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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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Julien JA, Rousseau A, Perone TV, LaGatta DM, Hong C, Root KT, Park S, Fuanta R, Im W, Glover KJ. One-step site-specific S-alkylation of full-length caveolin-1: Lipidation modulates the topology of its C-terminal domain. Protein Sci 2023; 32:e4791. [PMID: 37801623 PMCID: PMC10599104 DOI: 10.1002/pro.4791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/20/2023] [Accepted: 09/25/2023] [Indexed: 10/08/2023]
Abstract
Caveolin-1 is an integral membrane protein that is known to acquire a number of posttranslational modifications upon trafficking to the plasma membrane. In particular, caveolin-1 is palmitoylated at three cysteine residues (C133, C143, and C156) located within the C-terminal domain of the protein which could have structural and topological implications. Herein, a reliable preparation of full-length S-alkylated caveolin-1, which closely mimics the palmitoylation observed in vivo, is described. HPLC and ESI-LC-MS analyses verified the addition of the C16 alkyl groups to caveolin-1 constructs containing one (C133), two (C133 and C143), and three (C133, C143, and C156) cysteine residues. Circular dichroism spectroscopy analysis of the constructs revealed that S-alkylation does not significantly affect the global helicity of the protein; however, molecular dynamics simulations revealed that there were local regions where the helicity was altered positively or negatively by S-alkylation. In addition, the simulations showed that lipidation tames the topological promiscuity of the C-terminal domain, resulting in a disposition within the bilayer characterized by increased depth.
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Affiliation(s)
| | - Alain Rousseau
- Department of ChemistryLehigh UniversityBethlehemPennsylvaniaUSA
| | - Thomas V. Perone
- Department of ChemistryLehigh UniversityBethlehemPennsylvaniaUSA
| | - David M. LaGatta
- Department of ChemistryLehigh UniversityBethlehemPennsylvaniaUSA
| | - Chan Hong
- Department of ChemistryLehigh UniversityBethlehemPennsylvaniaUSA
| | - Kyle T. Root
- Department of Chemistry, Biochemistry, Engineering & PhysicsCommonwealth University of PennsylvaniaLock HavenPennsylvaniaUSA
| | - Soohyung Park
- Department of ChemistryLehigh UniversityBethlehemPennsylvaniaUSA
| | - René Fuanta
- Department of Chemistry & BiochemistryEast Stroudsburg UniversityEast StroudsburgPennsylvaniaUSA
| | - Wonpil Im
- Department of ChemistryLehigh UniversityBethlehemPennsylvaniaUSA
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Vasquez Rodriguez SY, Lazaridis T. Simulations suggest a scaffolding mechanism of membrane deformation by the caveolin 8S complex. Biophys J 2023; 122:4082-4090. [PMID: 37742070 PMCID: PMC10598286 DOI: 10.1016/j.bpj.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 09/25/2023] Open
Abstract
Caveolins form complexes of various sizes that deform membranes into polyhedral shapes. However, the recent structure of the 8S complex was disk-like with a flat membrane-binding surface. How can a flat complex deform membranes into nonplanar structures? Molecular dynamics simulations revealed that the 8S complex rapidly takes the form of a suction cup. Simulations on implicit membrane vesicles determined that binding is stronger when E140 gets protonated. In that case, the complex binds much more strongly to 5- and 10-nm-radius vesicles. A concave membrane-binding surface readily explains the membrane-deforming ability of caveolins by direct scaffolding. We propose that the 8S complex sits at the vertices of the caveolar polyhedra, rather than at the center of the polyhedral faces.
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Affiliation(s)
| | - Themis Lazaridis
- Department of Chemistry, City College of New York/CUNY, New York, New York; Graduate Programs in Chemistry, Biochemistry, and Physics, The Graduate Center, City University of New York, New York, New York.
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Kenworthy AK. The building blocks of caveolae revealed: caveolins finally take center stage. Biochem Soc Trans 2023; 51:855-869. [PMID: 37082988 PMCID: PMC10212548 DOI: 10.1042/bst20221298] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 04/07/2023] [Accepted: 04/14/2023] [Indexed: 04/22/2023]
Abstract
The ability of cells to divide, migrate, relay signals, sense mechanical stimuli, and respond to stress all rely on nanoscale invaginations of the plasma membrane known as caveolae. The caveolins, a family of monotopic membrane proteins, form the inner layer of the caveolar coat. Caveolins have long been implicated in the generation of membrane curvature, in addition to serving as scaffolds for signaling proteins. Until recently, however, the molecular architecture of caveolins was unknown, making it impossible to understand how they operate at a mechanistic level. Over the past year, two independent lines of evidence - experimental and computational - have now converged to provide the first-ever glimpse into the structure of the oligomeric caveolin complexes that function as the building blocks of caveolae. Here, we summarize how these discoveries are transforming our understanding of this long-enigmatic protein family and their role in caveolae assembly and function. We present new models inspired by the structure for how caveolins oligomerize, remodel membranes, interact with their binding partners, and reorganize when mutated. Finally, we discuss emerging insights into structural differences among caveolin family members that enable them to support the proper functions of diverse tissues and organisms.
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Affiliation(s)
- Anne K. Kenworthy
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA, U.S.A
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, U.S.A
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Luo S, Yang M, Zhao H, Han Y, Jiang N, Yang J, Chen W, Li C, Liu Y, Zhao C, Sun L. Caveolin-1 Regulates Cellular Metabolism: A Potential Therapeutic Target in Kidney Disease. Front Pharmacol 2021; 12:768100. [PMID: 34955837 PMCID: PMC8703113 DOI: 10.3389/fphar.2021.768100] [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: 08/31/2021] [Accepted: 11/08/2021] [Indexed: 01/09/2023] Open
Abstract
The kidney is an energy-consuming organ, and cellular metabolism plays an indispensable role in kidney-related diseases. Caveolin-1 (Cav-1), a multifunctional membrane protein, is the main component of caveolae on the plasma membrane. Caveolae are represented by tiny invaginations that are abundant on the plasma membrane and that serve as a platform to regulate cellular endocytosis, stress responses, and signal transduction. However, caveolae have received increasing attention as a metabolic platform that mediates the endocytosis of albumin, cholesterol, and glucose, participates in cellular metabolic reprogramming and is involved in the progression of kidney disease. It is worth noting that caveolae mainly depend on Cav-1 to perform the abovementioned cellular functions. Furthermore, the mechanism by which Cav-1 regulates cellular metabolism and participates in the pathophysiology of kidney diseases has not been completely elucidated. In this review, we introduce the structure and function of Cav-1 and its functions in regulating cellular metabolism, autophagy, and oxidative stress, focusing on the relationship between Cav-1 in cellular metabolism and kidney disease; in addition, Cav-1 that serves as a potential therapeutic target for treatment of kidney disease is also described.
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Affiliation(s)
- Shilu Luo
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Ming Yang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Hao Zhao
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Yachun Han
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Na Jiang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Jinfei Yang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Wei Chen
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Chenrui Li
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Yan Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Chanyue Zhao
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Lin Sun
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
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Zhang Y, Zhang X, Kong W, Wang S. Reconstitution of Caveolin-1 into Artificial Lipid Membrane: Characterization by Transmission Electron Microscopy and Solid-State Nuclear Magnetic Resonance. Molecules 2021; 26:molecules26206201. [PMID: 34684779 PMCID: PMC8539922 DOI: 10.3390/molecules26206201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/09/2021] [Accepted: 10/11/2021] [Indexed: 12/26/2022] Open
Abstract
Caveolin-1 (CAV1), a membrane protein that is necessary for the formation and maintenance of caveolae, is a promising drug target for the therapy of various diseases, such as cancer, diabetes, and liver fibrosis. The biology and pathology of caveolae have been widely investigated; however, very little information about the structural features of full-length CAV1 is available, as well as its biophysical role in reshaping the cellular membrane. Here, we established a method, with high reliability and reproducibility, for the expression and purification of CAV1. Amyloid-like properties of CAV1 and its C-terminal peptide CAV1(168-178) suggest a structural basis for the short linear CAV1 assemblies that have been recently observed in caveolin polyhedral cages in Escherichia coli (E. coli). Reconstitution of CAV1 into artificial lipid membranes induces a caveolae-like membrane curvature. Structural characterization of CAV1 in the membrane by solid-state nuclear magnetic resonance (ssNMR) indicate that it is largely α-helical, with very little β-sheet content. Its scaffolding domain adopts a α-helical structure as identified by chemical shift analysis of threonine (Thr). Taken together, an in vitro model was developed for the CAV1 structural study, which will further provide meaningful evidences for the design and screening of bioactive compounds targeting CAV1.
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Affiliation(s)
- Yanli Zhang
- Department of Pharmacy, Qilu Hospital of Shandong University, Cheeloo College of Medicine, Jinan 250012, China;
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Xinyan Zhang
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Wenru Kong
- School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China;
| | - Shuqi Wang
- School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China;
- Correspondence: ; Tel.: +86-0531-88382014
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Egger AN, Rajabi‐Estarabadi A, Williams NM, Resnik SR, Fox JD, Wong LL, Jozic I. The importance of caveolins and caveolae to dermatology: Lessons from the caves and beyond. Exp Dermatol 2020; 29:136-148. [PMID: 31845391 PMCID: PMC7028117 DOI: 10.1111/exd.14068] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/25/2019] [Accepted: 11/28/2019] [Indexed: 12/15/2022]
Abstract
Caveolae are flask-shaped invaginations of the cell membrane rich in cholesterol and sphingomyelin, with caveolin proteins acting as their primary structural components that allow compartmentalization and orchestration of various signalling molecules. In this review, we discuss how pleiotropic functions of caveolin-1 (Cav1) and its intricate roles in numerous cellular functions including lipid trafficking, signalling, cell migration and proliferation, as well as cellular senescence, infection and inflammation, are integral for normal development and functioning of skin and its appendages. We then examine how disruption of the homeostatic levels of Cav1 can lead to development of various cutaneous pathophysiologies including skin cancers, cutaneous fibroses, psoriasis, alopecia, age-related changes in skin and aberrant wound healing and propose how levels of Cav1 may have theragnostic value in skin physiology/pathophysiology.
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Affiliation(s)
- Andjela N. Egger
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Ali Rajabi‐Estarabadi
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Natalie M. Williams
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Sydney R. Resnik
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Joshua D. Fox
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Lulu L. Wong
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Ivan Jozic
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
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