1
|
Samhan-Arias AK, Poejo J, Marques-da-Silva D, Martínez-Costa OH, Gutierrez-Merino C. Are There Lipid Membrane-Domain Subtypes in Neurons with Different Roles in Calcium Signaling? Molecules 2023; 28:7909. [PMID: 38067638 PMCID: PMC10708093 DOI: 10.3390/molecules28237909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 11/24/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Lipid membrane nanodomains or lipid rafts are 10-200 nm diameter size cholesterol- and sphingolipid-enriched domains of the plasma membrane, gathering many proteins with different roles. Isolation and characterization of plasma membrane proteins by differential centrifugation and proteomic studies have revealed a remarkable diversity of proteins in these domains. The limited size of the lipid membrane nanodomain challenges the simple possibility that all of them can coexist within the same lipid membrane domain. As caveolin-1, flotillin isoforms and gangliosides are currently used as neuronal lipid membrane nanodomain markers, we first analyzed the structural features of these components forming nanodomains at the plasma membrane since they are relevant for building supramolecular complexes constituted by these molecular signatures. Among the proteins associated with neuronal lipid membrane nanodomains, there are a large number of proteins that play major roles in calcium signaling, such as ionotropic and metabotropic receptors for neurotransmitters, calcium channels, and calcium pumps. This review highlights a large variation between the calcium signaling proteins that have been reported to be associated with isolated caveolin-1 and flotillin-lipid membrane nanodomains. Since these calcium signaling proteins are scattered in different locations of the neuronal plasma membrane, i.e., in presynapses, postsynapses, axonal or dendritic trees, or in the neuronal soma, our analysis suggests that different lipid membrane-domain subtypes should exist in neurons. Furthermore, we conclude that classification of lipid membrane domains by their content in calcium signaling proteins sheds light on the roles of these domains for neuronal activities that are dependent upon the intracellular calcium concentration. Some examples described in this review include the synaptic and metabolic activity, secretion of neurotransmitters and neuromodulators, neuronal excitability (long-term potentiation and long-term depression), axonal and dendritic growth but also neuronal cell survival and death.
Collapse
Affiliation(s)
- Alejandro K. Samhan-Arias
- Departamento de Bioquímica, Universidad Autónoma de Madrid (UAM), C/Arturo Duperier 4, 28029 Madrid, Spain;
- Instituto de Investigaciones Biomédicas ‘Sols-Morreale’ (CSIC-UAM), C/Arturo Duperier 4, 28029 Madrid, Spain
| | - Joana Poejo
- Instituto de Biomarcadores de Patologías Moleculares, Universidad de Extremadura, 06006 Badajoz, Spain;
| | - Dorinda Marques-da-Silva
- LSRE—Laboratory of Separation and Reaction Engineering and LCM—Laboratory of Catalysis and Materials, School of Management and Technology, Polytechnic Institute of Leiria, Morro do Lena-Alto do Vieiro, 2411-901 Leiria, Portugal;
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- School of Technology and Management, Polytechnic Institute of Leiria, Morro do Lena-Alto do Vieiro, 2411-901 Leiria, Portugal
| | - Oscar H. Martínez-Costa
- Departamento de Bioquímica, Universidad Autónoma de Madrid (UAM), C/Arturo Duperier 4, 28029 Madrid, Spain;
- Instituto de Investigaciones Biomédicas ‘Sols-Morreale’ (CSIC-UAM), C/Arturo Duperier 4, 28029 Madrid, Spain
| | - Carlos Gutierrez-Merino
- Instituto de Biomarcadores de Patologías Moleculares, Universidad de Extremadura, 06006 Badajoz, Spain;
| |
Collapse
|
2
|
Isik OA, Cizmecioglu O. Rafting on the Plasma Membrane: Lipid Rafts in Signaling and Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1436:87-108. [PMID: 36648750 DOI: 10.1007/5584_2022_759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The plasma membrane is not a uniform phospholipid bilayer; it has specialized membrane nano- or microdomains called lipid rafts. Lipid rafts are small cholesterol and sphingolipid-rich plasma membrane islands. Although their existence was long debated, their presence in the plasma membrane of living cells is now well accepted with the advent of super-resolution imaging techniques. It is interesting to note that lipid rafts function to compartmentalize receptors and their regulators and substantially modulate cellular signaling. In this review, we will examine the role of lipid rafts and caveolae-lipid raft-like microdomains with a distinct 3D morphology-in cellular signaling. Moreover, we will investigate how raft compartmentalized signaling regulates diverse physiological processes such as proliferation, apoptosis, immune signaling, and development. Also, the deregulation of lipid raft-mediated signaling during tumorigenesis and metastasis will be explored.
Collapse
Affiliation(s)
- Ozlem Aybuke Isik
- Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey
| | - Onur Cizmecioglu
- Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey.
| |
Collapse
|
3
|
Wagner-Altendorf TA, Wandinger KP, Markewitz R, Antufjew A, Boppel T, Münte TF. Anti-flotillin-1/2 antibodies in a patient with neurogenic muscle atrophy and mild neuropsychological impairment. Neurol Res Pract 2022; 4:43. [PMID: 36131297 PMCID: PMC9494886 DOI: 10.1186/s42466-022-00208-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/26/2022] [Indexed: 11/10/2022] Open
Abstract
Autoimmune-mediated neural inflammation can affect both the central and the peripheral nervous system. Recently, antibodies against the peripheral membrane protein flotillin have been described in patients with multiple sclerosis, limbic encephalitis and sensorimotor demyelinating polyneuropathy. Here, we report the case of a 75-year-old male patient presenting with slowly progressive muscle weakness, as well as mild cognitive impairment. MR neurography of the leg showed fascicular enlargement and inflammation of ischiadic nerve fibers, while cerebral MRI showed bilateral hippocampal atrophy. Serological testing revealed positive anti-flotillin-1/2 antibodies in serum (1:100) and CSF (1:1). Assuming autoimmune anti-flotillin antibody-associated neurogenic muscle atrophy, the patient was treated with immunoglobulins, which led to a clinical improvement of muscle weakness. In light of the positive anti-flotillin antibodies and the local CNS immunoglobulin production, the mild cognitive impairment and hippocampal atrophy were interpreted as a cerebral involvement in the sense of a subclinical limbic encephalitis. We conclude that anti-flotillin antibodies can be associated with central and peripheral nervous system autoimmunity and should be considered in diagnostical workup.
Collapse
|
4
|
Biernatowska A, Wójtowicz K, Trombik T, Sikorski AF, Czogalla A. MPP1 Determines the Mobility of Flotillins and Controls the Confinement of Raft-Associated Molecules. Cells 2022; 11:cells11030311. [PMID: 35159121 PMCID: PMC8834348 DOI: 10.3390/cells11030311] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 01/02/2023] Open
Abstract
MPP1 (membrane palmitoylated protein 1) belongs to the MAGUK (membrane-associated guanylate kinase homologs) scaffolding protein family. These proteins organize molecules into complexes, thereby maintaining the structural heterogeneity of the plasma membrane (PM). Our previous results indicated that direct, high-affinity interactions between MPP1 and flotillins (raft marker proteins) display dominant PM-modulating capacity in erythroid cells. In this study, with high-resolution structured illuminated imaging, we investigated how these complexes are organized within erythroid cells on the nanometer scale. Furthermore, using other spectroscopic techniques, namely fluorescence recovery after photobleaching (FRAP) and spot-variation fluorescence correlation spectroscopy (svFCS), we revealed that MPP1 acts as a key raft-capturing molecule, regulating temporal immobilization of flotillin-based nanoclusters, and controls local concentration and confinement of sphingomyelin and Thy-1 in raft nanodomains. Our data enabled us to uncover molecular principles governing the key involvement of MPP1-flotillin complexes in the dynamic nanoscale organization of PM of erythroid cells.
Collapse
Affiliation(s)
- Agnieszka Biernatowska
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wrocław, ul. F. Joliot-Curie 14a, 50-383 Wrocław, Poland
- Correspondence: (A.B.); (A.C.); Tel.: +48-71-375-6417 (A.B.); +48-71-375-6356 (A.C.)
| | - Karolina Wójtowicz
- Department of Biotransformation, Faculty of Biotechnology, University of Wrocław, ul. F. Joliot-Curie 14a, 50-383 Wrocław, Poland;
| | - Tomasz Trombik
- Department of Biophysics, Faculty of Biotechnology, University of Wrocław, ul. F. Joliot-Curie 14a, 50-383 Wrocław, Poland;
| | - Aleksander F. Sikorski
- Research and Development Center, Regional Specialist Hospital, Kamieńskiego 73a, 51-154 Wrocław, Poland;
| | - Aleksander Czogalla
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wrocław, ul. F. Joliot-Curie 14a, 50-383 Wrocław, Poland
- Correspondence: (A.B.); (A.C.); Tel.: +48-71-375-6417 (A.B.); +48-71-375-6356 (A.C.)
| |
Collapse
|
5
|
Shang K, Cheng C, Qin C, Xiao J, Deng G, Bu BT, Xu SB, Tian DS. Case Report: Clinical and Imaging Characteristics of a Patient with Anti-flotillin Autoantibodies: Neuromyelitis Optica or Multiple Sclerosis? Front Immunol 2022; 12:808420. [PMID: 35003138 PMCID: PMC8733162 DOI: 10.3389/fimmu.2021.808420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/09/2021] [Indexed: 11/13/2022] Open
Abstract
Background Demyelination diseases are complex puzzles that are not always straightforward to diagnose. Multiple sclerosis and neuromyelitis optica are two that are frequently encountered. Numerous autoantibodies newly discovered in recent years have significantly aided clinical reasoning and diagnosis in differentiating demyelination disorders. Here we report a case of demyelination disease with anti-flotillin autoantibodies positive, which is not common in past references. Case summary The patient presented with characteristic neuromyelitis optica symptoms and had remission and relapse. But his images exhibited characteristics of both neuromyelitis optica spectrum illness and multiple sclerosis. Conclusion This is the first case report describing the clinical course and imaging characteristics of demyelination illness associated with anti-flotillin autoantibodies. Although so far it appears to be a subtype of multiple sclerosis, there is still a potential that it is separate from MS and NMOSD.
Collapse
Affiliation(s)
- Ke Shang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chang Cheng
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chuan Qin
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jun Xiao
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gang Deng
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bi-Tao Bu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sha-Bei Xu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dai-Shi Tian
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
6
|
Mohanraj N, Joshi NS, Poulose R, Patil RR, Santhoshkumar R, Kumar A, Waghmare GP, Saha AK, Haider SZ, Markandeya YS, Dey G, Rao LT, Govindaraj P, Mehta B. A proteomic study to unveil lead toxicity-induced memory impairments invoked by synaptic dysregulation. Toxicol Rep 2022; 9:1501-1513. [DOI: 10.1016/j.toxrep.2022.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/02/2022] [Accepted: 07/05/2022] [Indexed: 11/17/2022] Open
|
7
|
Videira G, Albuquerque L, Oliveira V, Carneiro P, Neves E, Martins da Silva A, Samões R. Limbic Encephalitis With Positivity for Anti-Flotillin Antibodies in Serum and CSF. Neurol Clin Pract 2021; 11:e8-e10. [PMID: 33968480 DOI: 10.1212/cpj.0000000000000741] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 08/08/2019] [Indexed: 11/15/2022]
Affiliation(s)
- Gonçalo Videira
- Neurology Department (GV, VO, AMdS, RS), Centro Hospitalar Universitário do Porto; Neuroradiology Department (LA), Centro Hospitalar Universitário do Porto; Immunology Department (PC, EN), Centro Hospitalar Universitário do Porto; and Biomedical Investigation Multidisciplinary Unit (PC, EN, AMdS), Porto, Portugal
| | - Luís Albuquerque
- Neurology Department (GV, VO, AMdS, RS), Centro Hospitalar Universitário do Porto; Neuroradiology Department (LA), Centro Hospitalar Universitário do Porto; Immunology Department (PC, EN), Centro Hospitalar Universitário do Porto; and Biomedical Investigation Multidisciplinary Unit (PC, EN, AMdS), Porto, Portugal
| | - Vanessa Oliveira
- Neurology Department (GV, VO, AMdS, RS), Centro Hospitalar Universitário do Porto; Neuroradiology Department (LA), Centro Hospitalar Universitário do Porto; Immunology Department (PC, EN), Centro Hospitalar Universitário do Porto; and Biomedical Investigation Multidisciplinary Unit (PC, EN, AMdS), Porto, Portugal
| | - Paula Carneiro
- Neurology Department (GV, VO, AMdS, RS), Centro Hospitalar Universitário do Porto; Neuroradiology Department (LA), Centro Hospitalar Universitário do Porto; Immunology Department (PC, EN), Centro Hospitalar Universitário do Porto; and Biomedical Investigation Multidisciplinary Unit (PC, EN, AMdS), Porto, Portugal
| | - Esmeralda Neves
- Neurology Department (GV, VO, AMdS, RS), Centro Hospitalar Universitário do Porto; Neuroradiology Department (LA), Centro Hospitalar Universitário do Porto; Immunology Department (PC, EN), Centro Hospitalar Universitário do Porto; and Biomedical Investigation Multidisciplinary Unit (PC, EN, AMdS), Porto, Portugal
| | - Ana Martins da Silva
- Neurology Department (GV, VO, AMdS, RS), Centro Hospitalar Universitário do Porto; Neuroradiology Department (LA), Centro Hospitalar Universitário do Porto; Immunology Department (PC, EN), Centro Hospitalar Universitário do Porto; and Biomedical Investigation Multidisciplinary Unit (PC, EN, AMdS), Porto, Portugal
| | - Raquel Samões
- Neurology Department (GV, VO, AMdS, RS), Centro Hospitalar Universitário do Porto; Neuroradiology Department (LA), Centro Hospitalar Universitário do Porto; Immunology Department (PC, EN), Centro Hospitalar Universitário do Porto; and Biomedical Investigation Multidisciplinary Unit (PC, EN, AMdS), Porto, Portugal
| |
Collapse
|
8
|
Brandel A, Aigal S, Lagies S, Schlimpert M, Meléndez AV, Xu M, Lehmann A, Hummel D, Fisch D, Madl J, Eierhoff T, Kammerer B, Römer W. The Gb3-enriched CD59/flotillin plasma membrane domain regulates host cell invasion by Pseudomonas aeruginosa. Cell Mol Life Sci 2021; 78:3637-3656. [PMID: 33555391 PMCID: PMC8038999 DOI: 10.1007/s00018-021-03766-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 12/22/2020] [Accepted: 01/15/2021] [Indexed: 12/11/2022]
Abstract
The opportunistic pathogen Pseudomonas aeruginosa has gained precedence over the years due to its ability to develop resistance to existing antibiotics, thereby necessitating alternative strategies to understand and combat the bacterium. Our previous work identified the interaction between the bacterial lectin LecA and its host cell glycosphingolipid receptor globotriaosylceramide (Gb3) as a crucial step for the engulfment of P. aeruginosa via the lipid zipper mechanism. In this study, we define the LecA-associated host cell membrane domain by pull-down and mass spectrometry analysis. We unraveled a predilection of LecA for binding to saturated, long fatty acyl chain-containing Gb3 species in the extracellular membrane leaflet and an induction of dynamic phosphatidylinositol (3,4,5)-trisphosphate (PIP3) clusters at the intracellular leaflet co-localizing with sites of LecA binding. We found flotillins and the GPI-anchored protein CD59 not only to be an integral part of the LecA-interacting membrane domain, but also majorly influencing bacterial invasion as depletion of either of these host cell proteins resulted in about 50% reduced invasiveness of the P. aeruginosa strain PAO1. In summary, we report that the LecA-Gb3 interaction at the extracellular leaflet induces the formation of a plasma membrane domain enriched in saturated Gb3 species, CD59, PIP3 and flotillin thereby facilitating efficient uptake of PAO1.
Collapse
Affiliation(s)
- Annette Brandel
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
| | - Sahaja Aigal
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Simon Lagies
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- Center for Biological Systems Analysis, University of Freiburg, Habsburgerstraße 49, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Manuel Schlimpert
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- Center for Biological Systems Analysis, University of Freiburg, Habsburgerstraße 49, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Ana Valeria Meléndez
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Maokai Xu
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
| | - Anika Lehmann
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
| | - Daniel Hummel
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Department of Biochemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland
| | - Daniel Fisch
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Department of Infectious Disease, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK
| | - Josef Madl
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, and Faculty of Medicine, University of Freiburg, Elsässer Straße 2q, 79110, Freiburg, Germany
| | - Thorsten Eierhoff
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Clinic for Vascular and Endovascular Surgery, University Hospital Münster, Albert Schweitzer Campus 1, 48149, Münster, Germany
| | - Bernd Kammerer
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Center for Biological Systems Analysis, University of Freiburg, Habsburgerstraße 49, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Winfried Römer
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany.
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany.
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany.
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany.
| |
Collapse
|
9
|
Differential expression of two ATPases revealed by lipid raft isolation from gills of euryhaline teleosts with different salinity preferences. Comp Biochem Physiol B Biochem Mol Biol 2021; 253:110562. [PMID: 33453387 DOI: 10.1016/j.cbpb.2021.110562] [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: 07/25/2020] [Revised: 12/29/2020] [Accepted: 01/10/2021] [Indexed: 12/12/2022]
Abstract
In euryhaline teleosts, Na+, K+-ATPase (NKA) and V-type H + -ATPase A (VHA A) are important ion-transporters located in cell membrane. Lipid rafts (LR) are plasma membrane microdomains enriched in cholesterol, sphingolipids, and proteins (e.g., flotillin). Flotillin is a LR-associated protein, commonly used as the LR marker. Previous mammalian studies showed that LR may play a crucial role in ion exchanges. Meanwhile, studies on mammals and rainbow trout showed that NKA were found to be present mainly in LR. However, little is known about LR in fish. Therefore, the present study aimed to investigate the involvement of branchial LR in osmoregulation of tilapia and milkfish, two euryhaline teleosts with different salinity preferences, by (i) extracting LR from the gills of euryhaline teleosts; (ii) detecting the abundance of LR marker protein (flotillin-2) and ion-transporters (NKA and VHA A) in branchial LR and non-LR of fresh water- and seawater-acclimated milkfish and tilapia. The results indicated that the protein abundance of LR marker, flotillin-2, changed with environmental salinities in branchial LR of tilapia. In addition, flotillin-2 and NKA were only found in LR in both tilapia and milkfish gills, while VHA A were mainly present in non-LR. Relative protein abundance of NKA was found to be significantly higher in gills of freshwater milkfish and seawater tilapia, while VHA A was significantly higher in gills of freshwater tilapia and milkfish. This study illustrated differential distribution and salinity-dependent expression of NKA and VHA A in cell membrane of gill tissues of euryhaline teleosts with different salinity preferences.
Collapse
|
10
|
Cellular Prion Protein (PrPc): Putative Interacting Partners and Consequences of the Interaction. Int J Mol Sci 2020; 21:ijms21197058. [PMID: 32992764 PMCID: PMC7583789 DOI: 10.3390/ijms21197058] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/20/2020] [Accepted: 09/23/2020] [Indexed: 02/08/2023] Open
Abstract
Cellular prion protein (PrPc) is a small glycosylphosphatidylinositol (GPI) anchored protein most abundantly found in the outer leaflet of the plasma membrane (PM) in the central nervous system (CNS). PrPc misfolding causes neurodegenerative prion diseases in the CNS. PrPc interacts with a wide range of protein partners because of the intrinsically disordered nature of the protein’s N-terminus. Numerous studies have attempted to decipher the physiological role of the prion protein by searching for proteins which interact with PrPc. Biochemical characteristics and biological functions both appear to be affected by interacting protein partners. The key challenge in identifying a potential interacting partner is to demonstrate that binding to a specific ligand is necessary for cellular physiological function or malfunction. In this review, we have summarized the intracellular and extracellular interacting partners of PrPc and potential consequences of their binding. We also briefly describe prion disease-related mutations at the end of this review.
Collapse
|
11
|
Flotillins promote T cell receptor sorting through a fast Rab5-Rab11 endocytic recycling axis. Nat Commun 2019; 10:4392. [PMID: 31558725 PMCID: PMC6763463 DOI: 10.1038/s41467-019-12352-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 08/28/2019] [Indexed: 12/25/2022] Open
Abstract
The targeted endocytic recycling of the T cell receptor (TCR) to the immunological synapse is essential for T cell activation. Despite this, the mechanisms that underlie the sorting of internalised receptors into recycling endosomes remain poorly understood. To build a comprehensive picture of TCR recycling during T cell activation, we developed a suite of new imaging and quantification tools centred on photoactivation of fluorescent proteins. We show that the membrane-organising proteins, flotillin-1 and -2, are required for TCR to reach Rab5-positive endosomes immediately after endocytosis and for transfer from Rab5- to Rab11a-positive compartments. We further observe that after sorting into in Rab11a-positive vesicles, TCR recycles to the plasma membrane independent of flotillin expression. Our data suggest a mechanism whereby flotillins delineate a fast Rab5-Rab11a endocytic recycling axis and functionally contribute to regulate the spatial organisation of these endosomes. Internalized receptors are recycled back to the cell surface, but their precise mechanisms are unclear. Here, the authors show that the flotillin membrane proteins may regulate the transfer of internalized T cell receptors into Rab5 and Rab11-positive endosomes to support its rapid recycling.
Collapse
|
12
|
Bai C, Kang N, Zhao J, Dai J, Gao H, Chen Y, Dong H, Huang C, Dong Q. Cryopreservation disrupts lipid rafts and heat shock proteins in yellow catfish sperm. Cryobiology 2019; 87:32-39. [PMID: 30876909 DOI: 10.1016/j.cryobiol.2019.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/06/2019] [Accepted: 03/08/2019] [Indexed: 11/25/2022]
Abstract
Lipid rafts and associated membrane proteins (flotillin, caveolin) play important roles in cell signaling and sperm fertilization while heat shock proteins (Hsp) ensure properly protein folding to fulfill their physiological functions. The markedly reduced fertility in thawed sperm after cryopreservation could result from disrupted membrane lipid rafts and these proteins. To explore the effect of sperm cryopreservation on lipid rafts and heat shock proteins, we compared lipid raft integrity, and the expression levels of lipid raft associated proteins (Flot-1, Flot-2, Cav-1) as well as heat shock proteins (Hsp90, Hsp70) in fresh and thawed sperm cryopreserved under different scenarios in yellow catfish. We found higher lipid raft integrity, higher protein expression levels of Flot-1, Flot-2, Cav-1, Hsp90, and Hsp70 in fresh sperm samples than in thawed sperm samples, in thawed sperm samples cryopreserved with optimal cooling rate than those cryopreserved with sub-optimal cooling rate, and in thawed sperm samples cryopreserved with extenders supplemented with cholesterol than those supplemented with methyl-β-cyclodextrin (for cholesterol removal). Our findings indicate that lipid raft integrity, and expression levels of Flot-1, Flot-2, Cav-1, Hsp90, and Hsp70 are clearly associated with sperm quality, and together they may play a cumulative role in reduced fertility associated with thawed sperm in aquatic species.
Collapse
Affiliation(s)
- Chenglian Bai
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou 325035, PR China; Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Ning Kang
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Junping Zhao
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Jun Dai
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Hui Gao
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou 325035, PR China; Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Yuanhong Chen
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Haojia Dong
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Changjiang Huang
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou 325035, PR China; Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Qiaoxiang Dong
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou 325035, PR China; Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China.
| |
Collapse
|
13
|
Kessler EL, van Stuijvenberg L, van Bavel JJA, van Bennekom J, Zwartsen A, Rivaud MR, Vink A, Efimov IR, Postma AV, van Tintelen JP, Remme CA, Vos MA, Banning A, de Boer TP, Tikkanen R, van Veen TAB. Flotillins in the intercalated disc are potential modulators of cardiac excitability. J Mol Cell Cardiol 2018; 126:86-95. [PMID: 30452906 DOI: 10.1016/j.yjmcc.2018.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 01/24/2023]
Abstract
BACKGROUND The intercalated disc (ID) is important for cardiac remodeling and has become a subject of intensive research efforts. However, as yet the composition of the ID has still not been conclusively resolved and the role of many proteins identified in the ID, like Flotillin-2, is often unknown. The Flotillin proteins are known to be involved in the stabilization of cadherins and desmosomes in the epidermis and upon cancer development. However, their role in the heart has so far not been investigated. Therefore, in this study, we aimed at identifying the role of Flotillin-1 and Flotillin-2 in the cardiac ID. METHODS Location of Flotillins in human and murine cardiac tissue was evaluated by fluorescent immunolabeling and co-immunoprecipitation. In addition, the effect of Flotillin knockout (KO) on proteins of the ID and in electrical excitation and conduction was investigated in cardiac samples of wildtype (WT), Flotillin-1 KO, Flotilin-2 KO and Flotilin-1/2 double KO mice. Consequences of Flotillin knockdown (KD) on cardiac function were studied (patch clamp and Multi Electrode Array (MEA)) in neonatal rat cardiomyocytes (NRCMs) transfected with siRNAs against Flotillin-1 and/or Flotillin-2. RESULTS First, we confirmed presence in the ID and mutual binding of Flotillin-1 and Flotillin-2 in murine and human cardiac tissue. Flotillin KO mice did not show cardiac fibrosis, nor hypertrophy or changes in expression of the desmosomal ID proteins. However, protein expression of the cardiac sodium channel NaV1.5 was significantly decreased in Flotillin-1 and Flotillin-1/2 KO mice compared to WT mice. In addition, sodium current density showed a significant decrease upon Flotillin-1/2 KD in NRCMs as compared to scrambled siRNA-transfected NRCMs. MEA recordings of Flotillin-2 KD NRCM cultures showed a significantly decreased spike amplitude and a tendency of a reduced spike slope when compared to control and scrambled siRNA-transfected cultures. CONCLUSIONS In this study, we demonstrate the presence of Flotillin-1, in addition to Flotillin-2 in the cardiac ID. Our findings indicate a modulatory role of Flotillins on NaV1.5 expression at the ID, with potential consequences for cardiac excitation.
Collapse
Affiliation(s)
- Elise L Kessler
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands.
| | - Leonie van Stuijvenberg
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Joanne J A van Bavel
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Joëlle van Bennekom
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Anne Zwartsen
- Dutch Poisons Information Center (DPIC), University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands; Neurotoxicology Research Group, Division Toxicology, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | - Mathilde R Rivaud
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Aryan Vink
- Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Igor R Efimov
- Department of Biomedical Engineering, George Washington University, Washington, DC, USA
| | - Alex V Postma
- Department of Clinical Genetics, Amsterdam University Medical Center, Location AMC, the Netherlands
| | - J Peter van Tintelen
- Department of Clinical Genetics, Amsterdam University Medical Center, Location AMC, the Netherlands; Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Carol A Remme
- Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, the Netherlands
| | - Marc A Vos
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Antje Banning
- Institute of Biochemistry, Medical Faculty, University of Giessen, Germany
| | - Teun P de Boer
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Ritva Tikkanen
- Institute of Biochemistry, Medical Faculty, University of Giessen, Germany
| | - Toon A B van Veen
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| |
Collapse
|
14
|
Liu XX, Liu WD, Wang L, Zhu B, Shi X, Peng ZX, Zhu HC, Liu XD, Zhong MZ, Xie D, Zeng MS, Ren CP. Roles of flotillins in tumors. J Zhejiang Univ Sci B 2018; 19:171-182. [PMID: 29504311 DOI: 10.1631/jzus.b1700102] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The identification and use of molecular biomarkers have greatly improved the diagnosis and treatment of malignant tumors. However, a much deeper understanding of oncogenic proteins is needed for the benefit to cancer patients. The lipid raft marker proteins, flotillin-1 and flotillin-2, were first found in goldfish retinal ganglion cells during axon regeneration. They have since been found in a variety of cells, mainly on the inner surface of cell membranes, and not only act as a skeleton to provide a platform for protein-protein interactions, but also are involved in signal transduction, nerve regeneration, endocytosis, and lymphocyte activation. Previous studies have shown that flotillins are closely associated with tumor development, invasion, and metastasis. In this article, we review the functions of flotillins in relevant cell processes, their underlying mechanisms of action in a variety of tumors, and their potential applications to tumor molecular diagnosis and targeted therapy.
Collapse
Affiliation(s)
- Xu-Xu Liu
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, Central South University, Changsha 410078, China
| | - Wei-Dong Liu
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, Central South University, Changsha 410078, China
| | - Lei Wang
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, Central South University, Changsha 410078, China
| | - Bin Zhu
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, Central South University, Changsha 410078, China
| | - Xiao Shi
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, Central South University, Changsha 410078, China
| | - Zi-Xuan Peng
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, Central South University, Changsha 410078, China
| | - He-Cheng Zhu
- Changsha Kexin Cancer Hospital, Changsha 410205, China
| | - Xing-Dong Liu
- Changsha Kexin Cancer Hospital, Changsha 410205, China
| | - Mei-Zuo Zhong
- Changsha Kexin Cancer Hospital, Changsha 410205, China
| | - Dan Xie
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China
| | - Mu-Sheng Zeng
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China
| | - Cai-Ping Ren
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, Central South University, Changsha 410078, China
| |
Collapse
|
15
|
Moretto E, Passafaro M. Recent Findings on AMPA Receptor Recycling. Front Cell Neurosci 2018; 12:286. [PMID: 30233324 PMCID: PMC6129582 DOI: 10.3389/fncel.2018.00286] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 08/10/2018] [Indexed: 02/04/2023] Open
Abstract
α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPA-Rs) are tetrameric protein complexes that mediate most of the fast-excitatory transmission in response to the neurotransmitter glutamate in neurons. The abundance of AMPA-Rs at the surface of excitatory synapses establishes the strength of the response to glutamate. It is thus evident that neurons need to tightly regulate this feature, particularly in the context of all synaptic plasticity events, which are considered the biological correlates of higher cognitive functions such as learning and memory. AMPA-R levels at the synapse are regulated by insertion of newly synthesized receptors, lateral diffusion on the plasma membrane and endosomal cycling. The latter is likely the most important especially for synaptic plasticity. This process starts with the endocytosis of the receptor from the cell surface and is followed by either degradation, if the receptor is directed to the lysosomal compartment, or reinsertion at the cell surface through a specialized endosomal compartment called recycling endosomes. Although the basic steps of this process have been discovered, the details and participation of additional regulatory proteins are still being discovered. In this review article, we describe the most recent findings shedding light on this crucial mechanism of synaptic regulation.
Collapse
Affiliation(s)
- Edoardo Moretto
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche (CNR), Milan, Italy
| | - Maria Passafaro
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche (CNR), Milan, Italy
| |
Collapse
|
16
|
Santos AL, Preta G. Lipids in the cell: organisation regulates function. Cell Mol Life Sci 2018; 75:1909-1927. [PMID: 29427074 PMCID: PMC11105414 DOI: 10.1007/s00018-018-2765-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 01/04/2018] [Accepted: 01/29/2018] [Indexed: 12/19/2022]
Abstract
Lipids are fundamental building blocks of all cells and play important roles in the pathogenesis of different diseases, including inflammation, autoimmune disease, cancer, and neurodegeneration. The lipid composition of different organelles can vary substantially from cell to cell, but increasing evidence demonstrates that lipids become organised specifically in each compartment, and this organisation is essential for regulating cell function. For example, lipid microdomains in the plasma membrane, known as lipid rafts, are platforms for concentrating protein receptors and can influence intra-cellular signalling. Lipid organisation is tightly regulated and can be observed across different model organisms, including bacteria, yeast, Drosophila, and Caenorhabditis elegans, suggesting that lipid organisation is evolutionarily conserved. In this review, we summarise the importance and function of specific lipid domains in main cellular organelles and discuss recent advances that investigate how these specific and highly regulated structures contribute to diverse biological processes.
Collapse
Affiliation(s)
- Ana L Santos
- Institut National de la Santé et de la Recherche Médicale, U1001 and Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Giulio Preta
- Institute of Biochemistry, Vilnius University, Sauletekio 7, LT-10257, Vilnius, Lithuania.
| |
Collapse
|
17
|
Riquelme M, Aguirre J, Bartnicki-García S, Braus GH, Feldbrügge M, Fleig U, Hansberg W, Herrera-Estrella A, Kämper J, Kück U, Mouriño-Pérez RR, Takeshita N, Fischer R. Fungal Morphogenesis, from the Polarized Growth of Hyphae to Complex Reproduction and Infection Structures. Microbiol Mol Biol Rev 2018; 82:e00068-17. [PMID: 29643171 PMCID: PMC5968459 DOI: 10.1128/mmbr.00068-17] [Citation(s) in RCA: 183] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Filamentous fungi constitute a large group of eukaryotic microorganisms that grow by forming simple tube-like hyphae that are capable of differentiating into more-complex morphological structures and distinct cell types. Hyphae form filamentous networks by extending at their tips while branching in subapical regions. Rapid tip elongation requires massive membrane insertion and extension of the rigid chitin-containing cell wall. This process is sustained by a continuous flow of secretory vesicles that depends on the coordinated action of the microtubule and actin cytoskeletons and the corresponding motors and associated proteins. Vesicles transport cell wall-synthesizing enzymes and accumulate in a special structure, the Spitzenkörper, before traveling further and fusing with the tip membrane. The place of vesicle fusion and growth direction are enabled and defined by the position of the Spitzenkörper, the so-called cell end markers, and other proteins involved in the exocytic process. Also important for tip extension is membrane recycling by endocytosis via early endosomes, which function as multipurpose transport vehicles for mRNA, septins, ribosomes, and peroxisomes. Cell integrity, hyphal branching, and morphogenesis are all processes that are largely dependent on vesicle and cytoskeleton dynamics. When hyphae differentiate structures for asexual or sexual reproduction or to mediate interspecies interactions, the hyphal basic cellular machinery may be reprogrammed through the synthesis of new proteins and/or the modification of protein activity. Although some transcriptional networks involved in such reprogramming of hyphae are well studied in several model filamentous fungi, clear connections between these networks and known determinants of hyphal morphogenesis are yet to be established.
Collapse
Affiliation(s)
- Meritxell Riquelme
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Jesús Aguirre
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Salomon Bartnicki-García
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - Michael Feldbrügge
- Institute for Microbiology, Heinrich Heine University Düsseldorf, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Ursula Fleig
- Institute for Functional Genomics of Microorganisms, Heinrich Heine University Düsseldorf, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Wilhelm Hansberg
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Alfredo Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Irapuato, Mexico
| | - Jörg Kämper
- Karlsruhe Institute of Technology-South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Ulrich Kück
- Ruhr University Bochum, Lehrstuhl für Allgemeine und Molekulare Botanik, Bochum, Germany
| | - Rosa R Mouriño-Pérez
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Norio Takeshita
- University of Tsukuba, Faculty of Life and Environmental Sciences, Tsukuba, Japan
| | - Reinhard Fischer
- Karlsruhe Institute of Technology-South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| |
Collapse
|
18
|
Biernatowska A, Augoff K, Podkalicka J, Tabaczar S, Gajdzik-Nowak W, Czogalla A, Sikorski AF. MPP1 directly interacts with flotillins in erythrocyte membrane - Possible mechanism of raft domain formation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2203-2212. [PMID: 28865798 DOI: 10.1016/j.bbamem.2017.08.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 08/21/2017] [Accepted: 08/27/2017] [Indexed: 10/18/2022]
Abstract
Flotillins are prominent, oligomeric protein components of erythrocyte (RBC) membrane raft domains and are considered to play an important structural role in lateral organization of the plasma membrane. In our previous work on erythroid membranes and giant plasma membrane vesicles (GPMVs) derived from them we have shown that formation of functional domains (resting state rafts) depends on the presence of membrane palmitoylated protein 1 (MPP1/p55), pointing to its new physiological role. Exploration of the molecular mechanism of MPP1 function in organizing membrane domains described here, through searching for its molecular partners in RBC membrane by using different methods, led to the identification of the raft-marker proteins, flotillin 1 and flotillin 2, as hitherto unreported direct MPP1 binding-partners in the RBC membrane. These proteins are found in high molecular-weight complexes in native RBC membrane and, significantly, their presence was shown to be separate from the well-known protein 4.1-dependent interactions of MPP1 with membrane proteins. Furthermore, FLIM analysis revealed that loss of the endogenous MPP1-flotillins interactions resulted in significant changes in RBC membrane-fluidity, emphasizing the physiological importance of such interactions in vivo. Therefore, our data establish a new perspective on the role of MPP1 in erythroid cells and suggests that direct MPP1-flotillins interactions could be the major driving-force behind the formation of raft domains in RBC.
Collapse
Affiliation(s)
- Agnieszka Biernatowska
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroc1aw, Wroclaw, Poland
| | - Katarzyna Augoff
- Department of Gastrointestinal and General Surgery, Wroclaw Medical University, Wroclaw, Poland
| | - Joanna Podkalicka
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroc1aw, Wroclaw, Poland
| | - Sabina Tabaczar
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroc1aw, Wroclaw, Poland
| | - Weronika Gajdzik-Nowak
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroc1aw, Wroclaw, Poland
| | - Aleksander Czogalla
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroc1aw, Wroclaw, Poland
| | - Aleksander F Sikorski
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroc1aw, Wroclaw, Poland.
| |
Collapse
|
19
|
Plattner H. Evolutionary Cell Biology of Proteins from Protists to Humans and Plants. J Eukaryot Microbiol 2017; 65:255-289. [PMID: 28719054 DOI: 10.1111/jeu.12449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/04/2017] [Accepted: 07/07/2017] [Indexed: 01/10/2023]
Abstract
During evolution, the cell as a fine-tuned machine had to undergo permanent adjustments to match changes in its environment, while "closed for repair work" was not possible. Evolution from protists (protozoa and unicellular algae) to multicellular organisms may have occurred in basically two lineages, Unikonta and Bikonta, culminating in mammals and angiosperms (flowering plants), respectively. Unicellular models for unikont evolution are myxamoebae (Dictyostelium) and increasingly also choanoflagellates, whereas for bikonts, ciliates are preferred models. Information accumulating from combined molecular database search and experimental verification allows new insights into evolutionary diversification and maintenance of genes/proteins from protozoa on, eventually with orthologs in bacteria. However, proteins have rarely been followed up systematically for maintenance or change of function or intracellular localization, acquirement of new domains, partial deletion (e.g. of subunits), and refunctionalization, etc. These aspects are discussed in this review, envisaging "evolutionary cell biology." Protozoan heritage is found for most important cellular structures and functions up to humans and flowering plants. Examples discussed include refunctionalization of voltage-dependent Ca2+ channels in cilia and replacement by other types during evolution. Altogether components serving Ca2+ signaling are very flexible throughout evolution, calmodulin being a most conservative example, in contrast to calcineurin whose catalytic subunit is lost in plants, whereas both subunits are maintained up to mammals for complex functions (immune defense and learning). Domain structure of R-type SNAREs differs in mono- and bikonta, as do Ca2+ -dependent protein kinases. Unprecedented selective expansion of the subunit a which connects multimeric base piece and head parts (V0, V1) of H+ -ATPase/pump may well reflect the intriguing vesicle trafficking system in ciliates, specifically in Paramecium. One of the most flexible proteins is centrin when its intracellular localization and function throughout evolution is traced. There are many more examples documenting evolutionary flexibility of translation products depending on requirements and potential for implantation within the actual cellular context at different levels of evolution. From estimates of gene and protein numbers per organism, it appears that much of the basic inventory of protozoan precursors could be transmitted to highest eukaryotic levels, with some losses and also with important additional "inventions."
Collapse
Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, P. O. Box M625, Konstanz, 78457, Germany
| |
Collapse
|
20
|
Bodrikov V, Welte C, Wiechers M, Weschenfelder M, Kaur G, Shypitsyna A, Pinzon-Olejua A, Bastmeyer M, Stuermer CAO. Substrate properties of zebrafish Rtn4b/Nogo and axon regeneration in the zebrafish optic nerve. J Comp Neurol 2017; 525:2991-3009. [PMID: 28560734 DOI: 10.1002/cne.24253] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/16/2017] [Accepted: 05/24/2017] [Indexed: 11/08/2022]
Abstract
This study explored why lesioned retinal ganglion cell (RGC) axons regenerate successfully in the zebrafish optic nerve despite the presence of Rtn4b, the homologue of the rat neurite growth inhibitor RTN4-A/Nogo-A. Rat Nogo-A and zebrafish Rtn4b possess characteristic motifs (M1-4) in the Nogo-A-specific region, which contains delta20, the most inhibitory region of rat Nogo-A. To determine whether zebrafish M1-4 is inhibitory as rat M1-4 and Nogo-A delta20, proteins were recombinantly expressed and used as substrates for zebrafish single cell RGCs, mouse hippocampal neurons and goldfish, zebrafish and chick retinal explants. When offered as homogenous substrates, neurites of hippocampal neurons and of zebrafish single cell RGCs were inhibited by zebrafish M1-4, rat M1-4, and Nogo-A delta20. Neurite length increased when zebrafish single cell RGCs were treated with receptor-type-specific antagonists and, respectively, with morpholinos (MO) against S1PR2 and S1PR5a-which represent candidate zebrafish Nogo-A receptors. In a stripe assay, however, where M1-4 lanes alternate with polylysine-(Plys)-only lanes, RGC axons from goldfish, zebrafish, and chick retinal explants avoided rat M1-4 but freely crossed zebrafish M1-4 lanes-suggesting that zebrafish M1-4 is growth permissive and less inhibitory than rat M1-4. Moreover, immunostainings and dot blots of optic nerve and myelin showed that expression of Rtn4b is very low in tissue and myelin at 3-5 days after lesion when axons regenerate. Thus, Rtn4b seems to represent no major obstacle for axon regeneration in vivo because it is less inhibitory for RGC axons from retina explants, and because of its low abundance.
Collapse
Affiliation(s)
| | - Cornelia Welte
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Markus Weschenfelder
- Zoological Institute, Cell and Neurobiology Biology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Gurjot Kaur
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | | | - Martin Bastmeyer
- Zoological Institute, Cell and Neurobiology Biology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | | |
Collapse
|
21
|
Lopez D, Koch G. Exploring functional membrane microdomains in bacteria: an overview. Curr Opin Microbiol 2017; 36:76-84. [PMID: 28237903 DOI: 10.1016/j.mib.2017.02.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/01/2017] [Indexed: 01/08/2023]
Abstract
Recent studies show that internal organization of bacterial cells is more complex than previously appreciated. A clear example of this is the assembly of the nanoscale membrane platforms termed functional membrane microdomains. The lipid composition of these regions differs from that of the surrounding membrane; these domains confine a set of proteins involved in specific cellular processes such as protease secretion and signal transduction. It is currently thought that functional membrane microdomains act as oligomerization platforms and promote efficient oligomerization of interacting protein partners in bacterial membranes. In this review, we highlight the most noteworthy achievements, challenges and controversies of this emerging research field over the past five years.
Collapse
Affiliation(s)
- Daniel Lopez
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany; Spanish National Centre for Biotechnology (CNB), Madrid 28049, Spain.
| | - Gudrun Koch
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| |
Collapse
|
22
|
Bodrikov V, Pauschert A, Kochlamazashvili G, Stuermer CAO. Reggie-1 and reggie-2 (flotillins) participate in Rab11a-dependent cargo trafficking, spine synapse formation and LTP-related AMPA receptor (GluA1) surface exposure in mouse hippocampal neurons. Exp Neurol 2016; 289:31-45. [PMID: 27993509 DOI: 10.1016/j.expneurol.2016.12.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 12/13/2016] [Accepted: 12/14/2016] [Indexed: 10/20/2022]
Abstract
Reggie-1 and -2 (flotillins) reside at recycling vesicles and promote jointly with Rab11a the targeted delivery of cargo. Recycling is essential for synapse formation suggesting that reggies and Rab11a may regulate the development of spine synapses. Recycling vesicles provide cargo for dendritic growth and recycle surface glutamate receptors (AMPAR, GluA) for long-term potentiation (LTP) induced surface exposure. Here, we show reduced number of spine synapses and impairment of an in vitro correlate of LTP in hippocampal neurons from reggie-1 k.o. (Flot2-/-) mice maturating in culture. These defects apparently result from reduced trafficking of PSD-95 revealed by live imaging of 10 div reggie-1 k.o. (Flot2-/-) neurons and likely impairs co-transport of cargo destined for spines: N-cadherin and the glutamate receptors GluA1 and GluN1. Impaired cargo trafficking and fewer synapses also emerged in reggie-1 siRNA, reggie-2 siRNA, and reggie-1 and -2 siRNA-treated neurons and was in siRNA and k.o. neurons rescued by reggie-1-EGFP and CA-Rab11a-EGFP. While correlative expressional changes of specific synapse proteins were observed in reggie-1 k.o. (Flot2-/-) brains in vivo, this did not occur in neurons maturating in vitro. Our work suggests that reggie-1 and reggie-2 function at Rab11a recycling containers in the transport of PSD-95, N-cadherin, GluA1 and GluN1, and promote (together with significant signaling molecules) spine-directed trafficking, spine synapse formation and the in vitro correlate of LTP.
Collapse
Affiliation(s)
| | - Aline Pauschert
- Dept. Biology, University Konstanz, 78464 Konstanz, Germany.
| | - Gaga Kochlamazashvili
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Roessle-Straße 10, 13125 Berlin, Germany.
| | | |
Collapse
|
23
|
Functional Membrane Microdomains Organize Signaling Networks in Bacteria. J Membr Biol 2016; 250:367-378. [PMID: 27566471 DOI: 10.1007/s00232-016-9923-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 08/16/2016] [Indexed: 11/27/2022]
Abstract
Membrane organization is usually associated with the correct function of a number of cellular processes in eukaryotic cells as diverse as signal transduction, protein sorting, membrane trafficking, or pathogen invasion. It has been recently discovered that bacterial membranes are able to compartmentalize their signal transduction pathways in functional membrane microdomains (FMMs). In this review article, we discuss the biological significance of the existence of FMMs in bacteria and comment on possible beneficial roles that FMMs play on the harbored signal transduction cascades. Moreover, four different membrane-associated signal transduction cascades whose functions are linked to the integrity of FMMs are introduced, and the specific role that FMMs play in stabilizing and promoting interactions of their signaling components is discussed. Altogether, FMMs seem to play a relevant role in promoting more efficient activation of signal transduction cascades in bacterial cells and show that bacteria are more sophisticated organisms than previously appreciated.
Collapse
|
24
|
4.1N is involved in a flotillin-1/β-catenin/Wnt pathway and suppresses cell proliferation and migration in non-small cell lung cancer cell lines. Tumour Biol 2016; 37:12713-12723. [DOI: 10.1007/s13277-016-5146-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/11/2016] [Indexed: 01/14/2023] Open
|
25
|
Dempwolff F, Schmidt FK, Hervás AB, Stroh A, Rösch TC, Riese CN, Dersch S, Heimerl T, Lucena D, Hülsbusch N, Stuermer CAO, Takeshita N, Fischer R, Eckhardt B, Graumann PL. Super Resolution Fluorescence Microscopy and Tracking of Bacterial Flotillin (Reggie) Paralogs Provide Evidence for Defined-Sized Protein Microdomains within the Bacterial Membrane but Absence of Clusters Containing Detergent-Resistant Proteins. PLoS Genet 2016; 12:e1006116. [PMID: 27362352 PMCID: PMC4928834 DOI: 10.1371/journal.pgen.1006116] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 05/20/2016] [Indexed: 12/14/2022] Open
Abstract
Biological membranes have been proposed to contain microdomains of a specific lipid composition, in which distinct groups of proteins are clustered. Flotillin-like proteins are conserved between pro—and eukaryotes, play an important function in several eukaryotic and bacterial cells, and define in vertebrates a type of so-called detergent-resistant microdomains. Using STED microscopy, we show that two bacterial flotillins, FloA and FloT, form defined assemblies with an average diameter of 85 to 110 nm in the model bacterium Bacillus subtilis. Interestingly, flotillin microdomains are of similar size in eukaryotic cells. The soluble domains of FloA form higher order oligomers of up to several hundred kDa in vitro, showing that like eukaryotic flotillins, bacterial assemblies are based in part on their ability to self-oligomerize. However, B. subtilis paralogs show significantly different diffusion rates, and consequently do not colocalize into a common microdomain. Dual colour time lapse experiments of flotillins together with other detergent-resistant proteins in bacteria show that proteins colocalize for no longer than a few hundred milliseconds, and do not move together. Our data reveal that the bacterial membrane contains defined-sized protein domains rather than functional microdomains dependent on flotillins. Based on their distinct dynamics, FloA and FloT confer spatially distinguishable activities, but do not serve as molecular scaffolds. Many membrane proteins are not uniformly distributed within biological membranes, and may prefer specific lipid environments to function optimally. Using super resolution fluorescence microscopy, we show that several Bacillus subtilis membrane proteins indeed cluster into structures of 60 to 110 nm, verifying the existence of defined-size protein microdomains. Biochemical co-isolation of specific membrane proteins and flotillins, a family of proteins highly conserved between eukaryotic and bacterial cells, suggested that common “functional” microdomains exist, containing so-called “detergent-resistant” membrane proteins, that are centered by flotillins. Through high speed tracking of Bacillus subtilis FloA and FloT we show that both proteins are not present in the same microdomain, but move through the membrane with different velocities. Dual colour time lapse microscopy showed that contrarily to vertebrate flotillins, bacterial flotillins do not move together with detergent-resistant proteins, ruling out the existence of coclusters. The lack of both flotillins, but not of a single one, leads to striking defects in cell shape and in cell growth, indicating important overlapping functions of flotillin paralogs. Our data show that FloA and FloT perform spatially distinct functions, possibly in the insertion of membrane proteins that require a specific lipid environment, based on a close connection between FloA and FloT with the Sec membrane insertion machinery, but do not act as scaffolds for detergent resistant proteins. Our tracking analyses provide an important basis for the understanding of interactions between membrane proteins in living cells.
Collapse
Affiliation(s)
- Felix Dempwolff
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Felix K. Schmidt
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Physics, Philipps Universität Marburg, Marburg, Germany
| | - Ana B. Hervás
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Alex Stroh
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Thomas C. Rösch
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Cornelius N. Riese
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Biology, Philipps Universität Marburg, Marburg, Germany
| | - Simon Dersch
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Thomas Heimerl
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Biology, Philipps Universität Marburg, Marburg, Germany
| | - Daniella Lucena
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
| | - Nikola Hülsbusch
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Norio Takeshita
- University of Tsukuba, Faculty of Life and Environmental Sciences, Tsukuba, Ibaraki, Japan
- Department of Microbiology, Institute for Applied Bioscience, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Reinhard Fischer
- Department of Microbiology, Institute for Applied Bioscience, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Bruno Eckhardt
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Physics, Philipps Universität Marburg, Marburg, Germany
| | - Peter L. Graumann
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps Universität Marburg, Marburg, Germany
- Department of Chemistry, Philipps Universität Marburg, Marburg, Germany
- * E-mail:
| |
Collapse
|
26
|
Iwamaru Y, Kitani H, Okada H, Takenouchi T, Shimizu Y, Imamura M, Miyazawa K, Murayama Y, Hoover EA, Yokoyama T. Proximity of SCG10 and prion protein in membrane rafts. J Neurochem 2015; 136:1204-1218. [PMID: 26663033 DOI: 10.1111/jnc.13488] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 12/14/2022]
Abstract
The conversion of normal cellular prion protein (PrPC) into its pathogenic isoform (PrPSc) is an essential event in prion pathogenesis. In culture models, membrane rafts are suggested to play a critical role in PrPSc formation. To identify the candidate molecules capable of interacting with PrPC and facilitating PrPSc formation in membrane rafts, we applied a novel biochemical labeling method termed enzyme-mediated activation of radical sources. Enzyme-mediated activation of radical sources was applied to the Lubrol WX insoluble detergent-resistant membrane fractions from mouse neuroblastoma (N2a) cells in which the surface PrPC was labeled with HRP-conjugated anti-PrP antibody. Two-dimensional western blots of these preparations revealed biotinylated spots of approximately 20 kDa with an isoelectric point of 8.0-9.0. Liquid chromatography-tandem mass spectrometry analysis resulted in the identification of peptides containing SCG10, the neuron-specific microtubule regulator. Proximity of SCG10 and PrPC was confirmed using proximity ligation assay and co-immunoprecipitation assay. Transfection of persistently 22L prion-infected N2a cells with SCG10 small interfering RNA reduced SCG10 expression, but did not prevent PrPSc accumulation, indicating that SCG10 appears to be unrelated to PrPSc formation of 22L prion. Immunofluorescence and western blot analyses showed reduced levels of SCG10 in the hippocampus of prion-infected mice, suggesting a possible association between SCG10 levels and the prion neuropathogenesis. By applying a novel biochemical labeling method against detergent-resistant membrane fractions from mouse neuroblastoma cells, the neuron-specific microtubule-destabilization protein, SCG10 was identified as a novel candidate that is proximate to normal prion protein (PrP) in membrane rafts. SCG10 seemed unrelated to disease-related PrP formation under certain conditions, while there is a possible association between SCG10 levels and prion neuropathogenesis. Cover Image for this issue: doi: 10.1111/jnc.13310.
Collapse
Affiliation(s)
- Yoshifumi Iwamaru
- Influenza and Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan.,Prion Research Center, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Hiroshi Kitani
- Animal Immune and Cell Biology Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Hiroyuki Okada
- Influenza and Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Takato Takenouchi
- Animal Immune and Cell Biology Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Yoshihisa Shimizu
- Influenza and Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Morikazu Imamura
- Influenza and Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Kohtaro Miyazawa
- Influenza and Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Yuichi Murayama
- Influenza and Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| | - Edward A Hoover
- Prion Research Center, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Takashi Yokoyama
- Influenza and Prion Disease Research Center, National Institute of Animal Health, Tsukuba, Ibaraki, Japan
| |
Collapse
|
27
|
Burkhardt P. The origin and evolution of synaptic proteins - choanoflagellates lead the way. ACTA ACUST UNITED AC 2015; 218:506-14. [PMID: 25696814 DOI: 10.1242/jeb.110247] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The origin of neurons was a key event in evolution, allowing metazoans to evolve rapid behavioral responses to environmental cues. Reconstructing the origin of synaptic proteins promises to reveal their ancestral functions and might shed light on the evolution of the first neuron-like cells in metazoans. By analyzing the genomes of diverse metazoans and their closest relatives, the evolutionary history of diverse presynaptic and postsynaptic proteins has been reconstructed. These analyses revealed that choanoflagellates, the closest relatives of metazoans, possess diverse synaptic protein homologs. Recent studies have now begun to investigate their ancestral functions. A primordial neurosecretory apparatus in choanoflagellates was identified and it was found that the mechanism, by which presynaptic proteins required for secretion of neurotransmitters interact, is conserved in choanoflagellates and metazoans. Moreover, studies on the postsynaptic protein homolog Homer revealed unexpected localization patterns in choanoflagellates and new binding partners, both which are conserved in metazoans. These findings demonstrate that the study of choanoflagellates can uncover ancient and previously undescribed functions of synaptic proteins.
Collapse
Affiliation(s)
- Pawel Burkhardt
- Marine Biological Association, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
| |
Collapse
|
28
|
Frontotemporal dementia-associated N279K tau mutant disrupts subcellular vesicle trafficking and induces cellular stress in iPSC-derived neural stem cells. Mol Neurodegener 2015; 10:46. [PMID: 26373282 PMCID: PMC4572645 DOI: 10.1186/s13024-015-0042-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 09/07/2015] [Indexed: 11/10/2022] Open
Abstract
Background Pallido-ponto-nigral degeneration (PPND), a major subtype of frontotemporal dementia with parkinsonism related to chromosome 17 (FTDP-17), is a progressive and terminal neurodegenerative disease caused by c.837 T > G mutation in the MAPT gene encoding microtubule-associated protein tau (rs63750756; N279K). This MAPT mutation induces alternative splicing of exon 10, resulting in a modification of microtubule-binding region of tau. Although mutations in the MAPT gene have been linked to multiple tauopathies including Alzheimer’s disease, frontotemporal dementia and progressive supranuclear palsy, knowledge regarding how tau N279K mutation causes PPND/FTDP-17 is limited. Results We investigated the underlying disease mechanism associated with the N279K tau mutation using PPND/FTDP-17 patient-derived induced pluripotent stem cells (iPSCs) and autopsy brains. In iPSC-derived neural stem cells (NSCs), the N279K tau mutation induced an increased ratio of 4-repeat to 3-repeat tau and accumulation of stress granules indicating elevated cellular stress. More significant, NSCs derived from patients with the N279K tau mutation displayed impaired endocytic trafficking as evidenced by accumulation of endosomes and exosomes, and a reduction of lysosomes. Since there were no significant differences in cellular stress and distribution of subcellular organelles between control and N279K skin fibroblasts, N279K-related vesicle trafficking defects are likely specific to the neuronal lineage. Consistently, the levels of intracellular/luminal vesicle and exosome marker flotillin-1 were significantly increased in frontal and temporal cortices of PPND/FTDP-17 patients with the N279K tau mutation, events that were not seen in the occipital cortex which is the most spared cortical region in the patients. Conclusion Together, our results demonstrate that alterations of intracellular vesicle trafficking in NSCs/neurons likely contribute to neurodegeneration as an important disease mechanism underlying the N279K tau mutation in PPND/FTDP-17.
Collapse
|
29
|
Lopez D. Molecular composition of functional microdomains in bacterial membranes. Chem Phys Lipids 2015; 192:3-11. [PMID: 26320704 DOI: 10.1016/j.chemphyslip.2015.08.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 08/10/2015] [Accepted: 08/24/2015] [Indexed: 12/14/2022]
Abstract
Membranes of eukaryotic cells organize a number of proteins related to signal transduction and membrane trafficking into microdomains, which are enriched in particular lipids, like cholesterol and sphingolipids and are commonly referred as to lipid rafts or membrane rafts. The existence of this type of signaling platforms was traditionally associated with eukaryotic membranes because prokaryotic cells were considered too simple organisms to require a sophisticated organization of their signaling networks. However, the research that have been performed during last years have shown that bacteria organize many signaling transduction processes in Functional Membrane Microdomains (FMMs), which are similar to the lipid rafts that are found in eukaryotic cells. The current knowledge of the existence of FMMs in bacteria is described in this review and the specific structural and biological properties of these membrane microdomains are introduced. The organization of FMMs in bacterial membranes reveals an unexpected level of sophistication in signaling transduction and membrane organization that is unprecedented in bacteria, suggesting that bacteria as more complex organisms than previously considered.
Collapse
Affiliation(s)
- Daniel Lopez
- Research Center for Infectious Diseases (ZINF), Institute for Molecular Infection Biology (IMIB), University of Würzburg, Josef-Schneider Strasse (2), 97080 Würzburg, Germany; Spanish National Center for Biotechnology (CNB), Campus de Cantoblanco, Darwin 3, 28049 Madrid, Spain.
| |
Collapse
|
30
|
Dubois L, Ronquist KKG, Ek B, Ronquist G, Larsson A. Proteomic Profiling of Detergent Resistant Membranes (Lipid Rafts) of Prostasomes. Mol Cell Proteomics 2015; 14:3015-22. [PMID: 26272980 DOI: 10.1074/mcp.m114.047530] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Indexed: 01/11/2023] Open
Abstract
Prostasomes are exosomes derived from prostate epithelial cells through exocytosis by multivesicular bodies. Prostasomes have a bilayered membrane and readily interact with sperm. The membrane lipid composition is unusual with a high contribution of sphingomyelin at the expense of phosphatidylcholine and saturated and monounsaturated fatty acids are dominant. Lipid rafts are liquid-ordered domains that are more tightly packed than the surrounding nonraft phase of the bilayer. Lipid rafts are proposed to be highly dynamic, submicroscopic assemblies that float freely within the liquid disordered membrane bilayer and some proteins preferentially partition into the ordered raft domains. We asked the question whether lipid rafts do exist in prostasomes and, if so, which proteins might be associated with them. Prostasomes of density range 1.13-1.19g/ml were subjected to density gradient ultracentrifugation in sucrose fabricated by phosphate buffered saline (PBS) containing 1% Triton X-100 with capacity for banding at 1.10 g/ml, i.e. the classical density of lipid rafts. Prepared prostasomal lipid rafts (by gradient ultracentrifugation) were analyzed by mass spectrometry. The clearly visible band on top of 1.10g/ml sucrose in the Triton X-100 containing gradient was subjected to liquid chromatography-tandem MS and more than 370 lipid raft associated proteins were identified. Several of them were involved in intraluminal vesicle formation, e.g. tetraspanins, ESCRTs, and Ras-related proteins. This is the first comprehensive liquid chromatography-tandem MS profiling of proteins in lipid rafts derived from exosomes. Data are available via ProteomeXchange with identifier PXD002163.
Collapse
Affiliation(s)
- Louise Dubois
- From the ‡Department of Medical Sciences, Uppsala University, 75185 Uppsala, Sweden
| | - Karl K Göran Ronquist
- From the ‡Department of Medical Sciences, Uppsala University, 75185 Uppsala, Sweden;
| | - Bo Ek
- §Department of Analytical Chemistry, Science for Life Laboratory, Uppsala University, 751 24 Uppsala, Sweden
| | - Gunnar Ronquist
- From the ‡Department of Medical Sciences, Uppsala University, 75185 Uppsala, Sweden
| | - Anders Larsson
- From the ‡Department of Medical Sciences, Uppsala University, 75185 Uppsala, Sweden
| |
Collapse
|
31
|
Hülsbusch N, Solis GP, Katanaev VL, Stuermer CAO. Reggie-1/Flotillin-2 regulates integrin trafficking and focal adhesion turnover via Rab11a. Eur J Cell Biol 2015; 94:531-45. [PMID: 26299802 DOI: 10.1016/j.ejcb.2015.07.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/28/2015] [Accepted: 07/30/2015] [Indexed: 12/24/2022] Open
Abstract
Reggies/flotillins are implicated in trafficking of membrane proteins to their target sites and in the regulation of the Rab11a-dependent targeted recycling of E-cadherin to adherens junctions (AJs). Here we demonstrate a function of reggies in focal adhesion (FA) formation and α5- and β1-integrin recycling to FAs. Downregulation of reggie-1 in HeLa and A431 cells by siRNA and shRNA increased the number of FAs, impaired their distribution and modified FA turnover. This was coupled to enhanced focal adhesion kinase (FAK) and Rac1 signaling and gain in plasma membrane motility. Wild type and constitutively-active (CA) Rab11a rescued the phenotype (normal number of FAs) whereas dominant-negative (DN) Rab11a mimicked the loss-of-reggie phenotype in control cells. That reggie-1 affects integrin trafficking emerged from the faster loss of internalized antibody-labeled β1-integrin in reggie-deficient cells. Moreover, live imaging using TIRF microscopy revealed vesicles containing reggie-1 and α5- or β1-integrin, trafficking close to the substrate-near membrane and making kiss-and-run contacts with FAs. Thus, reggie-1 in interaction with Rab11a controls Rac1 and FAK activation and coordinates the targeted recycling of α5- and β1-integrins to FAs to regulate FA formation and membrane dynamics.
Collapse
Affiliation(s)
- Nikola Hülsbusch
- Department of Biology, University of Konstanz, 78467 Konstanz, Germany.
| | - Gonzalo P Solis
- Department of Pharmacology and Toxicology, University of Lausanne, CH-1005 Lausanne, Switzerland
| | - Vladimir L Katanaev
- Department of Pharmacology and Toxicology, University of Lausanne, CH-1005 Lausanne, Switzerland
| | | |
Collapse
|
32
|
Functional Analysis of Sterol Transporter Orthologues in the Filamentous Fungus Aspergillus nidulans. EUKARYOTIC CELL 2015; 14:908-21. [PMID: 26116213 DOI: 10.1128/ec.00027-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 06/24/2015] [Indexed: 11/20/2022]
Abstract
Polarized growth in filamentous fungi needs a continuous supply of proteins and lipids to the growing hyphal tip. One of the important membrane compounds in fungi is ergosterol. At the apical plasma membrane ergosterol accumulations, which are called sterol-rich plasma membrane domains (SRDs). The exact roles and formation mechanism of the SRDs remained unclear, although the importance has been recognized for hyphal growth. Transport of ergosterol to hyphal tips is thought to be important for the organization of the SRDs. Oxysterol binding proteins, which are conserved from yeast to human, are involved in nonvesicular sterol transport. In Saccharomyces cerevisiae seven oxysterol-binding protein homologues (OSH1 to -7) play a role in ergosterol distribution between closely located membranes independent of vesicle transport. We found five homologous genes (oshA to oshE) in the filamentous fungi Aspergillus nidulans. The functions of OshA-E were characterized by gene deletion and subcellular localization. Each gene-deletion strain showed characteristic phenotypes and different sensitivities to ergosterol-associated drugs. Green fluorescent protein-tagged Osh proteins showed specific localization in the late Golgi compartments, puncta associated with the endoplasmic reticulum, or diffusely in the cytoplasm. The genes expression and regulation were investigated in a medically important species Aspergillus fumigatus, as well as A. nidulans. Our results suggest that each Osh protein plays a role in ergosterol distribution at distinct sites and contributes to proper fungal growth.
Collapse
|
33
|
Abstract
It has been over 20 years since the discovery that caveolar lipid rafts function as signalling organelles. Lipid rafts create plasma membrane heterogeneity, and caveolae are the most extensively studied subset of lipid rafts. A newly emerging paradigm is that changes in caveolae also generate tumour metabolic heterogeneity. Altered caveolae create a catabolic tumour microenvironment, which supports oxidative mitochondrial metabolism in cancer cells and which contributes to dismal survival rates for cancer patients. In this Review, we discuss the role of caveolae in tumour progression, with a special emphasis on their metabolic and cell signalling effects, and their capacity to transform the tumour microenvironment.
Collapse
Affiliation(s)
- Ubaldo E Martinez-Outschoorn
- Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
| | - Federica Sotgia
- 1] Breakthrough Breast Cancer Research Unit, Institute of Cancer Sciences, University of Manchester, Manchester M20 4BX, UK. [2] Manchester Centre for Cellular Metabolism (MCCM), University of Manchester, Manchester M20 4BX, UK
| | - Michael P Lisanti
- 1] Breakthrough Breast Cancer Research Unit, Institute of Cancer Sciences, University of Manchester, Manchester M20 4BX, UK. [2] Manchester Centre for Cellular Metabolism (MCCM), University of Manchester, Manchester M20 4BX, UK
| |
Collapse
|
34
|
Welte C, Engel S, Stuermer CAO. Upregulation of the zebrafish Nogo-A homologue, Rtn4b, in retinal ganglion cells is functionally involved in axon regeneration. Neural Dev 2015; 10:6. [PMID: 25888884 PMCID: PMC4374419 DOI: 10.1186/s13064-015-0034-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/04/2015] [Indexed: 11/10/2022] Open
Abstract
Background In contrast to mammals, zebrafish successfully regenerate retinal ganglion cell (RGC) axons after optic nerve section (ONS). This difference is explained on the one hand by neurite growth inhibitors in mammals (including Nogo-A), as opposed to growth-promoting glial cells in the fish visual pathway, and on the other hand by the neuron-intrinsic properties allowing the upregulation of growth-associated proteins in fish RGCs but not in mammals. Results Here, we report that Rtn4b, the zebrafish homologue of mammalian Nogo-A/RTN4-A, is upregulated in axotomized zebrafish RGCs and is primarily associated with the endoplasmic reticulum (ER). Rtn4b functions as a neuron-intrinsic determinant for axon regeneration, as was shown by downregulating Rtn4b through retrogradely transported morpholinos (MOs), applied to the optic nerve at the time of ONS. MO1 and MO2 reduced the number of axons from retina explants in a concentration-dependent manner. With MO1, the reduction was 55% (70 μM MO1) and 74% (140 μM MO1), respectively, with MO2: 59% (70 μM MO2) and 73% (140 μM MO2), respectively (compared to the control MO-treated side). Moreover, regenerating axons 7d after ONS and MO1 or MO2 application were labeled by Alexa488, applied distal to the first lesion. The number of Alexa488 labeled RGCs, containing the Rtn4b MO1 or MO2, was reduced by 54% and 62%, respectively, over control MO. Conclusions Thus, Rtn4b is an important neuron-intrinsic component and required for the success of axon regeneration in the zebrafish visual system. The spontaneous lesion-induced upregulation of Rtn4b in fish correlates with an increase in ER, soma size, biosynthetic activity, and thus growth and predicts that mammalian neurons require the same upregulation in order to successfully regenerate RGC axons.
Collapse
Affiliation(s)
- Cornelia Welte
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany.
| | - Sarah Engel
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany.
| | - Claudia A O Stuermer
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany.
| |
Collapse
|
35
|
Abstract
An interesting concept in the organization of cellular membranes is the proposed existence of lipid rafts. Membranes of eukaryotic cells organize signal transduction proteins into membrane rafts or lipid rafts that are enriched in particular lipids such as cholesterol and are important for the correct functionality of diverse cellular processes. The assembly of lipid rafts in eukaryotes has been considered a fundamental step during the evolution of cellular complexity, suggesting that bacteria and archaea were organisms too simple to require such a sophisticated organization of their cellular membranes. However, it was recently discovered that bacteria organize many signal transduction, protein secretion, and transport processes in functional membrane microdomains, which are equivalent to the lipid rafts of eukaryotic cells. This review contains the most significant advances during the last 4 years in understanding the structural and biological role of lipid rafts in bacteria. Furthermore, this review shows a detailed description of a number of molecular and genetic approaches related to the discovery of bacterial lipid rafts as well as an overview of the group of tentative lipid-protein and protein-protein interactions that give consistency to these sophisticated signaling platforms. Additional data suggesting that lipid rafts are widely distributed in bacteria are presented in this review. Therefore, we discuss the available techniques and optimized protocols for the purification and analysis of raft-associated proteins in various bacterial species to aid in the study of bacterial lipid rafts in other laboratories that could be interested in this topic. Overall, the discovery of lipid rafts in bacteria reveals a new level of sophistication in signal transduction and membrane organization that was unexpected for bacteria and shows that bacteria are more complex than previously appreciated.
Collapse
Affiliation(s)
- Marc Bramkamp
- Department of Biology I, University of Munich (LMU), Planegg/Martinsried, Germany
| | - Daniel Lopez
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
| |
Collapse
|
36
|
Petit CSV, Besnier L, Morel E, Rousset M, Thenet S. Roles of the cellular prion protein in the regulation of cell-cell junctions and barrier function. Tissue Barriers 2014; 1:e24377. [PMID: 24665391 PMCID: PMC3887058 DOI: 10.4161/tisb.24377] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 03/18/2013] [Accepted: 03/19/2013] [Indexed: 01/12/2023] Open
Abstract
The cellular prion protein was historically characterized owing to its misfolding in prion disease. Although its physiological role remains incompletely understood, PrP(C) has emerged as an evolutionary conserved, multifaceted protein involved in a wide-range of biological processes. PrP(C) is a GPI-anchored protein targeted to the plasma membrane, in raft microdomains, where its interaction with a repertoire of binding partners, which differ depending on cell models, mediates its functions. Among identified PrP(C) partners are cell adhesion molecules. This review will focus on the multiple implications of PrP(C) in cell adhesion processes, mainly the regulation of cell-cell junctions in epithelial and endothelial cells and the consequences on barrier properties. We will show how recent findings argue for a role of PrP(C) in the recruitment of signaling molecules, which in turn control the targeting or the stability of adhesion complexes at the plasma membrane.
Collapse
Affiliation(s)
- Constance S V Petit
- Centre de Recherche des Cordeliers; Université Pierre et Marie Curie; Paris, France ; INSERM; Paris, France ; Université Paris Descartes; Paris, France
| | - Laura Besnier
- Centre de Recherche des Cordeliers; Université Pierre et Marie Curie; Paris, France ; INSERM; Paris, France ; Université Paris Descartes; Paris, France
| | - Etienne Morel
- Centre de Recherche des Cordeliers; Université Pierre et Marie Curie; Paris, France ; INSERM; Paris, France ; Université Paris Descartes; Paris, France
| | - Monique Rousset
- Centre de Recherche des Cordeliers; Université Pierre et Marie Curie; Paris, France ; INSERM; Paris, France ; Université Paris Descartes; Paris, France
| | - Sophie Thenet
- Centre de Recherche des Cordeliers; Université Pierre et Marie Curie; Paris, France ; INSERM; Paris, France ; Université Paris Descartes; Paris, France ; Ecole Pratique des Hautes Etudes; Laboratoire de Pharmacologie Cellulaire et Moléculaire ; Paris, France
| |
Collapse
|
37
|
Burkhardt P, Grønborg M, McDonald K, Sulur T, Wang Q, King N. Evolutionary insights into premetazoan functions of the neuronal protein homer. Mol Biol Evol 2014; 31:2342-55. [PMID: 24899667 PMCID: PMC4137706 DOI: 10.1093/molbev/msu178] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Reconstructing the evolution and ancestral functions of synaptic proteins promises to shed light on how neurons first evolved. The postsynaptic density (PSD) protein Homer scaffolds membrane receptors and regulates Ca2+ signaling in diverse metazoan cell types (including neurons and muscle cells), yet its ancestry and core functions are poorly understood. We find that the protein domain organization and essential biochemical properties of metazoan Homer proteins, including their ability to tetramerize, are conserved in the choanoflagellate Salpingoeca rosetta, one of the closest living relatives of metazoans. Unlike in neurons, Homer localizes to the nucleoplasm in S. rosetta and interacts directly with Flotillin, a protein more commonly associated with cell membranes. Surprisingly, we found that the Homer/Flotillin interaction and its localization to the nucleus are conserved in metazoan astrocytes. These findings suggest that Homer originally interacted with Flotillin in the nucleus of the last common ancestor of metazoans and choanoflagellates and was later co-opted to function as a membrane receptor scaffold in the PSD.
Collapse
Affiliation(s)
- Pawel Burkhardt
- Howard Hughes Medical Institute and the Department of Molecular and Cell Biology, University of California, Berkeley
| | | | - Kent McDonald
- Electron Microscopy Laboratory, University of California, Berkeley
| | - Tara Sulur
- Howard Hughes Medical Institute and the Department of Molecular and Cell Biology, University of California, Berkeley
| | - Qi Wang
- California Institute for Quantitative Biosciences, University of California, Berkeley
| | - Nicole King
- Howard Hughes Medical Institute and the Department of Molecular and Cell Biology, University of California, Berkeley
| |
Collapse
|
38
|
Neu3 sialidase-mediated ganglioside conversion is necessary for axon regeneration and is blocked in CNS axons. J Neurosci 2014; 34:2477-92. [PMID: 24523539 DOI: 10.1523/jneurosci.4432-13.2014] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
PNS axons have a high intrinsic regenerative ability, whereas most CNS axons show little regenerative response. We show that activation of Neu3 sialidase, also known as Neuraminidase-3, causing conversion of GD1a and GT1b to GM1 ganglioside, is an essential step in regeneration occurring in PNS (sensory) but not CNS (retinal) axons in adult rat. In PNS axons, axotomy activates Neu3 sialidase, increasing the ratio of GM1/GD1a and GM1/GT1b gangliosides immediately after injury in vitro and in vivo. No change in the GM1/GD1a ratio after axotomy was observed in retinal axons (in vitro and in vivo), despite the presence of Neu3 sialidase. Externally applied sialidase converted GD1a ganglioside to GM1 and rescued axon regeneration in CNS axons and in PNS axons after Neu3 sialidase blockade. Neu3 sialidase activation in DRGs is initiated by an influx of extracellular calcium, activating P38MAPK and then Neu3 sialidase. Ganglioside conversion by Neu3 sialidase further activates the ERK pathway. In CNS axons, P38MAPK and Neu3 sialidase were not activated by axotomy.
Collapse
|
39
|
Ji YJ, Hwang YS, Mood K, Cho HJ, Lee HS, Winterbottom E, Cousin H, Daar IO. EphrinB2 affects apical constriction in Xenopus embryos and is regulated by ADAM10 and flotillin-1. Nat Commun 2014; 5:3516. [PMID: 24662724 PMCID: PMC4120273 DOI: 10.1038/ncomms4516] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 02/26/2014] [Indexed: 01/19/2023] Open
Abstract
The Eph/ephrin signalling pathways have a critical function in cell adhesion and repulsion, and thus play key roles in various morphogenetic events during development. Here we show that a decrease in ephrinB2 protein causes neural tube closure defects during Xenopus laevis embryogenesis. Such a decrease in ephrinB2 protein levels is observed on the loss of flotillin-1 scaffold protein, a newly identified ephrinB2-binding partner. This dramatic decline in ephrinB2 protein levels on the absence of flotillin-1 expression is specific, and is partly the result of an increased susceptibility to cleavage by the metalloprotease ADAM10. These findings indicate that flotillin-1 regulates ephrinB2 protein levels through ADAM10, and is required for appropriate neural tube morphogenesis in the Xenopus embryo.
Collapse
Affiliation(s)
- Yon Ju Ji
- Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA
| | - Yoo-Seok Hwang
- Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA
| | - Kathleen Mood
- Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA
| | - Hee-Jun Cho
- Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA
| | - Hyun-Shik Lee
- ABRC, CMRI School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu 702-701, South Korea
| | - Emily Winterbottom
- Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA
| | - Hèléne Cousin
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA
| | - Ira O. Daar
- Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA
| |
Collapse
|
40
|
McGuinn KP, Mahoney MG. Lipid rafts and detergent-resistant membranes in epithelial keratinocytes. Methods Mol Biol 2014; 1195:133-44. [PMID: 24504930 DOI: 10.1007/7651_2014_71] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Our understanding of the plasma membrane has markedly increased since Singer and Nicolson proposed the fluid mosaic model in 1972. While their revolutionary theory of the lipid bilayer remains largely valid, it is now known that lipids and proteins are not randomly dispersed throughout the plasma membrane but instead may be organized within membrane microdomains, commonly referred to as lipid rafts. Lipid rafts are highly dynamic, detergent resistant, and enriched with both cholesterol and glycosphingolipids. The two main types are flotillin-rich planar lipid rafts and caveolin-rich caveolae. It is proposed that flotillin and caveolin proteins regulate cell communication by compartmentalizing and interacting with signal transduction proteins within their respective lipid microdomains. Consequently, membrane rafts play an important role in vital cellular functions including migration, invasion, and signaling; thus, alterations in their microenvironment can initiate signaling pathways that affect cellular function and behavior. Therefore, the identification of lipid rafts and their associated proteins is integral to the study of transmembrane signaling. Here, we review the current standard protocols and biochemical approaches used to isolate and define raft proteins from epithelial cells and tissues. Furthermore, in Section 3 of this chapter, detailed protocols are offered for isolating lipid rafts by subjection to detergent and sucrose density centrifugation, as well as an approach for selectively isolating caveolae. Methods to manipulate rafts with treatments such as methyl-β-cyclodextrin and flotillin III are also described.
Collapse
Affiliation(s)
- Kathleen P McGuinn
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, 233 S. 10th Street, Suite 428 BLSB, Philadelphia, PA, 19107, USA
| | | |
Collapse
|
41
|
Ji H, Greening DW, Barnes TW, Lim JW, Tauro BJ, Rai A, Xu R, Adda C, Mathivanan S, Zhao W, Xue Y, Xu T, Zhu HJ, Simpson RJ. Proteome profiling of exosomes derived from human primary and metastatic colorectal cancer cells reveal differential expression of key metastatic factors and signal transduction components. Proteomics 2013; 13:1672-86. [PMID: 23585443 DOI: 10.1002/pmic.201200562] [Citation(s) in RCA: 258] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 03/08/2013] [Accepted: 03/26/2013] [Indexed: 12/14/2022]
Abstract
Exosomes are small extracellular 40-100 nm diameter membrane vesicles of late endosomal origin that can mediate intercellular transfer of RNAs and proteins to assist premetastatic niche formation. Using primary (SW480) and metastatic (SW620) human isogenic colorectal cancer cell lines we compared exosome protein profiles to yield valuable insights into metastatic factors and signaling molecules fundamental to tumor progression. Exosomes purified using OptiPrep™ density gradient fractionation were 40-100 nm in diameter, were of a buoyant density ~1.09 g/mL, and displayed stereotypic exosomal markers TSG101, Alix, and CD63. A major finding was the selective enrichment of metastatic factors (MET, S100A8, S100A9, TNC), signal transduction molecules (EFNB2, JAG1, SRC, TNIK), and lipid raft and lipid raft-associated components (CAV1, FLOT1, FLOT2, PROM1) in exosomes derived from metastatic SW620 cells. Additionally, using cryo-electron microscopy, ultrastructural components in exosomes were identified. A key finding of this study was the detection and colocalization of protein complexes EPCAM-CLDN7 and TNIK-RAP2A in colorectal cancer cell exosomes. The selective enrichment of metastatic factors and signaling pathway components in metastatic colon cancer cell-derived exosomes contributes to our understanding of the cross-talk between tumor and stromal cells in the tumor microenvironment.
Collapse
Affiliation(s)
- Hong Ji
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Abstract
UNLABELLED Bacteria organize many membrane-related signaling processes in functional microdomains that are structurally and functionally similar to the lipid rafts of eukaryotic cells. An important structural component of these microdomains is the protein flotillin, which seems to act as a chaperone in recruiting other proteins to lipid rafts to facilitate their interaction. In eukaryotic cells, the occurrence of severe diseases is often observed in combination with an overproduction of flotillin, but a functional link between these two phenomena is yet to be demonstrated. In this work, we used the bacterial model Bacillus subtilis as a tractable system to study the physiological alterations that occur in cells that overproduce flotillin. We discovered that an excess of flotillin altered specific signal transduction pathways that are associated with the membrane microdomains of bacteria. As a consequence of this, we detected significant defects in cell division and cell differentiation. These physiological alterations were in part caused by an unusual stabilization of the raft-associated protease FtsH. This report opens the possibility of using bacteria as a working model to better understand fundamental questions related to the functionality of lipid rafts. IMPORTANCE The identification of signaling platforms in the membrane of bacteria that are functionally and structurally equivalent to eukaryotic lipid rafts reveals a level of sophistication in signal transduction and membrane organization unexpected in bacteria. It opens new and promising venues to address intricate questions related to the functionality of lipid rafts by using bacteria as a more tractable system. This is the first report that uses bacteria as a working model to investigate a fundamental question that was previously raised while studying the role of eukaryotic lipid rafts. It also provides evidence of the critical role of these signaling platforms in orchestrating diverse physiological processes in prokaryotic cells.
Collapse
|
43
|
Fujita A, Koinuma S, Yasuda S, Nagai H, Kamiguchi H, Wada N, Nakamura T. GTP hydrolysis of TC10 promotes neurite outgrowth through exocytic fusion of Rab11- and L1-containing vesicles by releasing exocyst component Exo70. PLoS One 2013; 8:e79689. [PMID: 24223996 PMCID: PMC3817099 DOI: 10.1371/journal.pone.0079689] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 09/23/2013] [Indexed: 11/24/2022] Open
Abstract
The use of exocytosis for membrane expansion at nerve growth cones is critical for neurite outgrowth. TC10 is a Rho family GTPase that is essential for specific types of vesicular trafficking to the plasma membrane. Recent studies have shown that TC10 and its effector Exo70, a component of the exocyst tethering complex, contribute to neurite outgrowth. However, the molecular mechanisms of the neuritogenesis-promoting functions of TC10 remain to be established. Here, we propose that GTP hydrolysis of vesicular TC10 near the plasma membrane promotes neurite outgrowth by accelerating vesicle fusion by releasing Exo70. Using Förster resonance energy transfer (FRET)-based biosensors, we show that TC10 activity at the plasma membrane decreased at extending growth cones in hippocampal neurons and nerve growth factor (NGF)-treated PC12 cells. In neuronal cells, TC10 activity at vesicles was higher than its activity at the plasma membrane, and TC10-positive vesicles were found to fuse to the plasma membrane in NGF-treated PC12 cells. Therefore, activity of TC10 at vesicles is presumed to be inactivated near the plasma membrane during neuronal exocytosis. Our model is supported by functional evidence that constitutively active TC10 could not rescue decrease in NGF-induced neurite outgrowth induced by TC10 depletion. Furthermore, TC10 knockdown experiments and colocalization analyses confirmed the involvement of Exo70 in TC10-mediated trafficking in neuronal cells. TC10 frequently resided on vesicles containing Rab11, which is a key regulator of recycling pathways and implicated in neurite outgrowth. In growth cones, most of the vesicles containing the cell adhesion molecule L1 had TC10. Exocytosis of Rab11- and L1-positive vesicles may play a central role in TC10-mediated neurite outgrowth. The combination of this study and our previous work on the role of TC10 in EGF-induced exocytosis in HeLa cells suggests that the signaling machinery containing TC10 proposed here may be broadly used for exocytosis.
Collapse
Affiliation(s)
- Akane Fujita
- Division of Biosignaling, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Shingo Koinuma
- Division of Biosignaling, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Sayaka Yasuda
- Division of Biosignaling, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Hiroyuki Nagai
- Division of Biosignaling, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Hiroyuki Kamiguchi
- Laboratory for Neuronal Growth Mechanism, RIKEN Brain Science Institute, Wako, Saitama, Japan
| | - Naoyuki Wada
- Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba, Japan
| | - Takeshi Nakamura
- Division of Biosignaling, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan
- * E-mail:
| |
Collapse
|
44
|
Guillaume E, Comunale F, Do Khoa N, Planchon D, Bodin S, Gauthier-Rouvière C. Flotillin microdomains stabilize cadherins at cell-cell junctions. J Cell Sci 2013; 126:5293-304. [PMID: 24046456 DOI: 10.1242/jcs.133975] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Cadherins are essential in many fundamental processes and assemble at regions of cell-cell contact in large macromolecular complexes named adherens junctions. We have identified flotillin 1 and 2 as new partners of the cadherin complexes. We show that flotillins are localised at cell-cell junctions (CCJs) in a cadherin-dependent manner. Flotillins and cadherins are constitutively associated at the plasma membrane and their colocalisation at CCJ increases with CCJ maturation. Using three-dimensional structured illumination super-resolution microscopy, we found that cadherin and flotillin complexes are associated with F-actin bundles at CCJs. The knockdown of flotillins dramatically affected N- and E-cadherin recruitment at CCJs in mesenchymal and epithelial cell types and perturbed CCJ integrity and functionality. Moreover, we determined that flotillins are required for cadherin association with GM1-containing plasma membrane microdomains. This allows p120 catenin binding to the cadherin complex and its stabilization at CCJs. Altogether, these data demonstrate that flotillin microdomains are required for cadherin stabilization at CCJs and for the formation of functional CCJs.
Collapse
Affiliation(s)
- Emilie Guillaume
- Equipe Labellisée Ligue Contre le Cancer, Universités Montpellier 2 et 1, CRBM, CNRS, UMR 5237, 1919 Route de Mende, 34293 Montpellier, France
| | | | | | | | | | | |
Collapse
|
45
|
Interaction of membrane/lipid rafts with the cytoskeleton: impact on signaling and function: membrane/lipid rafts, mediators of cytoskeletal arrangement and cell signaling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:532-45. [PMID: 23899502 DOI: 10.1016/j.bbamem.2013.07.018] [Citation(s) in RCA: 379] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 05/14/2013] [Accepted: 07/16/2013] [Indexed: 12/14/2022]
Abstract
The plasma membrane in eukaryotic cells contains microdomains that are enriched in certain glycosphingolipids, gangliosides, and sterols (such as cholesterol) to form membrane/lipid rafts (MLR). These regions exist as caveolae, morphologically observable flask-like invaginations, or as a less easily detectable planar form. MLR are scaffolds for many molecular entities, including signaling receptors and ion channels that communicate extracellular stimuli to the intracellular milieu. Much evidence indicates that this organization and/or the clustering of MLR into more active signaling platforms depends upon interactions with and dynamic rearrangement of the cytoskeleton. Several cytoskeletal components and binding partners, as well as enzymes that regulate the cytoskeleton, localize to MLR and help regulate lateral diffusion of membrane proteins and lipids in response to extracellular events (e.g., receptor activation, shear stress, electrical conductance, and nutrient demand). MLR regulate cellular polarity, adherence to the extracellular matrix, signaling events (including ones that affect growth and migration), and are sites of cellular entry of certain pathogens, toxins and nanoparticles. The dynamic interaction between MLR and the underlying cytoskeleton thus regulates many facets of the function of eukaryotic cells and their adaptation to changing environments. Here, we review general features of MLR and caveolae and their role in several aspects of cellular function, including polarity of endothelial and epithelial cells, cell migration, mechanotransduction, lymphocyte activation, neuronal growth and signaling, and a variety of disease settings. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé.
Collapse
|
46
|
Solis GP, Hülsbusch N, Radon Y, Katanaev VL, Plattner H, Stuermer CAO. Reggies/flotillins interact with Rab11a and SNX4 at the tubulovesicular recycling compartment and function in transferrin receptor and E-cadherin trafficking. Mol Biol Cell 2013; 24:2689-702. [PMID: 23825023 PMCID: PMC3756921 DOI: 10.1091/mbc.e12-12-0854] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
In this study reggie-1/flotillin-2 is identified as a component of the tubulovesicular sorting and recycling compartment, where it interacts with and controls the activity of Rab11a and SNX4. Evidence is given that reggie-1 expression is necessary for the proper recycling of transferrin receptor and E-cadherin in HeLa and A431 cells, respectively. The lipid raft proteins reggie-1 and -2 (flotillins) are implicated in membrane protein trafficking but exactly how has been elusive. We find that reggie-1 and -2 associate with the Rab11a, SNX4, and EHD1–decorated tubulovesicular recycling compartment in HeLa cells and that reggie-1 directly interacts with Rab11a and SNX4. Short hairpin RNA–mediated down-regulation of reggie-1 (and -2) in HeLa cells reduces association of Rab11a with tubular structures and impairs recycling of the transferrin–transferrin receptor (TfR) complex to the plasma membrane. Overexpression of constitutively active Rab11a rescues TfR recycling in reggie-deficient HeLa cells. Similarly, in a Ca2+ switch assay in reggie-depleted A431 cells, internalized E-cadherin is not efficiently recycled to the plasma membrane upon Ca2+ repletion. E-cadherin recycling is rescued, however, by overexpression of constitutively active Rab11a or SNX4 in reggie-deficient A431 cells. This suggests that the function of reggie-1 in sorting and recycling occurs in association with Rab11a and SNX4. Of interest, impaired recycling in reggie-deficient cells leads to de novo E-cadherin biosynthesis and cell contact reformation, showing that cells have ways to compensate the loss of reggies. Together our results identify reggie-1 as a regulator of the Rab11a/SNX4-controlled sorting and recycling pathway, which is, like reggies, evolutionarily conserved.
Collapse
Affiliation(s)
- Gonzalo P Solis
- Department of Biology, University of Konstanz, 78467 Konstanz, Germany.
| | | | | | | | | | | |
Collapse
|
47
|
Bach JN, Bramkamp M. Flotillins functionally organize the bacterial membrane. Mol Microbiol 2013; 88:1205-17. [PMID: 23651456 DOI: 10.1111/mmi.12252] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2013] [Indexed: 01/24/2023]
Abstract
Proteins and lipids are heterogeneously distributed in biological membranes. The correct function of membrane proteins depends on spatiotemporal organization into defined membrane areas, called lipid domains or rafts. Lipid microdomains are therefore thought to assist compartmentalization of membranes. However, how lipid and protein assemblies are organized and whether proteins are actively involved in these processes remains poorly understood. We now have identified flotillins to be responsible for lateral segregation of defined membrane domains in the model organism Bacillus subtilis. We show that flotillins form large, dynamic assemblies that are able to influence membrane fluidity and prevent condensation of Laurdan stained membrane regions. Absence of flotillins in vivo leads to coalescence of distinct domains of high membrane order and, hence, loss of flotillins in the bacterial plasma-membrane reduces membrane heterogeneity. We show that flotillins interact with various proteins involved in protein secretion, cell wall metabolism, transport and membrane-related signalling processes. Importantly, maintenance of membrane heterogeneity is critical for vital cellular processes such as protein secretion.
Collapse
Affiliation(s)
- Juri Niño Bach
- Department of Biology I, Ludwig-Maximilians-University, Munich, Großhaderner Str. 2-4, 82152, Planegg-Martinsried, Germany
| | | |
Collapse
|
48
|
Buschiazzo J, Ialy-Radio C, Auer J, Wolf JP, Serres C, Lefèvre B, Ziyyat A. Cholesterol depletion disorganizes oocyte membrane rafts altering mouse fertilization. PLoS One 2013; 8:e62919. [PMID: 23638166 PMCID: PMC3636221 DOI: 10.1371/journal.pone.0062919] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 03/29/2013] [Indexed: 11/18/2022] Open
Abstract
Drastic membrane reorganization occurs when mammalian sperm binds to and fuses with the oocyte membrane. Two oocyte protein families are essential for fertilization, tetraspanins and glycosylphosphatidylinositol-anchored proteins. The firsts are associated to tetraspanin-enriched microdomains and the seconds to lipid rafts. Here we report membrane raft involvement in mouse fertilization assessed by cholesterol modulation using methyl-β-cyclodextrin. Cholesterol removal induced: (1) a decrease of the fertilization rate and index; and (2) a delay in the extrusion of the second polar body. Cholesterol repletion recovered the fertilization ability of cholesterol-depleted oocytes, indicating reversibility of these effects. In vivo time-lapse analyses using fluorescent cholesterol permitted to identify the time-point at which the probe is mainly located at the plasma membrane enabling the estimation of the extent of the cholesterol depletion. We confirmed that the mouse oocyte is rich in rafts according to the presence of the raft marker lipid, ganglioside GM1 on the membrane of living oocytes and we identified the coexistence of two types of microdomains, planar rafts and caveolae-like structures, by terms of two differential rafts markers, flotillin-2 and caveolin-1, respectively. Moreover, this is the first report that shows characteristic caveolae-like invaginations in the mouse oocyte identified by electron microscopy. Raft disruption by cholesterol depletion disturbed the subcellular localization of the signal molecule c-Src and the inhibition of Src kinase proteins prevented second polar body extrusion, consistent with a role of Src-related kinases in fertilization via signaling complexes. Our data highlight the functional importance of intact membrane rafts for mouse fertilization and its dependence on cholesterol.
Collapse
Affiliation(s)
- Jorgelina Buschiazzo
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), Bahía Blanca, Argentina
| | - Come Ialy-Radio
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
| | - Jana Auer
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
| | - Jean-Philippe Wolf
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
- Service d’Histologie Embryologie Biologie de la Reproduction Hôpital Cochin, AP-HP, F75014 Paris, France
| | - Catherine Serres
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
| | - Brigitte Lefèvre
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
| | - Ahmed Ziyyat
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
| |
Collapse
|
49
|
Koch JC, Solis GP, Bodrikov V, Michel U, Haralampieva D, Shypitsyna A, Tönges L, Bähr M, Lingor P, Stuermer CA. Upregulation of reggie-1/flotillin-2 promotes axon regeneration in the rat optic nerve in vivo and neurite growth in vitro. Neurobiol Dis 2013; 51:168-76. [DOI: 10.1016/j.nbd.2012.11.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 10/14/2012] [Accepted: 11/09/2012] [Indexed: 01/23/2023] Open
|
50
|
Wnt secretion and gradient formation. Int J Mol Sci 2013; 14:5130-45. [PMID: 23455472 PMCID: PMC3634490 DOI: 10.3390/ijms14035130] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 02/20/2013] [Accepted: 02/22/2013] [Indexed: 12/14/2022] Open
Abstract
Concentration gradients formed by the lipid-modified morphogens of the Wnt family are known for their pivotal roles during embryogenesis and adult tissue homeostasis. Wnt morphogens are also implicated in a variety of human diseases, especially cancer. Therefore, the signaling cascades triggered by Wnts have received considerable attention during recent decades. However, how Wnts are secreted and how concentration gradients are formed remains poorly understood. The use of model organisms such as Drosophila melanogaster has provided important advances in this area. For instance, we have previously shown that the lipid raft-associated reggie/flotillin proteins influence Wnt secretion and spreading in Drosophila. Our work supports the notion that producing cells secrete Wnt molecules in at least two pools: a poorly diffusible one and a reggie/flotillin-dependent highly diffusible pool which allows morphogen spreading over long distances away from its source of production. Here we revise the current views of Wnt secretion and spreading, and propose two models for the role of the reggie/flotillin proteins in these processes: (i) reggies/flotillins regulate the basolateral endocytosis of the poorly diffusible, membrane-bound Wnt pool, which is then sorted and secreted to apical compartments for long-range diffusion, and (ii) lipid rafts organized by reggies/flotillins serve as “dating points” where extracellular Wnt transiently interacts with lipoprotein receptors to allow its capture and further spreading via lipoprotein particles. We further discuss these processes in the context of human breast cancer. A better understanding of these phenomena may be relevant for identification of novel drug targets and therapeutic strategies.
Collapse
|