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Wolfram M, Greif A, Baidukova O, Voll H, Tauber S, Lindacher J, Hegemann P, Kreimer G. Insights into degradation and targeting of the photoreceptor channelrhodopsin-1. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38935876 DOI: 10.1111/pce.15017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 06/05/2024] [Accepted: 06/11/2024] [Indexed: 06/29/2024]
Abstract
In Chlamydomonas, the directly light-gated, plasma membrane-localized cation channels channelrhodopsins ChR1 and ChR2 are the primary photoreceptors for phototaxis. Their targeting and abundance is essential for optimal movement responses. However, our knowledge how Chlamydomonas achieves this is still at its infancy. Here we show that ChR1 internalization occurs via light-stimulated endocytosis. Prior or during endocytosis ChR1 is modified and forms high molecular mass complexes. These are the solely detectable ChR1 forms in extracellular vesicles and their abundance therein dynamically changes upon illumination. The ChR1-containing extracellular vesicles are secreted via the plasma membrane and/or the ciliary base. In line with this, ciliogenesis mutants exhibit increased ChR1 degradation rates. Further, we establish involvement of the cysteine protease CEP1, a member of the papain-type C1A subfamily. ΔCEP1-knockout strains lack light-induced ChR1 degradation, whereas ChR2 degradation was unaffected. Low light stimulates CEP1 expression, which is regulated via phototropin, a SPA1 E3 ubiquitin ligase and cyclic AMP. Further, mutant and inhibitor analyses revealed involvement of the small GTPase ARL11 and SUMOylation in ChR1 targeting to the eyespot and cilia. Our study thus defines the degradation pathway of this central photoreceptor of Chlamydomonas and identifies novel elements involved in its homoeostasis and targeting.
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Affiliation(s)
- Michaela Wolfram
- Department of Biology, Cell Biology, Friedrich-Alexander Universität, Erlangen-Nürnberg, Germany
| | - Arne Greif
- Department of Biology, Cell Biology, Friedrich-Alexander Universität, Erlangen-Nürnberg, Germany
| | - Olga Baidukova
- Institute of Biology, Experimental Biophysics, Humboldt Universität, Berlin, Germany
| | - Hildegard Voll
- Department of Biology, Cell Biology, Friedrich-Alexander Universität, Erlangen-Nürnberg, Germany
| | - Sandra Tauber
- Department of Biology, Cell Biology, Friedrich-Alexander Universität, Erlangen-Nürnberg, Germany
| | - Jana Lindacher
- Department of Biology, Cell Biology, Friedrich-Alexander Universität, Erlangen-Nürnberg, Germany
| | - Peter Hegemann
- Institute of Biology, Experimental Biophysics, Humboldt Universität, Berlin, Germany
| | - Georg Kreimer
- Department of Biology, Cell Biology, Friedrich-Alexander Universität, Erlangen-Nürnberg, Germany
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2
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Fitzpatrick M, Szalanczy A, Beeson A, Vora A, Scott C, Grzybowski M, Klotz J, Der N, Chen R, Geurts AM, Woods LCS. Protein-coding mutation in Adcy3 increases adiposity and alters emotional behaviors sex-dependently in rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.16.598846. [PMID: 38916175 PMCID: PMC11195162 DOI: 10.1101/2024.06.16.598846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Objective Adenylate cyclase 3 (Adcy3) has been linked to both obesity and major depressive disorder (MDD). Our lab identified a protein-coding variant in the 2nd transmembrane (TM) helix of Adcy3 in rats, and similar obesity variants have been identified in humans. The current study investigates the role of a TM variant in adiposity and behavior. Methods We used CRISPR-SpCas9 to mutate the TM domain of Adcy3 in WKY rats (Adcy3mut/mut). We also created a heterozygous knockout rat in the same strain (Adcy3+/-). Wild-type (WT), Adcy3+/-, and Adcy3mut/mut rats were fed a high-fat diet for 12 weeks. We measured body weight, fat mass, glucose tolerance, food intake, metabolism, emotion-like behaviors, and memory. Results Adcy3+/- and Adcy3mut/mut rats weighed more than WT rats due to increased fat mass. There were key sex differences: adiposity was driven by increased food intake in males but by decreased energy expenditure in females. Adcy3mut/mut males displayed increased passive coping and decreased memory while Adcy3mut/mut females displayed increased anxiety-like behavior. Conclusions These studies show that the ADCY3 TM domain plays a role in protein function, that Adcy3 may contribute to the relationship between obesity and MDD, and that sex influences the relationships between Adcy3, metabolism, and behavior.
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Affiliation(s)
- Mackenzie Fitzpatrick
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem NC, USA
| | - Alexandria Szalanczy
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem NC, USA
| | - Angela Beeson
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem NC, USA
| | - Anusha Vora
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem NC, USA
| | - Christina Scott
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem NC, USA
| | - Michael Grzybowski
- Department of Physiology, Medical College of Wisconsin, Milwaukee WI, USA
| | - Jason Klotz
- Department of Physiology, Medical College of Wisconsin, Milwaukee WI, USA
| | - Nataley Der
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem NC, USA
| | - Rong Chen
- Department of Translational Neuroscience, Wake Forest University School of Medicine, Winston-Salem NC, USA
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee WI, USA
| | - Leah C Solberg Woods
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem NC, USA
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3
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Fitzpatrick M, Solberg Woods LC. Adenylate cyclase 3: a potential genetic link between obesity and major depressive disorder. Physiol Genomics 2024; 56:1-8. [PMID: 37955134 DOI: 10.1152/physiolgenomics.00056.2023] [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: 06/14/2023] [Revised: 11/02/2023] [Accepted: 11/02/2023] [Indexed: 11/14/2023] Open
Abstract
Obesity and major depressive disorder (MDD) are both significant health issues that have been increasing in prevalence and are associated with multiple comorbidities. Obesity and MDD have been shown to be bidirectionally associated, and they are both influenced by genetics and environmental factors. However, the molecular mechanisms that link these two diseases are not yet fully understood. It is possible that these diseases are connected through the actions of the cAMP/protein kinase A (PKA) pathway. Within this pathway, adenylate cyclase 3 (Adcy3) has emerged as a key player in both obesity and MDD. Numerous genetic variants in Adcy3 have been identified in humans in association with obesity. Rodent knockout studies have also validated the importance of this gene for energy homeostasis. Furthermore, Adcy3 has been identified as a top candidate gene and even a potential blood biomarker for MDD. Adcy3 and the cAMP/PKA pathway may therefore serve as an important genetic and functional link between these two diseases. In this mini-review, we discuss the role of both Adcy3 and the cAMP/PKA pathway, including specific genetic mutations, in both diseases. Understanding the role that Adcy3 mutations play in obesity and MDD could open the door for precision medicine approaches and treatments for both diseases that target this gene.
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Affiliation(s)
- Mackenzie Fitzpatrick
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States
| | - Leah C Solberg Woods
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States
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4
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Bhat S, Dietz A, Senf K, Nietzsche S, Hirabayashi Y, Westermann M, Neuhaus EM. GPRC5C regulates the composition of cilia in the olfactory system. BMC Biol 2023; 21:292. [PMID: 38110903 PMCID: PMC10729543 DOI: 10.1186/s12915-023-01790-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 11/30/2023] [Indexed: 12/20/2023] Open
Abstract
BACKGROUND Olfactory sensory neurons detect odourants via multiple long cilia that protrude from their dendritic endings. The G protein-coupled receptor GPRC5C was identified as part of the olfactory ciliary membrane proteome, but its function and localization is unknown. RESULTS High-resolution confocal and electron microscopy revealed that GPRC5C is located at the base of sensory cilia in olfactory neurons, but not in primary cilia of immature neurons or stem cells. Additionally, GPRC5C localization in sensory cilia parallels cilia formation and follows the formation of the basal body. In closer examination, GPRC5C was found in the ciliary transition zone. GPRC5C deficiency altered the structure of sensory cilia and increased ciliary layer thickness. However, primary cilia were unaffected. Olfactory sensory neurons from Gprc5c-deficient mice exhibited altered localization of olfactory signalling cascade proteins, and of ciliary phosphatidylinositol-4,5-bisphosphat. Sensory neurons also exhibited increased neuronal activity as well as altered mitochondrial morphology, and knockout mice had an improved ability to detect food pellets based on smell. CONCLUSIONS Our study shows that GPRC5C regulates olfactory cilia composition and length, thereby controlling odour perception.
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Affiliation(s)
- Sneha Bhat
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, 07747, Jena, Germany
| | - André Dietz
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, 07747, Jena, Germany
| | - Katja Senf
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, 07747, Jena, Germany
| | - Sandor Nietzsche
- Centre for Electron Microscopy, Jena University Hospital, Friedrich Schiller University Jena, Ziegelmühlenweg 1, 07743, Jena, Germany
| | - Yoshio Hirabayashi
- Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Chiba, 279-0021, Japan
- RIKEN Cluster for Pioneering Research, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Martin Westermann
- Centre for Electron Microscopy, Jena University Hospital, Friedrich Schiller University Jena, Ziegelmühlenweg 1, 07743, Jena, Germany
| | - Eva Maria Neuhaus
- Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Drackendorfer Str. 1, 07747, Jena, Germany.
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Barbeito P, Martin-Morales R, Palencia-Campos A, Cerrolaza J, Rivas-Santos C, Gallego-Colastra L, Caparros-Martin JA, Martin-Bravo C, Martin-Hurtado A, Sánchez-Bellver L, Marfany G, Ruiz-Perez VL, Garcia-Gonzalo FR. EVC-EVC2 complex stability and ciliary targeting are regulated by modification with ubiquitin and SUMO. Front Cell Dev Biol 2023; 11:1190258. [PMID: 37576597 PMCID: PMC10413113 DOI: 10.3389/fcell.2023.1190258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 07/17/2023] [Indexed: 08/15/2023] Open
Abstract
Ellis van Creveld syndrome and Weyers acrofacial dysostosis are two rare genetic diseases affecting skeletal development. They are both ciliopathies, as they are due to malfunction of primary cilia, microtubule-based plasma membrane protrusions that function as cellular antennae and are required for Hedgehog signaling, a key pathway during skeletal morphogenesis. These ciliopathies are caused by mutations affecting the EVC-EVC2 complex, a transmembrane protein heterodimer that regulates Hedgehog signaling from inside primary cilia. Despite the importance of this complex, the mechanisms underlying its stability, targeting and function are poorly understood. To address this, we characterized the endogenous EVC protein interactome in control and Evc-null cells. This proteomic screen confirmed EVC's main known interactors (EVC2, IQCE, EFCAB7), while revealing new ones, including USP7, a deubiquitinating enzyme involved in Hedgehog signaling. We therefore looked at EVC-EVC2 complex ubiquitination. Such ubiquitination exists but is independent of USP7 (and of USP48, also involved in Hh signaling). We did find, however, that monoubiquitination of EVC-EVC2 cytosolic tails greatly reduces their protein levels. On the other hand, modification of EVC-EVC2 cytosolic tails with the small ubiquitin-related modifier SUMO3 has a different effect, enhancing complex accumulation at the EvC zone, immediately distal to the ciliary transition zone, possibly via increased binding to the EFCAB7-IQCE complex. Lastly, we find that EvC zone targeting of EVC-EVC2 depends on two separate EFCAB7-binding motifs within EVC2's Weyers-deleted peptide. Only one of these motifs had been characterized previously, so we have mapped the second herein. Altogether, our data shed light on EVC-EVC2 complex regulatory mechanisms, with implications for ciliopathies.
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Affiliation(s)
- 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
- CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), 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
- CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain
| | - Adrian Palencia-Campos
- Instituto de Investigaciones Biomédicas “Alberto Sols” (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
- CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Juan Cerrolaza
- 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
| | - Celia Rivas-Santos
- 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
| | - Leticia Gallego-Colastra
- 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
| | - Jose Antonio Caparros-Martin
- Instituto de Investigaciones Biomédicas “Alberto Sols” (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
- CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Carolina Martin-Bravo
- Instituto de Investigaciones Biomédicas “Alberto Sols” (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
| | - Ana Martin-Hurtado
- 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
| | - Laura Sánchez-Bellver
- CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
| | - Gemma Marfany
- CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institut de Biomedicina—Institut de Recerca Sant Joan de Déu (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
- DBGen Ocular Genomics, Barcelona, Spain
| | - Victor L. Ruiz-Perez
- Instituto de Investigaciones Biomédicas “Alberto Sols” (IIBM), Consejo Superior de Investigaciones Científicas (CSIC)-UAM, Madrid, Spain
- CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - 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
- CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Instituto de Investigación del Hospital Universitario de La Paz (IdiPAZ), Madrid, Spain
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Wang K, Papadopoulos N, Hamidi A, Lennartsson J, Heldin CH. SUMOylation of PDGF receptor α affects signaling via PLCγ and STAT3, and cell proliferation. BMC Mol Cell Biol 2023; 24:19. [PMID: 37193980 DOI: 10.1186/s12860-023-00481-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 05/05/2023] [Indexed: 05/18/2023] Open
Abstract
BACKGROUND The platelet-derived growth factor (PDGF) family of ligands exerts their cellular effects by binding to α- and β-tyrosine kinase receptors (PDGFRα and PDGFRβ, respectively). SUMOylation is an important posttranslational modification (PTM) which regulates protein stability, localization, activation and protein interactions. A mass spectrometry screen has demonstrated SUMOylation of PDGFRα. However, the functional role of SUMOylation of PDGFRα has remained unknown. RESULTS In the present study, we validated that PDGFRα is SUMOylated on lysine residue 917 as was previously reported using a mass spectrometry approach. Mutation of lysine residue 917 to arginine (K917R) in PDGFRα substantially decreased SUMOylation, indicating that this amino acid residue is a major SUMOylation site. Whereas no difference in the stability of wild-type and mutant receptor was observed, the K917R mutant PDGFRα was less ubiquitinated than wild-type PDGFRα. The internalization and trafficking of the receptor to early and late endosomes were not affected by the mutation, neither was the localization of the PDGFRα to Golgi. However, the K917R mutant PDGFRα showed delayed activation of PLC-γ and enhanced activation of STAT3. Functional assays showed that the mutation of K917 of PDGFRα decreased cell proliferation in response to PDGF-BB stimulation. CONCLUSIONS SUMOylation of PDGFRα decreases ubiquitination of the receptor and affects ligand-induced signaling and cell proliferation.
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Affiliation(s)
- Kehuan Wang
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Box 582, Sweden
| | - Natalia Papadopoulos
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Box 582, Sweden
| | - Anahita Hamidi
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Box 582, Sweden
| | - Johan Lennartsson
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Carl-Henrik Heldin
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Box 582, Sweden.
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7
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DeMars KM, Ross MR, Starr A, McIntyre JC. Neuronal primary cilia integrate peripheral signals with metabolic drives. Front Physiol 2023; 14:1150232. [PMID: 37064917 PMCID: PMC10090425 DOI: 10.3389/fphys.2023.1150232] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023] Open
Abstract
Neuronal primary cilia have recently emerged as important contributors to the central regulation of energy homeostasis. As non-motile, microtubule-based organelles, primary cilia serve as signaling antennae for metabolic status. The impairment of ciliary structure or function can produce ciliopathies for which obesity is a hallmark phenotype and global ablation of cilia induces non-syndromic adiposity in mouse models. This organelle is not only a hub for metabolic signaling, but also for catecholamine neuromodulation that shapes neuronal circuitry in response to sensory input. The objective of this review is to highlight current research investigating the mechanisms of primary cilium-regulated metabolic drives for maintaining energy homeostasis.
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Affiliation(s)
- Kelly M. DeMars
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
| | - Madeleine R. Ross
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
- Summer Neuroscience Internship Program, University of Florida, Gainesville, FL, United States
| | - Alana Starr
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
| | - Jeremy C. McIntyre
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
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8
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Habif JC, Xie C, Martens JR. Visualizing and Manipulating Olfactory Cilia Through Viral Delivery Coupled with En Face Imaging of Intact OE. Methods Mol Biol 2023; 2710:1-18. [PMID: 37688720 DOI: 10.1007/978-1-0716-3425-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/11/2023]
Abstract
Olfactory cilia are the obligate transducers of the odorant signal, and thus their study has been a focus of investigation in the olfactory field. Various methodologies have been established to visualize the cilia of olfactory sensory neurons; however, these approaches are limited to static imaging and often lack the ability to resolve individual cilia projecting from solitary neurons in the postnatal mouse. Here we detail a procedure of the visualization of olfactory cilia by ectopic expression of fluorescently tagged proteins. The procedure can be used for the observation and manipulation of the olfactory cilia and ciliary proteins in both static and dynamic conditions.
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Affiliation(s)
- Julien C Habif
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA
| | - Chao Xie
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA
| | - Jeffrey R Martens
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL, USA.
- Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA.
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9
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Polymodal Control of TMEM16x Channels and Scramblases. Int J Mol Sci 2022; 23:ijms23031580. [PMID: 35163502 PMCID: PMC8835819 DOI: 10.3390/ijms23031580] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/20/2022] [Accepted: 01/20/2022] [Indexed: 02/01/2023] Open
Abstract
The TMEM16A/anoctamin-1 calcium-activated chloride channel (CaCC) contributes to a range of vital functions, such as the control of vascular tone and epithelial ion transport. The channel is a founding member of a family of 10 proteins (TMEM16x) with varied functions; some members (i.e., TMEM16A and TMEM16B) serve as CaCCs, while others are lipid scramblases, combine channel and scramblase function, or perform additional cellular roles. TMEM16x proteins are typically activated by agonist-induced Ca2+ release evoked by Gq-protein-coupled receptor (GqPCR) activation; thus, TMEM16x proteins link Ca2+-signalling with cell electrical activity and/or lipid transport. Recent studies demonstrate that a range of other cellular factors—including plasmalemmal lipids, pH, hypoxia, ATP and auxiliary proteins—also control the activity of the TMEM16A channel and its paralogues, suggesting that the TMEM16x proteins are effectively polymodal sensors of cellular homeostasis. Here, we review the molecular pathophysiology, structural biology, and mechanisms of regulation of TMEM16x proteins by multiple cellular factors.
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10
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Jana SC, Dutta P, Jain A, Singh A, Adusumilli L, Girotra M, Kumari D, Shirolikar S, Ray K. Kinesin-2 transports Orco into the olfactory cilium of Drosophila melanogaster at specific developmental stages. PLoS Genet 2021; 17:e1009752. [PMID: 34411092 PMCID: PMC8407544 DOI: 10.1371/journal.pgen.1009752] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 08/31/2021] [Accepted: 07/29/2021] [Indexed: 12/21/2022] Open
Abstract
The cilium, the sensing centre for the cell, displays an extensive repertoire of receptors for various cell signalling processes. The dynamic nature of ciliary signalling indicates that the ciliary entry of receptors and associated proteins must be regulated and conditional. To understand this process, we studied the ciliary localisation of the odour-receptor coreceptor (Orco), a seven-pass transmembrane protein essential for insect olfaction. Little is known about when and how Orco gets into the cilia. Here, using Drosophila melanogaster, we show that the bulk of Orco selectively enters the cilia on adult olfactory sensory neurons in two discrete, one-hour intervals after eclosion. A conditional loss of heterotrimeric kinesin-2 during this period reduces the electrophysiological response to odours and affects olfactory behaviour. We further show that Orco binds to the C-terminal tail fragments of the heterotrimeric kinesin-2 motor, which is required to transfer Orco from the ciliary base to the outer segment and maintain within an approximately four-micron stretch at the distal portion of the ciliary outer-segment. The Orco transport was not affected by the loss of critical intraflagellar transport components, IFT172/Oseg2 and IFT88/NompB, respectively, during the adult stage. These results highlight a novel developmental regulation of seven-pass transmembrane receptor transport into the cilia and indicate that ciliary signalling is both developmentally and temporally regulated.
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Affiliation(s)
- Swadhin Chandra Jana
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
- Instituto Gulbenkian de Ciência (IGC), Oeiras, Portugal
| | - Priya Dutta
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Akanksha Jain
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Anjusha Singh
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Lavanya Adusumilli
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Mukul Girotra
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Diksha Kumari
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Seema Shirolikar
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Krishanu Ray
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
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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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12
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May EA, Sroka TJ, Mick DU. Phosphorylation and Ubiquitylation Regulate Protein Trafficking, Signaling, and the Biogenesis of Primary Cilia. Front Cell Dev Biol 2021; 9:664279. [PMID: 33912570 PMCID: PMC8075051 DOI: 10.3389/fcell.2021.664279] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/09/2021] [Indexed: 12/30/2022] Open
Abstract
The primary cilium is a solitary, microtubule-based membrane protrusion extending from the surface of quiescent cells that senses the cellular environment and triggers specific cellular responses. The functions of primary cilia require not only numerous different components but also their regulated interplay. The cilium performs highly dynamic processes, such as cell cycle-dependent assembly and disassembly as well as delivery, modification, and removal of signaling components to perceive and process external signals. On a molecular level, these processes often rely on a stringent control of key modulatory proteins, of which the activity, localization, and stability are regulated by post-translational modifications (PTMs). While an increasing number of PTMs on ciliary components are being revealed, our knowledge on the identity of the modifying enzymes and their modulation is still limited. Here, we highlight recent findings on cilia-specific phosphorylation and ubiquitylation events. Shedding new light onto the molecular mechanisms that regulate the sensitive equilibrium required to maintain and remodel primary cilia functions, we discuss their implications for cilia biogenesis, protein trafficking, and cilia signaling processes.
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Affiliation(s)
- Elena A May
- Center of Human and Molecular Biology (ZHMB), Saarland University School of Medicine, Homburg, Germany.,Center for Molecular Signaling (PZMS), Department of Medical Biochemistry and Molecular Biology, Saarland University School of Medicine, Homburg, Germany
| | - Tommy J Sroka
- Center of Human and Molecular Biology (ZHMB), Saarland University School of Medicine, Homburg, Germany.,Center for Molecular Signaling (PZMS), Department of Medical Biochemistry and Molecular Biology, Saarland University School of Medicine, Homburg, Germany
| | - David U Mick
- Center of Human and Molecular Biology (ZHMB), Saarland University School of Medicine, Homburg, Germany.,Center for Molecular Signaling (PZMS), Department of Medical Biochemistry and Molecular Biology, Saarland University School of Medicine, Homburg, Germany
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13
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Corey EA, Ukhanov K, Bobkov YV, McIntyre JC, Martens JR, Ache BW. Inhibitory signaling in mammalian olfactory transduction potentially mediated by Gα o. Mol Cell Neurosci 2020; 110:103585. [PMID: 33358996 DOI: 10.1016/j.mcn.2020.103585] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/27/2020] [Accepted: 12/09/2020] [Indexed: 01/12/2023] Open
Abstract
Olfactory GPCRs (ORs) in mammalian olfactory receptor neurons (ORNs) mediate excitation through the Gαs family member Gαolf. Here we tentatively associate a second G protein, Gαo, with inhibitory signaling in mammalian olfactory transduction by first showing that odor evoked phosphoinositide 3-kinase (PI3K)-dependent inhibition of signal transduction is absent in the native ORNs of mice carrying a conditional OMP-Cre based knockout of Gαo. We then identify an OR from native rat ORNs that are activated by octanol through cyclic nucleotide signaling and inhibited by citral in a PI3K-dependent manner. We show that the OR activates cyclic nucleotide signaling and PI3K signaling in a manner that reflects its functionality in native ORNs. Our findings lay the groundwork to explore the interesting possibility that ORs can interact with two different G proteins in a functionally identified, ligand-dependent manner to mediate opponent signaling in mature mammalian ORNs.
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Affiliation(s)
- Elizabeth A Corey
- Whitney Laboratory, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America
| | - Kirill Ukhanov
- Dept. of Pharmacology and Therapeutics, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America
| | - Yuriy V Bobkov
- Whitney Laboratory, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America
| | - Jeremy C McIntyre
- Dept. of Neuroscience, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America
| | - Jeffrey R Martens
- Dept. of Pharmacology and Therapeutics, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America
| | - Barry W Ache
- Whitney Laboratory, Dept. of Biology, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America; Whitney Laboratory, Dept. of Neuroscience, Center for Smell and Taste, University of Florida, Gainesville, FL 32610, United States of America.
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14
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Craveur P, Narwani TJ, Rebehmed J, de Brevern AG. Investigation of the impact of PTMs on the protein backbone conformation. Amino Acids 2019; 51:1065-1079. [DOI: 10.1007/s00726-019-02747-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/18/2019] [Indexed: 12/17/2022]
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15
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SUMO1/sentrin/SMT3 specific peptidase 2 modulates target molecules and its corresponding functions. Biochimie 2018; 152:6-13. [PMID: 29908207 DOI: 10.1016/j.biochi.2018.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 06/11/2018] [Indexed: 12/11/2022]
Abstract
Small ubiquitin-like modifier (SUMOylation) is a reversible post-translational modification, which plays important roles in numerous biological processes. SUMO could be covalently attached to target proteins in an isopeptide bond manner that occurs via a lysine ε-amino group on the target proteins and the glycine on SUMO C-terminus. This covalent binding could affect the subcellular localization and stability of target proteins. SUMO modification can be reversed by members of the Sentrin/SUMO-specific proteases (SENPs) family, which are highly evolutionarily conserved from yeast to human. SENP2, a member of the SENPs family, mainly plays a physiological function in the nucleus. SENP2 can promote maturity of the SUMO and deSUMOylate for single-SUMO modified or poly-SUMO modified proteins. SENP2 can affect the related biological processes through its peptidase activity or the amino terminal transcriptional repression domain. It plays important roles by inhibiting or activating some molecular functions. Therefore, the research achievements of SENP2 are reviewed in order to understand its related functions and the underlying molecular mechanisms and provide a clue for future research on SENP2.
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16
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Lv B, Wan L, Taschner M, Cheng X, Lorentzen E, Huang K. Intraflagellar transport protein IFT52 recruits IFT46 to the basal body and flagella. J Cell Sci 2017; 130:1662-1674. [PMID: 28302912 DOI: 10.1242/jcs.200758] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/14/2017] [Indexed: 12/17/2022] Open
Abstract
Cilia are microtubule-based organelles and perform motile, sensing and signaling functions. The assembly and maintenance of cilia depend on intraflagellar transport (IFT). Besides ciliary localization, most IFT proteins accumulate at basal bodies. However, little is known about the molecular mechanism of basal body targeting of IFT proteins. We first identified the possible basal body-targeting sequence in IFT46 by expressing IFT46 truncation constructs in an ift46-1 mutant. The C-terminal sequence between residues 246-321, termed BBTS3, was sufficient to target YFP to basal bodies in the ift46-1 strain. Interestingly, BBTS3 is also responsible for the ciliary targeting of IFT46. BBTS3::YFP moves bidirectionally in flagella and interacts with other IFT complex B (IFT-B) proteins. Using IFT and motor mutants, we show that the basal body localization of IFT46 depends on IFT52, but not on IFT81, IFT88, IFT122, FLA10 or DHC1b. IFT52 interacts with IFT46 through residues L285 and L286 of IFT46 and recruits it to basal bodies. Ectopic expression of the C-terminal domain of IFT52 in the nucleus resulted in accumulation of IFT46 in nuclei. These data suggest that IFT52 and IFT46 can preassemble as a complex in the cytoplasm, which is then targeted to basal bodies.
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Affiliation(s)
- Bo Lv
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China.,University of Chinese Academy of Sciences, Beijing 100039, China
| | - Lei Wan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Michael Taschner
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Martinsried D-82152, Germany
| | - Xi Cheng
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China.,University of Chinese Academy of Sciences, Beijing 100039, China
| | - Esben Lorentzen
- Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Martinsried D-82152, Germany
| | - Kaiyao Huang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
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17
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Guadiana SM, Parker AK, Filho GF, Sequeira A, Semple-Rowland S, Shaw G, Mandel RJ, Foster TC, Kumar A, Sarkisian MR. Type 3 Adenylyl Cyclase and Somatostatin Receptor 3 Expression Persists in Aged Rat Neocortical and Hippocampal Neuronal Cilia. Front Aging Neurosci 2016; 8:127. [PMID: 27303293 PMCID: PMC4885836 DOI: 10.3389/fnagi.2016.00127] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 05/17/2016] [Indexed: 01/09/2023] Open
Abstract
The primary cilia of forebrain neurons assemble around birth and become enriched with neuromodulatory receptors. Our understanding of the permanence of these structures and their associated signaling pathways in the aging brain is poor, but they are worthy of investigation because disruptions in neuronal cilia signaling have been implicated in changes in learning and memory, depression-like symptoms, and sleep anomalies. Here, we asked whether neurons in aged forebrain retain primary cilia and whether the staining characteristics of aged cilia for type 3 adenylyl cyclase (ACIII), somatostatin receptor 3 (SSTR3), and pericentrin resemble those of cilia in younger forebrain. To test this, we analyzed immunostained sections of forebrain tissues taken from young and aged male Fischer 344 (F344) and F344 × Brown Norway (F344 × BN) rats. Analyses of ACIII and SSTR3 in young and aged cortices of both strains of rats revealed that the staining patterns in the neocortex and hippocampus were comparable. Virtually every NeuN positive cell examined possessed an ACIII positive cilium. The lengths of ACIII positive cilia in neocortex were similar between young and aged for both strains, whereas in F344 × BN hippocampus, the cilia lengths increased with age in CA1 and CA3, but not in dentate gyrus (DG). Additionally, the percentages of ACIII positive cilia that were also SSTR3 positive did not differ between young and aged tissues in either strain. We also found that pericentrin, a protein that localizes to the basal bodies of neuronal cilia and functions in primary cilia assembly, persisted in aged cortical neurons of both rat strains. Collectively, our data show that neurons in aged rat forebrain possess primary cilia and that these cilia, like those present in younger brain, continue to localize ACIII, SSTR3, and pericentrin. Further studies will be required to determine if the function and signaling pathways regulated by cilia are similar in aged compared to young brain.
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Affiliation(s)
- Sarah M Guadiana
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Alexander K Parker
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Gileno F Filho
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Ashton Sequeira
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Susan Semple-Rowland
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Gerry Shaw
- Department of Neuroscience, McKnight Brain Institute, University of FloridaGainesville, FL, USA; EnCor Biotechnology Inc.Gainesville, FL, USA
| | - Ronald J Mandel
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Matthew R Sarkisian
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
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18
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Genetic Ablation of Type III Adenylyl Cyclase Exerts Region-Specific Effects on Cilia Architecture in the Mouse Nose. PLoS One 2016; 11:e0150638. [PMID: 26942602 PMCID: PMC4778765 DOI: 10.1371/journal.pone.0150638] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 02/17/2016] [Indexed: 12/18/2022] Open
Abstract
We recently reported that olfactory sensory neurons in the dorsal zone of the mouse olfactory epithelium exhibit drastic location-dependent differences in cilia length. Furthermore, genetic ablation of type III adenylyl cyclase (ACIII), a key olfactory signaling protein and ubiquitous marker for primary cilia, disrupts the cilia length pattern and results in considerably shorter cilia, independent of odor-induced activity. Given the significant impact of ACIII on cilia length in the dorsal zone, we sought to further investigate the relationship between cilia length and ACIII level in various regions throughout the mouse olfactory epithelium. We employed whole-mount immunohistochemical staining to examine olfactory cilia morphology in phosphodiesterase (PDE) 1C-/-;PDE4A-/- (simplified as PDEs-/- hereafter) and ACIII-/- mice in which ACIII levels are reduced and ablated, respectively. As expected, PDEs-/- animals exhibit dramatically shorter cilia in the dorsal zone (i.e., where the cilia pattern is found), similar to our previous observation in ACIII-/- mice. Remarkably, in a region not included in our previous study, ACIII-/- animals (but not PDEs-/- mice) have dramatically elongated, comet-shaped cilia, as opposed to characteristic star-shaped olfactory cilia. Here, we reveal that genetic ablation of ACIII has drastic, location-dependent effects on cilia architecture in the mouse nose. These results add a new dimension to our current understanding of olfactory cilia structure and regional organization of the olfactory epithelium. Together, these findings have significant implications for both cilia and sensory biology.
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19
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Abstract
In the last decade highly conserved cellular appendages called cilia have enjoyed a renewed interest from basic, biomedical scientists, and clinicians alike. This interest has grown upon the elucidation that cilia throughout the body serve as important sensory and signaling centers in both development and adult homeostasis. Furthermore, the identification of several rare genetic disorders associated with cilia dysfunction has broadened the field. However, even though their potential role in human health and disease is now recognized many basic questions about their functions remain. This chapter seeks to explore the trafficking of cilia-specific G protein-coupled receptors (GPCRs) and discusses several model systems in which this has been explored. We open the chapter by briefly discussing cilia and GPCRs then begin discussing some aspects of rhodopsin trafficking, arguably the most well studied of cilia GPCRs. We continue with sections on neuronal cilia and olfactory cilia receptor trafficking. Finally, we conclude with the emerging area of dynamic ciliary GPCR trafficking and speculate about future directions and some of the questions that remain for ciliary GPCRs.
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Affiliation(s)
- Jeremy C McIntyre
- Department of Neuroscience, University of Florida, Gainesville, FL, USA; Center for Smell and Taste, University of Florida, Gainesville, FL, USA
| | - Mellisa M Hege
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Nicolas F Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
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20
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Takao D, Verhey KJ. Gated entry into the ciliary compartment. Cell Mol Life Sci 2016; 73:119-27. [PMID: 26472341 PMCID: PMC4959937 DOI: 10.1007/s00018-015-2058-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 09/28/2015] [Accepted: 09/29/2015] [Indexed: 11/26/2022]
Abstract
Cilia and flagella play important roles in cell motility and cell signaling. These functions require that the cilium establishes and maintains a unique lipid and protein composition. Recent work indicates that a specialized region at the base of the cilium, the transition zone, serves as both a barrier to entry and a gate for passage of select components. For at least some cytosolic proteins, the barrier and gate functions are provided by a ciliary pore complex (CPC) that shares molecular and mechanistic properties with nuclear gating. Specifically, nucleoporins of the CPC limit the diffusional entry of cytosolic proteins in a size-dependent manner and enable the active transport of large molecules and complexes via targeting signals, importins, and the small G protein Ran. For membrane proteins, the septin protein SEPT2 is part of the barrier to entry whereas the gating function is carried out and/or regulated by proteins associated with ciliary diseases (ciliopathies) such as nephronophthisis, Meckel–Gruber syndrome and Joubert syndrome. Here, we discuss the evidence behind these models of ciliary gating as well as the similarities to and differences from nuclear gating.
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Affiliation(s)
- Daisuke Takao
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl, Ann Arbor, MI 48109 USA
| | - Kristen J. Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Pl, Ann Arbor, MI 48109 USA
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21
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22
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An Olfactory Cilia Pattern in the Mammalian Nose Ensures High Sensitivity to Odors. Curr Biol 2015; 25:2503-12. [PMID: 26365258 DOI: 10.1016/j.cub.2015.07.065] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/29/2015] [Accepted: 07/28/2015] [Indexed: 11/22/2022]
Abstract
In many sensory organs, specialized receptors are strategically arranged to enhance detection sensitivity and acuity. It is unclear whether the olfactory system utilizes a similar organizational scheme to facilitate odor detection. Curiously, olfactory sensory neurons (OSNs) in the mouse nose are differentially stimulated depending on the cell location. We therefore asked whether OSNs in different locations evolve unique structural and/or functional features to optimize odor detection and discrimination. Using immunohistochemistry, computational fluid dynamics modeling, and patch clamp recording, we discovered that OSNs situated in highly stimulated regions have much longer cilia and are more sensitive to odorants than those in weakly stimulated regions. Surprisingly, reduction in neuronal excitability or ablation of the olfactory G protein in OSNs does not alter the cilia length pattern, indicating that neither spontaneous nor odor-evoked activity is required for its establishment. Furthermore, the pattern is evident at birth, maintained into adulthood, and restored following pharmacologically induced degeneration of the olfactory epithelium, suggesting that it is intrinsically programmed. Intriguingly, type III adenylyl cyclase (ACIII), a key protein in olfactory signal transduction and ubiquitous marker for primary cilia, exhibits location-dependent gene expression levels, and genetic ablation of ACIII dramatically alters the cilia pattern. These findings reveal an intrinsically programmed configuration in the nose to ensure high sensitivity to odors.
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23
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Warrington NM, Sun T, Rubin JB. Targeting brain tumor cAMP: the case for sex-specific therapeutics. Front Pharmacol 2015; 6:153. [PMID: 26283963 PMCID: PMC4516881 DOI: 10.3389/fphar.2015.00153] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 07/10/2015] [Indexed: 12/20/2022] Open
Abstract
A relationship between cyclic adenosine 3′, 5′-monophosphate (cAMP) levels and brain tumor biology has been evident for nearly as long as cAMP and its synthetase, adenylate cyclase (ADCY) have been known. The importance of the pathway in brain tumorigenesis has been demonstrated in vitro and in multiple animal models. Recently, we provided human validation for a cooperating oncogenic role for cAMP in brain tumorigenesis when we found that SNPs in ADCY8 were correlated with glioma (brain tumor) risk in individuals with Neurofibromatosis type 1 (NF1). Together, these studies provide a strong rationale for targeting cAMP in brain tumor therapy. However, the cAMP pathway is well-known to be sexually dimorphic, and SNPs in ADCY8 affected glioma risk in a sex-specific fashion, elevating the risk for females while protecting males. The cAMP pathway can be targeted at multiple levels in the regulation of its synthesis and degradation. Sex differences in response to drugs that target cAMP regulators indicate that successful targeting of the cAMP pathway for brain tumor patients is likely to require matching specific mechanisms of drug action with patient sex.
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Affiliation(s)
- Nicole M Warrington
- Department of Pediatrics, Washington University School of Medicine St Louis, MO, USA
| | - Tao Sun
- Department of Pediatrics, Washington University School of Medicine St Louis, MO, USA
| | - Joshua B Rubin
- Department of Pediatrics, Washington University School of Medicine St Louis, MO, USA ; Department of Anatomy and Neurobiology, Washington University School of Medicine St Louis, MO, USA
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