1
|
Dudas EF, Tully MD, Foldes T, Kelly G, Tartaglia GG, Pastore A. The structural properties of full-length annexin A11. Front Mol Biosci 2024; 11:1347741. [PMID: 38516187 PMCID: PMC10955470 DOI: 10.3389/fmolb.2024.1347741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/17/2024] [Indexed: 03/23/2024] Open
Abstract
Annexin A11 (ANXA11) is a calcium-dependent phospholipid-binding protein belonging to the annexin protein family and implicated in the neurodegenerative amyotrophic lateral sclerosis. Structurally, ANXA11 contains a conserved calcium-binding C-terminal domain common to all annexins and a putative intrinsically unfolded N-terminus specific for ANXA11. Little is known about the structure and functions of this region of the protein. By analogy with annexin A1, it was suggested that residues 38 to 59 within the ANXA11 N-terminus could form a helical region that would be involved in interactions. Interestingly, this region contains residues that, when mutated, may lead to clinical manifestations. In the present study, we have studied the structural features of the full-length protein with special attention to the N-terminal region using a combination of biophysical techniques which include nuclear magnetic resonance and small angle X-ray scattering. We show that the N-terminus is intrinsically disordered and that the overall features of the protein are not markedly affected by the presence of calcium. We also analyzed the 38-59 helix hypothesis using synthetic peptides spanning both the wild-type sequence and clinically relevant mutations. We show that the peptides have a remarkable character typical of a native helix and that mutations do not alter the behaviour suggesting that they are required for interactions rather than being structurally important. Our work paves the way to a more thorough understanding of the ANXA11 functions.
Collapse
Affiliation(s)
- Erika F. Dudas
- Dementia Research Institute at King’s College London, The Wohl Institute, London, United Kingdom
- European Synchrotron Radiation Facility, Grenoble, France
| | - Mark D. Tully
- European Synchrotron Radiation Facility, Grenoble, France
| | - Tamas Foldes
- University College London, Department of Physics and Astronomy, University College London, London, United Kingdom
- Institut de Biologie Structurale (IBS), Institut Laue-Langevin, University Grenoble Alpes, Grenoble, France
| | - Geoff Kelly
- MRC Biomedical NMR Centre, The Francis Crick Institute, London, United Kingdom
| | | | - Annalisa Pastore
- Dementia Research Institute at King’s College London, The Wohl Institute, London, United Kingdom
- European Synchrotron Radiation Facility, Grenoble, France
| |
Collapse
|
2
|
Heparan sulfate binds the extracellular Annexin A1 and blocks its effects on pancreatic cancer cells. Biochem Pharmacol 2020; 182:114252. [DOI: 10.1016/j.bcp.2020.114252] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 12/12/2022]
|
3
|
Fabbiano F, Corsi J, Gurrieri E, Trevisan C, Notarangelo M, D'Agostino VG. RNA packaging into extracellular vesicles: An orchestra of RNA-binding proteins? J Extracell Vesicles 2020; 10:e12043. [PMID: 33391635 PMCID: PMC7769857 DOI: 10.1002/jev2.12043] [Citation(s) in RCA: 130] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 11/17/2020] [Accepted: 12/03/2020] [Indexed: 12/11/2022] Open
Abstract
Extracellular vesicles (EVs) are heterogeneous membranous particles released from the cells through different biogenetic and secretory mechanisms. We now conceive EVs as shuttles mediating cellular communication, carrying a variety of molecules resulting from intracellular homeostatic mechanisms. The RNA is a widely detected cargo and, impressively, a recognized functional intermediate that elects EVs as modulators of cancer cell phenotypes, determinants of disease spreading, cell surrogates in regenerative medicine, and a source for non-invasive molecular diagnostics. The mechanistic elucidation of the intracellular events responsible for the engagement of RNA into EVs will significantly improve the comprehension and possibly the prediction of EV "quality" in association with cell physiology. Interestingly, the application of multidisciplinary approaches, including biochemical as well as cell-based and computational strategies, is increasingly revealing an active RNA-packaging process implicating RNA-binding proteins (RBPs) in the sorting of coding and non-coding RNAs. In this review, we provide a comprehensive view of RBPs recently emerging as part of the EV biology, considering the scenarios where: (i) individual RBPs were detected in EVs along with their RNA substrates, (ii) RBPs were detected in EVs with inferred RNA targets, and (iii) EV-transcripts were found to harbour sequence motifs mirroring the activity of RBPs. Proteins so far identified are members of the hnRNP family (hnRNPA2B1, hnRNPC1, hnRNPG, hnRNPH1, hnRNPK, and hnRNPQ), as well as YBX1, HuR, AGO2, IGF2BP1, MEX3C, ANXA2, ALIX, NCL, FUS, TDP-43, MVP, LIN28, SRP9/14, QKI, and TERT. We describe the RBPs based on protein domain features, current knowledge on the association with human diseases, recognition of RNA consensus motifs, and the need to clarify the functional significance in different cellular contexts. We also summarize data on previously identified RBP inhibitor small molecules that could also be introduced in EV research as potential modulators of vesicular RNA sorting.
Collapse
Affiliation(s)
- Fabrizio Fabbiano
- Department of CellularComputational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Jessica Corsi
- Department of CellularComputational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Elena Gurrieri
- Department of CellularComputational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Caterina Trevisan
- Department of CellularComputational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Michela Notarangelo
- Department of CellularComputational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Vito G. D'Agostino
- Department of CellularComputational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| |
Collapse
|
4
|
Koerdt SN, Ashraf APK, Gerke V. Annexins and plasma membrane repair. CURRENT TOPICS IN MEMBRANES 2019; 84:43-65. [PMID: 31610865 DOI: 10.1016/bs.ctm.2019.07.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Plasma membrane wound repair is a cell-autonomous process that is triggered by Ca2+ entering through the site of injury and involves membrane resealing, i.e., re-establishment of a continuous plasma membrane, as well as remodeling of the cortical actin cytoskeleton. Among other things, the injury-induced Ca2+ elevation initiates the wound site recruitment of Ca2+-regulated proteins that function in the course of repair. Annexins are a class of such Ca2+-regulated proteins. They associate with acidic phospholipids of cellular membranes in their Ca2+ bound conformation with Ca2+ sensitivities ranging from the low to high micromolar range depending on the respective annexin protein. Annexins accumulate at sites of plasma membrane injury in a temporally controlled manner and are thought to function by controlling membrane rearrangements at the wound site, most likely in conjunction with other repair proteins such as dysferlin. Their role in membrane repair, which has been evidenced in several model systems, will be discussed in this chapter.
Collapse
Affiliation(s)
- Sophia N Koerdt
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Arsila P K Ashraf
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Volker Gerke
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation, University of Münster, Münster, Germany.
| |
Collapse
|
5
|
Ampomah PB, Kong WT, Zharkova O, Chua SCJH, Perumal Samy R, Lim LHK. Annexins in Influenza Virus Replication and Pathogenesis. Front Pharmacol 2018; 9:1282. [PMID: 30498445 PMCID: PMC6249340 DOI: 10.3389/fphar.2018.01282] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 10/18/2018] [Indexed: 12/26/2022] Open
Abstract
Influenza A viruses (IAVs) are important human respiratory pathogens which cause seasonal or periodic endemic infections. IAV can result in severe or fatal clinical complications including pneumonia and respiratory distress syndrome. Treatment of IAV infections is complicated because the virus can evade host immunity through antigenic drifts and antigenic shifts, to establish infections making new treatment options desirable. Annexins (ANXs) are a family of calcium and phospholipid binding proteins with immunomodulatory roles in viral infections, lung injury, and inflammation. A current understanding of the role of ANXs in modulating IAV infection and host responses will enable the future development of more effective antiviral therapies. This review presents a comprehensive understanding of the advances made in the field of ANXs, in particular, ANXA1 and IAV research and highlights the importance of ANXs as a suitable target for IAV therapy.
Collapse
Affiliation(s)
- Patrick Baah Ampomah
- Department of Physiology, NUS Immunology Program, Centre for Life Sciences, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Wan Ting Kong
- Department of Physiology, NUS Immunology Program, Centre for Life Sciences, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Olga Zharkova
- Department of Physiology, NUS Immunology Program, Centre for Life Sciences, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Sonja C. J. H. Chua
- Department of Physiology, NUS Immunology Program, Centre for Life Sciences, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - R. Perumal Samy
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Lina H. K. Lim
- Department of Physiology, NUS Immunology Program, Centre for Life Sciences, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, Singapore
| |
Collapse
|
6
|
Gobbetti T, Cooray SN. Annexin A1 and resolution of inflammation: tissue repairing properties and signalling signature. Biol Chem 2017; 397:981-93. [PMID: 27447237 DOI: 10.1515/hsz-2016-0200] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 07/14/2016] [Indexed: 01/03/2023]
Abstract
Inflammation is essential to protect the host from exogenous and endogenous dangers that ultimately lead to tissue injury. The consequent tissue repair is intimately associated with the fate of the inflammatory response. Restoration of tissue homeostasis is achieved through a balance between pro-inflammatory and anti-inflammatory/pro-resolving mediators. In chronic inflammatory diseases such balance is compromised, resulting in persistent inflammation and impaired healing. During the last two decades the glucocorticoid-regulated protein Annexin A1 (AnxA1) has emerged as a potent pro-resolving mediator acting on several facets of the innate immune system. Here, we review the therapeutic effects of AnxA1 on tissue healing and repairing together with the molecular targets responsible for these complex biological properties.
Collapse
|
7
|
Niu S, Ruotolo BT. Collisional unfolding of multiprotein complexes reveals cooperative stabilization upon ligand binding. Protein Sci 2015; 24:1272-81. [PMID: 25970849 DOI: 10.1002/pro.2699] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 04/13/2015] [Accepted: 04/29/2015] [Indexed: 12/19/2022]
Abstract
Cooperative binding mechanisms are a common feature in biology, enabling a diverse range of protein-based molecular machines to regulate activities ranging from oxygen uptake to cellular membrane transport. Much, however, is not known about such cooperative binding mechanisms, including how such events typically add to the overall stability of such protein systems. Measurements of such cooperative stabilization events are challenging, as they require the separation and resolution of individual protein complex bound states within a mixture of potential stoichiometries to individually assess protein stabilities. Here, we report ion mobility-mass spectrometry results for the concanavalin A tetramer bound to a range of polysaccharide ligands. We use collision induced unfolding, a relatively new methodology that functions as a gas-phase analog of calorimetry experiments in solution, to individually assess the stabilities of concanavalin A bound states. By comparing the differences in activation voltage required to unfold different concanavalin A-ligand stoichiometries, we find evidence suggesting a cooperative stabilization of concanavalin A occurs upon binding most carbohydrate ligands. We critically evaluate this observation by assessing a broad range of ligands, evaluating the unfolding properties of multiple protein charge states, and by comparing our gas-phase results with those obtained from calorimetry experiments carried out in solution.
Collapse
Affiliation(s)
- Shuai Niu
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, 48109
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, 48109
| |
Collapse
|
8
|
Qin C, Yang YH, May L, Gao X, Stewart AG, Tu Y, Woodman OL, Ritchie RH. Cardioprotective potential of annexin-A1 mimetics in myocardial infarction. Pharmacol Ther 2014; 148:47-65. [PMID: 25460034 DOI: 10.1016/j.pharmthera.2014.11.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 11/14/2014] [Indexed: 12/15/2022]
Abstract
Myocardial infarction (MI) and its resultant heart failure remains a major cause of death in the world. The current treatments for patients with MI are revascularization with thrombolytic agents or interventional procedures. These treatments have focused on restoring blood flow to the ischemic tissue to prevent tissue necrosis and preserve organ function. The restoration of blood flow after a period of ischemia, however, may elicit further myocardial damage, called reperfusion injury. Pharmacological interventions, such as antioxidant and Ca(2+) channel blockers, have shown premises in experimental settings; however, clinical studies have shown limited success. Thus, there is a need for the development of novel therapies to treat reperfusion injury. The therapeutic potential of glucocorticoid-regulated anti-inflammatory mediator annexin-A1 (ANX-A1) has recently been recognized in a range of systemic inflammatory disorders. ANX-A1 binds to and activates the family of formyl peptide receptors (G protein-coupled receptor family) to inhibit neutrophil activation, migration and infiltration. Until recently, studies on the cardioprotective actions of ANX-A1 and its peptide mimetics (Ac2-26, CGEN-855A) have largely focused on its anti-inflammatory effects as a mechanism of preserving myocardial viability following I-R injury. Our laboratory provided the first evidence of the direct protective action of ANX-A1 on myocardium, independent of inflammatory cells in vitro. We now review the potential for ANX-A1 based therapeutics to be seen as a "triple shield" therapy against myocardial I-R injury, limiting neutrophil infiltration and preserving both cardiomyocyte viability and contractile function. This novel therapy may thus represent a valuable clinical approach to improve outcome after MI.
Collapse
Affiliation(s)
- Chengxue Qin
- Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia; Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria, Australia
| | - Yuan H Yang
- Centre for Inflammatory Diseases Monash University and Monash Medical Centre, Clayton, Victoria, Australia
| | - Lauren May
- Department of Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, and Department of Pharmacology, Monash University, Parkville, Victoria, Australia
| | - Xiaoming Gao
- Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia
| | - Alastair G Stewart
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria, Australia
| | - Yan Tu
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria, Australia
| | - Owen L Woodman
- School of Medical Sciences, RMIT University, Bundoora 3083, Victoria, Australia
| | - Rebecca H Ritchie
- Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia; Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria, Australia; Department of Medicine, Monash University, Clayton, Victoria, Australia.
| |
Collapse
|
9
|
Gauer JW, Knutson KJ, Jaworski SR, Rice AM, Rannikko AM, Lentz BR, Hinderliter A. Membrane modulates affinity for calcium ion to create an apparent cooperative binding response by annexin a5. Biophys J 2014; 104:2437-47. [PMID: 23746516 DOI: 10.1016/j.bpj.2013.03.060] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 03/20/2013] [Indexed: 10/26/2022] Open
Abstract
Isothermal titration calorimetry was used to characterize the binding of calcium ion (Ca²⁺) and phospholipid to the peripheral membrane-binding protein annexin a5. The phospholipid was a binary mixture of a neutral and an acidic phospholipid, specifically phosphatidylcholine and phosphatidylserine in the form of large unilamellar vesicles. To stringently define the mode of binding, a global fit of data collected in the presence and absence of membrane concentrations exceeding protein saturation was performed. A partition function defined the contribution of all heat-evolving or heat-absorbing binding states. We find that annexin a5 binds Ca²⁺ in solution according to a simple independent-site model (solution-state affinity). In the presence of phosphatidylserine-containing liposomes, binding of Ca²⁺ differentiates into two classes of sites, both of which have higher affinity compared with the solution-state affinity. As in the solution-state scenario, the sites within each class were described with an independent-site model. Transitioning from a solution state with lower Ca²⁺ affinity to a membrane-associated, higher Ca²⁺ affinity state, results in cooperative binding. We discuss how weak membrane association of annexin a5 prior to Ca²⁺ influx is the basis for the cooperative response of annexin a5 toward Ca²⁺, and the role of membrane organization in this response.
Collapse
Affiliation(s)
- Jacob W Gauer
- Department of Chemistry and Biochemistry, University of Minnesota Duluth, Duluth, MN, USA
| | | | | | | | | | | | | |
Collapse
|
10
|
Gavins FNE, Hickey MJ. Annexin A1 and the regulation of innate and adaptive immunity. Front Immunol 2012; 3:354. [PMID: 23230437 PMCID: PMC3515881 DOI: 10.3389/fimmu.2012.00354] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 11/07/2012] [Indexed: 12/23/2022] Open
Abstract
Inflammation is the body’s way of defending itself against noxious stimuli and pathogens. Under normal circumstances, the body is able to eliminate the insult and subsequently promote the resolution of inflammation and the repair of damaged tissues. The concept of homeostasis is one that not only requires a fine balance between both pro-inflammatory mediators and pro-resolving/anti-inflammatory mediators, but also that this balance occurs in a time and space-specific manner. This review examines annexin A1, an anti-inflammatory protein that, when used as an exogenous therapeutic, has been shown to be very effective in limiting inflammation in a diverse range of experimental models, including myocardial ischemia/reperfusion injury, arthritis, stroke, multiple sclerosis, and sepsis. Notably, this glucocorticoid-inducible protein, along with another anti-inflammatory mediator, lipoxin A4, is starting to help explain and shape our understanding of the resolution phase of inflammation. In so doing, these molecules are carving the way for innovative drug discovery, based on the stimulation of endogenous pro-resolving pathways.
Collapse
Affiliation(s)
- Felicity N E Gavins
- Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Imperial College London London, UK
| | | |
Collapse
|
11
|
Yazid S, Norling LV, Flower RJ. Anti-inflammatory drugs, eicosanoids and the annexin A1/FPR2 anti-inflammatory system. Prostaglandins Other Lipid Mediat 2012; 98:94-100. [DOI: 10.1016/j.prostaglandins.2011.11.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 11/11/2011] [Accepted: 11/14/2011] [Indexed: 02/02/2023]
|
12
|
Quesada-Soriano I, Parker LJ, Primavera A, Casas-Solvas JM, Vargas-Berenguel A, Barón C, Morton CJ, Mazzetti AP, Lo Bello M, Parker MW, García-Fuentes L. Influence of the H-site residue 108 on human glutathione transferase P1-1 ligand binding: structure-thermodynamic relationships and thermal stability. Protein Sci 2010; 18:2454-70. [PMID: 19780048 DOI: 10.1002/pro.253] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The effect of the Y108V mutation of human glutathione S-transferase P1-1 (hGST P1-1) on the binding of the diuretic drug ethacrynic acid (EA) and its glutathione conjugate (EASG) was investigated by calorimetric, spectrofluorimetric, and crystallographic studies. The mutation Tyr 108 --> Val resulted in a 3D-structure very similar to the wild type (wt) enzyme, where both the hydrophobic ligand binding site (H-site) and glutathione binding site (G-site) are unchanged except for the mutation itself. However, due to a slight increase in the hydrophobicity of the H-site, as a consequence of the mutation, an increase in the entropy was observed. The Y108V mutation does not affect the affinity of EASG for the enzyme, which has a higher affinity (K(d) approximately 0.5 microM) when compared with those of the parent compounds, K(d) (EA) approximately 13 microM, K(d) (GSH) approximately 25 microM. The EA moiety of the conjugate binds in the H-site of Y108V mutant in a fashion completely different to those observed in the crystal structures of the EA or EASG wt complex structures. We further demonstrate that the Delta C(p) values of binding can also be correlated with the potential stacking interactions between ligand and residues located in the binding sites as predicted from crystal structures. Moreover, the mutation does not significantly affect the global stability of the enzyme. Our results demonstrate that calorimetric measurements maybe useful in determining the preference of binding (the binding mode) for a drug to a specific site of the enzyme, even in the absence of structural information.
Collapse
Affiliation(s)
- Indalecio Quesada-Soriano
- Physical Chemistry, Faculty of Experimental Sciences, University of Almería, La Cañada de San Urbano, 04120 Almería, Spain
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Perretti M, Dalli J. Exploiting the Annexin A1 pathway for the development of novel anti-inflammatory therapeutics. Br J Pharmacol 2010; 158:936-46. [PMID: 19845684 DOI: 10.1111/j.1476-5381.2009.00483.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The appreciation that the inflammatory reaction does not 'spontaneously' finish, but rather that inflammatory resolution is an active phenomenon brought about by endogenous anti-inflammatory agonists opens multiple opportunities for a reassessment of the complexity of inflammation and its main mediators. This review dwells on one of these pathways, the one centred around the glucocorticoid-regulated protein Annexin A1 and its G protein-coupled receptor. In recent years, much of the knowledge detailing the processes by which Annexin A1 expresses its anti-inflammatory role on innate immunity has been produced. Moreover, the generation of the Annexin A1 null mouse colony has provided important proof-of-concept experiments demonstrating the inhibitory properties of this mediator in the context of inflammatory and/or tissue-injury models. Therefore, Annexin A1 acts as a pivotal homeostatic mediator, where if absent, inflammation would overshoot and be prolonged. This new understanding scientific information could guide us onto the exploitation of the biological properties of Annexin A1 and its receptor to instigate novel drug discovery programmes for anti-inflammatory therapeutics. This line of research relies on the assumption that anti-inflammatory drugs designed upon endogenous anti-inflammatory mediators would be burdened by a lower degree of secondary effects as these agonists would be mimicking specific pathways activated in our body for safe disposal of inflammation. We believe that the next few years will produce examples of such new drugs and the validity of this speculation could then be assessed.
Collapse
Affiliation(s)
- Mauro Perretti
- The William Harvey Research Institute, Barts and The London School of Medicine, Queen Mary University of London, Charterhouse Square, London, UK.
| | | |
Collapse
|
14
|
Abstract
The glucocorticoids are the most potent anti-inflammatory drugs that we possess and are effective in a wide variety of diseases. Although their action is known to involve receptor mediated changes in gene transcription, the exact mechanisms whereby these bring about their pleiotropic action in inflammation are yet to be totally understood. Whilst many different genes are regulated by the glucocorticoids, we have identified one particular protein-annexin A1 (Anx-A1)-whose synthesis and release is strongly regulated by the glucocorticoids in many cell types. The biology of this protein, as revealed by studies using transgenic animals, peptide mimetics and neutralizing antibodies, speaks to its role as a key modulator of both of the innate and adaptive immune systems. The mechanism whereby this protein exerts its effects is likely to be through the FPR receptor family-a hitherto rather enigmatic family of G protein coupled receptors, which are increasingly implicated in the regulation of many inflammatory processes. Here we review some of the key findings that have led up to the elucidation of this key pathway in inflammatory resolution.
Collapse
|
15
|
Aukrust I, Hollås H, Strand E, Evensen L, Travé G, Flatmark T, Vedeler A. The mRNA-binding site of annexin A2 resides in helices C-D of its domain IV. J Mol Biol 2007; 368:1367-78. [PMID: 17395201 DOI: 10.1016/j.jmb.2007.02.094] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Revised: 02/26/2007] [Accepted: 02/27/2007] [Indexed: 11/27/2022]
Abstract
Annexin A2 (AnxA2) is a Ca(2+)-binding and phospholipid-binding protein involved in different intracellular processes including exocytosis, endocytosis and membrane-cytoskeleton movements. We have previously identified AnxA2 as an mRNA-binding protein present in cytoskeleton-bound polysomes, that binds to a specific approximately 100 nucleotide region in the 3'-untranslated region of c-myc and its cognate mRNA. In the present study, we show by UV cross-linking assays and surface plasmon resonance analyses that the mRNA-binding site of AnxA2 resides in its domain IV. Furthermore, the interaction of full-length AnxA2 with the 3'-untranslated region of anxA2 mRNA is Ca(2+)-dependent. By contrast, the interaction is Ca(2+)-independent for the isolated domain IV of AnxA2, suggesting that the mRNA-binding site is masked in Apo-AnxA2 and gains exposure through a Ca(2+)-induced conformational change of AnxA2 generating a favourable mRNA-binding site. The AnxA2-mRNA interaction is specific and involves helices C and D in domain IV of AnxA2, since point mutagenesis of several charged and polar exposed residues of these helices in the full-length protein strongly reduce RNA binding. The interaction appears to be sequential involving an initial phase of recognition dominated by electrostatic interactions, most likely between lysine residues and the phosphate backbone of RNA, followed by a second phase contributing to the specificity of the interaction.
Collapse
Affiliation(s)
- Ingvild Aukrust
- Department of Biomedicine, University of Bergen, Jonas Lies Vei 91, N-5009 Bergen, Norway
| | | | | | | | | | | | | |
Collapse
|
16
|
A DSC study of zinc binding to bovine serum albumin (BSA). JOURNAL OF THE SERBIAN CHEMICAL SOCIETY 2007. [DOI: 10.2298/jsc0704331o] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The thermal denaturation of bovine serum albumin (BSA) is a kinetically and thermodynamically controlled process. The effects of zinc binding to bovine serum albumin (BSA), followed by differential scanning calorimetry (DSC), were investigated in this work, with the purpose of obtaining a better understanding of the albumin/zinc interaction. From the DSC curves, the thermodynamic parameters of protein denaturation were obtained, i.e., the temperature of thermal transition maximum (T m), calorimetric enthalpy (?Hcal), van't Hoff enthalpy (?HvH), the number of binding sites (I, II), the binding constants for each binding site (K bI, K bII) and the average number of ligands bound per mole of native protein X N. The thermodynamic data of protein unfolding showed that zinc binding to bovine serum albumin increases the stability of the protein (higher values of ?Hcal) and the different ratio ?Hcal/?HvH indicates the perturbation of the protein during thermal denaturation.
Collapse
|
17
|
Kamal AM, Hayhoe RPG, Paramasivam A, Cooper D, Flower RJ, Solito E, Perretti M. Antiflammin-2 activates the human formyl-peptide receptor like 1. ScientificWorldJournal 2006; 6:1375-84. [PMID: 17072491 PMCID: PMC1868079 DOI: 10.1100/tsw.2006.247] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The anti-inflammatory actions of the nonapeptide antiflammin-2, identified by homology with uteroglobin and annexin-A1 sequences, have been described in some detail, yet its mechanisms of action remain elusive. Since recent data indicate an involvement of the formyl peptide receptor (FPR)-like 1 (or FPRL-1) in the effects of annexin-A1, we have tested here the effect of antiflammin-2 with respect to this receptor family. Using HEK-293 cells expressing either human FPR and FPRL-1, and an annexin-A1 peptide as tracer ([125I-Tyr]-Ac2-26), we found that antiflammin-2 competed for binding only at FPRL-1, and not FPR, with an approximate EC50 of 1 μM. In line with data produced for the full-length protein, genuine receptor activation by antiflammin-2 was confirmed by rapid phosphorylation of extracellular-regulated kinase 1 and 2. Finally, study of the neutrophil interaction with activated endothelium under flow demonstrated an inhibitory effect of antiflammin-2, thus providing functional support to a role for the antiflammin-2/FPRL-1 anti-inflammatory axis.
Collapse
Affiliation(s)
- Ahmad M Kamal
- The William Harvey Research Institute, Charterhouse Square, London EC1M 6BQ, U.K.
| | | | | | | | | | | | | |
Collapse
|
18
|
Aukrust I, Evensen L, Hollås H, Berven F, Atkinson RA, Travé G, Flatmark T, Vedeler A. Engineering, Biophysical Characterisation and Binding Properties of a Soluble Mutant form of Annexin A2 Domain IV that Adopts a Partially Folded Conformation. J Mol Biol 2006; 363:469-81. [PMID: 16963080 DOI: 10.1016/j.jmb.2006.08.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Revised: 08/15/2006] [Accepted: 08/16/2006] [Indexed: 11/15/2022]
Abstract
The four approximately 75-residue domains (repeats) that constitute the annexin core structure all possess an identical five-alpha-helix bundle topology, but the physico-chemical properties of the isolated domains are different. Domain IV of the annexins has previously been expressed only as inclusion bodies, resistant to solubilisation. Analysis of the conserved, exposed hydrophobic residues of the four annexin domains reveals that domain IV contains the largest number of hydrophobic residues involved in interfacial contacts with the other domains. We designed five constructs of domain IV of annexin A2 in which several interfacial hydrophobic residues were substituted by hydrophilic residues. The mutant domain, in which all fully exposed hydrophobic interfacial residues were substituted, was isolated as a soluble protein. Circular dichroism measurements indicate that it harbours a high content of alpha-helical secondary structure and some tertiary structure. The CD-monitored (lambda=222 nm) thermal melting profile suggests a weak cooperative transition. Nuclear magnetic resonance (1H-15N) correlation spectroscopy reveals heterogeneous line broadening and an intermediate spectral dispersion. These properties are indicative of a partially folded protein in which some residues are in a fairly structured conformation, whereas others are in an unfolded state. This conclusion is corroborated by 1-anilinonaphthalene-8-sulfonate fluorescence (ANS) analyses. Surface plasmon resonance measurements also indicate that this domain binds heparin, a known ligand of domain IV in the full-length annexin A2, although with lower affinity.
Collapse
Affiliation(s)
- Ingvild Aukrust
- Department of Biomedicine, University of Bergen, N-5009 Bergen, Norway
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Abstract
It is shown here that phase diagrams of ligand-binding biological macromolecules provide a powerful tool for the analysis of reaction mechanisms. The present study provides simple rules for the construction and interpretation of such phase diagrams. We give examples for the derivation of reaction schemes for macromolecules that can bind two different kinds of ligands. By sampling one dimension of a phase diagram it is possible to reconstruct the second dimension, including the correct stoichiometry, positive and negative linkage between the ligands and equilibrium binding constants for the complete series of reactions. The discussion is generalised to temperature and pressure-dependent phase diagrams. To exemplify the new diagram method we analyse the pH-dependent binding of trans-beta-indole acrylic acid to apo-Trp repressor, the pH-dependent thermal denaturation of alpha-chymotrypsinogen A, calcium binding and denaturation of annexin I, high affinity zinc binding to a metallo-beta-lactamase and high-pressure and temperature denaturation of RNase A and staphylococcal nuclease.
Collapse
Affiliation(s)
- Jörg Rösgen
- Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, Schlossplatz 4/7, 48149 Münster, Germany.
| | | |
Collapse
|
20
|
Rösgen J, Hinz HJ. The heat capacity paradox of ligand binding proteins: reconciling the microscopic and macroscopic world. Biophys Chem 2002; 96:109-16. [PMID: 12034433 DOI: 10.1016/s0301-4622(02)00016-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Differential scanning microcalorimetry (DSC) is a superb method for the analysis of protein energetics. However, the relative simplicity of application has led astray many to assume that a proper analysis of the data was possible without a sound knowledge of the underlying statistical thermodynamic principles. In this study, the question is addressed of how to calculate properly the heat capacity signal of a protein in the presence of high affinity ligands. It is shown that the signal corresponds neither to grand canonic nor to canonic heat capacity. Statistical thermodynamic model calculations result only in the observed macroscopic heat capacity signal, if the protein in the calorimetric cell is assumed to form a grand canonic ensemble (T, p, mu controlled) which is, however, heated under constraints typical for a canonic ensemble (T, p, N controlled). As a consequence, the microscopic statistical thermodynamic heat capacity must be carefully distinguished from the macroscopically observable thermodynamic heat capacity in those cases where proteins unfold in the presence of high affinity ligands.
Collapse
Affiliation(s)
- Jörg Rösgen
- Institut für Physikalische Chemie, Westfälische Wilhelms-Universität, Münster, Germany
| | | |
Collapse
|
21
|
Abstract
Annexins are Ca2+ and phospholipid binding proteins forming an evolutionary conserved multigene family with members of the family being expressed throughout animal and plant kingdoms. Structurally, annexins are characterized by a highly alpha-helical and tightly packed protein core domain considered to represent a Ca2+-regulated membrane binding module. Many of the annexin cores have been crystallized, and their molecular structures reveal interesting features that include the architecture of the annexin-type Ca2+ binding sites and a central hydrophilic pore proposed to function as a Ca2+ channel. In addition to the conserved core, all annexins contain a second principal domain. This domain, which NH2-terminally precedes the core, is unique for a given member of the family and most likely specifies individual annexin properties in vivo. Cellular and animal knock-out models as well as dominant-negative mutants have recently been established for a number of annexins, and the effects of such manipulations are strikingly different for different members of the family. At least for some annexins, it appears that they participate in the regulation of membrane organization and membrane traffic and the regulation of ion (Ca2+) currents across membranes or Ca2+ concentrations within cells. Although annexins lack signal sequences for secretion, some members of the family have also been identified extracellularly where they can act as receptors for serum proteases on the endothelium as well as inhibitors of neutrophil migration and blood coagulation. Finally, deregulations in annexin expression and activity have been correlated with human diseases, e.g., in acute promyelocytic leukemia and the antiphospholipid antibody syndrome, and the term annexinopathies has been coined.
Collapse
Affiliation(s)
- Volker Gerke
- Institute for Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | | |
Collapse
|
22
|
|