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Brooks JW, Tillu V, Eckert J, Verma S, Collins BM, Parton RG, Yap AS. Caveola mechanotransduction reinforces the cortical cytoskeleton to promote epithelial resilience. Mol Biol Cell 2023; 34:ar120. [PMID: 37672337 PMCID: PMC10846620 DOI: 10.1091/mbc.e23-05-0163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/22/2023] [Accepted: 08/29/2023] [Indexed: 09/08/2023] Open
Abstract
As physical barriers, epithelia must preserve their integrity when challenged by mechanical stresses. Cell-cell junctions linked to the cortical cytoskeleton play key roles in this process, often with mechanotransduction mechanisms that reinforce tissues. Caveolae are mechanosensitive organelles that buffer tension via disassembly. Loss of caveolae, through caveolin-1 or cavin1 depletion, causes activation of PtdIns(4, 5)P2 signaling, recruitment of FMNL2 formin, and enhanced-cortical actin assembly. How this equates to physiological responses in epithelial cells containing endogenous caveolae is unknown. Here we examined the effect of mechanically inducing acute disassembly of caveolae in epithelia. We show that perturbation of caveolae, through direct mechanical stress, reinforces the actin cortex at adherens junctions. Increasing interactions with membrane lipids by introducing multiple phosphatidylserine-binding undecad cavin1 (UC1) repeat domains into cavin1 rendered caveolae more stable to mechanical stimuli. This molecular stabilization blocked cortical reinforcement in response to mechanical stress. Cortical reinforcement elicited by the mechanically induced disassembly of caveolae increased epithelial resilience against tensile stresses. These findings identify the actin cortex as a target of caveola mechanotransduction that contributes to epithelial integrity.
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Affiliation(s)
- John W. Brooks
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia 4072
| | - Vikas Tillu
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia 4072
| | - Julia Eckert
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia 4072
| | - Suzie Verma
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia 4072
| | - Brett M. Collins
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia 4072
| | - Robert G. Parton
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia 4072
- Centre for Microscopy and Microanalysis, The University of Queensland, St. Lucia, Brisbane, Australia 4072
| | - Alpha S. Yap
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Australia 4072
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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: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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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] [What about the content of this article? (0)] [Affiliation(s)] [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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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: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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5
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Healy MD, Hospenthal MK, Hall RJ, Chandra M, Chilton M, Tillu V, Chen KE, Celligoi DJ, McDonald FJ, Cullen PJ, Lott JS, Collins BM, Ghai R. Structural insights into the architecture and membrane interactions of the conserved COMMD proteins. eLife 2018; 7:e35898. [PMID: 30067224 PMCID: PMC6089597 DOI: 10.7554/elife.35898] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 07/31/2018] [Indexed: 12/31/2022] Open
Abstract
The COMMD proteins are a conserved family of proteins with central roles in intracellular membrane trafficking and transcription. They form oligomeric complexes with each other and act as components of a larger assembly called the CCC complex, which is localized to endosomal compartments and mediates the transport of several transmembrane cargos. How these complexes are formed however is completely unknown. Here, we have systematically characterised the interactions between human COMMD proteins, and determined structures of COMMD proteins using X-ray crystallography and X-ray scattering to provide insights into the underlying mechanisms of homo- and heteromeric assembly. All COMMD proteins possess an α-helical N-terminal domain, and a highly conserved C-terminal domain that forms a tightly interlocked dimeric structure responsible for COMMD-COMMD interactions. The COMM domains also bind directly to components of CCC and mediate non-specific membrane association. Overall these studies show that COMMD proteins function as obligatory dimers with conserved domain architectures.
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Affiliation(s)
- Michael D Healy
- Institute for Molecular BioscienceThe University of QueenslandSt. LuciaAustralia
| | | | - Ryan J Hall
- Institute for Molecular BioscienceThe University of QueenslandSt. LuciaAustralia
| | - Mintu Chandra
- Institute for Molecular BioscienceThe University of QueenslandSt. LuciaAustralia
| | - Molly Chilton
- School of Biochemistry, Biomedical Sciences BuildingUniversity of BristolBristolUnited Kingdom
| | - Vikas Tillu
- Institute for Molecular BioscienceThe University of QueenslandSt. LuciaAustralia
| | - Kai-En Chen
- Institute for Molecular BioscienceThe University of QueenslandSt. LuciaAustralia
| | - Dion J Celligoi
- School of Biological SciencesThe University of AucklandAucklandNew Zealand
| | | | - Peter J Cullen
- School of Biochemistry, Biomedical Sciences BuildingUniversity of BristolBristolUnited Kingdom
| | - J Shaun Lott
- School of Biological SciencesThe University of AucklandAucklandNew Zealand
| | - Brett M Collins
- Institute for Molecular BioscienceThe University of QueenslandSt. LuciaAustralia
| | - Rajesh Ghai
- Institute for Molecular BioscienceThe University of QueenslandSt. LuciaAustralia
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