1
|
He L, McAndrew R, Barbu R, Gifford G, Halacoglu C, Drouin-Allaire C, Weber L, Kristensen LG, Gupta S, Chen Y, Petzold CJ, Allaire M, Li KH, Ralston CY, Gochin M. Structure and Interactions of HIV-1 gp41 CHR-NHR Reverse Hairpin Constructs Reveal Molecular Determinants of Antiviral Activity. J Mol Biol 2024; 436:168650. [PMID: 38866091 DOI: 10.1016/j.jmb.2024.168650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 06/05/2024] [Accepted: 06/05/2024] [Indexed: 06/14/2024]
Abstract
Engineered reverse hairpin constructs containing a partial C-heptad repeat (CHR) sequence followed by a short loop and full-length N-heptad repeat (NHR) were previously shown to form trimers in solution and to be nanomolar inhibitors of HIV-1 Env mediated fusion. Their target is the in situ gp41 fusion intermediate, and they have similar potency to other previously reported NHR trimers. However, their design implies that the NHR is partially covered by CHR, which would be expected to limit potency. An exposed hydrophobic pocket in the folded structure may be sufficient to confer the observed potency, or they may exist in a partially unfolded state exposing full length NHR. Here we examined their structure by crystallography, CD and fluorescence, establishing that the proteins are folded hairpins both in crystal form and in solution. We examined unfolding in the milieu of the fusion reaction by conducting experiments in the presence of a membrane mimetic solvent and by engineering a disulfide bond into the structure to prevent partial unfolding. We further examined the role of the hydrophobic pocket, using a hairpin-small molecule adduct that occluded the pocket, as confirmed by X-ray footprinting. The results demonstrated that the NHR region nominally covered by CHR in the engineered constructs and the hydrophobic pocket region that is exposed by design were both essential for nanomolar potency and that interaction with membrane is likely to play a role in promoting the required inhibitor structure. The design concepts can be applied to other Class 1 viral fusion proteins.
Collapse
Affiliation(s)
- Li He
- Department of Foundational Biomedical Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA
| | - Ryan McAndrew
- Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Razvan Barbu
- Master of Science in Medical Health Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA
| | - Grant Gifford
- Master of Science in Medical Health Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA
| | - Cari Halacoglu
- Master of Science in Medical Health Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA
| | - Camille Drouin-Allaire
- Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Lindsey Weber
- Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Line G Kristensen
- Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Sayan Gupta
- Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Yan Chen
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Christopher J Petzold
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Marc Allaire
- Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, UCSF School of Pharmacy, San Francisco, CA 94143, USA
| | - Corie Y Ralston
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Miriam Gochin
- Department of Foundational Biomedical Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA; Department of Pharmaceutical Chemistry, UCSF School of Pharmacy, San Francisco, CA 94143, USA.
| |
Collapse
|
2
|
Rujas E, Apellániz B, Torralba J, Andreu D, Caaveiro JMM, Wang S, Lu S, Nieva JL. Liposome-based peptide vaccines to elicit immune responses against the membrane active domains of the HIV-1 Env glycoprotein. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184235. [PMID: 37793559 DOI: 10.1016/j.bbamem.2023.184235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/12/2023] [Accepted: 09/27/2023] [Indexed: 10/06/2023]
Abstract
The fusion peptide (FP) and the Trp-rich membrane proximal external region (MPER) display membrane activity during HIV-1 fusion. These domains are highly conserved in the envelope glycoprotein (Env) and, consequently, antibodies targeting these regions block entry of divergent HIV strains and isolates into target cells. With the aim of recovering concurrent responses against the membrane-active Env domains, we have produced hybrid peptides that connect FP and MPER sequences via flexible aminohexanoic acid tethers, and tested their potential as immunogens. We demonstrate that liposome-based formulations containing FP-MPER hybrid peptides could elicit in rabbits, antibodies with the binding sequence specificity of neutralizing antibodies that engage with the N-terminal MPER sub-region. Determination of the thermodynamic parameters of binding using the Fab 2F5 as an N-terminal MPER antibody model, revealed that the hydrophobic interaction surface for epitope engagement appears to be optimal in the FP-MPER hybrid. In general, our data support: i) the use of liposomes as carriers for membrane active peptides; ii) the capacity of these liposome-based vaccines to focus humoral responses to N-terminal MPER epitopes; and iii) the need to include lipid membranes in immunogens to elicit such specific responses.
Collapse
Affiliation(s)
- Edurne Rujas
- Instituto Biofisika (CSIC, UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain.
| | - Beatriz Apellániz
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Bioaraba, Microbiology, Infectious Disease, Antimicrobial Agents, and Gene Therapy, 01006 Vitoria-Gasteiz, Spain
| | - Johana Torralba
- Instituto Biofisika (CSIC, UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - David Andreu
- Laboratory of Proteomics and Protein Chemistry, Department of Medicine and Life Sciences, Pompeu Fabra University, Barcelona Biomedical Research Park, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Jose M M Caaveiro
- Laboratory of Global Healthcare, School of Pharmaceutical Sciences, Kyushu University, Fukuoka 819-0395, Japan
| | - Shixia Wang
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, United States of America
| | - Shan Lu
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, United States of America
| | - Jose L Nieva
- Instituto Biofisika (CSIC, UPV/EHU) and Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain.
| |
Collapse
|
3
|
Klug YA, Schwarzer R, Ravula T, Rotem E, Ramamoorthy A, Shai Y. Structural and Mechanistic Evidence for Calcium Interacting Sites in the HIV Transmembrane Protein gp41 Involved in Membrane Fusion. Biochemistry 2022; 61:1915-1922. [PMID: 35994087 PMCID: PMC9454089 DOI: 10.1021/acs.biochem.2c00372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/05/2022] [Indexed: 11/29/2022]
Abstract
The HIV envelope protein gp160 comprises two subunits, gp120 and gp41, responsible for receptor binding and membrane fusion during viral entry, respectively. In the course of the membrane fusion process, gp41 undergoes a conformational change, leading to the formation of a six-helix bundle (SHB), which ultimately drives membrane fusion. The gp41 C-terminal and N-terminal heptad repeats (CHR and NHR) interact with one another to form the SHB, and this step can be targeted by peptide inhibitors, which are used in the clinic to mitigate HIV infection. Here, we discover the calcium interaction motifs (CIMs) in the gp41 CHR and NHR regions via NMR spectroscopy. We find that the assembly of the CHR-NHR SHB is facilitated in Ca2+-containing media and impaired in CIM mutants. Of note, the clinically approved, gp41-derived fusion inhibitor T20, which does not contain the CIM motif, exhibits reduced inhibitory efficiency when challenged with calcium. This finding could have important implications for the development of better fusion inhibitors for HIV.
Collapse
Affiliation(s)
- Yoel A. Klug
- Department
of Biomolecular Sciences, The Weizmann Institute
of Science, Rehovot 7632701, Israel
| | - Roland Schwarzer
- Department
of Biomolecular Sciences, The Weizmann Institute
of Science, Rehovot 7632701, Israel
- Institute
for Translational HIV Research, University Hospital Essen, University of Duisburg-Essen, Essen 45147, Germany
| | - Thirupathi Ravula
- Biophysics
Program, Department of Chemistry, Macromolecular Science and Engineering,
Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Etai Rotem
- Department
of Biomolecular Sciences, The Weizmann Institute
of Science, Rehovot 7632701, Israel
| | - Ayyalusamy Ramamoorthy
- Biophysics
Program, Department of Chemistry, Macromolecular Science and Engineering,
Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Yechiel Shai
- Department
of Biomolecular Sciences, The Weizmann Institute
of Science, Rehovot 7632701, Israel
| |
Collapse
|
4
|
Rogers JR, Espinoza Garcia G, Geissler PL. Membrane hydrophobicity determines the activation free energy of passive lipid transport. Biophys J 2021; 120:3718-3731. [PMID: 34302793 PMCID: PMC8456290 DOI: 10.1016/j.bpj.2021.07.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 07/07/2021] [Accepted: 07/19/2021] [Indexed: 12/16/2022] Open
Abstract
The collective behavior of lipids with diverse chemical and physical features determines a membrane's thermodynamic properties. Yet, the influence of lipid physicochemical properties on lipid dynamics, in particular interbilayer transport, remains underexplored. Here, we systematically investigate how the activation free energy of passive lipid transport depends on lipid chemistry and membrane phase. Through all-atom molecular dynamics simulations of 11 chemically distinct glycerophospholipids, we determine how lipid acyl chain length, unsaturation, and headgroup influence the free energy barriers for two elementary steps of lipid transport: lipid desorption, which is rate limiting, and lipid insertion into a membrane. Consistent with previous experimental measurements, we find that lipids with longer, saturated acyl chains have increased activation free energies compared to lipids with shorter, unsaturated chains. Lipids with different headgroups exhibit a range of activation free energies; however, no clear trend based solely on chemical structure can be identified, mirroring difficulties in the interpretation of previous experimental results. Compared to liquid-crystalline phase membranes, gel phase membranes exhibit substantially increased free energy barriers. Overall, we find that the activation free energy depends on a lipid's local hydrophobic environment in a membrane and that the free energy barrier for lipid insertion depends on a membrane's interfacial hydrophobicity. Both of these properties can be altered through changes in lipid acyl chain length, lipid headgroup, and membrane phase. Thus, the rate of lipid transport can be tuned through subtle changes in local membrane composition and order, suggesting an unappreciated role for nanoscale membrane domains in regulating cellular lipid dynamics.
Collapse
Affiliation(s)
- Julia R Rogers
- Department of Chemistry, University of California Berkeley, Berkeley, California.
| | | | - Phillip L Geissler
- Department of Chemistry, University of California Berkeley, Berkeley, California; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California.
| |
Collapse
|
5
|
Zhou G, Chu S, Kohli A, Szoka FC, Gochin M. Biophysical studies of HIV-1 glycoprotein-41 interactions with peptides and small molecules - Effect of lipids and detergents. Biochim Biophys Acta Gen Subj 2020; 1864:129724. [PMID: 32889078 DOI: 10.1016/j.bbagen.2020.129724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/18/2020] [Accepted: 08/26/2020] [Indexed: 01/30/2023]
Abstract
BACKGROUND The hydrophobic pocket (HP) of HIV-1 glycoprotein-41 ectodomain is defined by two chains of the N-heptad repeat trimer, within the protein-protein interface that mediates 6HB formation. It is a potential target for inhibitors of viral fusion, but its hydrophobic nature and proximity to membrane in situ has precluded ready analysis of inhibitor interactions. METHODS We evaluated the sensitivity of 19F NMR and fluorescence for detecting peptide and small molecule binding to the HP and explored the effect of non-denaturing detergent or phospholipid as cosolvents and potential mimics of the membrane environment surrounding gp41. RESULTS Chemical shifts of aromatic fluorines were found to be sensitive to changes in the hydrogen bonding network that occurred when inhibitors transitioned from solvent into the HP or into ordered detergent micelles. Fluorescence intensities and emission maxima of autofluorescent compounds responded to changes in the local environment. CONCLUSIONS Gp41 - ligand binding occurred under all conditions, but was diminished in the presence of detergents. NMR and fluorescence studies revealed that dodecylphosphocholine (DPC) was a poor substitute for membrane in this system, while liposomes could mimic the membrane surroundings. GENERAL SIGNIFICANCE Our findings suggest that development of high potency small molecule binders to the HP may be frustrated by competition between binding to the HP and binding to the bilayer membrane.
Collapse
Affiliation(s)
- Guangyan Zhou
- Department of Basic Sciences, College of Osteopathic Medicine, Touro University California, Vallejo, CA 94592, United States of America
| | - Shidong Chu
- Department of Basic Sciences, College of Osteopathic Medicine, Touro University California, Vallejo, CA 94592, United States of America
| | - Aditya Kohli
- Department of Bioengineering and Therapeutic Sciences, UCSF School of Pharmacy, San Francisco, CA 94143, United States of America
| | - Francis C Szoka
- Department of Bioengineering and Therapeutic Sciences, UCSF School of Pharmacy, San Francisco, CA 94143, United States of America; Department of Pharmaceutical Chemistry, UCSF School of Pharmacy, San Francisco, CA 94143, United States of America
| | - Miriam Gochin
- Department of Basic Sciences, College of Osteopathic Medicine, Touro University California, Vallejo, CA 94592, United States of America; Department of Pharmaceutical Chemistry, UCSF School of Pharmacy, San Francisco, CA 94143, United States of America.
| |
Collapse
|
6
|
Moon Y, Jun Y. The Effects of Regulatory Lipids on Intracellular Membrane Fusion Mediated by Dynamin-Like GTPases. Front Cell Dev Biol 2020; 8:518. [PMID: 32671068 PMCID: PMC7326814 DOI: 10.3389/fcell.2020.00518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/02/2020] [Indexed: 12/04/2022] Open
Abstract
Membrane fusion mediates a number of fundamental biological processes such as intracellular membrane trafficking, fertilization, and viral infection. Biological membranes are composed of lipids and proteins; while lipids generally play a structural role, proteins mediate specific functions in the membrane. Likewise, although proteins are key players in the fusion of biological membranes, there is emerging evidence supporting a functional role of lipids in various membrane fusion events. Intracellular membrane fusion is mediated by two protein families: SNAREs and membrane-bound GTPases. SNARE proteins are involved in membrane fusion between transport vesicles and their target compartments, as well as in homotypic fusion between organelles of the same type. Membrane-bound GTPases mediate mitochondrial fusion and homotypic endoplasmic reticulum fusion. Certain membrane lipids, known as regulatory lipids, regulate these membrane fusion events by directly affecting the function of membrane-bound GTPases, instead of simply changing the biophysical and biochemical properties of lipid bilayers. In this review, we provide a summary of the current understanding of how regulatory lipids affect GTPase-mediated intracellular membrane fusion by focusing on the functions of regulatory lipids that directly affect fusogenic GTPases.
Collapse
Affiliation(s)
- Yeojin Moon
- School of Life Sciences and Cell Logistics Research Center, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Youngsoo Jun
- School of Life Sciences and Cell Logistics Research Center, Gwangju Institute of Science and Technology, Gwangju, South Korea
| |
Collapse
|
7
|
Oregano Oil and Its Principal Component, Carvacrol, Inhibit HIV-1 Fusion into Target Cells. J Virol 2020; 94:JVI.00147-20. [PMID: 32461309 DOI: 10.1128/jvi.00147-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 05/01/2020] [Indexed: 02/07/2023] Open
Abstract
Oregano essential oil has long been known for its health-promoting benefits. Here, we report its activity against viral replication. Oregano oil was found to specifically inhibit lentiviruses, such as human and simian immunodeficiency viruses (HIV and SIV), irrespective of virus tropism, but not hepatitis C virus, adenovirus 5 (ADV5), Zika virus, and influenza (H1N1) virus. Oregano oil's most abundant components, carvacrol and its isomer, thymol, were shown to block virus-target cell fusion while not perturbing other stages of the virus life cycle. We detected changes in virus particle density, suggesting that cholesterol depletion from the HIV-1 envelope membrane reduces virus entry. Furthermore, infection was rescued by adding exogenous cholesterol. The evolution of viral resistance to carvacrol supported this mechanism of action with the identification of mutations in the viral gp41 fusion protein that counteracted cholesterol depletion. In addition, resistance to carvacrol emerged later than typically observed for other clinically used drugs, strengthening its antiviral potential. Structure-activity relationship studies revealed key motifs of carvacrol and thymol required for HIV neutralization and identified previously unknown active analogs. Carvacrol was also shown to additively cooperate with antiretroviral therapy. In sum, oregano oil and improved carvacrol and thymol analogs could be considered to supplement current HIV therapeutics.IMPORTANCE Oregano essential oil has multiple benefits in traditional medicine, cosmetics, and food industries. Carvacrol and its analog, thymol, are well-described components of oregano oil. Here, we show that these compounds inhibit HIV-target cell fusion independently of viral tropism. Our results suggest that carvacrol and thymol alter the cholesterol content of the viral membrane, blocking HIV-1 entry into the target cell. Resistance to carvacrol has selected for viruses with mutations in the viral envelope glycoprotein, gp41. This protein is known for its interaction with cholesterol present in membrane lipid rafts. Together, these results demonstrate the potential of therapies targeting the viral envelope membrane, and oregano oil is a safe supplement to antiretrovirals, potentially delaying disease progression and resistance development.
Collapse
|
8
|
Structure, interactions and membrane topology of HIV gp41 ectodomain sequences. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183274. [DOI: 10.1016/j.bbamem.2020.183274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/06/2020] [Accepted: 03/10/2020] [Indexed: 11/21/2022]
|
9
|
Barrett CT, Dutch RE. Viral Membrane Fusion and the Transmembrane Domain. Viruses 2020; 12:v12070693. [PMID: 32604992 PMCID: PMC7412173 DOI: 10.3390/v12070693] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 01/05/2023] Open
Abstract
Initiation of host cell infection by an enveloped virus requires a viral-to-host cell membrane fusion event. This event is mediated by at least one viral transmembrane glycoprotein, termed the fusion protein, which is a key therapeutic target. Viral fusion proteins have been studied for decades, and numerous critical insights into their function have been elucidated. However, the transmembrane region remains one of the most poorly understood facets of these proteins. In the past ten years, the field has made significant advances in understanding the role of the membrane-spanning region of viral fusion proteins. We summarize developments made in the past decade that have contributed to the understanding of the transmembrane region of viral fusion proteins, highlighting not only their critical role in the membrane fusion process, but further demonstrating their involvement in several aspects of the viral lifecycle.
Collapse
|
10
|
Hung Y, Wang YL, Lin YZ, Chiang SF, Wu WR, Wang SC. The exosomal compartment protects epidermal growth factor receptor from small molecule inhibitors. Biochem Biophys Res Commun 2019; 510:42-47. [PMID: 30683316 DOI: 10.1016/j.bbrc.2018.12.187] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 12/31/2018] [Indexed: 01/19/2023]
Abstract
Epidermal growth factor receptor (EGFR) plays a significant role in promoting breast cancer progression. However, targeting EGFR as a single treatment only resulted in moderate efficacy to the disease. The underlying mechanism of low responsiveness to EGFR inhibition remains largely unclear. Tumor-secreted extracellular vesicles (EVs) play a crucial role in mediating intercellular communication between tumor and stromal cells in local microenvironment and distant metastatic niche. Extracellular vesicles mediate cell-to-cell transfer of lipids, nucleic acids, and proteins. Although numerous recent studies have demonstrated exchanges of extracellular vesicles between cancer cells and the recipient cells contribute to tumor proliferation, invasion, and metastasis, yet little is known how the exosomal compartment responds to targeted therapies and their role in promoting drug resistance. In the current study we used a triple-negative breast cancer model to show that EV-encapsulated EGFR is protected from targeted inhibitors of EGFR and can trigger signaling pathway in recipient cancer cells, promoting proliferation and migration ability in vitro. Taken together, our study suggested a novel mechanism of drug resistance entailing the EV compartment, such as exosomes, as a target shelter which when released can signal for tumor promotion in the recipient cancer cells.
Collapse
Affiliation(s)
- Yu Hung
- Center for Molecular Medicine, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Yuan-Liang Wang
- Center for Molecular Medicine, China Medical University Hospital, Taichung, 40447, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University, Taichung, 40402, Taiwan
| | - You-Zhe Lin
- Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University, Taichung, 40402, Taiwan
| | - Shu-Fen Chiang
- Cancer Center, China Medical University Hospital, China Medical University, Taichung, Taiwan
| | - Wan-Rong Wu
- Center for Molecular Medicine, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Shao-Chun Wang
- Center for Molecular Medicine, China Medical University Hospital, Taichung, 40447, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University, Taichung, 40402, Taiwan; Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, 45267, USA; Department of Biotechnology, Asia University, Taichung, 413, Taiwan.
| |
Collapse
|
11
|
Fantini J, Epand RM, Barrantes FJ. Cholesterol-Recognition Motifs in Membrane Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1135:3-25. [PMID: 31098808 DOI: 10.1007/978-3-030-14265-0_1] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The impact of cholesterol on the structure and function of membrane proteins was recognized several decades ago, but the molecular mechanisms underlying these effects have remained elusive. There appear to be multiple mechanisms by which cholesterol interacts with proteins. A complete understanding of cholesterol-sensing motifs is still undergoing refinement. Initially, cholesterol was thought to exert only non-specific effects on membrane fluidity. It was later shown that this lipid could specifically interact with membrane proteins and affect both their structure and function. In this article, we have summarized and critically analyzed our evolving understanding of the affinity, specificity and stereoselectivity of the interactions of cholesterol with membrane proteins. We review the different computational approaches that are currently used to identify cholesterol binding sites in membrane proteins and the biochemical logic that governs each type of site, including CRAC, CARC, SSD and amphipathic helix motifs. There are physiological implications of these cholesterol-recognition motifs for G-protein coupled receptors (GPCR) and ion channels, in membrane trafficking and membrane fusion (SNARE) proteins. There are also pathological implications of cholesterol binding to proteins involved in neurological disorders (Alzheimer, Parkinson, Creutzfeldt-Jakob) and HIV fusion. In each case, our discussion is focused on the key molecular aspects of the cholesterol and amino acid motifs in membrane-embedded regions of membrane proteins that define the physiologically relevant crosstalk between the two. Our understanding of the factors that determine if these motifs are functional in cholesterol binding will allow us enhanced predictive capabilities.
Collapse
Affiliation(s)
- Jacques Fantini
- INSERM UMR_S 1072, Marseille, France. .,Aix-Marseille Université, Marseille, France.
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON, Canada
| | - Francisco J Barrantes
- Laboratory of Molecular Neurobiology, Biomedical Research Institute (BIOMED), UCA-CONICET, Buenos Aires, Argentina
| |
Collapse
|
12
|
Abstract
Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) remain a common end-organ manifestation of viral infection. Subclinical and mild symptoms lead to neurocognitive and behavioral abnormalities. These are associated, in part, with viral penetrance and persistence in the central nervous system. Infections of peripheral blood monocytes, macrophages, and microglia are the primary drivers of neuroinflammation and neuronal impairments. While current antiretroviral therapy (ART) has reduced the incidence of HIV-associated dementia, milder forms of HAND continue. Depression, comorbid conditions such as infectious liver disease, drugs of abuse, antiretroviral drugs themselves, age-related neurodegenerative diseases, gastrointestinal maladies, and concurrent social and economic issues can make accurate diagnosis of HAND challenging. Increased life expectancy as a result of ART clearly creates this variety of comorbid conditions that often blur the link between the virus and disease. With the discovery of novel biomarkers, neuropsychologic testing, and imaging techniques to better diagnose HAND, the emergence of brain-penetrant ART, adjunctive therapies, longer life expectancy, and better understanding of disease pathogenesis, disease elimination is perhaps a realistic possibility. This review focuses on HIV-associated disease pathobiology with an eye towards changing trends in the face of widespread availability of ART.
Collapse
|
13
|
Oakes V, Torralba J, Rujas E, Nieva JL, Domene C, Apellaniz B. Exposure of the HIV-1 broadly neutralizing antibody 10E8 MPER epitope on the membrane surface by gp41 transmembrane domain scaffolds. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1259-1271. [PMID: 29477358 DOI: 10.1016/j.bbamem.2018.02.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 01/30/2018] [Accepted: 02/20/2018] [Indexed: 12/27/2022]
Abstract
The 10E8 antibody achieves near-pan neutralization of HIV-1 by targeting the remarkably conserved gp41 membrane-proximal external region (MPER) and the connected transmembrane domain (TMD) of the HIV-1 envelope glycoprotein (Env). Thus, recreating the structure that generates 10E8-like antibodies is a major goal of the rational design of anti-HIV vaccines. Unfortunately, high-resolution information of this segment in the native Env is lacking, limiting our understanding of the behavior of the crucial 10E8 epitope residues. In this report, two sequences, namely, MPER-TMD1 (gp41 residues 671-700) and MPER-TMD2 (gp41 residues 671-709) were compared both experimentally and computationally, to assess the TMD as a potential membrane integral scaffold for the 10E8 epitope. These sequences were selected to represent a minimal (MPER-TMD1) or full-length (MPER-TMD2) TMD membrane anchor according to mutagenesis results reported by Yue et al. (2009) J. Virol. 83, 11,588. Immunochemical assays revealed that MPER-TMD1, but not MPER-TMD2, effectively exposed the MPER C-terminal stretch, harboring the 10E8 epitope on the surface of phospholipid bilayers containing a cholesterol concentration equivalent to that of the viral envelope. Molecular dynamics simulations, using the recently resolved TMD trimer structure combined with the MPER in a cholesterol-enriched model membrane confirmed these results and provided an atomistic mechanism of epitope exposure which revealed that TMD truncation at position A700 combined with N-terminal addition of lysine residues positively impacts epitope exposure. Overall, these results provide crucial insights into the design of effective MPER-TMD derived immunogens.
Collapse
Affiliation(s)
- Victoria Oakes
- Department of Chemistry, Britannia House, 7 Trinity Street, King's College London, London SE1 1DB, UK; Department of Chemistry, 1 South Building, Claverton Down Road, University of Bath, Bath BA2 7AY, UK
| | - Johana Torralba
- Biofisika Institute (CSIC, UPV/EHU), Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Edurne Rujas
- Biofisika Institute (CSIC, UPV/EHU), Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - José L Nieva
- Biofisika Institute (CSIC, UPV/EHU), Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
| | - Carmen Domene
- Department of Chemistry, 1 South Building, Claverton Down Road, University of Bath, Bath BA2 7AY, UK; Chemistry Research Laboratory, Mansfield Road, University of Oxford, Oxford OX1 3TA, UK.
| | - Beatriz Apellaniz
- Biofisika Institute (CSIC, UPV/EHU), Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain.
| |
Collapse
|
14
|
Mahajan M, Chatterjee D, Bhuvaneswari K, Pillay S, Bhattacharjya S. NMR structure and localization of a large fragment of the SARS-CoV fusion protein: Implications in viral cell fusion. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:407-415. [PMID: 28988778 PMCID: PMC7094225 DOI: 10.1016/j.bbamem.2017.10.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/16/2017] [Accepted: 10/03/2017] [Indexed: 01/20/2023]
Abstract
The lethal Coronaviruses (CoVs), Severe Acute Respiratory Syndrome-associated Coronavirus (SARS-CoV) and most recently Middle East Respiratory Syndrome Coronavirus, (MERS-CoV) are serious human health hazard. A successful viral infection requires fusion between virus and host cells carried out by the surface spike glycoprotein or S protein of CoV. Current models propose that the S2 subunit of S protein assembled into a hexameric helical bundle exposing hydrophobic fusogenic peptides or fusion peptides (FPs) for membrane insertion. The N-terminus of S2 subunit of SARS-CoV reported to be active in cell fusion whereby FPs have been identified. Atomic-resolution structure of FPs derived either in model membranes or in membrane mimic environment would glean insights toward viral cell fusion mechanism. Here, we have solved 3D structure, dynamics and micelle localization of a 64-residue long fusion peptide or LFP in DPC detergent micelles by NMR methods. Micelle bound structure of LFP is elucidated by the presence of discretely folded helical and intervening loops. The C-terminus region, residues F42-Y62, displays a long hydrophobic helix, whereas the N-terminus is defined by a short amphipathic helix, residues R4-Q12. The intervening residues of LFP assume stretches of loops and helical turns. The N-terminal helix is sustained by close aromatic and aliphatic sidechain packing interactions at the non-polar face. 15N{1H}NOE studies indicated dynamical motion, at ps-ns timescale, of the helices of LFP in DPC micelles. PRE NMR showed that insertion of several regions of LFP into DPC micelle core. Together, the current study provides insights toward fusion mechanism of SARS-CoV.
Collapse
Affiliation(s)
- Mukesh Mahajan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Deepak Chatterjee
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Kannaian Bhuvaneswari
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Shubhadra Pillay
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
| |
Collapse
|
15
|
Carravilla P, Cruz A, Martin-Ugarte I, Oar-Arteta IR, Torralba J, Apellaniz B, Pérez-Gil J, Requejo-Isidro J, Huarte N, Nieva JL. Effects of HIV-1 gp41-Derived Virucidal Peptides on Virus-like Lipid Membranes. Biophys J 2017; 113:1301-1310. [PMID: 28797705 DOI: 10.1016/j.bpj.2017.06.061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 06/22/2017] [Accepted: 06/29/2017] [Indexed: 12/11/2022] Open
Abstract
Membrane fusion induced by the envelope glycoprotein enables the intracellular replication of HIV-1; hence, this process constitutes a major target for antiretroviral compounds. It has been proposed that peptides having propensity to interact with membrane interfaces might exert broad antiviral activity against enveloped viruses. To test this hypothesis, in this contribution we have analyzed the antiviral effects of peptides derived from the membrane-proximal external region and the transmembrane domain of the envelope glycoprotein subunit gp41, which display different degrees of interfacial hydrophobicity. Our data support the virucidal activity of a region that combines hydrophobic-at-interface membrane-proximal external region aromatics with hydrophobic residues of the transmembrane domain, and contains the absolutely conserved 679LWYIK/R683 sequence, proposed to embody a "cholesterol recognition/interaction amino acid consensus" motif. We further sought to correlate the antiviral activity of these peptides and their effects on membranes that mimic lipid composition and biophysical properties of the viral envelope. The data revealed that peptides endowed with virucidal activity were membrane active and induced permeabilization and fusion of virus-like lipid vesicles. In addition, they modulated lipid packing and miscibility of laterally segregated liquid domains, two properties that depend on the high cholesterol content of the viral membrane. Thus, the overall experimental evidence is consistent with a pattern of HIV inhibition that involves direct alteration of the physical chemistry of the virus membrane. Furthermore, the sequence-dependent effects observed might guide the development of new virucidal peptides.
Collapse
Affiliation(s)
- Pablo Carravilla
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Antonio Cruz
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Complutense University, Madrid, Spain; Healthcare Research Institute of Hospital 12 de Octubre, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Itziar Martin-Ugarte
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Itziar R Oar-Arteta
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Johanna Torralba
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Beatriz Apellaniz
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Jesús Pérez-Gil
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Complutense University, Madrid, Spain; Healthcare Research Institute of Hospital 12 de Octubre, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - José Requejo-Isidro
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Nerea Huarte
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain.
| | - José L Nieva
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain.
| |
Collapse
|
16
|
Schneider D. Border controls: Lipids control proteins and proteins control lipids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:507-508. [DOI: 10.1016/j.bbamem.2016.12.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|