presenting with craniosynostosis. To investigate whether Fuz has a direct role in regulating osteogenic fate and mineralisation, we cultured primary osteoblasts and mouse embryonic fibroblasts (MEFs) from Fuz mutant mice. Loss of Fuz resulted in increased osteoblastic mineralisation. This suggests that FUZ protein normally acts as a negative regulator of osteogenesis. We then used Fuz mutant MEFs, which lose functional primary cilia, to test whether the FUZ p.(Arg284Pro) variant could restore FUZ function during ciliogenesis. We found that expression of the FUZ p.(Arg284Pro) variant was sufficient to partially restore cilia numbers, but did not mediate a comparable response to Hedgehog pathway activation. Together, this suggests the osteogenic effects of FUZ p.(Arg284Pro) do not depend upon initiation of ciliogenesis.
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Affiliation(s)
- William B Barrell
- Centre for Craniofacial and Regenerative Biology, King's College London, London, SE1 9RT, UK
| | - Hadeel Adel Al-Lami
- Centre for Craniofacial and Regenerative Biology, King's College London, London, SE1 9RT, UK
- Department of Orthodontics, College of Dentistry, University of Baghdad, Baghdad, Iraq
| | - Jacqueline A C Goos
- Department of Plastic and Reconstructive Surgery and Hand Surgery, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Sigrid M A Swagemakers
- Department of Bioinformatics, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Marieke van Dooren
- Department of Plastic and Reconstructive Surgery and Hand Surgery, Erasmus University Medical Centre, Rotterdam, The Netherlands
- Department of Clinical Genetics, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Elena Torban
- Department of Medicine, McGill University Health Centre, Montreal, Canada
| | - Peter J van der Spek
- Department of Bioinformatics, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Irene M J Mathijssen
- Department of Plastic and Reconstructive Surgery and Hand Surgery, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Karen J Liu
- Centre for Craniofacial and Regenerative Biology, King's College London, London, SE1 9RT, UK.
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14
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Structure of the Mon1-Ccz1 complex reveals molecular basis of membrane binding for Rab7 activation. Proc Natl Acad Sci U S A 2022; 119:2121494119. [PMID: 35105815 PMCID: PMC8833172 DOI: 10.1073/pnas.2121494119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2021] [Indexed: 01/02/2023] Open
Abstract
Activation of the GTPase Rab7/Ypt7 by its cognate guanine nucleotide exchange factor (GEF) Mon1-Ccz1 marks organelles such as endosomes and autophagosomes for fusion with lysosomes/vacuoles and degradation of their content. Here, we present a high-resolution cryogenic electron microscopy structure of the Mon1-Ccz1 complex that reveals its architecture in atomic detail. Mon1 and Ccz1 are arranged side by side in a pseudo-twofold symmetrical heterodimer. The three Longin domains of each Mon1 and Ccz1 are triangularly arranged, providing a strong scaffold for the catalytic center of the GEF. At the opposite side of the Ypt7-binding site, a positively charged and relatively flat patch stretches the Longin domains 2/3 of Mon1 and functions as a phosphatidylinositol phosphate-binding site, explaining how the GEF is targeted to membranes. Our work provides molecular insight into the mechanisms of endosomal Rab activation and serves as a blueprint for understanding the function of members of the Tri Longin domain Rab-GEF family.
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15
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Wang IY, Chung CF, Babayeva S, Sogomonian T, Torban E. Loss of Planar Cell Polarity Effector Fuzzy Causes Renal Hypoplasia by Disrupting Several Signaling Pathways. J Dev Biol 2021; 10:jdb10010001. [PMID: 35076510 PMCID: PMC8788523 DOI: 10.3390/jdb10010001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/09/2021] [Accepted: 12/19/2021] [Indexed: 12/20/2022] Open
Abstract
In vertebrates, the planar cell polarity (PCP) pathway regulates tissue morphogenesis during organogenesis, including the kidney. Mutations in human PCP effector proteins have been associated with severe syndromic ciliopathies. Importantly, renal hypoplasia has been reported in some patients. However, the developmental disturbance that causes renal hypoplasia is unknown. Here, we describe the early onset of profound renal hypoplasia in mice homozygous for null mutation of the PCP effector gene, Fuzzy. We found that this phenotype is caused by defective branching morphogenesis of the ureteric bud (UB) in the absence of defects in nephron progenitor specification or in early steps of nephrogenesis. By using various experimental approaches, we show that the loss of Fuzzy affects multiple signaling pathways. Specifically, we found mild involvement of GDNF/c-Ret pathway that drives UB branching. We noted the deficient expression of molecules belonging to the Bmp, Fgf and Shh pathways. Analysis of the primary cilia in the UB structures revealed a significant decrease in ciliary length. We conclude that renal hypoplasia in the mouse Fuzzy mutants is caused by defective UB branching associated with dysregulation of ciliary and non-ciliary signaling pathways. Our work suggests a PCP effector-dependent pathogenetic mechanism that contributes to renal hypoplasia in mice and humans.
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Affiliation(s)
- Irene-Yanran Wang
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada; (I.-Y.W.); (C.-F.C.); (S.B.); (T.S.)
- McGill University Health Center Research Institute, Montreal, QC H4A 3J1, Canada
| | - Chen-Fang Chung
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada; (I.-Y.W.); (C.-F.C.); (S.B.); (T.S.)
- McGill University Health Center Research Institute, Montreal, QC H4A 3J1, Canada
| | - Sima Babayeva
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada; (I.-Y.W.); (C.-F.C.); (S.B.); (T.S.)
- McGill University Health Center Research Institute, Montreal, QC H4A 3J1, Canada
| | - Tamara Sogomonian
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada; (I.-Y.W.); (C.-F.C.); (S.B.); (T.S.)
- McGill University Health Center Research Institute, Montreal, QC H4A 3J1, Canada
| | - Elena Torban
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada; (I.-Y.W.); (C.-F.C.); (S.B.); (T.S.)
- McGill University Health Center Research Institute, Montreal, QC H4A 3J1, Canada
- Correspondence:
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16
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Khairat R, Elhossini R, Sobreira N, Wohler E, Otaify G, Mohamed AM, Abdel Raouf ER, Sayed I, Aglan M, Ismail S, Temtamy SA. Expansion of the phenotypic and mutational spectrum of Carpenter syndrome. Eur J Med Genet 2021; 65:104377. [PMID: 34748996 DOI: 10.1016/j.ejmg.2021.104377] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 10/14/2021] [Accepted: 11/02/2021] [Indexed: 11/29/2022]
Abstract
Carpenter syndrome 1 (CRPT1) is an acrocephalopolysyndactyly (ACPS) disorder characterized by craniosynostosis, polysyndactyly, obesity, and other malformations. It is caused by mutations in the gene RAB23. We are reporting on two patients from two unrelated consanguineous Egyptian families. Patient 1 presented with an atypical clinical presentation of Carpenter syndrome including overgrowth with advanced bone age, epileptogenic changes on electroencephalogram and autistic features. Patient 2 presented with typical clinical features suggestive of Carpenter syndrome. Therefore, Patient 1 was subjected to whole exome sequencing (WES) to find an explanation for his unusual features and Patient 2 was subjected to Sanger sequencing of the coding exons of theRAB23 gene to confirm the diagnosis. We identified a novel homozygous missense RAB23 variant (NM_001278668:c.T416C:p.Leu139Pro) in Patient 1 and a novel homozygous splicing variant (NM_016277.5:c.398+1G > A) in Patient 2. We suggest that the overgrowth with advanced bone age, electroencephalogram epileptogenic changes, and autistic features seen in Patient 1 are an expansion of the Carpenter phenotype and could be due to the novel missense RAB23 variant. Additionally, the novel identified RAB23 variants in Patient 1 and 2 broaden the spectrum of variants associated with Carpenter syndrome.
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Affiliation(s)
- Rabab Khairat
- Department of Medical Molecular Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt.
| | - Rasha Elhossini
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Nara Sobreira
- Department of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Elizabeth Wohler
- Department of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Ghada Otaify
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Amal M Mohamed
- Department of Human Cytogenetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Ehab R Abdel Raouf
- Department of Children of Special Needs, Medicine and Clinical Studies Research Institute, National Research Centre, Cairo, Egypt
| | - Inas Sayed
- Department of Oro-dental Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Mona Aglan
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Samira Ismail
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Samia A Temtamy
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
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17
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Quidwai T, Wang J, Hall EA, Petriman NA, Leng W, Kiesel P, Wells JN, Murphy LC, Keighren MA, Marsh JA, Lorentzen E, Pigino G, Mill P. A WDR35-dependent coat protein complex transports ciliary membrane cargo vesicles to cilia. eLife 2021; 10:e69786. [PMID: 34734804 PMCID: PMC8754431 DOI: 10.7554/elife.69786] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
Intraflagellar transport (IFT) is a highly conserved mechanism for motor-driven transport of cargo within cilia, but how this cargo is selectively transported to cilia is unclear. WDR35/IFT121 is a component of the IFT-A complex best known for its role in ciliary retrograde transport. In the absence of WDR35, small mutant cilia form but fail to enrich in diverse classes of ciliary membrane proteins. In Wdr35 mouse mutants, the non-core IFT-A components are degraded and core components accumulate at the ciliary base. We reveal deep sequence homology of WDR35 and other IFT-A subunits to α and ß' COPI coatomer subunits and demonstrate an accumulation of 'coat-less' vesicles that fail to fuse with Wdr35 mutant cilia. We determine that recombinant non-core IFT-As can bind directly to lipids and provide the first in situ evidence of a novel coat function for WDR35, likely with other IFT-A proteins, in delivering ciliary membrane cargo necessary for cilia elongation.
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Affiliation(s)
- Tooba Quidwai
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Jiaolong Wang
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
| | - Emma A Hall
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Narcis A Petriman
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
| | - Weihua Leng
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Petra Kiesel
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Jonathan N Wells
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Laura C Murphy
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Margaret A Keighren
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Joseph A Marsh
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
| | - Gaia Pigino
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Human TechnopoleMilanItaly
| | - Pleasantine Mill
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
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18
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Hor CHH, Lo JCW, Cham ALS, Leong WY, Goh ELK. Multifaceted Functions of Rab23 on Primary Cilium-Mediated and Hedgehog Signaling-Mediated Cerebellar Granule Cell Proliferation. J Neurosci 2021; 41:6850-6863. [PMID: 34210780 PMCID: PMC8360682 DOI: 10.1523/jneurosci.3005-20.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 06/20/2021] [Accepted: 06/23/2021] [Indexed: 01/04/2023] Open
Abstract
Sonic hedgehog (Shh) signaling from the primary cilium drives cerebellar granule cell precursor (GCP) proliferation. Mutations of hedgehog (Hh) pathway repressors commonly cause medulloblastoma, the most prevalent and malignant childhood brain tumor that arises from aberrant GCP proliferation. We demonstrate that Nestin Cre-driven conditional knock-out (CKO) of a Shh pathway repressor-Rab23 in the mouse brain of both genders caused mis-patterning of cerebellar folia and elevated GCP proliferation during early development, but with no prevalent occurrence of medulloblastoma at adult stage. Strikingly, Rab23-depleted GCPs exhibited upregulated basal level of Shh pathway activities despite showing an abnormal ciliogenesis of primary cilia. In line with the compromised ciliation, Rab23-depleted GCPs were desensitized against Hh pathway activity stimulations by Shh ligand and Smoothened (Smo) agonist-SAG, and exhibited attenuated stimulation of Smo-localization on the primary cilium in response to SAG. These results implicate multidimensional actions of Rab23 on Hh signaling cascade. Rab23 represses the basal level of Shh signaling, while facilitating primary cilium-dependent extrinsic Shh signaling activation. Collectively, our findings unravel instrumental roles of Rab23 in GCP proliferation and ciliogenesis. Furthermore, Rab23's potentiation of Shh signaling pathway through the primary cilium and Smo suggests a potential new therapeutic strategy for Smo/primary cilium-driven medulloblastoma.SIGNIFICANCE STATEMENT Primary cilium and Sonic hedgehog (Shh) signaling are known to regulate granule cell precursor (GCP) proliferation. Aberrant overactivation of Shh signaling pathway ectopically increases GCP proliferation and causes malignant childhood tumor called medulloblastoma. However, the genetic and molecular regulatory cascade of GCP tumorigenesis remains incompletely understood. Our finding uncovers Rab23 as a novel regulator of hedgehog (Hh) signaling pathway activity and cell proliferation in GCP. Intriguingly, we demonstrated that Rab23 confers dual functions in regulating Shh signaling; it potentiates primary cilium and Shh/Smoothened (Smo)-dependent signaling activation, while antagonizes basal level Hh activity. Our data present a previously underappreciated aspect of Rab23 in mediating extrinsic Shh signaling upstream of Smo. This study sheds new light on the mechanistic insights underpinning Shh signaling-mediated GCP proliferation and tumorigenesis.
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Affiliation(s)
- C H H Hor
- Department of Chemistry, Faculty of Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
- Duke-NUS Medical School, Neuroscience Academic Clinical Programme, Singapore, 169857
| | - J C W Lo
- Department of Chemistry, Faculty of Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - A L S Cham
- Department of Chemistry, Faculty of Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - W Y Leong
- Duke-NUS Medical School, Neuroscience Academic Clinical Programme, Singapore, 169857
| | - E L K Goh
- Duke-NUS Medical School, Neuroscience Academic Clinical Programme, Singapore, 169857
- Department of Research, National Neuroscience Institute, Singapore, 308433
- Neuroscience and Mental Health Faculty, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232
- KK Research Center, KK Women's and Children's Hospital, Singapore, 229899
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19
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Torban E, Sokol SY. Planar cell polarity pathway in kidney development, function and disease. Nat Rev Nephrol 2021; 17:369-385. [PMID: 33547419 PMCID: PMC8967065 DOI: 10.1038/s41581-021-00395-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2021] [Indexed: 02/08/2023]
Abstract
Planar cell polarity (PCP) refers to the coordinated orientation of cells in the tissue plane. Originally discovered and studied in Drosophila melanogaster, PCP is now widely recognized in vertebrates, where it is implicated in organogenesis. Specific sets of PCP genes have been identified. The proteins encoded by these genes become asymmetrically distributed to opposite sides of cells within a tissue plane and guide many processes that include changes in cell shape and polarity, collective cell movements or the uniform distribution of cell appendages. A unifying characteristic of these processes is that they often involve rearrangement of actomyosin. Mutations in PCP genes can cause malformations in organs of many animals, including humans. In the past decade, strong evidence has accumulated for a role of the PCP pathway in kidney development including outgrowth and branching morphogenesis of ureteric bud and podocyte development. Defective PCP signalling has been implicated in the pathogenesis of developmental kidney disorders of the congenital anomalies of the kidney and urinary tract spectrum. Understanding the origins, molecular constituents and cellular targets of PCP provides insights into the involvement of PCP molecules in normal kidney development and how dysfunction of PCP components may lead to kidney disease.
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Affiliation(s)
- Elena Torban
- McGill University and McGill University Health Center Research Institute, 1001 Boulevard Decarie, Block E, Montreal, Quebec, Canada, H4A3J1.,Corresponding authors: Elena Torban (); Sergei Sokol ()
| | - Sergei Y. Sokol
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, USA,Corresponding authors: Elena Torban (); Sergei Sokol ()
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20
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Oguchi ME, Homma Y, Fukuda M. The N-terminal Leu-Pro-Gln sequence of Rab34 is required for ciliogenesis in hTERT-RPE1 cells. Small GTPases 2021; 13:77-83. [PMID: 33860735 DOI: 10.1080/21541248.2021.1894910] [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: 10/21/2022] Open
Abstract
We have previously shown that Rab34 is an important regulator of ciliogenesis and that its unique long N-terminal region (amino acids 1-49) is essential for ciliogenesis in certain cultured mammalian cells. In the present study, we performed an in-depth deletion analysis of the N-terminal region of Rab34 together with Ala-based site-directed mutagenesis to identify the essential amino acids that are required for serum-starvation-induced ciliogenesis in hTERT-RPE1 cells. The results showed that a Rab34 mutant lacking an N-terminal 18 amino acids and a Rab34 mutant carrying an LPQ-to-AAA mutation (amino acids 16-18) failed to rescue a Rab34-KO phenotype (i.e., defect in ciliogenesis). Our findings suggest that the LPQ sequence of Rab34 is crucial for ciliogenesis in hTERT-RPE1 cells.Abbreviations: AA, amino acid(s); ac-Tub, acetylated tubulin; bsr, blasticidin S-resistant gene; HRP, horseradish peroxidase; hTERT-RPE1, human telomerase reverse transcriptase retinal pigment epithelium 1; KO, knockout; NS, not significant; PBS, phosphate-buffered saline; puro, puromycin-resistant gene.
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Affiliation(s)
- Mai E Oguchi
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Yuta Homma
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
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21
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Chen ZS, Lin X, Chan TF, Chan HYE. Pan-cancer investigation reveals mechanistic insights of planar cell polarity gene Fuz in carcinogenesis. Aging (Albany NY) 2021; 13:7259-7283. [PMID: 33658400 PMCID: PMC7993721 DOI: 10.18632/aging.202582] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 01/13/2021] [Indexed: 04/14/2023]
Abstract
The fuzzy planar cell polarity protein (Fuz) is an effector component of the planar cell polarity (PCP) signaling. Together with other core and effector proteins, the PCP pathway controls polarized cell movements. Fuz was also reported as a negative regulator of cell survival. In this study, we performed a pan-cancer survey to demonstrate the role of Fuz in multiple types of cancer. In head-neck squamous cell carcinoma and lung adenocarcinoma tumor samples, a reduction of Fuz transcript expression was detected. This coincides with the poor overall survival probabilities of these patients. We further showed that Fuz promoter hypermethylation contributes to its transcriptional downregulation. Meanwhile, we also identified a relatively higher mutation frequency at the 404th arginine amino acid residue in the coding sequence of Fuz locus, and further demonstrated that mutant Fuz proteins perturb the pro-apoptotic function of Fuz. In summary, our study unveiled an intriguing relationship between Fuz dysregulation and cancer prognosis, and further provides mechanistic insights of Fuz's involvement in carcinogenesis.
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Affiliation(s)
- Zhefan Stephen Chen
- Nexus of Rare Neurodegenerative Diseases, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Xiao Lin
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Ting-Fung Chan
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
- Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Ho Yin Edwin Chan
- Nexus of Rare Neurodegenerative Diseases, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
- Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
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22
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Abstract
Ciliogenesis describes the assembly of cilia in interphase cells. Several hundred proteins have been linked to ciliogenesis, which proceeds through a highly coordinated multistage process at the distal end of centrioles requiring membranes. In this short review, we focus on recently reported insights into the biogenesis of the primary cilium membrane and its association with other ciliogenic processes in the intracellular ciliogenesis pathway.
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Affiliation(s)
- Saurabh Shakya
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Laboratory of Cellular and Developmental Signaling, Frederick, MD 21702, USA
| | - Christopher J Westlake
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Laboratory of Cellular and Developmental Signaling, Frederick, MD 21702, USA
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23
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Strutt H, Strutt D. How do the Fat-Dachsous and core planar polarity pathways act together and independently to coordinate polarized cell behaviours? Open Biol 2021; 11:200356. [PMID: 33561385 PMCID: PMC8061702 DOI: 10.1098/rsob.200356] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Planar polarity describes the coordinated polarization of cells within the plane of a tissue. This is controlled by two main pathways in Drosophila: the Frizzled-dependent core planar polarity pathway and the Fat–Dachsous pathway. Components of both of these pathways become asymmetrically localized within cells in response to long-range upstream cues, and form intercellular complexes that link polarity between neighbouring cells. This review examines if and when the two pathways are coupled, focusing on the Drosophila wing, eye and abdomen. There is strong evidence that the pathways are molecularly coupled in tissues that express a specific isoform of the core protein Prickle, namely Spiny-legs. However, in other contexts, the linkages between the pathways are indirect. We discuss how the two pathways act together and independently to mediate a diverse range of effects on polarization of cell structures and behaviours.
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Affiliation(s)
- Helen Strutt
- Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - David Strutt
- Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
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24
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Labat-de-Hoz L, Rubio-Ramos A, Casares-Arias J, Bernabé-Rubio M, Correas I, Alonso MA. A Model for Primary Cilium Biogenesis by Polarized Epithelial Cells: Role of the Midbody Remnant and Associated Specialized Membranes. Front Cell Dev Biol 2021; 8:622918. [PMID: 33585461 PMCID: PMC7873843 DOI: 10.3389/fcell.2020.622918] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/09/2020] [Indexed: 12/14/2022] Open
Abstract
Primary cilia are solitary, microtubule-based protrusions surrounded by a ciliary membrane equipped with selected receptors that orchestrate important signaling pathways that control cell growth, differentiation, development and homeostasis. Depending on the cell type, primary cilium assembly takes place intracellularly or at the cell surface. The intracellular route has been the focus of research on primary cilium biogenesis, whereas the route that occurs at the cell surface, which we call the "alternative" route, has been much less thoroughly characterized. In this review, based on recent experimental evidence, we present a model of primary ciliogenesis by the alternative route in which the remnant of the midbody generated upon cytokinesis acquires compact membranes, that are involved in compartmentalization of biological membranes. The midbody remnant delivers part of those membranes to the centrosome in order to assemble the ciliary membrane, thereby licensing primary cilium formation. The midbody remnant's involvement in primary cilium formation, the regulation of its inheritance by the ESCRT machinery, and the assembly of the ciliary membrane from the membranes originally associated with the remnant are discussed in the context of the literature concerning the ciliary membrane, the emerging roles of the midbody remnant, the regulation of cytokinesis, and the role of membrane compartmentalization. We also present a model of cilium emergence during evolution, and summarize the directions for future research.
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Affiliation(s)
- Leticia Labat-de-Hoz
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Armando Rubio-Ramos
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Javier Casares-Arias
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel Bernabé-Rubio
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Isabel Correas
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
- Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel A. Alonso
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
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25
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Homma Y, Hiragi S, Fukuda M. Rab family of small GTPases: an updated view on their regulation and functions. FEBS J 2021; 288:36-55. [PMID: 32542850 PMCID: PMC7818423 DOI: 10.1111/febs.15453] [Citation(s) in RCA: 219] [Impact Index Per Article: 73.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/27/2020] [Accepted: 06/11/2020] [Indexed: 12/13/2022]
Abstract
The Rab family of small GTPases regulates intracellular membrane trafficking by orchestrating the biogenesis, transport, tethering, and fusion of membrane-bound organelles and vesicles. Like other small GTPases, Rabs cycle between two states, an active (GTP-loaded) state and an inactive (GDP-loaded) state, and their cycling is catalyzed by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Because an active form of each Rab localizes on a specific organelle (or vesicle) and recruits various effector proteins to facilitate each step of membrane trafficking, knowing when and where Rabs are activated and what effectors Rabs recruit is crucial to understand their functions. Since the discovery of Rabs, they have been regarded as one of the central hubs for membrane trafficking, and numerous biochemical and genetic studies have revealed the mechanisms of Rab functions in recent years. The results of these studies have included the identification and characterization of novel GEFs, GAPs, and effectors, as well as post-translational modifications, for example, phosphorylation, of Rabs. Rab functions beyond the simple effector-recruiting model are also emerging. Furthermore, the recently developed CRISPR/Cas technology has enabled acceleration of knockout analyses in both animals and cultured cells and revealed previously unknown physiological roles of many Rabs. In this review article, we provide the most up-to-date and comprehensive lists of GEFs, GAPs, effectors, and knockout phenotypes of mammalian Rabs and discuss recent findings in regard to their regulation and functions.
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Affiliation(s)
- Yuta Homma
- Laboratory of Membrane Trafficking MechanismsDepartment of Integrative Life SciencesGraduate School of Life SciencesTohoku UniversitySendaiJapan
| | - Shu Hiragi
- Laboratory of Membrane Trafficking MechanismsDepartment of Integrative Life SciencesGraduate School of Life SciencesTohoku UniversitySendaiJapan
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking MechanismsDepartment of Integrative Life SciencesGraduate School of Life SciencesTohoku UniversitySendaiJapan
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26
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Brücker L, Kretschmer V, May-Simera HL. The entangled relationship between cilia and actin. Int J Biochem Cell Biol 2020; 129:105877. [PMID: 33166678 DOI: 10.1016/j.biocel.2020.105877] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/23/2020] [Accepted: 10/26/2020] [Indexed: 12/14/2022]
Abstract
Primary cilia are microtubule-based sensory cell organelles that are vital for tissue and organ development. They act as an antenna, receiving and transducing signals, enabling communication between cells. Defects in ciliogenesis result in severe genetic disorders collectively termed ciliopathies. In recent years, the importance of the direct and indirect involvement of actin regulators in ciliogenesis came into focus as it was shown that F-actin polymerisation impacts ciliation. The ciliary basal body was further identified as both a microtubule and actin organising centre. In the current review, we summarize recent studies on F-actin in and around primary cilia, focusing on different actin regulators and their effect on ciliogenesis, from the initial steps of basal body positioning and regulation of ciliary assembly and disassembly. Since primary cilia are also involved in several intracellular signalling pathways such as planar cell polarity (PCP), subsequently affecting actin rearrangements, the multiple effectors of this pathway are highlighted in more detail with a focus on the feedback loops connecting actin networks and cilia proteins. Finally, we elucidate the role of actin regulators in the development of ciliopathy symptoms and cancer.
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Affiliation(s)
- Lena Brücker
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, Germany
| | - Viola Kretschmer
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, Germany
| | - Helen Louise May-Simera
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, Germany.
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27
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Oguchi ME, Okuyama K, Homma Y, Fukuda M. A comprehensive analysis of Rab GTPases reveals a role for Rab34 in serum starvation-induced primary ciliogenesis. J Biol Chem 2020; 295:12674-12685. [PMID: 32669361 DOI: 10.1074/jbc.ra119.012233] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 07/14/2020] [Indexed: 12/17/2022] Open
Abstract
Primary cilia are sensors of chemical and mechanical signals in the extracellular environment. The formation of primary cilia (i.e. ciliogenesis) requires dynamic membrane trafficking events, and several Rab small GTPases, key regulators of membrane trafficking, have recently been reported to participate in ciliogenesis. However, the precise mechanisms of Rab-mediated membrane trafficking during ciliogenesis remain largely unknown. In the present study, we used a collection of siRNAs against 62 human Rabs to perform a comprehensive knockdown screening for Rabs that regulate serum starvation-induced ciliogenesis in human telomerase reverse transcriptase retinal pigment epithelium 1 (hTERT-RPE1) cells and succeeded in identifying Rab34 as an essential Rab. Knockout (KO) of Rab34, but not of Rabs previously reported to regulate ciliogenesis (e.g. Rab8 and Rab10) in hTERT-RPE1 cells, drastically impaired serum starvation-induced ciliogenesis. Rab34 was also required for serum starvation-induced ciliogenesis in NIH/3T3 cells and MCF10A cells but not for ciliogenesis in Madin-Darby canine kidney (MDCK)-II cysts. We then attempted to identify a specific region(s) of Rab34 that is essential for ciliogenesis by performing deletion and mutation analyses of Rab34. Unexpectedly, instead of a specific sequence in the switch II region, which is generally important for recognizing effector proteins (e.g. Rab interacting lysosomal protein [RILP]), a unique long N-terminal region of Rab34 before the conserved GTPase domain was found to be essential. These findings suggest that Rab34 is an atypical Rab that regulates serum starvation-induced ciliogenesis through its unique N-terminal region.
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Affiliation(s)
- Mai E Oguchi
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi, Japan
| | - Koki Okuyama
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi, Japan
| | - Yuta Homma
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi, Japan
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi, Japan
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28
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Langemeyer L, Borchers AC, Herrmann E, Füllbrunn N, Han Y, Perz A, Auffarth K, Kümmel D, Ungermann C. A conserved and regulated mechanism drives endosomal Rab transition. eLife 2020; 9:56090. [PMID: 32391792 PMCID: PMC7239660 DOI: 10.7554/elife.56090] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/07/2020] [Indexed: 12/31/2022] Open
Abstract
Endosomes and lysosomes harbor Rab5 and Rab7 on their surface as key proteins involved in their identity, biogenesis, and fusion. Rab activation requires a guanine nucleotide exchange factor (GEF), which is Mon1-Ccz1 for Rab7. During endosome maturation, Rab5 is replaced by Rab7, though the underlying mechanism remains poorly understood. Here, we identify the molecular determinants for Rab conversion in vivo and in vitro, and reconstitute Rab7 activation with yeast and metazoan proteins. We show (i) that Mon1-Ccz1 is an effector of Rab5, (ii) that membrane-bound Rab5 is the key factor to directly promote Mon1-Ccz1 dependent Rab7 activation and Rab7-dependent membrane fusion, and (iii) that this process is regulated in yeast by the casein kinase Yck3, which phosphorylates Mon1 and blocks Rab5 binding. Our study thus uncovers the minimal feed-forward machinery of the endosomal Rab cascade and a novel regulatory mechanism controlling this pathway.
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Affiliation(s)
- Lars Langemeyer
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany
| | - Ann-Christin Borchers
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany
| | - Eric Herrmann
- University of Münster, Institute of Biochemistry, Münster, Germany
| | - Nadia Füllbrunn
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany
| | - Yaping Han
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany
| | - Angela Perz
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany
| | - Kathrin Auffarth
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany
| | - Daniel Kümmel
- University of Münster, Institute of Biochemistry, Münster, Germany
| | - Christian Ungermann
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany.,University of Osnabrück, Center of Cellular Nanoanalytics (CellNanOs), Osnabrück, Germany
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29
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Sanchez-Pulido L, Ponting CP. Hexa-Longin domain scaffolds for inter-Rab signalling. Bioinformatics 2020; 36:990-993. [PMID: 31562761 PMCID: PMC7703760 DOI: 10.1093/bioinformatics/btz739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 08/26/2019] [Accepted: 09/25/2019] [Indexed: 11/13/2022] Open
Abstract
Summary CPLANE is a protein complex required for assembly and maintenance of primary cilia. It contains several proteins, such as INTU, FUZ, WDPCP, JBTS17 and RSG1 (REM2- and RAB-like small GTPase 1), whose genes are mutated in ciliopathies. Using two contrasting evolutionary analyses, coevolution-based contact prediction and sequence conservation, we first identified the INTU/FUZ heterodimer as a novel member of homologous HerMon (Hermansky-Pudlak syndrome and MON1-CCZ1) complexes. Subsequently, we identified homologous Longin domains that are triplicated in each of these six proteins (MON1A, CCZ1, HPS1, HPS4, INTU and FUZ). HerMon complexes are known to be Rab effectors and Rab GEFs (Guanine nucleotide Exchange Factors) that regulate vesicular trafficking. Consequently, INTU/FUZ, their homologous complex, is likely to act as a GEF during activation of Rab GTPases involved in ciliogenesis. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Luis Sanchez-Pulido
- Medical Research Council Human Genetics Unit, IGMM, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Chris P Ponting
- Medical Research Council Human Genetics Unit, IGMM, University of Edinburgh, Edinburgh EH4 2XU, UK
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