1
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Fagan RR, Lee DF, Geron M, Scherrer G, von Zastrow M, Ehrlich AT. Selective targeting of mu opioid receptors to primary cilia. Cell Rep 2024; 43:114164. [PMID: 38678559 PMCID: PMC11257377 DOI: 10.1016/j.celrep.2024.114164] [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: 01/09/2023] [Revised: 03/21/2024] [Accepted: 04/11/2024] [Indexed: 05/01/2024] Open
Abstract
Opioid receptors are therapeutically important G protein-coupled receptors (GPCRs) with diverse neuromodulatory effects. The functional consequences of opioid receptor activation are known to depend on receptor location in the plasma membrane, but mechanisms mediating selective localization of receptors to any particular membrane domain remain elusive. Here, we demonstrate the targeting of the mu opioid receptor (MOR) to the primary cilium, a discrete microdomain of the somatic plasma membrane, both in vivo and in cultured cells. We further show that ciliary targeting is specific to MORs, requires a 17-residue sequence unique to the MOR cytoplasmic tail, and additionally requires the Tubby-like protein 3 (TULP3) ciliary adaptor protein. Our results reveal the potential for opioid receptors to undergo selective localization to the primary cilium. We propose that ciliary targeting is mediated through an elaboration of the recycling pathway, directed by a specific C-terminal recycling sequence in cis and requiring TULP3 in trans.
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Affiliation(s)
- Rita R Fagan
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - David F Lee
- Department of Cell Biology and Physiology, UNC Neuroscience Center, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Matan Geron
- Department of Cell Biology and Physiology, UNC Neuroscience Center, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Grégory Scherrer
- Department of Cell Biology and Physiology, UNC Neuroscience Center, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; New York Stem Cell Foundation, Chapel Hill, NC 27599, USA
| | - Mark von Zastrow
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Aliza T Ehrlich
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, San Francisco, CA 94158, USA.
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2
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Melluso A, Secondulfo F, Capolongo G, Capasso G, Zacchia M. Bardet-Biedl Syndrome: Current Perspectives and Clinical Outlook. Ther Clin Risk Manag 2023; 19:115-132. [PMID: 36741589 PMCID: PMC9896974 DOI: 10.2147/tcrm.s338653] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/20/2023] [Indexed: 02/04/2023] Open
Abstract
The Bardet Biedl syndrome (BBS) is a rare inherited disorder considered a model of non-motile ciliopathy. It is in fact caused by mutations of genes encoding for proteins mainly localized to the base of the cilium. Clinical features of BBS patients are widely shared with patients suffering from other ciliopathies, especially autosomal recessive syndromic disorders; moreover, mutations in cilia-related genes can cause different clinical ciliopathy entities. Besides the best-known clinical features, as retinal degeneration, learning disabilities, polydactyly, obesity and renal defects, several additional clinical signs have been reported in BBS, expanding our understanding of the complexity of its clinical spectrum. The present review aims to describe the current knowledge of BBS i) pathophysiology, ii) clinical manifestations, highlighting both the most common and the less described features, iii) current and future perspective for treatment.
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Affiliation(s)
- Andrea Melluso
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Floriana Secondulfo
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Giovanna Capolongo
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Giovambattista Capasso
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy,Biogem Scarl, Ariano Irpino, AV, 83031, Italy
| | - Miriam Zacchia
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy,Correspondence: Miriam Zacchia, Via Pansini 5, Naples, 80131, Italy, Tel +39 081 566 6650, Fax +39 081 566 6671, Email
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3
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Cilleros-Rodriguez D, Martin-Morales R, Barbeito P, Deb Roy A, Loukil A, Sierra-Rodero B, Herranz G, Pampliega O, Redrejo-Rodriguez M, Goetz SC, Izquierdo M, Inoue T, Garcia-Gonzalo FR. Multiple ciliary localization signals control INPP5E ciliary targeting. eLife 2022; 11:78383. [PMID: 36063381 PMCID: PMC9444247 DOI: 10.7554/elife.78383] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 08/21/2022] [Indexed: 12/04/2022] Open
Abstract
Primary cilia are sensory membrane protrusions whose dysfunction causes ciliopathies. INPP5E is a ciliary phosphoinositide phosphatase mutated in ciliopathies like Joubert syndrome. INPP5E regulates numerous ciliary functions, but how it accumulates in cilia remains poorly understood. Herein, we show INPP5E ciliary targeting requires its folded catalytic domain and is controlled by four conserved ciliary localization signals (CLSs): LLxPIR motif (CLS1), W383 (CLS2), FDRxLYL motif (CLS3) and CaaX box (CLS4). We answer two long-standing questions in the field. First, partial CLS1-CLS4 redundancy explains why CLS4 is dispensable for ciliary targeting. Second, the essential need for CLS2 clarifies why CLS3-CLS4 are together insufficient for ciliary accumulation. Furthermore, we reveal that some Joubert syndrome mutations perturb INPP5E ciliary targeting, and clarify how each CLS works: (i) CLS4 recruits PDE6D, RPGR and ARL13B, (ii) CLS2-CLS3 regulate association to TULP3, ARL13B, and CEP164, and (iii) CLS1 and CLS4 cooperate in ATG16L1 binding. Altogether, we shed light on the mechanisms of INPP5E ciliary targeting, revealing a complexity without known parallels among ciliary cargoes.
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Affiliation(s)
- Dario Cilleros-Rodriguez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Raquel Martin-Morales
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Pablo Barbeito
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Abhijit Deb Roy
- Department of Cell Biology, Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Abdelhalim Loukil
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, United States
| | - Belen Sierra-Rodero
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Gonzalo Herranz
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
| | - Olatz Pampliega
- Department of Neurosciences, University of the Basque Country, Achucarro Basque Center for Neuroscience-UPV/EHU, Leioa, Spain
| | - Modesto Redrejo-Rodriguez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
| | - Sarah C Goetz
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, United States
| | - Manuel Izquierdo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
| | - Takanari Inoue
- Department of Cell Biology, Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Francesc R Garcia-Gonzalo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas "Alberto Sols" (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
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4
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Inaba M, Ridwan SM, Antel M. Removal of cellular protrusions. Semin Cell Dev Biol 2022; 129:126-134. [PMID: 35260295 PMCID: PMC9378436 DOI: 10.1016/j.semcdb.2022.02.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/24/2022] [Accepted: 02/25/2022] [Indexed: 02/08/2023]
Abstract
Cell-cell communications are central to a variety of physiological and pathological processes in multicellular organisms. Cells often rely on cellular protrusions to communicate with one another, which enable highly selective and efficient signaling within complex tissues. Owing to significant improvements in imaging techniques, identification of signaling protrusions has increased in recent years. These protrusions are structurally specialized for signaling and facilitate interactions between cells. Therefore, physical regulation of these structures must be key for the appropriate strength and pattern of signaling outcomes. However, the typical approaches for understanding signaling regulation tend to focus solely on changes in signaling molecules, such as gene expression, protein-protein interaction, and degradation. In this short review, we summarize the studies proposing the removal of different types of signaling protrusions-including cilia, neurites, MT (microtubule based)-nanotubes and microvilli-and discuss their mechanisms and significance in signaling regulation.
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Affiliation(s)
- Mayu Inaba
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030, USA.
| | - Sharif M Ridwan
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Matthew Antel
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
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5
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Lindemann CB. The flagellar germ-line hypothesis: How flagellate and ciliate gametes significantly shaped the evolution of organismal complexity. Bioessays 2021; 44:e2100143. [PMID: 34967029 DOI: 10.1002/bies.202100143] [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: 06/08/2021] [Revised: 12/10/2021] [Accepted: 12/15/2021] [Indexed: 11/10/2022]
Abstract
This essay presents a hypothesis which contends that the development of organismic complexity in the eukaryotes depended extensively on propagation via flagellated and ciliated gametes. Organisms utilizing flagellate and ciliate gametes to propagate their germ line have contributed most of the organismic complexity found in the higher animals. The genes of the flagellum and the flagellar assembly system (intraflagellar transport) have played a disproportionately important role in the construction of complex tissues and organs. The hypothesis also proposes that competition between large numbers of haploid flagellated male gametes rigorously conserved the functionality of a key set of flagellar genes for more than 700 million years. This in turn has insured that a large set (>600) of highly functional cytoskeletal and signal pathway genes is always present in the lineage of organisms with flagellated or ciliated gametes to act as a dependable resource, or "toolkit," for organ elaboration.
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6
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Chandra B, Tung ML, Hsu Y, Scheetz T, Sheffield VC. Retinal ciliopathies through the lens of Bardet-Biedl Syndrome: Past, present and future. Prog Retin Eye Res 2021; 89:101035. [PMID: 34929400 DOI: 10.1016/j.preteyeres.2021.101035] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 12/15/2022]
Abstract
The primary cilium is a highly specialized and evolutionary conserved organelle in eukaryotes that plays a significant role in cell signaling and trafficking. Over the past few decades tremendous progress has been made in understanding the physiology of cilia and the underlying pathomechanisms of various ciliopathies. Syndromic ciliopathies consist of a group of disorders caused by ciliary dysfunction or abnormal ciliogenesis. These disorders have multiorgan involvement in addition to retinal degeneration underscoring the ubiquitous distribution of primary cilia in different cell types. Genotype-phenotype correlation is often challenging due to the allelic heterogeneity and pleiotropy of these disorders. In this review, we discuss the clinical and genetic features of syndromic ciliopathies with a focus on Bardet-Biedl syndrome (BBS) as a representative disorder. We discuss the structure and function of primary cilia and their role in retinal photoreceptors. We describe the progress made thus far in understanding the functional and genetic characterization including expression quantitative trait locus (eQTL) analysis of BBS genes. In the future directions section, we discuss the emerging technologies, such as gene therapy, as well as anticipated challenges and their implications in therapeutic development for ciliopathies.
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Affiliation(s)
- Bharatendu Chandra
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Moon Ley Tung
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ying Hsu
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA
| | - Todd Scheetz
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA
| | - Val C Sheffield
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA.
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7
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Baldi P, Alhassen W, Chen S, Nguyen H, Khoudari M, Alachkar A. Large-scale analysis reveals spatiotemporal circadian patterns of cilia transcriptomes in the primate brain. J Neurosci Res 2021; 99:2610-2624. [PMID: 34310750 DOI: 10.1002/jnr.24919] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/08/2021] [Accepted: 06/24/2021] [Indexed: 01/13/2023]
Abstract
Cilia are dynamic subcellular systems, with core structural and functional components operating in a highly coordinated manner. Since many environmental stimuli sensed by cilia are circadian in nature, it is reasonable to speculate that genes encoding cilia structural and functional components follow rhythmic circadian patterns of expression. Using computational methods and the largest spatiotemporal gene expression atlas of primates, we identified and analyzed the circadian rhythmic expression of cilia genes across 22 primate brain areas. We found that around 73% of cilia transcripts exhibited circadian rhythmicity across at least one of 22 brain regions. In 12 brain regions, cilia transcriptomes were significantly enriched with circadian oscillating transcripts, as compared to the rest of the transcriptome. The phase of the cilia circadian transcripts deviated from the phase of the majority of the background circadian transcripts, and transcripts coding for cilia basal body components accounted for the majority of cilia circadian transcripts. In addition, adjacent or functionally connected brain nuclei had large overlapping complements of circadian cilia genes. Most remarkably, cilia circadian transcripts shared across the basal ganglia nuclei and the prefrontal cortex peaked in these structures in sequential fashion that is similar to the sequential order of activation of the basal ganglia-cortical circuitry in connection with movement coordination, albeit on completely different timescales. These findings support a role for the circadian spatiotemporal orchestration of cilia gene expression in the normal physiology of the basal ganglia-cortical circuit and motor control. Studying orchestrated cilia rhythmicity in the basal ganglia-cortical circuits and other brain circuits may help develop better functional models, and shed light on the causal effects cilia functions have on these circuits and on the regulation of movement and other behaviors.
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Affiliation(s)
- Pierre Baldi
- Department of Computer Science, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA, USA.,Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA, USA
| | - Wedad Alhassen
- Department of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, Irvine, CA, USA
| | - Siwei Chen
- Department of Computer Science, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA, USA.,Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA, USA
| | - Henry Nguyen
- Department of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, Irvine, CA, USA
| | - Mohammad Khoudari
- Department of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, Irvine, CA, USA
| | - Amal Alachkar
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA, USA.,Department of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, Irvine, CA, USA
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8
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Jasso KR, Kamba TK, Zimmerman AD, Bansal R, Engle SE, Everett T, Wu CH, Kulaga H, Reed RR, Berbari NF, McIntyre JC. An N-terminal fusion allele to study melanin concentrating hormone receptor 1. Genesis 2021; 59:e23438. [PMID: 34124835 DOI: 10.1002/dvg.23438] [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: 04/28/2021] [Revised: 06/01/2021] [Accepted: 06/03/2021] [Indexed: 11/10/2022]
Abstract
Cilia on neurons play critical roles in both the development and function of the central nervous system (CNS). While it remains challenging to elucidate the precise roles for neuronal cilia, it is clear that a subset of G-protein-coupled receptors (GPCRs) preferentially localize to the cilia membrane. Further, ciliary GPCR signaling has been implicated in regulating a variety of behaviors. Melanin concentrating hormone receptor 1 (MCHR1), is a GPCR expressed centrally in rodents known to be enriched in cilia. Here we have used MCHR1 as a model ciliary GPCR to develop a strategy to fluorescently tag receptors expressed from the endogenous locus in vivo. Using CRISPR/Cas9, we inserted the coding sequence of the fluorescent protein mCherry into the N-terminus of Mchr1. Analysis of the fusion protein (mCherry MCHR1) revealed its localization to neuronal cilia in the CNS, across multiple developmental time points and in various regions of the adult brain. Our approach simultaneously produced fortuitous in/dels altering the Mchr1 start codon resulting in a new MCHR1 knockout line. Functional studies using electrophysiology show a significant alteration of synaptic strength in MCHR1 knockout mice. A reduction in strength is also detected in mice homozygous for the mCherry insertion, suggesting that while the strategy is useful for monitoring the receptor, activity could be altered. However, both lines should aid in studies of MCHR1 function and contribute to our understanding of MCHR1 signaling in the brain. Additionally, this approach could be expanded to aid in the study of other ciliary GPCRs.
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Affiliation(s)
- Kalene R Jasso
- Department of Neuroscience and Center for Smell and Taste, University of Florida, Gainesville, Florida, USA.,Graduate Program in Biomedical Sciences, Neuroscience Concentration, University of Florida, Gainesville, Florida, USA
| | - Tisianna K Kamba
- Graduate Program in Biomedical Sciences, Neuroscience Concentration, University of Florida, Gainesville, Florida, USA
| | - Arthur D Zimmerman
- Department of Neuroscience and Center for Smell and Taste, University of Florida, Gainesville, Florida, USA
| | - Ruchi Bansal
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA
| | - Staci E Engle
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA
| | - Thomas Everett
- Department of Neuroscience and Center for Smell and Taste, University of Florida, Gainesville, Florida, USA
| | - Chang-Hung Wu
- Department of Neuroscience and Center for Smell and Taste, University of Florida, Gainesville, Florida, USA
| | - Heather Kulaga
- Department of Molecular Genetics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Randal R Reed
- Department of Molecular Genetics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Nicolas F Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA
| | - Jeremy C McIntyre
- Department of Neuroscience and Center for Smell and Taste, University of Florida, Gainesville, Florida, USA
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9
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Corey EA, Zolotukhin S, Ache BW, Ukhanov K. Mixture interactions at mammalian olfactory receptors are dependent on the cellular environment. Sci Rep 2021; 11:9278. [PMID: 33927269 PMCID: PMC8085013 DOI: 10.1038/s41598-021-88601-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/07/2021] [Indexed: 02/02/2023] Open
Abstract
Functional characterization of mammalian olfactory receptors (ORs) remains a major challenge to ultimately understanding the olfactory code. Here, we compare the responses of the mouse Olfr73 ectopically expressed in olfactory sensory neurons using AAV gene delivery in vivo and expressed in vitro in cell culture. The response dynamics and concentration-dependence of agonists for the ectopically expressed Olfr73 were similar to those reported for the endogenous Olfr73, however the antagonism previously reported between its cognate agonist and several antagonists was not replicated in vivo. Expressing the OR in vitro reproduced the antagonism reported for short odor pulses, but not for prolonged odor exposure. Our findings suggest that both the cellular environment and the stimulus dynamics shape the functionality of Olfr73 and argue that characterizing ORs in 'native' conditions, rather than in vitro, provides a more relevant understanding of ligand-OR interactions.
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Affiliation(s)
- Elizabeth A Corey
- Whitney Laboratory, University of Florida, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA
| | - Sergei Zolotukhin
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA
| | - Barry W Ache
- Whitney Laboratory, University of Florida, Gainesville, FL, USA
- Department of Biology and Neuroscience, University of Florida, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Kirill Ukhanov
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA.
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA.
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10
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HTR6 and SSTR3 targeting to primary cilia. Biochem Soc Trans 2021; 49:79-91. [PMID: 33599752 DOI: 10.1042/bst20191005] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 12/25/2020] [Accepted: 01/20/2021] [Indexed: 12/30/2022]
Abstract
Primary cilia are hair-like projections of the cell membrane supported by an inner microtubule scaffold, the axoneme, which polymerizes out of a membrane-docked centriole at the ciliary base. By working as specialized signaling compartments, primary cilia provide an optimal environment for many G protein-coupled receptors (GPCRs) and their effectors to efficiently transmit their signals to the rest of the cell. For this to occur, however, all necessary receptors and signal transducers must first accumulate at the ciliary membrane. Serotonin receptor 6 (HTR6) and Somatostatin receptor 3 (SSTR3) are two GPCRs whose signaling in brain neuronal cilia affects cognition and is implicated in psychiatric, neurodegenerative, and oncologic diseases. Over a decade ago, the third intracellular loops (IC3s) of HTR6 and SSTR3 were shown to contain ciliary localization sequences (CLSs) that, when grafted onto non-ciliary GPCRs, could drive their ciliary accumulation. Nevertheless, these CLSs were dispensable for ciliary targeting of HTR6 and SSTR3, suggesting the presence of additional CLSs, which we have recently identified in their C-terminal tails. Herein, we review the discovery and mapping of these CLSs, as well as the state of the art regarding how these CLSs may orchestrate ciliary accumulation of these GPCRs by controlling when and where they interact with the ciliary entry and exit machinery via adaptors such as TULP3, RABL2 and the BBSome.
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11
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Barbeito P, Tachibana Y, Martin-Morales R, Moreno P, Mykytyn K, Kobayashi T, Garcia-Gonzalo FR. HTR6 and SSTR3 ciliary targeting relies on both IC3 loops and C-terminal tails. Life Sci Alliance 2020; 4:4/3/e202000746. [PMID: 33372037 PMCID: PMC7772773 DOI: 10.26508/lsa.202000746] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 12/11/2022] Open
Abstract
Ciliary accumulation of G protein–coupled receptors HTR6 and SSTR3 depends on redundant ciliary targeting sequences acting via ciliary trafficking adapters TULP3 and RABL2. G protein-coupled receptors (GPCRs) are the most common pharmacological target in human clinical practice. To perform their functions, many GPCRs must accumulate inside primary cilia, microtubule-based plasma membrane protrusions working as cellular antennae. Nevertheless, the molecular mechanisms underlying GPCR ciliary targeting remain poorly understood. Serotonin receptor 6 (HTR6) and somatostatin receptor 3 (SSTR3) are two brain-enriched ciliary GPCRs involved in cognition and pathologies such as Alzheimer’s disease and cancer. Although the third intracellular loops (IC3) of HTR6 and SSTR3 suffice to target non-ciliary GPCRs to cilia, these IC3s are dispensable for ciliary targeting of HTR6 and SSTR3 themselves, suggesting these GPCRs contain additional ciliary targeting sequences (CTSs). Herein, we discover and characterize novel CTSs in HTR6 and SSTR3 C-terminal tails (CT). These CT-CTSs (CTS2) act redundantly with IC3-CTSs (CTS1), each being sufficient for ciliary targeting. In HTR6, RKQ and LPG motifs are critical for CTS1 and CTS2 function, respectively, whereas in SSTR3 these roles are mostly fulfilled by AP[AS]CQ motifs in IC3 and juxtamembrane residues in CT. Furthermore, we shed light on how these CTSs promote ciliary targeting by modulating binding to ciliary trafficking adapters TULP3 and RABL2.
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Affiliation(s)
- Pablo Barbeito
- Department of Biochemistry, School of Medicine, Autonomous University of Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain
| | - Yuki Tachibana
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
| | - Raquel Martin-Morales
- Department of Biochemistry, School of Medicine, Autonomous University of Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain
| | - Paula Moreno
- Department of Biochemistry, School of Medicine, Autonomous University of Madrid (UAM), Madrid, Spain.,Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
| | - Kirk Mykytyn
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA.,Neuroscience Research Institute, The Ohio State University, Columbus, OH, USA
| | - Tetsuo Kobayashi
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
| | - Francesc R Garcia-Gonzalo
- Department of Biochemistry, School of Medicine, Autonomous University of Madrid (UAM), Madrid, Spain .,Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain.,Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain
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12
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Ramos C, Roberts JB, Jasso KR, Ten Eyck TW, Everett T, Pozo P, Setlow B, McIntyre JC. Neuron-specific cilia loss differentially alters locomotor responses to amphetamine in mice. J Neurosci Res 2020; 99:827-842. [PMID: 33175436 DOI: 10.1002/jnr.24755] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 10/07/2020] [Accepted: 10/25/2020] [Indexed: 12/20/2022]
Abstract
The neural mechanisms that underlie responses to drugs of abuse are complex, and impacted by a number of neuromodulatory peptides. Within the past 10 years it has been discovered that several of the receptors for neuromodulators are enriched in the primary cilia of neurons. Primary cilia are microtubule-based organelles that project from the surface of nearly all mammalian cells, including neurons. Despite what we know about cilia, our understanding of how cilia regulate neuronal function and behavior is still limited. The primary objective of this study was to investigate the contributions of primary cilia on specific neuronal populations to behavioral responses to amphetamine. To test the consequences of cilia loss on amphetamine-induced locomotor activity we selectively ablated cilia from dopaminergic or GAD2-GABAergic neurons in mice. Cilia loss had no effect on baseline locomotion in either mouse strain. In mice lacking cilia on dopaminergic neurons, locomotor activity compared to wild- type mice was reduced in both sexes in response to acute administration of 3.0 mg/kg amphetamine. In contrast, changes in the locomotor response to amphetamine in mice lacking cilia on GAD2-GABAergic neurons were primarily driven by reductions in locomotor activity in males. Following repeated amphetamine administration (1.0 mg kg-1 day-1 over 5 days), mice lacking cilia on GAD2-GABAergic neurons exhibited enhanced sensitization of the locomotor stimulant response to the drug, whereas mice lacking cilia on dopaminergic neurons did not differ from wild-type controls. These results indicate that cilia play neuron-specific roles in both acute and neuroplastic responses to psychostimulant drugs of abuse.
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Affiliation(s)
- Carlos Ramos
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Jonté B Roberts
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Kalene R Jasso
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Tyler W Ten Eyck
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Thomas Everett
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Patricia Pozo
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Barry Setlow
- Department of Psychiatry, University of Florida, Gainesville, FL, USA.,Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Jeremy C McIntyre
- Department of Neuroscience, University of Florida, Gainesville, FL, USA.,Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
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13
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Prasai A, Schmidt Cernohorska M, Ruppova K, Niederlova V, Andelova M, Draber P, Stepanek O, Huranova M. The BBSome assembly is spatially controlled by BBS1 and BBS4 in human cells. J Biol Chem 2020; 295:14279-14290. [PMID: 32759308 DOI: 10.1074/jbc.ra120.013905] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/04/2020] [Indexed: 12/18/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is a pleiotropic ciliopathy caused by dysfunction of primary cilia. More than half of BBS patients carry mutations in one of eight genes encoding for subunits of a protein complex, the BBSome, which mediates trafficking of ciliary cargoes. In this study, we elucidated the mechanisms of the BBSome assembly in living cells and how this process is spatially regulated. We generated a large library of human cell lines deficient in a particular BBSome subunit and expressing another subunit tagged with a fluorescent protein. We analyzed these cell lines utilizing biochemical assays, conventional and expansion microscopy, and quantitative fluorescence microscopy techniques: fluorescence recovery after photobleaching and fluorescence correlation spectroscopy. Our data revealed that the BBSome formation is a sequential process. We show that the pre-BBSome is nucleated by BBS4 and assembled at pericentriolar satellites, followed by the translocation of the BBSome into the ciliary base mediated by BBS1. Our results provide a framework for elucidating how BBS-causative mutations interfere with the biogenesis of the BBSome.
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Affiliation(s)
- Avishek Prasai
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Marketa Schmidt Cernohorska
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Klara Ruppova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Veronika Niederlova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Monika Andelova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Peter Draber
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ondrej Stepanek
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martina Huranova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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14
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Martín‐Guerrero E, Tirado‐Cabrera I, Buendía I, Alonso V, Gortázar AR, Ardura JA. Primary cilia mediate parathyroid hormone receptor type 1 osteogenic actions in osteocytes and osteoblasts via Gli activation. J Cell Physiol 2020; 235:7356-7369. [DOI: 10.1002/jcp.29636] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 01/30/2020] [Indexed: 01/04/2023]
Affiliation(s)
- Eduardo Martín‐Guerrero
- Department of Basic Medical Sciences, Bone Physiopathology LaboratoryUniversidad San Pablo‐CEUAlcorcón Madrid Spain
| | - Irene Tirado‐Cabrera
- Department of Basic Medical Sciences, Bone Physiopathology LaboratoryUniversidad San Pablo‐CEUAlcorcón Madrid Spain
| | - Irene Buendía
- Department of Basic Medical Sciences, Bone Physiopathology LaboratoryUniversidad San Pablo‐CEUAlcorcón Madrid Spain
| | - Verónica Alonso
- Department of Basic Medical Sciences, Bone Physiopathology LaboratoryUniversidad San Pablo‐CEUAlcorcón Madrid Spain
- Departamento de Ciencias Médicas Básicas, Facultad de MedicinaUniversidad San Pablo‐CEU, CEU Universities, Campus MonteprincipeAlcorcón Madrid Spain
| | - Arancha R. Gortázar
- Department of Basic Medical Sciences, Bone Physiopathology LaboratoryUniversidad San Pablo‐CEUAlcorcón Madrid Spain
- Departamento de Ciencias Médicas Básicas, Facultad de MedicinaUniversidad San Pablo‐CEU, CEU Universities, Campus MonteprincipeAlcorcón Madrid Spain
| | - Juan A. Ardura
- Department of Basic Medical Sciences, Bone Physiopathology LaboratoryUniversidad San Pablo‐CEUAlcorcón Madrid Spain
- Departamento de Ciencias Médicas Básicas, Facultad de MedicinaUniversidad San Pablo‐CEU, CEU Universities, Campus MonteprincipeAlcorcón Madrid Spain
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15
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Niederlova V, Modrak M, Tsyklauri O, Huranova M, Stepanek O. Meta-analysis of genotype-phenotype associations in Bardet-Biedl syndrome uncovers differences among causative genes. Hum Mutat 2019; 40:2068-2087. [PMID: 31283077 DOI: 10.1002/humu.23862] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 06/17/2019] [Accepted: 07/03/2019] [Indexed: 12/16/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a recessive genetic disease causing multiple organ anomalies. Most patients carry mutations in genes encoding for the subunits of the BBSome, an octameric ciliary transport complex, or accessory proteins involved in the BBSome assembly or function. BBS proteins have been extensively studied using in vitro, cellular, and animal models. However, the molecular functions of particular BBS proteins and the etiology of the BBS symptoms are still largely elusive. In this study, we applied a meta-analysis approach to study the genotype-phenotype association in humans using our database of all reported BBS patients. The analysis revealed that the identity of the causative gene and the character of the mutation partially predict the clinical outcome of the disease. Besides their potential use for clinical prognosis, our analysis revealed functional differences of particular BBS genes in humans. Core BBSome subunits BBS2, BBS7, and BBS9 manifest as more critical for the function and development of kidneys than peripheral subunits BBS1, BBS4, and BBS8/TTC8, suggesting that incomplete BBSome retains residual function at least in the kidney.
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Affiliation(s)
- Veronika Niederlova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Modrak
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Oksana Tsyklauri
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martina Huranova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ondrej Stepanek
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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16
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Glauser DL, Milho R, Lawler C, Stevenson PG. Antibody arrests γ-herpesvirus olfactory super-infection independently of neutralization. J Gen Virol 2018; 100:246-258. [PMID: 30526737 DOI: 10.1099/jgv.0.001183] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Protecting against persistent viruses is an unsolved challenge. The clearest example for a gamma-herpesvirus is resistance to super-infection by Murid herpesvirus-4 (MuHV-4). Most experimental infections have delivered MuHV-4 into the lungs. A more likely natural entry site is the olfactory epithelium. Its protection remains unexplored. Here, prior exposure to olfactory MuHV-4 gave good protection against super-infection. The protection was upstream of B cell infection, which occurs in lymph nodes, and showed redundancy between antibody and T cells. Adding antibody to virions that blocked heparan binding strongly reduced olfactory host entry - unlike in the lungs, opsonized virions did not reach IgG Fc receptor+ myeloid cells. However, the nasal antibody response to primary infection was too low to reduce host entry. Instead, the antibody acted downstream, reducing viral replication in the olfactory epithelium. This depended on IgG Fc receptor engagement rather than virion neutralization. Thus antibody can protect against natural γ-herpesvirus infection before it reaches B cells and independently of neutralization.
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Affiliation(s)
- Daniel L Glauser
- 1Division of Virology, University of Cambridge, UK
- ‡Present address: Suisselab AG, Bern, Switzerland
| | - Ricardo Milho
- 1Division of Virology, University of Cambridge, UK
- §Present address: Costello Medical, Cambridge, UK
| | - Clara Lawler
- 2School of Chemistry and Molecular Biosciences, University of Queensland, Australia
| | - Philip G Stevenson
- 3Royal Children's Hospital, Brisbane, Australia
- 1Division of Virology, University of Cambridge, UK
- 2School of Chemistry and Molecular Biosciences, University of Queensland, Australia
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17
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Ciliary parathyroid hormone signaling activates transforming growth factor-β to maintain intervertebral disc homeostasis during aging. Bone Res 2018; 6:21. [PMID: 30038820 PMCID: PMC6050246 DOI: 10.1038/s41413-018-0022-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 05/25/2018] [Indexed: 02/05/2023] Open
Abstract
Degenerative disc disease (DDD) is associated with intervertebral disc degeneration of spinal instability. Here, we report that the cilia of nucleus pulposus (NP) cells mediate mechanotransduction to maintain anabolic activity in the discs. We found that mechanical stress promotes transport of parathyroid hormone 1 receptor (PTH1R) to the cilia and enhances parathyroid hormone (PTH) signaling in NP cells. PTH induces transcription of integrin αvβ6 to activate the transforming growth factor (TGF)-β-connective tissue growth factor (CCN2)-matrix proteins signaling cascade. Intermittent injection of PTH (iPTH) effectively attenuates disc degeneration of aged mice by direct signaling through NP cells, specifically improving intervertebral disc height and volume by increasing levels of TGF-β activity, CCN2, and aggrecan. PTH1R is expressed in both mouse and human NP cells. Importantly, knockout PTH1R or cilia in the NP cells results in significant disc degeneration and blunts the effect of PTH on attenuation of aged discs. Thus, mechanical stress-induced transport of PTH1R to the cilia enhances PTH signaling, which helps maintain intervertebral disc homeostasis, particularly during aging, indicating therapeutic potential of iPTH for DDD. Sensory structures found in the jelly-like space between spinal discs release a hormone that helps preserve back health in aging mice. Xu Cao from Johns Hopkins University in Baltimore, Maryland, USA, and colleagues observed that levels of a critical growth factor declined in the space between adjacent vertebrae as mice aged, and that injecting a naturally occurring hormone that activates this growth factor could attenuate disc degeneration in older animals. The researchers showed, in response to mechanical stresses, receptor proteins that respond to this hormone relocate themselves to particular sensory organelles known as cilia that found within cells of the intervertebral core. That results in elevated hormone signaling—and drugs designed to have the same effect could help treat degenerative disc disease, one of the most common causes of chronic back pain.
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18
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Garcia G, Raleigh DR, Reiter JF. How the Ciliary Membrane Is Organized Inside-Out to Communicate Outside-In. Curr Biol 2018; 28:R421-R434. [PMID: 29689227 PMCID: PMC6434934 DOI: 10.1016/j.cub.2018.03.010] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cilia, organelles that move to execute functions like fertilization and signal to execute functions like photoreception and embryonic patterning, are composed of a core of nine-fold doublet microtubules overlain by a membrane. Distinct types of cilia display distinct membrane morphologies, ranging from simple domed cylinders to the highly ornate invaginations and membrane disks of photoreceptor outer segments. Critical for the ability of cilia to signal, both the protein and the lipid compositions of ciliary membranes are different from those of other cellular membranes. This specialization presents a unique challenge for the cell as, unlike membrane-bounded organelles, the ciliary membrane is contiguous with the surrounding plasma membrane. This distinct ciliary membrane is generated in concert with multiple membrane remodeling events that comprise the process of ciliogenesis. Once the cilium is formed, control of ciliary membrane composition relies on discrete molecular machines, including a barrier to membrane proteins entering the cilium at a specialized region of the base of the cilium called the transition zone and a trafficking adaptor that controls G protein-coupled receptor (GPCR) localization to the cilium called the BBSome. The ciliary membrane can be further remodeled by the removal of membrane proteins by the release of ciliary extracellular vesicles that may function in intercellular communication, removal of unneeded proteins or ciliary disassembly. Here, we review the structures and transport mechanisms that control ciliary membrane composition, and discuss how membrane specialization enables the cilium to function as the antenna of the cell.
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Affiliation(s)
- Galo Garcia
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
| | - David R Raleigh
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA; Department of Radiation Oncology, University of California, San Francisco, CA 94143, USA; Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA.
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19
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Scheidel N, Kennedy J, Blacque OE. Endosome maturation factors Rabenosyn-5/VPS45 and caveolin-1 regulate ciliary membrane and polycystin-2 homeostasis. EMBO J 2018; 37:embj.201798248. [PMID: 29572244 DOI: 10.15252/embj.201798248] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 02/08/2018] [Accepted: 02/16/2018] [Indexed: 12/24/2022] Open
Abstract
Primary cilium structure and function relies on control of ciliary membrane homeostasis, regulated by membrane trafficking processes that deliver and retrieve ciliary components at the periciliary membrane. However, the molecular mechanisms controlling ciliary membrane establishment and maintenance, especially in relation to endocytosis, remain poorly understood. Here, using Caenorhabditis elegans, we describe closely linked functions for early endosome (EE) maturation factors RABS-5 (Rabenosyn-5) and VPS-45 (VPS45) in regulating cilium length and morphology, ciliary and periciliary membrane volume, and ciliary signalling-related sensory behaviour. We demonstrate that RABS-5 and VPS-45 control periciliary vesicle number and levels of select EE/endocytic markers (WDFY-2, CAV-1) and the ciliopathy membrane receptor PKD-2 (polycystin-2). Moreover, we show that CAV-1 (caveolin-1) also controls PKD-2 ciliary levels and associated sensory behaviour. These data link RABS-5 and VPS-45 ciliary functions to the processing of periciliary-derived endocytic vesicles and regulation of ciliary membrane homeostasis. Our findings also provide insight into the regulation of PKD-2 ciliary levels via integrated endosomal sorting and CAV-1-mediated endocytosis.
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Affiliation(s)
- Noémie Scheidel
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Julie Kennedy
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Oliver E Blacque
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
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20
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Dateyama I, Sugihara Y, Chiba S, Ota R, Nakagawa R, Kobayashi T, Itoh H. RABL2 positively controls localization of GPCRs in mammalian primary cilia. J Cell Sci 2018; 132:jcs.224428. [DOI: 10.1242/jcs.224428] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 12/17/2018] [Indexed: 12/19/2022] Open
Abstract
Primary cilium, a solitary protrusion from most mammalian cells, functions as a cell's sensor by receiving extra-cellular signals through receptors and channels accumulated in the organelle. Certain G-protein coupled receptors (GPCRs) specifically localize to membrane compartment of the primary cilia. To gain insight into the mechanisms that regulate ciliary GPCR sorting, we investigated an atypical small GTPase RAB-like 2 (RABL2). RABL2 recruitment to the mother centriole is dependent on distal appendage proteins, CEP164 and CEP83. We found that silencing of RABL2 causes mis-targeting of ciliary GPCRs, GPR161 and HTR6, whereas overexpression of RABL2 resulted in accumulation of these receptors in the organelle. Ablation of CEP19 and IFT-B, which interact with RABL2, also lead to mis-localization of GPR161. RABL2 controls localization of GPR161 independently of TULP3, which promotes entry of ciliary GPCRs. We further demonstrated that RABL2 physically associates with ciliary GPCRs. Altogether, these studies suggest that RABL2 plays an important role in trafficking of ciliary GPCRs at the ciliary base in mammalian cells.
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Affiliation(s)
- Izumi Dateyama
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Yoshihiro Sugihara
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Shuhei Chiba
- Department of Genetic Disease Research, Osaka City University Graduate School of Medicine, Asahi-machi 1-4-3 Abeno, Osaka, 545-8585, Japan
| | - Reo Ota
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Risa Nakagawa
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Tetsuo Kobayashi
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Hiroshi Itoh
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
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21
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Geithe C, Protze J, Kreuchwig F, Krause G, Krautwurst D. Structural determinants of a conserved enantiomer-selective carvone binding pocket in the human odorant receptor OR1A1. Cell Mol Life Sci 2017; 74:4209-4229. [PMID: 28656349 PMCID: PMC11107518 DOI: 10.1007/s00018-017-2576-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 05/29/2017] [Accepted: 06/16/2017] [Indexed: 12/17/2022]
Abstract
Chirality is a common phenomenon within odorants. Most pairs of enantiomers show only moderate differences in odor quality. One example for enantiomers that are easily discriminated by their odor quality is the carvones: humans significantly distinguish between the spearmint-like (R)-(-)-carvone and caraway-like (S)-(+)-carvone enantiomers. Moreover, for the (R)-(-)-carvone, an anosmia is observed in about 8% of the population, suggesting enantioselective odorant receptors (ORs). With only about 15% de-orphaned human ORs, the lack of OR crystal structures, and few comprehensive studies combining in silico and experimental approaches to elucidate structure-function relations of ORs, knowledge on cognate odorant/OR interactions is still sparse. An adjusted homology modeling approach considering OR-specific proline-caused conformations, odorant docking studies, single-nucleotide polymorphism (SNP) analysis, site-directed mutagenesis, and subsequent functional studies with recombinant ORs in a cell-based, real-time luminescence assay revealed 11 amino acid positions to constitute an enantioselective binding pocket necessary for a carvone function in human OR1A1 and murine Olfr43, respectively. Here, we identified enantioselective molecular determinants in both ORs that discriminate between minty and caraway odor. Comparison with orthologs from 36 mammalian species demonstrated a hominid-specific carvone binding pocket with about 100% conservation. Moreover, we identified loss-of-function SNPs associated with the carvone binding pocket of OR1A1. Given carvone enantiomer-specific receptor activation patterns including OR1A1, our data suggest OR1A1 as a candidate receptor for constituting a carvone enantioselective phenotype, which may help to explain mechanisms underlying a (R)-(-)-carvone-specific anosmia in humans.
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Affiliation(s)
- Christiane Geithe
- Deutsche Forschungsanstalt für Lebensmittelchemie Leibniz Institut (DFA), Freising, Germany
| | - Jonas Protze
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Franziska Kreuchwig
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany
| | - Gerd Krause
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany.
| | - Dietmar Krautwurst
- Deutsche Forschungsanstalt für Lebensmittelchemie Leibniz Institut (DFA), Freising, Germany.
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22
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Hedgehog signaling regulates ciliary localization of mouse odorant receptors. Proc Natl Acad Sci U S A 2017; 114:E9386-E9394. [PMID: 29078327 DOI: 10.1073/pnas.1708321114] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The ciliary localization of odorant receptors (ORs) is evolutionary conserved and essential for olfactory transduction. However, how the transport of ORs is regulated in mammalian olfactory sensory neurons is poorly understood. Here we demonstrate that odorant responsiveness and OR transport is regulated by the Hedgehog pathway. OR transport is inhibited by conditional gene inactivation of the Hedgehog signal mediator Smoothened (Smo) as well as by systemic administration of the Smo inhibitor vismodegib, a clinically used anticancer drug reported to distort smell perception in patients. The ciliary phenotype of Smo inhibition is haploinsufficient, cell autonomous, and correlates with the accumulation of OR-containing putative transport vesicles in the cytosol. The Smo-dependent OR transport route works in parallel with a low basal transport of vesicle containing both ORs and other olfactory transduction components. These findings both define a physiological function of Hedgehog signaling in olfaction and provide an important evolutionary link between olfaction and the requirement of a ciliary compartment for Hedgehog signaling.
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23
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Nager AR, Goldstein JS, Herranz-Pérez V, Portran D, Ye F, Garcia-Verdugo JM, Nachury MV. An Actin Network Dispatches Ciliary GPCRs into Extracellular Vesicles to Modulate Signaling. Cell 2016; 168:252-263.e14. [PMID: 28017328 DOI: 10.1016/j.cell.2016.11.036] [Citation(s) in RCA: 242] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 09/14/2016] [Accepted: 11/17/2016] [Indexed: 12/13/2022]
Abstract
Signaling receptors dynamically exit cilia upon activation of signaling pathways such as Hedgehog. Here, we find that when activated G protein-coupled receptors (GPCRs) fail to undergo BBSome-mediated retrieval from cilia back into the cell, these GPCRs concentrate into membranous buds at the tips of cilia before release into extracellular vesicles named ectosomes. Unexpectedly, actin and the actin regulators drebrin and myosin 6 mediate ectosome release from the tip of cilia. Mirroring signal-dependent retrieval, signal-dependent ectocytosis is a selective and effective process that removes activated signaling molecules from cilia. Congruently, ectocytosis compensates for BBSome defects as ectocytic removal of GPR161, a negative regulator of Hedgehog signaling, permits the appropriate transduction of Hedgehog signals in Bbs mutants. Finally, ciliary receptors that lack retrieval determinants such as the anorexigenic GPCR NPY2R undergo signal-dependent ectocytosis in wild-type cells. Our data show that signal-dependent ectocytosis regulates ciliary signaling in physiological and pathological contexts.
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Affiliation(s)
- Andrew R Nager
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA
| | - Jaclyn S Goldstein
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA
| | - Vicente Herranz-Pérez
- Laboratorio de Neurobiología Comparada, Instituto Cavanilles, Universitat de València, CIBERNED, 46980 Valencia, Spain; Unidad Mixta de Esclerosis Múltiple y Neurorregeneración, IIS Hospital La Fe-UVEG, 46026 Valencia, Spain
| | - Didier Portran
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA
| | - Fan Ye
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA
| | - Jose Manuel Garcia-Verdugo
- Laboratorio de Neurobiología Comparada, Instituto Cavanilles, Universitat de València, CIBERNED, 46980 Valencia, Spain; Unidad Mixta de Esclerosis Múltiple y Neurorregeneración, IIS Hospital La Fe-UVEG, 46026 Valencia, Spain
| | - Maxence V Nachury
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA.
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