1
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Doktorova M, Daum S, Ebenhan J, Neudorf S, Han B, Sharma S, Kasson P, Levental KR, Bacia K, Kenworthy AK, Levental I. Caveolin assemblies displace one bilayer leaflet to organize and bend membranes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.28.610209. [PMID: 39257813 PMCID: PMC11383982 DOI: 10.1101/2024.08.28.610209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Caveolin is a monotopic integral membrane protein, widely expressed in metazoa and responsible for constructing enigmatic membrane invaginations known as caveolae. Recently, the high-resolution structure of a purified human caveolin assembly, the CAV1-8S complex, revealed a unique organization of 11 protomers arranged in a tightly packed, radially symmetric spiral disc. One face and the outer rim of this disc are highly hydrophobic, suggesting that the complex incorporates into membranes by displacing hundreds of lipids from one leaflet. The feasibility of this unique molecular architecture and its biophysical and functional consequences are currently unknown. Using Langmuir film balance measurements, we find that CAV1-8S is highly surface active and intercalates into lipid monolayers. Molecular simulations of biomimetic bilayers support this 'leaflet replacement' model and reveal that while CAV1-8S effectively displaces phospholipids from one bilayer leaflet, it accumulates 40-70 cholesterol molecules into a disordered monolayer between the complex and its distal lipid leaflet. We find that CAV1-8S preferentially associates with positively curved membrane surfaces due to its influence on the conformations of distal leaflet lipids, and that these effects laterally sort lipids of the distal leaflet. Large-scale simulations of multiple caveolin assemblies confirmed their association with large, positively curved membrane morphologies, consistent with the shape of caveolae. Further, association with curved membranes regulates the exposure of caveolin residues implicated in protein-protein interactions. Altogether, the unique structure of CAV1-8S imparts unusual modes of membrane interaction with implications for membrane organization, morphology, and physiology.
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Affiliation(s)
- Milka Doktorova
- Department of Molecular Physiology and Biological Physics, University of Virginia, USA
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Sebastian Daum
- Department of Physical Chemistry, Martin Luther University Halle-Wittenberg, Germany
| | - Jan Ebenhan
- Department of Physical Chemistry, Martin Luther University Halle-Wittenberg, Germany
| | - Sarah Neudorf
- Department of Physical Chemistry, Martin Luther University Halle-Wittenberg, Germany
| | - Bing Han
- Department of Molecular Physiology and Biological Physics, University of Virginia, USA
| | - Satyan Sharma
- Department of Cell and Molecular Biology, Uppsala University, Sweden
| | - Peter Kasson
- Department of Cell and Molecular Biology, Uppsala University, Sweden
- Departments of Chemistry and Biochemistry and Biomedical Engineering, Georgia Institute of Technology, USA
| | - Kandice R Levental
- Department of Molecular Physiology and Biological Physics, University of Virginia, USA
| | - Kirsten Bacia
- Department of Physical Chemistry, Martin Luther University Halle-Wittenberg, Germany
| | - Anne K Kenworthy
- Department of Molecular Physiology and Biological Physics, University of Virginia, USA
| | - Ilya Levental
- Department of Molecular Physiology and Biological Physics, University of Virginia, USA
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2
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Kenworthy AK, Han B, Ariotti N, Parton RG. The Role of Membrane Lipids in the Formation and Function of Caveolae. Cold Spring Harb Perspect Biol 2023; 15:a041413. [PMID: 37277189 PMCID: PMC10513159 DOI: 10.1101/cshperspect.a041413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Caveolae are plasma membrane invaginations with a distinct lipid composition. Membrane lipids cooperate with the structural components of caveolae to generate a metastable surface domain. Recent studies have provided insights into the structure of essential caveolar components and how lipids are crucial for the formation, dynamics, and disassembly of caveolae. They also suggest new models for how caveolins, major structural components of caveolae, insert into membranes and interact with lipids.
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Affiliation(s)
- Anne K Kenworthy
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia 22903, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22903, USA
| | - Bing Han
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia 22903, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22903, USA
| | - Nicholas Ariotti
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, The University of Queensland, 4072 Brisbane, Australia
- Centre for Microscopy and Microanalysis, The University of Queensland, 4072 Brisbane, Australia
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3
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Zhou Y, Ariotti N, Rae J, Liang H, Tillu V, Tee S, Bastiani M, Bademosi AT, Collins BM, Meunier FA, Hancock JF, Parton RG. Caveolin-1 and cavin1 act synergistically to generate a unique lipid environment in caveolae. J Cell Biol 2021; 220:211716. [PMID: 33496726 PMCID: PMC7844427 DOI: 10.1083/jcb.202005138] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 11/20/2020] [Accepted: 12/21/2020] [Indexed: 01/09/2023] Open
Abstract
Caveolae are specialized domains of the vertebrate cell surface with a well-defined morphology and crucial roles in cell migration and mechanoprotection. Unique compositions of proteins and lipids determine membrane architectures. The precise caveolar lipid profile and the roles of the major caveolar structural proteins, caveolins and cavins, in selectively sorting lipids have not been defined. Here, we used quantitative nanoscale lipid mapping together with molecular dynamic simulations to define the caveolar lipid profile. We show that caveolin-1 (CAV1) and cavin1 individually sort distinct plasma membrane lipids. Intact caveolar structures composed of both CAV1 and cavin1 further generate a unique lipid nano-environment. The caveolar lipid sorting capability includes selectivities for lipid headgroups and acyl chains. Because lipid headgroup metabolism and acyl chain remodeling are tightly regulated, this selective lipid sorting may allow caveolae to act as transit hubs to direct communications among lipid metabolism, vesicular trafficking, and signaling.
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Affiliation(s)
- Yong Zhou
- Department of Integrative Biology and Pharmacology, University of Texas Medical School, Houston, TX
| | - Nicholas Ariotti
- University of New South Wales Sydney, Mark Wainwright Analytical Center, Sydney, New South Wales, Australia.,University of New South Wales Sydney, Department of Pathology, School of Medical Sciences, Kensington, Sydney, New South Wales, Australia
| | - James Rae
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, Australia
| | - Hong Liang
- Department of Integrative Biology and Pharmacology, University of Texas Medical School, Houston, TX
| | - Vikas Tillu
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, Australia
| | - Shern Tee
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Michele Bastiani
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, Australia
| | - Adekunle T Bademosi
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia.,Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland, Australia
| | - Brett M Collins
- University of New South Wales Sydney, Department of Pathology, School of Medical Sciences, Kensington, Sydney, New South Wales, Australia
| | - Frederic A Meunier
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia.,Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland, Australia
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, University of Texas Medical School, Houston, TX.,Program in Cell and Regulatory Biology, University of Texas Graduate School of Biomedical Sciences, Houston, TX
| | - Robert G Parton
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, Australia.,The University of Queensland, Centre for Microscopy and Microanalysis, Brisbane, Queensland, Australia
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4
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The male germline-specific protein MAPS is indispensable for pachynema progression and fertility. Proc Natl Acad Sci U S A 2021; 118:2025421118. [PMID: 33602822 PMCID: PMC7923350 DOI: 10.1073/pnas.2025421118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Meiosis is a specialized cell division that creates haploid germ cells from diploid progenitors. Through differential RNA expression analyses, we previously identified a number of mouse genes that were dramatically elevated in spermatocytes, relative to their very low expression in spermatogonia and somatic organs. Here, we investigated in detail 1700102P08Rik, one of these genes, and independently conclude that it encodes a male germline-specific protein, in agreement with a recent report. We demonstrated that it is essential for pachynema progression in spermatocytes and named it male pachynema-specific (MAPS) protein. Mice lacking Maps (Maps -/- ) suffered from pachytene arrest and spermatocyte death, leading to male infertility, whereas female fertility was not affected. Interestingly, pubertal Maps -/- spermatocytes were arrested at early pachytene stage, accompanied by defects in DNA double-strand break (DSB) repair, crossover formation, and XY body formation. In contrast, adult Maps -/- spermatocytes only exhibited partially defective crossover but nonetheless were delayed or failed in progression from early to mid- and late pachytene stage, resulting in cell death. Furthermore, we report a significant transcriptional dysregulation in autosomes and XY chromosomes in both pubertal and adult Maps -/- pachytene spermatocytes, including failed meiotic sex chromosome inactivation (MSCI). Further experiments revealed that MAPS overexpression in vitro dramatically decreased the ubiquitination levels of cellular proteins. Conversely, in Maps -/- pachytene cells, protein ubiquitination was dramatically increased, likely contributing to the large-scale disruption in gene expression in pachytene cells. Thus, MAPS is a protein essential for pachynema progression in male mice, possibly in mammals in general.
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5
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McMahon KA, Stroud DA, Gambin Y, Tillu V, Bastiani M, Sierecki E, Polinkovsky ME, Hall TE, Gomez GA, Wu Y, Parat MO, Martel N, Lo HP, Khanna KK, Alexandrov K, Daly R, Yap A, Ryan MT, Parton RG. Cavin3 released from caveolae interacts with BRCA1 to regulate the cellular stress response. eLife 2021; 10:61407. [PMID: 34142659 PMCID: PMC8279762 DOI: 10.7554/elife.61407] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 06/11/2021] [Indexed: 12/13/2022] Open
Abstract
Caveolae-associated protein 3 (cavin3) is inactivated in most cancers. We characterized how cavin3 affects the cellular proteome using genome-edited cells together with label-free quantitative proteomics. These studies revealed a prominent role for cavin3 in DNA repair, with BRCA1 and BRCA1 A-complex components being downregulated on cavin3 deletion. Cellular and cell-free expression assays revealed a direct interaction between BRCA1 and cavin3 that occurs when cavin3 is released from caveolae that are disassembled in response to UV and mechanical stress. Overexpression and RNAi-depletion revealed that cavin3 sensitized various cancer cells to UV-induced apoptosis. Supporting a role in DNA repair, cavin3-deficient cells were sensitive to PARP inhibition, where concomitant depletion of 53BP1 restored BRCA1-dependent sensitivity to PARP inhibition. We conclude that cavin3 functions together with BRCA1 in multiple cancer-related pathways. The loss of cavin3 function may provide tumor cell survival by attenuating apoptotic sensitivity and hindering DNA repair under chronic stress conditions.
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Affiliation(s)
- Kerrie-Ann McMahon
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - David A Stroud
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Australia
| | - Yann Gambin
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Vikas Tillu
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Michele Bastiani
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Emma Sierecki
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Mark E Polinkovsky
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Thomas E Hall
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Guillermo A Gomez
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Yeping Wu
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Marie-Odile Parat
- School of Pharmacy, The University of Queensland, Woolloongabba, Australia
| | - Nick Martel
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Harriet P Lo
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Kum Kum Khanna
- Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Queensland, Australia
| | - Kirill Alexandrov
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Roger Daly
- Monash Biomedicine Discovery Institute, Department of Biochemistry & Molecular Biology, Monash University, Melbourne, Australia
| | - Alpha Yap
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Michael T Ryan
- Monash Biomedicine Discovery Institute, Department of Biochemistry & Molecular Biology, Monash University, Melbourne, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia.,Centre for Microscopy and Microanalysis, The University of Queensland, Queensland, Australia
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6
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Parton RG, Tillu V, McMahon KA, Collins BM. Key phases in the formation of caveolae. Curr Opin Cell Biol 2021; 71:7-14. [PMID: 33677149 DOI: 10.1016/j.ceb.2021.01.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/28/2021] [Accepted: 01/30/2021] [Indexed: 12/20/2022]
Abstract
Caveolae are abundant plasma membrane pits formed by the coordinated action of peripheral and integral membrane proteins and membrane lipids. Here, we discuss recent studies that are starting to provide a glimpse of how filamentous cavin proteins, membrane-embedded caveolin proteins, and specific plasma membrane lipids are brought together to make the unique caveola surface domain. Protein assembly involves multiple low-affinity interactions that are dependent on 'fuzzy' charge-dependent interactions mediated in part by disordered cavin and caveolin domains. We propose that cavins help generate a lipid domain conducive to full insertion of caveolin into the bilayer to promote caveola formation. The synergistic assembly of these dynamic protein complexes supports the formation of a metastable membrane domain that can be readily disassembled both in response to cellular stress and during endocytic trafficking. We present a mechanistic model for generation of caveolae based on these new insights.
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Affiliation(s)
- Robert G Parton
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, 4072, Australia; The University of Queensland, Centre for Microscopy and Microanalysis, Brisbane, Queensland, 4072, Australia.
| | - Vikas Tillu
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, 4072, Australia
| | - Kerrie-Ann McMahon
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, 4072, Australia
| | - Brett M Collins
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, 4072, Australia.
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7
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Cavin1 intrinsically disordered domains are essential for fuzzy electrostatic interactions and caveola formation. Nat Commun 2021; 12:931. [PMID: 33568658 PMCID: PMC7875971 DOI: 10.1038/s41467-021-21035-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/06/2021] [Indexed: 01/30/2023] Open
Abstract
Caveolae are spherically shaped nanodomains of the plasma membrane, generated by cooperative assembly of caveolin and cavin proteins. Cavins are cytosolic peripheral membrane proteins with negatively charged intrinsically disordered regions that flank positively charged α-helical regions. Here, we show that the three disordered domains of Cavin1 are essential for caveola formation and dynamic trafficking of caveolae. Electrostatic interactions between disordered regions and α-helical regions promote liquid-liquid phase separation behaviour of Cavin1 in vitro, assembly of Cavin1 oligomers in solution, generation of membrane curvature, association with caveolin-1, and Cavin1 recruitment to caveolae in cells. Removal of the first disordered region causes irreversible gel formation in vitro and results in aberrant caveola trafficking through the endosomal system. We propose a model for caveola assembly whereby fuzzy electrostatic interactions between Cavin1 and caveolin-1 proteins, combined with membrane lipid interactions, are required to generate membrane curvature and a metastable caveola coat.
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8
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Parton RG, Kozlov MM, Ariotti N. Caveolae and lipid sorting: Shaping the cellular response to stress. J Cell Biol 2020; 219:133844. [PMID: 32328645 PMCID: PMC7147102 DOI: 10.1083/jcb.201905071] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 10/30/2019] [Accepted: 02/05/2020] [Indexed: 02/06/2023] Open
Abstract
Caveolae are an abundant and characteristic surface feature of many vertebrate cells. The uniform shape of caveolae is characterized by a bulb with consistent curvature connected to the plasma membrane (PM) by a neck region with opposing curvature. Caveolae act in mechanoprotection by flattening in response to increased membrane tension, and their disassembly influences the lipid organization of the PM. Here, we review evidence for caveolae as a specialized lipid domain and speculate on mechanisms that link changes in caveolar shape and/or protein composition to alterations in specific lipid species. We propose that high membrane curvature in specific regions of caveolae can enrich specific lipid species, with consequent changes in their localization upon caveolar flattening. In addition, we suggest how changes in the association of lipid-binding caveolar proteins upon flattening of caveolae could allow release of specific lipids into the bulk PM. We speculate that the caveolae-lipid system has evolved to function as a general stress-sensing and stress-protective membrane domain.
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Affiliation(s)
- Robert G Parton
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.,Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Australia
| | - Michael M Kozlov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Nicholas Ariotti
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.,Electron Microscope Unit, Mark Wainwright Analytical Centre, The University of New South Wales, Kensington, Australia.,Department of Pathology, School of Medical Sciences, The University of New South Wales, Kensington, Australia
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9
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Dudãu M, Codrici E, Tanase C, Gherghiceanu M, Enciu AM, Hinescu ME. Caveolae as Potential Hijackable Gates in Cell Communication. Front Cell Dev Biol 2020; 8:581732. [PMID: 33195223 PMCID: PMC7652756 DOI: 10.3389/fcell.2020.581732] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/08/2020] [Indexed: 12/16/2022] Open
Abstract
Caveolae are membrane microdomains described in many cell types involved in endocytocis, transcytosis, cell signaling, mechanotransduction, and aging. They are found at the interface with the extracellular environment and are structured by caveolin and cavin proteins. Caveolae and caveolins mediate transduction of chemical messages via signaling pathways, as well as non-chemical messages, such as stretching or shear stress. Various pathogens or signals can hijack these gates, leading to infectious, oncogenic and even caveolin-related diseases named caveolinopathies. By contrast, preclinical and clinical research have fallen behind in their attempts to hijack caveolae and caveolins for therapeutic purposes. Caveolae involvement in human disease is not yet fully explored or understood and, of all their scaffold proteins, only caveolin-1 is being considered in clinical trials as a possible biomarker of disease. This review briefly summarizes current knowledge about caveolae cell signaling and raises the hypothesis whether these microdomains could serve as hijackable “gatekeepers” or “gateways” in cell communication. Furthermore, because cell signaling is one of the most dynamic domains in translating data from basic to clinical research, we pay special attention to translation of caveolae, caveolin, and cavin research into clinical practice.
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Affiliation(s)
- Maria Dudãu
- Biochemistry-Proteomics Laboratory, Victor Babes National Institute of Pathology, Bucharest, Romania.,Cell Biology and Histology Department, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Elena Codrici
- Biochemistry-Proteomics Laboratory, Victor Babes National Institute of Pathology, Bucharest, Romania
| | - Cristiana Tanase
- Biochemistry-Proteomics Laboratory, Victor Babes National Institute of Pathology, Bucharest, Romania.,Clinical Biochemistry Department, Faculty of Medicine, Titu Maiorescu University, Bucharest, Romania
| | - Mihaela Gherghiceanu
- Biochemistry-Proteomics Laboratory, Victor Babes National Institute of Pathology, Bucharest, Romania.,Cell Biology and Histology Department, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Ana-Maria Enciu
- Biochemistry-Proteomics Laboratory, Victor Babes National Institute of Pathology, Bucharest, Romania.,Cell Biology and Histology Department, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Mihail E Hinescu
- Biochemistry-Proteomics Laboratory, Victor Babes National Institute of Pathology, Bucharest, Romania.,Cell Biology and Histology Department, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
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10
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Teo JL, Gomez GA, Weeratunga S, Davies EM, Noordstra I, Budnar S, Katsuno-Kambe H, McGrath MJ, Verma S, Tomatis V, Acharya BR, Balasubramaniam L, Templin RM, McMahon KA, Lee YS, Ju RJ, Stebhens SJ, Ladoux B, Mitchell CA, Collins BM, Parton RG, Yap AS. Caveolae Control Contractile Tension for Epithelia to Eliminate Tumor Cells. Dev Cell 2020; 54:75-91.e7. [PMID: 32485139 DOI: 10.1016/j.devcel.2020.05.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 03/17/2020] [Accepted: 05/01/2020] [Indexed: 01/24/2023]
Abstract
Epithelia are active materials where mechanical tension governs morphogenesis and homeostasis. But how that tension is regulated remains incompletely understood. We now report that caveolae control epithelial tension and show that this is necessary for oncogene-transfected cells to be eliminated by apical extrusion. Depletion of caveolin-1 (CAV1) increased steady-state tensile stresses in epithelial monolayers. As a result, loss of CAV1 in the epithelial cells surrounding oncogene-expressing cells prevented their apical extrusion. Epithelial tension in CAV1-depleted monolayers was increased by cortical contractility at adherens junctions. This reflected a signaling pathway, where elevated levels of phosphoinositide-4,5-bisphosphate (PtdIns(4,5)P2) recruited the formin, FMNL2, to promote F-actin bundling. Steady-state monolayer tension and oncogenic extrusion were restored to CAV1-depleted monolayers when tension was corrected by depleting FMNL2, blocking PtdIns(4,5)P2, or disabling the interaction between FMNL2 and PtdIns(4,5)P2. Thus, caveolae can regulate active mechanical tension for epithelial homeostasis by controlling lipid signaling to the actin cytoskeleton.
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Affiliation(s)
- Jessica L Teo
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Guillermo A Gomez
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia
| | - Saroja Weeratunga
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Elizabeth M Davies
- Cancer Program, Monash Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Ivar Noordstra
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Srikanth Budnar
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Hiroko Katsuno-Kambe
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Meagan J McGrath
- Cancer Program, Monash Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Suzie Verma
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Vanesa Tomatis
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Bipul R Acharya
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | | | - Rachel M Templin
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Kerrie-Ann McMahon
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Yoke Seng Lee
- Mater Research Institute, The University of Queensland, Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia
| | - Robert J Ju
- The University of Queensland Diamantina Institute, Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia
| | - Samantha J Stebhens
- The University of Queensland Diamantina Institute, Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia
| | - Benoit Ladoux
- Institut Jacques Monod, Université de Paris, CNRS UMR 7592, 75013 Paris, France
| | - Christina A Mitchell
- Cancer Program, Monash Biomedicine Discovery Institute, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Brett M Collins
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Robert G Parton
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; Centre for Microscopy and Microanalysis, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
| | - Alpha S Yap
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
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11
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Ohta K, Matsumoto Y, Nishio M. Inhibition of Cavin3 Degradation by the Human Parainfluenza Virus Type 2 V Protein Is Important for Efficient Viral Growth. Front Microbiol 2020; 11:803. [PMID: 32425917 PMCID: PMC7203785 DOI: 10.3389/fmicb.2020.00803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 04/03/2020] [Indexed: 01/01/2023] Open
Abstract
Cavin proteins have important roles in the formation of caveolae in lipid raft microdomains. Pulse-chase experiments of cells infected with human parainfluenza virus type 2 (hPIV-2) showed decreased proteasomal degradation of Cavin3. Overexpression of hPIV-2 V protein alone was sufficient to inhibit Cavin3 degradation. Immunoprecipitation analysis revealed that V protein bound to Cavin3. Trp residues within C-terminal region of V protein, as well as the N-terminal region of Cavin3, are important for V–Cavin3 interaction. Cavin3 knockdown suppressed hPIV-2 growth without affecting its entry, replication, transcription, or translation. Higher amounts of Cavin3 were observed in V protein-overexpressing cells than in control cells in lipid raft microdomains. Our data collectively suggest that hPIV-2 V protein binds to and stabilizes Cavin3, which in turn facilitates assembly and budding of hPIV-2 in lipid raft microdomains.
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Affiliation(s)
- Keisuke Ohta
- Department of Microbiology, School of Medicine, Wakayama Medical University, Wakayama, Japan
| | - Yusuke Matsumoto
- Department of Microbiology, School of Medicine, Wakayama Medical University, Wakayama, Japan
| | - Machiko Nishio
- Department of Microbiology, School of Medicine, Wakayama Medical University, Wakayama, Japan
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12
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Caveolae: Formation, dynamics, and function. Curr Opin Cell Biol 2020; 65:8-16. [PMID: 32146331 DOI: 10.1016/j.ceb.2020.02.001] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/28/2020] [Accepted: 02/02/2020] [Indexed: 12/22/2022]
Abstract
Caveolae are abundant surface pits formed by the assembly of cytoplasmic proteins on a platform generated by caveolin integral membrane proteins and membrane lipids. This membranous assembly can bud off into the cell or can be disassembled releasing the cavin proteins into the cytosol. Disassembly can be triggered by increased membrane tension, or by stress stimuli, such as UV. Here, we discuss recent mechanistic studies showing how caveolae are formed and how their unique properties allow them to function as multifunctional protective and signaling structures.
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13
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Identification of intracellular cavin target proteins reveals cavin-PP1alpha interactions regulate apoptosis. Nat Commun 2019; 10:3279. [PMID: 31332168 PMCID: PMC6646387 DOI: 10.1038/s41467-019-11111-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 06/14/2019] [Indexed: 12/20/2022] Open
Abstract
Caveolae are specialized domains of the plasma membrane. Formation of these invaginations is dependent on the expression of Caveolin-1 or -3 and proteins of the cavin family. In response to stress, caveolae disassemble and cavins are released from caveolae, allowing cavins to potentially interact with intracellular targets. Here, we describe the intracellular (non-plasma membrane) cavin interactome using biotin affinity proteomics and mass spectrometry. We validate 47 potential cavin-interactor proteins using a cell-free expression system and protein-protein binding assays. These data, together with pathway analyses, reveal unknown roles for cavin proteins in metabolism and stress signaling. We validated the interaction between one candidate interactor protein, protein phosphatase 1 alpha (PP1α), and Cavin-1 and -3 and show that UV treatment causes release of Cavin3 from caveolae allowing interaction with, and inhibition of, PP1α. This interaction increases H2AX phosphorylation to stimulate apoptosis, identifying a pro-apoptotic signaling pathway from surface caveolae to the nucleus.
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14
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Abstract
The plasma membrane of eukaryotic cells is not a simple sheet of lipids and proteins but is differentiated into subdomains with crucial functions. Caveolae, small pits in the plasma membrane, are the most abundant surface subdomains of many mammalian cells. The cellular functions of caveolae have long remained obscure, but a new molecular understanding of caveola formation has led to insights into their workings. Caveolae are formed by the coordinated action of a number of lipid-interacting proteins to produce a microdomain with a specific structure and lipid composition. Caveolae can bud from the plasma membrane to form an endocytic vesicle or can flatten into the membrane to help cells withstand mechanical stress. The role of caveolae as mechanoprotective and signal transduction elements is reviewed in the context of disease conditions associated with caveola dysfunction.
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Affiliation(s)
- Robert G. Parton
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland 4060, Australia
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15
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Wei Z, Liu T, Lei J, Wu Y, Wang S, Liao K. Fam198a, a member of secreted kinase, secrets through caveolae biogenesis pathway. Acta Biochim Biophys Sin (Shanghai) 2018; 50:968-975. [PMID: 30188967 DOI: 10.1093/abbs/gmy105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Indexed: 01/21/2023] Open
Abstract
Fam198a is a member of four-jointed protein kinases, a secreted protein kinase family. It was identified as a caveolae-associated protein and colocalized with cavin-1 and caveolin-1 in both tissues and cells. The newly synthesized Fam198a precursor in endoplasmic reticulum (ER) was transported by caveolae biogenesis vesicles to Golgi apparatus in which it was proteolytically cleaved into the secreted mature form. The amino acid mutation analysis identified Arg 120 and 437 as the proteolytic sites in Fam198a precursor during maturation. In mouse embryo fibroblasts (MEFs) obtained from cavin-1-/- or caveolin-1-/- mice, Fam198a precursor was retained in ER and no mature Fam198a could be formed in these cells. Ectopic expression of exogenous cavin-1 in cavin-1-/- MEFs restored the blocked Fam198a post-translational process and secretion. Cavin-1 was also required for Fam198a secretion after its maturation in Golgi apparatus. Ectopic expression of cavin-1 in A549 cells restored the blocked Fam198a secretion. These results suggest that protein secretion is an important function for caveolae biogenesis pathway and the disruption of caveolae system will affect those functions played by the secreted proteins.
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Affiliation(s)
- Zhuang Wei
- Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Tao Liu
- Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Jigang Lei
- Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
- School of Life Science and Technology, Tongji University, Shanghai, China
| | - Yuan Wu
- Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Shilong Wang
- School of Life Science and Technology, Tongji University, Shanghai, China
| | - Kan Liao
- Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
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16
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Tillu VA, Lim YW, Kovtun O, Mureev S, Ferguson C, Bastiani M, McMahon KA, Lo HP, Hall TE, Alexandrov K, Collins BM, Parton RG. A variable undecad repeat domain in cavin1 regulates caveola formation and stability. EMBO Rep 2018; 19:e45775. [PMID: 30021837 PMCID: PMC6123655 DOI: 10.15252/embr.201845775] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 06/05/2018] [Accepted: 06/14/2018] [Indexed: 11/09/2022] Open
Abstract
Caveolae are plasma membrane invaginations involved in transport, signalling and mechanical membrane sensing in metazoans. Their formation depends upon multiple interactions between membrane-embedded caveolins, lipids and cytosolic cavin proteins. Of the four cavin family members, only cavin1 is strictly required for caveola formation. Here, we demonstrate that an eleven residue (undecad) repeat sequence (UC1) exclusive to cavin1 is essential for caveolar localization and promotes membrane remodelling through binding to phosphatidylserine. In the notochord of mechanically stimulated zebrafish embryos, the UC1 domain is required for caveolar stability and resistance to membrane stress. The number of undecad repeats in the cavin1 UC1 domain varies throughout evolution, and we find that an increased number also correlates with increased caveolar stability. Lastly, we show that the cavin1 UC1 domain induces dramatic remodelling of the plasma membrane when grafted into cavin2 suggesting an important role in membrane sculpting. Overall, our work defines a novel conserved cavin1 modular domain that controls caveolar assembly and stability.
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Affiliation(s)
- Vikas A Tillu
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Ye-Wheen Lim
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Oleksiy Kovtun
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Sergey Mureev
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Charles Ferguson
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Michele Bastiani
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Kerrie-Ann McMahon
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Harriet P Lo
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Thomas E Hall
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Kirill Alexandrov
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, Australia
- Centre for Microscopy and Microanalysis, The University of Queensland, St. Lucia, Qld, Australia
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17
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Perez-Diaz S, Garcia-Sobreviela MP, Gonzalez-Irazabal Y, Garcia-Rodriguez B, Espina S, Arenaz I, Arbones-Mainar JM. PTRF acts as an adipokine contributing to adipocyte dysfunctionality and ectopic lipid deposition. J Physiol Biochem 2018; 74:613-622. [PMID: 29869069 DOI: 10.1007/s13105-018-0638-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/14/2018] [Indexed: 12/31/2022]
Abstract
Adipose tissue (AT) expands under obesogenic conditions. Yet, when the growth exceeds a certain limit, AT becomes dysfunctional and surplus lipids start depositing ectopically. Polymerase I and transcription release factor (PTRF) has been proposed as a mechanism leading to a dysfunctional AT by decreasing the adipogenic potential of human adipocyte precursors. However, whether or not PTRF can be secreted by the adipocytes into the bloodstream is not yet known. For this work, PTRF presence was investigated in plasma. We also produced a recombinant PTRF (rPTRF) and examined its impact on the functional interactions between the adipocyte and the hepatocyte in vitro. We demonstrated that PTRF can be found in human plasma, and is at least in part, carried by exosomes. In vitro treatment with rPTRF increased the hypertrophy and senescence of 3T3-L1 adipocytes. In turn, those rPTRF-treated adipocytes increased lipid accumulation in hepatocytes. Lastly, we found a positive correlation between circulating PTRF and the concentration of PTRF in the visceral fat depot. All these findings point toward the presence of an enlarged and dysfunctional visceral adipose tissue which secretes PTRF. This circulating PTRF behaves as an adipokine and may partially contribute to the well-known detrimental effects of visceral fat accumulation.
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Affiliation(s)
- Sergio Perez-Diaz
- Adipocyte and Fat Biology Laboratory (AdipoFat), Unidad de Investigación Traslacional, Instituto Aragonés de Ciencias de la Salud (IACS), Instituto de Investigación Sanitaria (IIS) Aragón, Hospital Universitario Miguel Servet, Isabel la Católica, 1-3, 50009, Zaragoza, Spain
| | - Maria P Garcia-Sobreviela
- Adipocyte and Fat Biology Laboratory (AdipoFat), Unidad de Investigación Traslacional, Instituto Aragonés de Ciencias de la Salud (IACS), Instituto de Investigación Sanitaria (IIS) Aragón, Hospital Universitario Miguel Servet, Isabel la Católica, 1-3, 50009, Zaragoza, Spain
| | | | | | - Silvia Espina
- Adipocyte and Fat Biology Laboratory (AdipoFat), Unidad de Investigación Traslacional, Instituto Aragonés de Ciencias de la Salud (IACS), Instituto de Investigación Sanitaria (IIS) Aragón, Hospital Universitario Miguel Servet, Isabel la Católica, 1-3, 50009, Zaragoza, Spain.,Servicio de Aparato Digestivo, Hospital Universitario Miguel Servet, Zaragoza, Spain
| | - Izaskun Arenaz
- Biobanco del Sistema de Salud de Aragón, Instituto Aragonés de Ciencias de la Salud (IACS), Zaragoza, Spain
| | - Jose M Arbones-Mainar
- Adipocyte and Fat Biology Laboratory (AdipoFat), Unidad de Investigación Traslacional, Instituto Aragonés de Ciencias de la Salud (IACS), Instituto de Investigación Sanitaria (IIS) Aragón, Hospital Universitario Miguel Servet, Isabel la Católica, 1-3, 50009, Zaragoza, Spain. .,CIBER Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, Madrid, Spain.
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18
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Lim JY, Barnett TC, Bastiani M, McMahon KA, Ferguson C, Webb RI, Parton RG, Walker MJ. Caveolin 1 restricts Group A Streptococcus invasion of nonphagocytic host cells. Cell Microbiol 2017; 19. [PMID: 28778116 DOI: 10.1111/cmi.12772] [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: 10/31/2016] [Revised: 07/19/2017] [Accepted: 07/21/2017] [Indexed: 01/08/2023]
Abstract
Caveolae are composed of 2 major proteins, caveolin 1 (CAV1) and cavin 1 or polymerase transcript release factor I (CAVIN1). Here, we demonstrate that CAV1 levels modulate invasion of Group A Streptococcus (GAS) into nonphagocytic mammalian cells. GAS showed enhanced internalisation into CAV1-knockout mouse embryonic fibroblasts and CAV1 knockdown human epithelial HEp-2 cells, whereas overexpression of CAV1 in HEp-2 cells reduced GAS invasion. This effect was not dependent on the expression of the GAS fibronectin binding protein SfbI, which had previously been implicated in caveolae-mediated uptake. Nor was this effect dependent on CAVIN1, as knockout of CAVIN1 in mouse embryonic fibroblasts resulted in reduced GAS internalisation. Although CAV1 restricted GAS invasion into host cells, we observed only minimal association of invading GAS (strain M1T15448 ) with CAV1 by immunofluorescence and very low association of invading M1T15448 with caveolae by transmission electron microscopy. These observations suggest that physical interaction with caveolae is not needed for CAV1 restriction of invading GAS. An indirect mechanism of action is also consistent with the finding that changing membrane fluidity reverses the increased invasion observed in CAV1-null cells. Together, these results suggest that CAV1 protects host cells against GAS invasion by a caveola-independent mechanism.
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Affiliation(s)
- Jin Yan Lim
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Timothy C Barnett
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Michele Bastiani
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Kerrie-Ann McMahon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Charles Ferguson
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Richard I Webb
- Centre for Microscopy and Microanalysis, The University of Queensland, St Lucia, Queensland, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia.,Centre for Microscopy and Microanalysis, The University of Queensland, St Lucia, Queensland, Australia
| | - Mark J Walker
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
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19
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Zhou LJ, Chen XY, Liu SP, Zhang LL, Xu YN, Mu PW, Geng DF, Tan Z. Downregulation of Cavin-1 Expression via Increasing Caveolin-1 Degradation Prompts the Proliferation and Migration of Vascular Smooth Muscle Cells in Balloon Injury-Induced Neointimal Hyperplasia. J Am Heart Assoc 2017; 6:e005754. [PMID: 28751541 PMCID: PMC5586430 DOI: 10.1161/jaha.117.005754] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 06/08/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND Percutaneous coronary intervention has been widely used in the treatment of ischemic heart disease, but vascular restenosis is a main limitation of percutaneous coronary intervention. Our previous work reported that caveolin-1 had a key functional role in intimal hyperplasia, whereas whether Cavin-1 (another important caveolae-related protein) was involved is still unknown. Therefore, we will investigate the effect of Cavin-1 on neointimal formation. METHODS AND RESULTS Balloon injury markedly reduced Cavin-1 protein and enhanced ubiquitin protein expression accompanied with neointimal hyperplasia in injured carotid arteries, whereas Cavin-1 mRNA had no change. In cultured vascular smooth muscle cells (VSMCs), Cavin-1 was downregulated after inhibition of protein synthesis by cycloheximide, which was distinctly prevented by pretreatment with proteasome inhibitor MG132 but not by lysosomal inhibitor chloroquine, suggesting that proteasomal degradation resulted in Cavin-1 downregulation. Knockdown of Cavin-1 by local injection of Cavin-1 short hairpin RNA (shRNA) into balloon-injured carotid arteries in vivo promoted neointimal formation. In addition, inhibition or overexpression of Cavin-1 in cultured VSMCs in vitro prompted or suppressed VSMC proliferation and migration via increasing or decreasing extracellular signal-regulated kinase phosphorylation and matrix-degrading metalloproteinases-9 activity, respectively. However, under basic conditions, the effect of Cavin-1 on VSMC migration was stronger than on proliferation. Moreover, our results indicated that Cavin-1 regulated caveolin-1 expression via lysosomal degradation pathway. CONCLUSIONS Our study revealed the role and the mechanisms of Cavin-1 downregulation in neointimal formation by promoting VSMC proliferation, migration, and synchronously enhancing caveolin-1 lysosomal degradation. Cavin-1 may be a potential therapeutic target for the treatment of postinjury vascular remodeling.
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MESH Headings
- Angioplasty, Balloon/adverse effects
- Animals
- Carotid Artery Injuries/etiology
- Carotid Artery Injuries/genetics
- Carotid Artery Injuries/metabolism
- Carotid Artery Injuries/pathology
- Carotid Artery, External/metabolism
- Carotid Artery, External/pathology
- Caveolin 1/metabolism
- Cell Movement
- Cell Proliferation
- Cells, Cultured
- Disease Models, Animal
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Lysosomes/metabolism
- Matrix Metalloproteinase 9/metabolism
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Muscle, Smooth, Vascular/injuries
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Neointima
- Proteasome Endopeptidase Complex/metabolism
- Proteolysis
- RNA Interference
- RNA, Small Interfering/administration & dosage
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Rats, Sprague-Dawley
- Signal Transduction
- Time Factors
- Transfection
- Vascular Remodeling
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Affiliation(s)
- Li-Jun Zhou
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Xue-Ying Chen
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Shui-Ping Liu
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Lin-Lin Zhang
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Ya-Nan Xu
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Pan-Wei Mu
- Department of Endocrinology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Deng-Feng Geng
- Department of Cardiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhi Tan
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
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20
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Hirama T, Das R, Yang Y, Ferguson C, Won A, Yip CM, Kay JG, Grinstein S, Parton RG, Fairn GD. Phosphatidylserine dictates the assembly and dynamics of caveolae in the plasma membrane. J Biol Chem 2017; 292:14292-14307. [PMID: 28698382 DOI: 10.1074/jbc.m117.791400] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/06/2017] [Indexed: 12/14/2022] Open
Abstract
Caveolae are bulb-shaped nanodomains of the plasma membrane that are enriched in cholesterol and sphingolipids. They have many physiological functions, including endocytic transport, mechanosensing, and regulation of membrane and lipid transport. Caveola formation relies on integral membrane proteins termed caveolins (Cavs) and the cavin family of peripheral proteins. Both protein families bind anionic phospholipids, but the precise roles of these lipids are unknown. Here, we studied the effects of phosphatidylserine (PtdSer), phosphatidylinositol 4-phosphate (PtdIns4P), and phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) on caveolar formation and dynamics. Using live-cell, single-particle tracking of GFP-labeled Cav1 and ultrastructural analyses, we compared the effect of PtdSer disruption or phosphoinositide depletion with caveola disassembly caused by cavin1 loss. We found that PtdSer plays a crucial role in both caveola formation and stability. Sequestration or depletion of PtdSer decreased the number of detectable Cav1-GFP puncta and the number of caveolae visualized by electron microscopy. Under PtdSer-limiting conditions, the co-localization of Cav1 and cavin1 was diminished, and cavin1 degradation was increased. Using rapamycin-recruitable phosphatases, we also found that the acute depletion of PtdIns4P and PtdIns(4,5)P2 has minimal impact on caveola assembly but results in decreased lateral confinement. Finally, we show in a model of phospholipid scrambling, a feature of apoptotic cells, that caveola stability is acutely affected by the scrambling. We conclude that the predominant plasmalemmal anionic lipid PtdSer is essential for proper Cav clustering, caveola formation, and caveola dynamics and that membrane scrambling can perturb caveolar stability.
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Affiliation(s)
- Takashi Hirama
- From the Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario M5B 1W8, Canada,; Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G1X8, Canada,; Department of Respiratory Medicine, Saitama Medical University, Moroyama, Saitama 3500495, Japan
| | - Raibatak Das
- Department of Integrative Biology, University of Colorado Denver, Denver, Colorado 80204
| | - Yanbo Yang
- From the Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario M5B 1W8, Canada,; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Charles Ferguson
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Amy Won
- The Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Christopher M Yip
- The Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Jason G Kay
- Department of Oral Biology, School of Dental Medicine, the State University of New York at Buffalo, Buffalo, New York 14214
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G1X8, Canada,; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Robert G Parton
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Gregory D Fairn
- From the Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario M5B 1W8, Canada,; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada,; Institute for Biomedical Engineering and Science Technology (iBEST), Ryerson University and St. Michael's Hospital, Toronto, Ontario M5B 2K3, Canada.
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21
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Ludwig A, Nguyen TH, Leong D, Ravi LI, Tan BH, Sandin S, Sugrue RJ. Caveolae provide a specialized membrane environment for respiratory syncytial virus assembly. J Cell Sci 2017; 130:1037-1050. [PMID: 28154158 PMCID: PMC5358342 DOI: 10.1242/jcs.198853] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/26/2017] [Indexed: 12/20/2022] Open
Abstract
Respiratory syncytial virus (RSV) is an enveloped virus that assembles into filamentous virus particles on the surface of infected cells. Morphogenesis of RSV is dependent upon cholesterol-rich (lipid raft) membrane microdomains, but the specific role of individual raft molecules in RSV assembly is not well defined. Here, we show that RSV morphogenesis occurs within caveolar membranes and that both caveolin-1 and cavin-1 (also known as PTRF), the two major structural and functional components of caveolae, are actively recruited to and incorporated into the RSV envelope. The recruitment of caveolae occurred just prior to the initiation of RSV filament assembly, and was dependent upon an intact actin network as well as a direct physical interaction between caveolin-1 and the viral G protein. Moreover, cavin-1 protein levels were significantly increased in RSV-infected cells, leading to a virus-induced change in the stoichiometry and biophysical properties of the caveolar coat complex. Our data indicate that RSV exploits caveolae for its assembly, and we propose that the incorporation of caveolae into the virus contributes to defining the biological properties of the RSV envelope.
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Affiliation(s)
- Alexander Ludwig
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Tra Huong Nguyen
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Daniel Leong
- Detection and Diagnostics Laboratory, DSO National Laboratories, 27 Medical Drive, Singapore 117510
| | - Laxmi Iyer Ravi
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Boon Huan Tan
- Detection and Diagnostics Laboratory, DSO National Laboratories, 27 Medical Drive, Singapore 117510
| | - Sara Sandin
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Richard J Sugrue
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
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22
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Busija AR, Patel HH, Insel PA. Caveolins and cavins in the trafficking, maturation, and degradation of caveolae: implications for cell physiology. Am J Physiol Cell Physiol 2017; 312:C459-C477. [PMID: 28122734 DOI: 10.1152/ajpcell.00355.2016] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 01/09/2023]
Abstract
Caveolins (Cavs) are ~20 kDa scaffolding proteins that assemble as oligomeric complexes in lipid raft domains to form caveolae, flask-shaped plasma membrane (PM) invaginations. Caveolae ("little caves") require lipid-lipid, protein-lipid, and protein-protein interactions that can modulate the localization, conformational stability, ligand affinity, effector specificity, and other functions of proteins that are partners of Cavs. Cavs are assembled into small oligomers in the endoplasmic reticulum (ER), transported to the Golgi for assembly with cholesterol and other oligomers, and then exported to the PM as an intact coat complex. At the PM, cavins, ~50 kDa adapter proteins, oligomerize into an outer coat complex that remodels the membrane into caveolae. The structure of caveolae protects their contents (i.e., lipids and proteins) from degradation. Cellular changes, including signal transduction effects, can destabilize caveolae and produce cavin dissociation, restructuring of Cav oligomers, ubiquitination, internalization, and degradation. In this review, we provide a perspective of the life cycle (biogenesis, degradation), composition, and physiologic roles of Cavs and caveolae and identify unanswered questions regarding the roles of Cavs and cavins in caveolae and in regulating cell physiology.1.
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Affiliation(s)
- Anna R Busija
- Department of Anesthesiology, University of California, San Diego, La Jolla, California.,Department of Pharmacology, University of California, San Diego, La Jolla, California
| | - Hemal H Patel
- Department of Anesthesiology, University of California, San Diego, La Jolla, California
| | - Paul A Insel
- Department of Medicine, University of California, San Diego, La Jolla, California; and .,Department of Pharmacology, University of California, San Diego, La Jolla, California
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